CA2212197C

CA2212197C - Double cemented carbide inserts

Info

Publication number: CA2212197C
Application number: CA002212197A
Authority: CA
Inventors: Zhigang Fang; J. Albert Sue
Original assignee: Smith International Inc
Current assignee: Smith International Inc
Priority date: 1996-08-01
Filing date: 1997-08-01
Publication date: 2000-10-17
Anticipated expiration: 2017-08-01
Also published as: GB2315777A; SG71036A1; AU3245997A; GB2315777B; CA2212197A1; AU695583B2; SE9702845D0; SE9702845L; GB9716236D0

Abstract

Double cemented carbide composites comprises a plurality of first regions and a second ductile phase that separate the first regions from each other. Each first region comprises a composite of grains and a first ductile phase bonding the grains. The grain are selected from the group of carbides consisting of W, Ti, Mo, Nb, V, Hf, Ta. and Cr carbides. The fist ductile phase is selected from the group consisting of Co, Ni, Fe, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, Si, and Mn. A preferred first region comprises tungsten carbide grains that are cemented with a cobalt first binder phase and which are in the form of substantially spherical pellets. The second ductile phase is selected from the group consisting of Co, Ni, Fe, W, Mo, Ti, Ta, V, Nb, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, and Mn. A preferred second ductile phase is cobalt. Additionally, additives such as those selected from the group consisting of carbides, nitrides, and borides can be added to the second ductile phase to provite improved properties of wear resistance. The composites are prepared by combining hard phase particles formed from the grains and first ductile phase, with the second ductile phase material under conditions of pressure and heat, and have improved properties of fracture toughness and equal or better wear resistance when compared to conventional cemented tungsten carbide materials.

Description

JUL 31'97 Z2:32 FR CHRISTIE P~RKER ~HRLE 13 577 e300 TO 916046~14031 P.03~3' 30760/Gl~JS61 DOUBLE CEMENrED CARBIDE COM~ O~

FIE:LD O~ ~E I~E~l~ON
1;v~lre~ to~ t~l.~4.t~ -carbidem ~ and~- t~-l~ofma~ingthe same and, more particularly ~is iu~ ,tio~ relatos to double C~---P ~~t~ carbide c~ s that have improved ~.J~ S of t~J~"t~- -t si without ~ - ing wcar ~ h~ ~ -re whcn CG~I ~p<~,d to CC~ c~ --o--t~l h~ - CL~

~ACKGROU~D O~ 'rHE INVENnON
~ t~ 4~lc~bi~: suchA~WC-Coiswcllknownforits.~ .u~ s of 1~.~, 1O-~J--- s~ rear ~ maldng it a populal Tn5~t~Aql of choice for u~e ~n s~ch ;At ~,~ g and drilling Wtl~: its J.~ ~o~os an~ highly desired.
15 ~. c~ of i~s desired ~D}~3, c~m~ed ~ . car~ide has been ~he ~lf~ t ' llsed as cutt~ng tools for 'L~ d facing, wear inse~, and a~ng inse~ts in rota~y cone rock bi~s, and sl~kct-at~ bodic:s for dIag bit shear cutte~s. The ~--P~ t~lu~ ie~ g~ t~ h c ~ t~ n~en carbide and o~her c~nn~t~ iolt~ ~he unique c~mhi--~io-- of }~.c~
t~ ..C~ ~nd wear ~i~nf~ make these lnpt~ more ~ haD ei~her n~e~ or 20 ceramics alone.
Forconv- ~t;~ AI c~~....t" ~ .t~l~b;dr,fi~ctule to~ 'CiS irl~ve~sely~ u~u.tional~o hardness. and w~ar ~ rC iS l ~OPO~UO~I to hahl~.~. Al~oug}i ~he LWL~ tC~ ... cc of C-~r~t ~t~ 1n~ c~ide has been soll.- .~t i~.,p,~._d over ~e years, it is still a I tinf~
factor ~n ~ Ah~g;n~ ;O~ such as hi~ p.~h ~ lling, whe~ c~ , ~ t~ ca~bide i~serts often cxhibit gross brittlc li~.lu.~ that leads to cdt~;~hic fiilure.
Traditional metallur~cal m~hn~lc for erlhA-~ ing E;L~ tuu~ , such as ~ain size r~,rlr~ , cob~lt contellt op~ n-~, and ,~ lh- ~,ing agents, have been ~ A ,I;-ily ek~ d ~lvith respectto con~ tir~ c~ carbidc. The ~ r~ vpe~lies of co.~ ial grade c~ .t~ carbide can be varied within a parricular envelope by adjusting cobal~ meral cotltenl and E~rain sizes. For ~AA ~ IC~ the Rockwell A h ~ s~ of ~ ," ~~t.~ h~ carbide can be var~ed f~om about 85 to 94, ant the Lacl~ i to~-~hn~ss can be vaIied fiom about 8 to l9 ksi-in~2. ArF~ Ationc of c~ t~ .. carbide are linuted to ~his envelopo.
Another cl~;s of mAt~ for cutting and wear ~rp?ir~tinrl~ is tool steel. In E~ene~l, the 3~ wear ~ e of steels. inclùding tool steel. is much lower ~ ha~ of cP ~ t~ n~cten carbide. U.S. Patcnt No. ~ '~90,507 tescribes a material that is fo~ned by i~ u~ti~ a certain pc.~ ,tage of c~ ,r.'~ d t~ cter~ carl~ide granules into a malrix of tool s~eel binder to in~lc;~ie 07/31/97 THU 22: 28 tTX/RX N0 6304 ]

CA 02212197 1997-08-Ol JUL 31 '97 22:32 FR CHRISTIE PRRKER ~HRLE 18 577 8800 TO 916046814081 P.04~3' the wear reCisp~ of the ~ool 5teel. Such tool s~el/c~ t~tl~G~ carbide c~
materisls ~clang to the r~t~l ~ of metal m~ t U~ 57 when the bnttlo phase, i.e., ~_,"..,t~t ~ cs~ide ~ j5 ~e n~nori~ ph~.
A problem Icnown to cxist with tool steeVc - - ' t...~ t~.~ carbide c~ , is that iro~ (Fe) present in the tool steel biTlder tend~ to ~act wi~ the ~....,.,,1 t ~ carbide t~
fo~m Fe3C, ~hich can be ~~ h:,,,.,t~l to dle ductility and lu.~ c of thc c~ . For this reason, such tool stee~ t~dt~ t;t~r~ carbite co~ t~ not desired for use in~ ~L~ S~ as tbose ~ d abo~e, where ~.u~ is nK~od. ~A~ ,11y~
the limited ductility of ~he tool steel that is uset to fonn the ~ tP~ car~ide ~v~ also acts to limit thc ove~ o~ r - ~ ofthe cY~ ;~, ~eby ~E, its use.
~t is, lh~rer,.. " .1.~ Ie tha~ a ~ "~ t~ ~ ca~ide ~ lu~d that has improved l,~ lies of fiacb~e ~v~ t ~ when ~ r ~ ,r~ ~0 COIIV~ l~t ~ cf.r~ ~~t~ d ~ ,n çarbide m~t~ C It is dc~ tle Tlu~ such r- ~-- .~t~ carbide c~ ha~ve such i~ v._~l fi~e t~U~h~ firi~g we~ ." i.c.... ha~ing cqu;~l o~ bettnr wear~ thatûfc~ c~ ncarbide ~ iPIC- Itigdesi~dtha~
such ~ u~,~h ~ G~oide c ~ c;1 ~ t~ for use in such P~ppli~ e as rolle~ cone bits, p_r~ ;on or 1~ r bits and clIag bits, and other ~ppl;~t;~.C such as min~ng ant 20 cor.;~ ion ~ooIs whe~ ~,.opc~u-s of i..,~.v~ _t fiacture t~ is de~e~

~UM~RY OF THE lNVENTION
Dwble ~ bide c- ~ of ~is ~vLlLo~ c- ~l" ;~ a plu~ality ûf fir5t re~ions and a second duc~ile phase that sc~ ~ the fin;t regions fi~m each other. Each fiIst ~on ~5 comprises a cor-~cit~ of ~ and a fi~st ductilc phase ~ di~ he ~rains. lhe g~ins are selçct~ fiom the group of c~lJ.~S cr~n~ of W, Ti, Mo, 1~, V, ~If~ Ta, and Cr . &bid ~ ~
llle first ductile phase is s~ t~ ~1 fiom the group co~ of Co, Ni, Fe, a11Oys ~ereo~, and alloys with ~ ~. Is ~ t ~ fi~m the g~oup cor~ of C, B, Cr, Si ant Mn. A p~ l fi~5t reg~on c 7 t~ t ~ carbide ~ains that are e ~ with a cobalt fi~n binder phase nle 30 seco~d ducti~c phase is ~1~r~ ~ ~om the ~roup CV~ of Co~ Ni, Fe, W, Mo, r,, Ta, V, N~
alloys t~f; and alloys with nl~e~lc ~lr~ d h~m the ~oup c~ g of C~ B. Cr, and Mrl.
A p,.~.lcd second ducule phase is co~alL Addi~ionally, additiYes such as ~ho~ ret~ ~1 fiom ~he additiYe sel~rcted fi oIn the ~oup con~ of c~ s, nir~ c,and bondc~ can be added to the scond ducdle phase to pn~de imp~ved p~o~~ ,5 of wear .~
3 5 Double c~ t~ t ~arbidc cG~ ;, of this invention are ~Ic~&~d by com~ining hard phase panicles (e.~., WC-Co) formed fi~m ~he ~ns and fi~st ductile pl~ase, with The _econd dllc~ile phase ~P~ der conditi~n~ of plc~c and heat. llle co...~.os;-~ .o.,.~";~s in the 07/31/97 TEIU 22: 28 [TX/RX N0 6304]

CA 02212197 1997-08-Ol JUL 31 ' 97 22: 32 FR CHR I ST I E PRRKER ~H~LE 18 577 8800 TO 916046814081 P.05~3' 1 30760/GllLJS61 mnge offnDm about40to 95 percent by voluunc f~ntrer~ and lessth~n ~bout60 percentby volurne secont ductiie phase based on thetotal volume ofthe co~.rnq;-e and more ~.ef~.a~ly S ~v~p~i~ 3 in the mnge offhDm about60 to gO percent by volu me f~s¢r~gions and h thc ran~e offio m about20~o 40 percent by volume secont ductile phase based on ~he tot~l volume of the ~o~ Sil~. C~ "ho~ t~ c~~ ..;c;.~ an add~ve in the secont ducdle binder ~ lessthan about40 pe~cent by volu me ofthe additive based on the total volulne of~hc second tuct~c b~nder.
Double ~ d c ~ ide c~ it - of ~s i~ Lon have i~ U~_t ~ en~es of fi~u~Luet~g~h.~ 4hen conn ~ dto uO~ t~d tungsten ca~bide ~ ale, without ~ e wear ~ , i e., ha~ing equ~ orbK~er wearre~sbance dhan ~h~tofconv~
c~ r~u,.c~ carbitc~otL~. ~ mabing t~e ~ 4ell ~ tEt forsuch ~p~ s nD~ercone biL~ or~ bi~,drag bit~ an~ o~ber~r~ nn~such e mining ~nd cnr.~ tool5 where ~o~e.~cs of ~ c~ tuuc t~n~ .f~s is desinod. For ~ . 'e, doublc Cf ~ r~ J carbide c~ , of this ;.~ un have a R~ r ~ tou~hn~ss of g~eater ~han 20 Icsi-i~Z, and a wear number of at least 1.5 (1,000 rev/cm3).

DESCRlPl~ON OF 1~ DRAW~GS
'Ihese an~i o~ feao~es and ~tag~s of the pre~ent invenuon will be~ r appreci~tetas the sE~ne ~ -~ ~f S be~rer u~.d~ ~r~ Qth l~fL.~n~ e s~ rio~, claims and dra~ ;,.
~vherein:
FIG. 1 is a s~ "~t~ h~t~ .v~ph of aportion of COllV~ ;nr~ C.. ~t ~alL:d., F~G. ~ is a ~ t~ti-~ of the r~lRt;~ Chir ~t~ the p~ .s of t~ughn~es,hL~ 3~ and wearlw;~ c fora conv~-.tir~ c ~, ~ dt~ carbide~,.at~.i31 hav~ng the mi..~u.~ ofFIG.l;
FIG.3 is a g~ h'~A~ t~1;nn of~he ~ ;0..-1.;r ~ ~L_~ ~he ~rvF~.lies offRsctlre ~J.~ and wear.~ fora con~ iv~P~IC~ t ~ n~Pn carbide m~ren~l of ~IG. I:
30FIG. 4 is a ~h~ ic photo-~;--vE~h of a por~on of a do~ble .~ .ttd carbide cn~ s;tP ~e~ l acco~ gto ~ in~irles of~si~vention;
FIG.5 is a ~ h;~ ;oi~ofthe rel~in~hip b.h ~ hc prPpo.lies offracblre tou~hn~ss and wear l~ Qr~r~ for both co~v~rio..~l cer- ~t~ t~ t~n c ~ ide and double ce.-- ~.n d carbide CO~ vSitL5 of~invention;
FIG.6is a ~ ~ ~de ~iew ofa doublet~ ~e--carbide co........................ j~s;-~in ~rt;
F~G. 7 is a p~ ~yc~ri~ side ~iew of a ~oller cone c~ill bi~ ,p.;iing a .. ~.IL~. of~he insens ofPIG.6;

07/31/97 THU 22:28 [TX/RX NO 6304]

JUL 31'97 22:33 FR CHRISTIE PRRKER ~HRLE 1~ 577 se00 TO 916046814081 P.06~35 FIG. 8 is ~ side ~ie~ of 8 ~..;u~ion or 1.7--....-- . bit compnsin~ a number of i~er s fonned fiom double .~ t~ c~bite co..~ ;h~ of ~ ~vendon;
FIG. 9 is a ~h~ t;r~ Si~ view of a pol~ ,t llhe ~1~A ~d she~ cu~er CO~ a ~vl, -~-t fom~ed fiom double l~ car~ide r~ as of this ~nv~.lt;on, ant FIG. 10 is a~ rL ~ide view of a drag bit c~ -;c~ a ~. of the pol~c~ystallinc 1 she~.r Cutteni of FIG. 9.

10 DETAILED DESCI~ION
r~ r . ~ cart~ide is a c~ ~l~ -;~ m~ at is rrlade f~om tvnE~ carbite (WC) grLuDs ~. a ~ lie binder such as cobalt (Co), thcn:~y f ~ g WC~o. FIG. I
illu.stra~ a c.,..~f .4:0-.~1 . v~t~.u~.lu.~ of ~. c .It i tUIl~ carbide ~e ~ 1~ 10, c~
t~ carbidc gr~ 12 tb.at arc bonded to one ar.othcr by the bindet pha~e ~4, e.g., coba.t 15 maten~. The ~.iq~e p~v~.~.~ of ~ ~ t~ -.cu~-~, e.g., t~u~ , h~.e~, ~.
wear rr~i~t~r, result from t~.c c~ .a~ of a r.gid carbide ~ct~ c ~.~ a tou~hc. metal substruct~ The gen~c ~u.r~ of cernentet t~..~t~-~ c~b:~ a k_t ~u~ ,CO~ ;,;t~
of a c~ .-r.. ic ph~se in eQ~ wi~h ~ maal pha~, is similar in all c~.. t~
The~ .h~ n ' -'--1 prop~u~s of I~J~~a~ lu~ ~s~ c and ~ear 20 ~r;~1~ is well kIlo~n for such co~ t1on~1 CC ~ t ~C;~I glade C~ ~-t ~~ carbide materials, and is ill~lr~t~ p~ ~' folm in FIG. 2. Hardnes~ is ;ndi~tPd by Rûck~vcll A
~R~) m-rnl~r, fiwtwe ~Q~ n~QQ i~ 1 by Kk ~ si-~), and wear .- Q ~ P iS
' bs~ ~ear number (l,00v n~tcm3). As ;ll ~ ~ ~t AL~ FlG. 2, p,o~.l;~s of tu-~ and h~dl.ess a~: inversely ~.v~.tiun~l to one anothe~ while l,.u~.ti~.~ of h~-L_~ and wear 2s resict~n~e are p.~m~ to one another. F~G. 3 ~s another F~ t~,t;~n of the relPtior~chir v~ La~tul~ t~ n--~c and wcar ~ for conve~ on~l co - ~ yade cF..-~r~l ~-n~ten c~ide.
For co"v~ P.~t~ ~ ~ carbide . ~t~ ru~.lics of h~
~ and wear 1. ~n~rcanbevarledwithin a defined wind.~ of between 85 to ~4 HR~
(hJIr~l~), ~t.. ~ 8 to 19 Icsi-in~ (&actu~e ~UI~ 1), and beh~een 1 to 15 (l,000 revlcm' -we~r r~3i~ ). For exarnp}e, it is blown to i.,c-c~ the fiac D ~û~J~ 5i of suchconventional c l~ y~,~t~.~ carl~ide ~ ~ to the higher end of the Kk e~ lo~ by ~eamountofcob~tp~n~inthe~ t~ r~ c~bite. The ~ ~n~ssof ~e . car'oide comes rnainly ~om ~he plastic ~f f~ ;o~ of the cobalt phase during 3~ the ~actlure p~ocess. Yet, the r~lting tS .L.~ ofthe ce~ - ~ t_.~ carbide de~;.~ as ~he amount of ductilc cobal~ c~as~s~ In most ro.~-~nn-1y used Cf .. ~t~ carbide gratcs, cobalt is no more than abou~ 20 pe~cent by weight of the total c~ .~ ;;tc.

07/31~97 T~U 22: 28 [TX/RX No 6304 ]

CA 02212197 1997-08-Ol JUL 31'97 22:33 FR CHRISTIE PRRKER 8.HfiLE 18 577 8800 TO 916046814081 P.07~3' 3 0760/GlIJS6 1 Conv~ ,t;~ 1 grades of c~ t~ tungs~en carbide used for she~r cutter '-~ ~ in drag bits and cutting ~h.l.lu.. inse~s in ~ock drilling bits contain in t~e ~nge of ~om about 6 to 16 S pacent by wdg~t cobalt, and have gra~n s~zes in the ra~ge o f fi om a~out one to tcn .~ .. t.r~.
Such c~Jn. ~ ~1 ;onA~ les of c~ At.~g n carbide u5ed for cut~ng ~ .1~l~. ins~ts in rock drillirlg bits have a Ra ~..~ in the range of fiom about 85 to 91, a f~ . in lhe range of ~om about 9 to 18 Icsi-in~2. and havc a wcar nurnber in thc range of ~om about 1.5 to 11 (1,000 re~/cm3).
Refe~g back to E~IG. 1, it is e~ndent ~at the cobalt phase 14 is not c~ in ~hc cc,l.._.lt;un~l cementet ~ carbide .. ~ua~ t~e~paltiCll~ y ~ c~ 4r'l nn~ with a low cobalt CCn~ h~ ,n ~he COnV~ n~t IJ.iC.~,~L~ ,-~, haS a ~ ,elY ~ fi"-....... rl;~;b~ Of t~ gs~:cncarbido ~n a cobalt m~ix. Thlls, c~k l,~v~ ~c~t;~n ~ h thc ~ ~11 o*en ~vcl tL.. I~ thc lcs~ ductile ~ L; t- ~- carbide ~ either transE~anularly IL.v~ t~-.
c~b;c~/wbalt ;.. t~- r-~c 15, or L~1L I ~ V~ en c ~ e'1~ t~ bide i~ f~ff 16. As aresult7c~ ,tP;~1~~-"_t~,~-carbide of~n e,.~ grossbrittlcL~ d~g mon~ ~ "9 ,A;-,~ A~ii~-l;otl~, which may lead to c~li.c fail~e.
FIG 4, i1' ~ - the~ .o~u..,~e of a doublc L- .. -,t~ .~ carbite c~ ;t~ 18 ~ d açcol~ling, ~o principles of this i~ -.. lhe class of c~ - t~y~ r~ling tothis invention have a double c~ -.t~1 l,fic~sh~l lu.c. A fi~ d ~f~,t~ c C~.~Ji~S
a con~enti~n~ t~-~ c~ide l~Cl~CtUX(C.g.,~ t~ ?~ .wc-co)~
describet above, while a second c~ ..- rtf~ v~ u l~ c~ ;~s hard ph e particles 20 fo~ned fiom the first ct..- .rl~d mi-1u~1~. (e.g., ~VC-Co ~icles) ~ O~C~ by a cu.~ ductile binder phaSG 22 (c.g.~ formcd from a ductilc metal or metal alloy). Ihus ~e 25 teml "double c~ .nt~d~ or "du~l .e ~ e~" is used to refer to the fact that the r~""~
matenal of this invention is in ~e form of a C~...P..~t~ A~lU-G that itself co ~ ~s a cemented mi-;-u.l,u~t~ as one of i¢s c~ tc Double cr~ t~ c~ .t~ ~ of thi5 tiol. re fo~med using m~t~ lc and IJIU-~eO~_S that achieve the desired ~"~h~ d p,u~ .s of f~act~re to~n~ss ~thou~ s-c rifi~ g wear ~t Si~ e.
Broadly, double .~ carbite c.". ~,i~- ~ of this in~ iO~ are made by mir~gJir~
c ~ d phase p~ticles ~th a ductile phase binder under cc ~ r.~ the cemented hard phase palticles to be c~ .,t~ ~ by thc ductile phase ~inder. ~rom a laminate ~, ~ e, -qCG~V~ strUC~l~ C~ a s~ack of shects tha~ r---t~ matenals along one g.o...etl;c di~ ,- ion ~ fi~er ~l~u~n~c ~rith a bind~ is corl~idcred to be a 2-D !~ir~lf 35 lhe double ~ t~ d carbide C~ G~ of this in~ention can, the.crole, be vicwed ~o be a 3-D
~in~t~.

07/31/97 TXU 22:28 [TX/RX NO 6304]

JUL 31 ' 97 Z2: 33 FR CHR I ST I E PRRKER 8~HIqLE I e 577 8800 TO 91 6046e 14081 P . 0e~35 The . ~ .,t~ of double . m~ carbide ~JI ~p~G~;r~'~ of ~his ir.~,ntiv.. provide~c a that h~s a much hig~ fi~ re tn~ P~c than con~rer ti~r~1 c~ t~, . carbide due to ~ h,.~ c~clc bluntlng and d-,fl~li~_ effect~ of lhe c~ ~ binder phase ~2 that ~iu~ u~d5 each hard phase particle 20. The c~ J~ b~nder pbase il~.~s ~e ove~all rrcL tu~ tou~ . of the c~ ., .~ite~ by b1~ or t1- a - ~; n~J the ~ont of a ~v~ t; ~ ~ c~ck if one occu~s, u,rithou~ ~~~firir~g eit~er the ove~ll l ~r~ or wPar resist~ce of ~e cc ~
l~e ovaall h~ c of the c.!A~ ,it~ is not ~Cnfir~ a~ ~e original ductile metal phase of the 10 hard ~clcs k.g., t~e cobalt p~ase of t~e c ~ Ar.~t ~ h ~ ~ carbite h~rt p ~ s) is mcrel~
~erl jc~r;huted ~,t~ ~... the h~d particle phsse and the new or scco~d binder p~ase~ Ihc overall wcar re i~11r~ of the double ~ ~ t-! ~1 cY~l~rr tl is much higher than that of a ~,.~._t.;~r ' c .. -.t~A l..~ t~ A c~r~ide ~ hc ;-1 that c.~ ~ c the sarne amount ofthe total ductile binter phase -~
DoublecementetcaIbide ~ r ~ ~ of 1~canbe fo~nedu~Cin~ ypcs of '~ as the h~d phase l~ s 20. ~Im'9~ gle for f~ the hard pha5e ~ - ~cl. s 20 an: c~- ...- 15 ~hat ~lude hard ~ fo~mcd ~om c_b~ or borides formed fi~ f metals such a~ ~, Ti, Mo, N~, V, Hf, Ta, Cr, and a m~ t; ~E agenl. ~ ha~
grain ~ t.,i~l~ include WC, TiC, TaC, r~2~ or Cr2C3, Ihe m~ C~ t;r~L agcnt may ~e 20 sel~d fil~m the groYp of ducdle m~t~ q ;~ onc or a c~n ~ of Co, ~i, Fe, which may be alloyet ~th each other or wi~ C, B, Cr, Si ~d Mn P~cfe~ vt~ usefill fot fo~g ~e har~l phas ~ es 20 include c ~-.. -,t~ ~ t ~ T~ n carbide w~th co~alt as the binder phase (~C-Co) and other ,-cj" 1~ such as ~C-Ni, WC-~e, WC~Co, l~i, Fe) ~ their alloy~.
lbe ha~ phase 1~ s 20 usefi~l for f~ ~ do~bk carbide co ~~l~osit~ - of ~hi5 invelltion include con~ tior~l c~,~ b, such a~ c~ ted 1~ carb;d- having the follo~ing comros;t;on ~ange: ca~bide cu..,~... ~~t in the ran~e of from about 7S to 97 percent by weight, and metallic ~ . .r.~l,~ agent Ot binder ~n ~e tange of ~om about 3 to 25 pe~cent by weight l'hc hard phaso ~l~cl~ 20 can also be fo~ned fiom ~henc~l cast ~- ~'d~. S~>~.i.~l cast carbide may l~ c-~t~ J using the ~in~in~ disk r~pid s ol;~ifi~ n process described in U.S.
Pa~ent l~o. 4,7~3,996 a~d U S. Patent No. 5,089,182. SF~h, ;~ ~l cast ca*lidc is a e ~t. ~tiG of WC
and ~2C. If des~red, the hard phase ~&~ ,S ~0 CaIl be formed ~om ~ es of c~"~.t~ ~1 tungsten ca~bide and sphP-r~l cast carbide, ot coll~h;n~t;v~c of other ha~d phase p~licles descri~ed above.
In 2UI e~ npl~ P~ t, ~he h~rd phase par~iclc~ are formed ftom con~ .ti~
35 c~ sten car'oide, as i ~ in ~ h~ . each particle compri~cs a c~~bc:l~
of t ~ carbide grains bonded by cobalt (WC-Co). The c~ t~ ~ h ~E~ . carbide pa~icles can be made ~ c~n.~ tionul miYi-~g, press~ng, and ~;nt~ to fonn a c~ t~ g~vn 07/31/97 THU 22:28 [TX/RX N0 6304]

JUL 31 ' 97 22: 34 FR CHR I ST I E P~RKER ~HRLE 18 577 8800 TO 916046814081 P .09~3' 30760~G IL/S61 carbide body. Such a baiy can then be ¢n~shed and sc~Ln~d to obtain a desired pa~ticle size fior use u~ ~is in~cntion. Alt~natively, the particle~ can be made dir~ctly by fi~ 8 ~k~ s of L~ . csrbide and cob~lt of ~ u~ size which are rhen ~te~,d to near net si~. I'his enables one to d~ the shEIpe ~s ~ell as tbe size of ~he par~cles.
Hard phase particles 20 made fiom c~ t-d h~ t -- carbite are p.of~.n~ in t~le form of s~ ts~l~tially ~ cles Sllch ~-k~ particles can be ma~e ~om p~llehz~
mixtures of cobalt ar~d Iv ~t~ .- c~ide pa~cles or by r~ l n~ crushed c~ r,r- ~i T~
10 c~bide. ~ f~ y~ C~ c~bidcpc~ctsa~bondedwi~
cobalt. Probsbly 90~XO or more of the pellets an~ r9l or ve~ ~y ,~ A small f~ 'don a~ smootll but su~ ' ' oval (oblate or prolste) or e~g shaped. This i~ r~ h ~ .te~ U~rith L~l~_l carbide which bas ~n angular profile.
The ~- " .~r. A j ~ a~bidc pcl1ets ha~re 8 partiClC SL~ ~hat is ~ f~ less ~hm about S00 ~J~ .. - h ~ whilc larger sked ~ Licl~s may exhibit ~etter wear ~ ~ - e~
~ey are blo~n to display a higher t_i~de~ for i~d ~ p~,.,l. ~-1 l,.Yt~les to ll.,cro~ or pull~t dunng ab,~;.~ wear sitl~ti ~ ~ ~,.f~ d r~.1;... n~ t~ ~ G~bid¢ pe~e~ have a pa~icle sze the Iange of fi~m about 20 to 300 ~.,r~ t .~ A hard phase pellet size within this range is ~.~;f~c~ ~ C~ it pro~idcs a good ~omhirqtinn of ~Y ~ tA~C~ to ~oth wear and c~
rç,~ t _ - ca~bide pellets ~bat are too fi~e, e g., that have a paIticle size of less than about 20 mi~ t~ ~, a~ ~I!;O no~ dcs~red ~ J~ while such paIticles Inay display a low tr~r~ tO cIack, as the particle size of the c~ t~ d nlngctr~ csrbide "1'~ s ~e size of the intividual carl~ide g~ains, ~e ~,-ic~ u~ i of ~e ~ ~Sjt~ ~p~ ,achcs ~at of co.~ I c - r r~ d tungstcn carbide.
The ~lative s~ze and volume fi~ction ofthe hard pha~e p~ticl~s ;~0 ~d the ductile binder phase 2~! yl~ro~ in~ the l~rd ph~se palticlcY ~- t~ the combined ~ rh~ l and tribolog~cal bebavior of ~e fin~l c~ o~ s. Double c~ t~d carbide c ~...p~;s;t~ i of this u.~ Lon may ~o ~l7 ;~ in the lange of ~om abo~t 40 to 95 percent by volurne of the hard phase 30 ~ cles 20 based on the total volume ofthe cc....~ lhe volume fj~tjon of tha~ hard pbase pa~icles is one of ~he most inlpc,~t facto~ he .~.~cl~ a.l ~ ~.Lc~ of the final ~ul It is desiled that touble c~ car~ite cc.~ ;tes be pnc~,~ed using g~atcr abo~ 40 percent by volumc hard phase particles bcc~ e using le~s than this 9~n~ can p~duce ~ final C~ ;t~ having an ove~all modull~s, and l,.u~.li~.s of ~hc,.~ d vvear ~ e ~hat 35 are ew low for t ~ n~ ~pplirqti~ nc such as shear cutter ~ ~k.~ ~t~ ~ for drag bit~ or inselts for ~ller cone roek bits It is desired that double ~ t~ A ca~bide co ~ c of this invention be p~c~ using less than 95 percent by volume hard phasc pa~icles L_c ~ us~ng more than this 07/31/97 TIIU 22:28 [TX/RX No 6304]

JUL 31 ' 97 22: 34 FR CHR I ST I E PRRKER 8~HRLE 18 577 ~800 TO 91 6046e14081 P.10~35 3 0760JG~IJS6 1 amount can ~ a final co~ hav~ng a low ~ t~ C s~milar to th~t of Cunv~ Qh~l c. .~ t.~ "r~ Fbide.
The e~ ~tno l~t ofthe hard phase particles 20 that are used wil~ Yary ~lepcn~in~ on the desired ~ p~oy.~ ;. for a palticYlar ~ t ~;nt~ Por CA_ _~Jlf~ when the double cemented carbitc r ~ . . ~ is uscd in an calth boring drill bit~ it is ~.efi".~i ~a~ t~e hard phase particles be in the range of *om about 60 to 80 percent by volume of ~e total volume of ~e ~-C~ .;t, The ductile bi~dcr p~c 22 of double cemented carbide ~ g of this invention is x~ d ~om dle Izroup of materi~ls co. .~ ~;Y;~g one ormore ductile metal, ductile melal alloy, re~actory metals, adJili._.., and ~JI~u~c:g thereof. In a first ~ double c~ ~ ~t~1 carbide cc l..po~;t~ the tuetile b~nder phasc 22 ~at ~ ~ The hard p~sse E ti~le~.20is selec~d Lvm tho g~up of duc~le meb~ls, ductilc met~l ~lloy~ and ~e1;~t~ metals. T~e ductile 1~ metals can include cobalt, niekel, iro~, cast iron, and the ductile mctal alloys can inclute s~eels of various carbon and alloying levels, s~ninl~<;s stecls, cobalt alloys, nickel alloys, Fe-Ni-Co alloy~ having a lo~r ~ ~ ".. ,-1 of thermal exp~n~ion such as Sealvar mA I, ~fi~ d by Am~çc I~c., of r~ ..7~1~ania, ~ t~ ~ alloys such as W-Ni-Fe7 a~d the lilce. Dc~ kl~ Iow ~ennal ~ ~1 .A-~Cll-n ~lloys includc ~ose having a c~ of Thermal exp~nsion of les~ than al~out 8 20 ,um/m-K. Such low ~ mal e~ ... alloys zlre desired ~ they a~o bo~h t~ y c ~ the hard phase ~ s, ~eby i,..~u~;..g the~al fatigue cn~ck ~c~ and because they ~e mole duc~le ~e most ~ r.,"~ rate steels The ductile binter phase 2Z can ~e one, or a ~n~h ~ -- o~, the follow~ng: W, Co, Ni, Fc, Mo, r, T~. Y, Nb. llle ductile binder phasc 22 can be alloyed with C. B, Cr and 1~
Co is a y~ef .~d duc~1e binder phase malerial ~hen the hard phase p~liclc~ are fonned fio~5l c~rn.~rlt~ carbide (WC-Co) ~ it bas ~etter ~ .~..ic cc-~,dtibility, wetting, and i..~ g with WC ~, as co~ to nickel or ir~n. C'---t~n~ct~n ca~ide cc.l ~ki~p coball as a binder offers the best comb~dlio~ of hz.t~.ss and t~ ~hel~ C r r~d to that folmet by usîng ot~er binder ~ L~ her bindcr rnS~t~ c 30 such as r~ckel are usefill in certain ~ ianC where othe~ ~ ~h~ ...,~.ties an: d~ e.g., nickel is uset as a bhder ~n ~ ..t~ where ~ nl ,f . i~ ,r corr~sion ~ c is ~ed~
~ n the fir~t emb~ t where the tuctile binder phj~ 22 comprises a ductile meral, ductilc met31 alloy. o~ ~o,~ ti~.~. thereof, it is tesired that the double ,_ .. r,~ carbide ~O1~rO~C~JI~J;~CIeSS than about 60 perc~nt by volunnc, and more p.~f~ in the nange of 35 lhm about ~0 to 40 percent by vol~me, of t:be ductile b~nder phase ba~ed on the total volumc of the cu...l~ir~ l~e fi~nc~on of the ductile binder phase is to enh~ the fiact~e to.,~ of ~he final c~.m~sir~ by p~ d- f~ ;r~g during crask pl~.p~ r The overall el~stic 07/31/97 T~U 22: 28 [TX/RX No 6304]

JUL 31'97 22:35 FR CHRISTIE P~RKER ~HRLE 18 577 ~8~0 TO 91~046~1 40el P.11~3' 30760/GTLtS61 mnt~ , c~ y~ re al~ ~h and wear .c~ c of ~he final CG~_it~, will de.,.ea ~ ,.tly~c$~t~ul 60 pq~ent by volume ofthe duct~e binder is ~d, ~9~i~e ~e final c~ f~r ~rplirS-tinnc v~here c~ cl~ hea~y load and ab.~ wesr is know~ to occur.
M~~jPI' usefill as the ductile binder phase 22 in~lude duaib steel. The te~m "ductile steel~ is used heroin to refer to e mild stcels that display greau~ an about 5 percent elongation a~r heat 1, ~ t,have a carbon content of less than a~out 0.8 pcrcent by weight, and ha~e 10 total ~lloy contem o~less than about ~ percent by weigi~t of the tot~l stcel c~ Such steels, ~IYa~ of their ~nake up and heat 1.. ~.. -1 ha~e a desi~d deg~ee of du~tilit~ to pl~stic~lly defo~m a ~.lT;~;o~ amount during crack ~op.a~ and, the~by i~..~ tbe fi7~ture t.~q;h,~ of the double c ~ d carbide co.~os'~ n is ~ - ,.~0~ that ~uch ductile steels do no~ includc sl~ls l~viIlg (l) an el- .~g,~1;o~ eater th~n abot~t 5 p~cnt after heat ~ ; or alloyed steels that both ha~e8 c~rbon content of grcatcr than about 0.8 percent by weight, and have a total alloy content of gres~er thall about 5 percent ~y weight, that may ~¢
ef~ d to a~ tool or hig~-speed steels. lhe term "alloyed steer' as us~d he~in refa~ to tbosc steels tha~ include alloy~ of such me~a}s as ~V, Co, Ni, Fe, Mo, Ti, Ta, V, Nb, Cr~ and ~he l~e The initial palticle size and size dismbution of the powrler &ts ~e mixing and ho...o~.n~ of the final ~ r .Ja1r~ of the ~ hr ~ç ~e f~nish of the as-conc~olt~1~ted part is also i.fT~,t. ~ b~ the ~n~tial particlc size and sizc ~ bvfior nf both dle ductilc binder phase an~ hard phase ~ After consolid~ion it is desired that ~e h~rd phase ~Lcl~ ~in ~eir ~ntegriy with some P.l~ . . ~.1~1 ~1; IT..';~.. -, which may occur dunn~ high 25 t~ .c consoli~ nn proccss. l~e duc~ile binder phase parlicle~, ho. _.~r, bc~.l._s a contin~Jous or ,~ v ~ onc matIix phase dunng such concnlirl-~jrn its orig~nal powder L~ t l;~riçs no long~exi~, and it has a ~ cl~ simllar to buLlc metals wit~ equi-axet ~, althouB~ h~~ t heat t~Jt ~ t ~ould ~lter its ~in s~ructure. For ~xa n ~1~, if duc{ile steel is used as ~be ductile b~nder p~ u~ lCtllIe Call be ~.,a.te~ c. pearlite, ba~nite or othe~s 30 depe"~i-tg on the ~ I;n heat ~c.~ ..t or thermal histoly of the IhaTerial. At the il~h.r~cc the binder allo~ and ~ard phase p~ l.s there could be ~lifTu~ , ~n~ g ~ g on the ~ ;f~c m~ s~l systems.
In a sccond ~b~ -t double c~ t~d ca~bide cG. p~Ji~ ~c duc~le binder pha.se ~ includcs OhO or ~o~ of Ihe .- ~ty ~ descnbed ~ove for the filst rrnbc~ -t plus one or 35 more particula~e additives. Sui~ablc additives include WC, VC7 N~C, TiB2, TiC, MoC, Cr3C;"
PUIYUYS~ ne ~ nQI~ (PCD), cB~, other carbides, borides. nilsites, c~ itl.t_"
c~ob~ les, and n~ixh~les thereof. Ad.li~ .s, in this secont e~ o~1;m~ are an in~e~al part 07/31/97 THU 22: 28 [TX/RX No 6304 ]

JUL 31'97 2Z:35 FR CHRISTIE PRRKER 8~HRLE 18 577 13800 TO 916046~140~31 P.lZ~35 30760/G~IIS61 oft~e ductile binder phase, In lnany ab~ e wear ~rpli~a~io~ r~ wear of ehe binder phaseist}lepri~wear~ ,S~............... h~ E antm~gthewcarr ~ ofthe S binder phase also e~h-~r. J ~e we~r .~ of ~e hn~l composite. The particle s~ze of the additi~res needs to be smaller than t~at of ~e hard ph~ palticles, and also llOedStO be small enoug~ to be lmifntmly dismbuted throu~h the bunder pha~e. As a general p.~;~le of ~ t,t;i~n or.1;~ n~c~ h~ g u~fi~ ~iclesincludc~osc~ngingfiom~ ~n to a few ~crons in s~. P~icle sizes of c~ P~ .3ar much smaller ~an 10 the mean ~ee pa~h bc~ cc~ pelle~. ~ o~her words, the paIticle sizes are smallc~ t}~ ~he width of the duc~le b~der phase b.~ he pe~ of c~ .n~h~
Dcp~ on ~ w~r ~,"~ ns, ~ L~ for f~.. ;.~ ~xond çml~o~ t co~r~itec of t~is il~ t;G~ ay have a pa~ticle size in as large as about 20 micru~ te~s. I~ a ~,~f..J~ sccond - :..ho~l;.~.~..t, the additi~ es have a .,~.~.i"v.~ cle si~, 15 or a paTticle sizc in ~e Iange of ~om a~out one to ten ~ ...- h ~ In some; t ~
hanol..ct~ ~ow~ ch a~ the N~oc~ powder (WC~Co) . lf ~ ed by ~od~ne, Illc., of New Bru~ ric~, New Je~sey, may be used The ~1. ~ " of ~ddl~ e on the particul~ ~rpli~A~ n Ihe use of such fine pa~ticle size 3dtil;._s is desired to ~ ,~
- ductile binter pllase, reduce l,rer~ ual vrear of the tuc'dle binde~ pha~c, and i,.,~,.o.~ tl e overallwear.~ /t~ n 4~com~n~,l.ofthedo~blec~ t- dc~oidec~ . it~
~ cond ~..4b~' n~rlt double ~ ,t~ carbide cc~ si~, whe~ ~e tuctile binder pl~se 22 con.E,.,~s an adtitive in~ iQr~o a ductile me~l or ductile metal alloy, it is tesired that the dollble c ..f ot~A c~ide cu...po~ite ~o...r~i _ less than about 60 pe~cenr by volume of thc b~nder (i,e. ,~ etil~ metal or ductile me~al alloy) based on the total volume of the CO".~ r, and l~q than abvu~ 30 prcent ~ olume of ~e ~d~ based on the total volume of the binder, ~1tl~o~ a plcr~.,~ amount of ~e ~ddi~ is - ~,ptY.xi~ately l S percent ~y ~ol~ne The use of such stren~ dtitives may have an advelse impaa on the duc~li~ of the binder. A~c a general ~ule, as you increase the ,~;,."1h of ~he binter you d~ the duc~i~ity of the binder Using less than about 30 pe~cent by ~rolume of The ad~iti~-, based on the total Yolume of the bindcr, has been shown to p~ovide a d.,~ de~ree of vvear ~ wjthout ci~ifir~ ly 5~rrjfiri~g ductili~ or t~ ~nt ss. while if the ~olume fi~ction of ~e ad~ ,.s is gn~ater than abou~ 30 pe~nt, ~e fia~t~l-e to~lu.css or ~e final e~ t- may be below what is neeted for pa~iC~I~rFIir~tin~c Double c~- ~ car~ide co~ of this invention c~ &~:l by u number of different, ~ c c g., by rapid G~n~ I;nrt~ t ~r ~ROC) p~cess, hot ~.~,ng, infilt~ti~ solid s~ale or liquid phase cinte~ing ho~ iSO~ticln~ 6, (H ~)~rr~ t;c j~5~-jr forE~ng, and eu, . ~h;~ cthe~eof. ~e_c pr~e~s are desi~ !; - thcy are needed to form 07/31/97 T~U 22:28 [TX/RX N0 6304]

JUL 31'97 22:35 FR CHRISTIE PRRKER ~HRLE 18 577 8800 TO 916046814081 P.13~35 30760/GlVS61 the desin:d &0~ 0~ 5~u~ c~ of this ~n~ention having a ~ .if~ o . of ha~d phase particl~ withi~ ~e ductile phase~ thercby l,n~ .vr~ ,.v~.Lcs of ~acTure S to.JJ.. ~ wi~vU~ P wear ~ a~ ~ bald phase p~iclcs du~ ~ used to make c~ m..~tl,n carbide .~ it~ ~ of lhis i ~ t;C~ can be formed into pellets by Cu~ n~l ~ ~h~A~
Speci~ y, whe~e the ha~d phase pa~ticles 20 arc formed f~om sintcrcd or c~ t~d tu~ . c~bide ha~ing, for ~ , about 1 to 1~ ~c.oh~_ter WC particles bonded to~;c 10 by SLX percent cobalt~ suc~ pellet~, are made by co,.~ n~l closed die ~ ;lg of a c~ ~, ,t~ ~
t -- v5~ ~ car~ite powder ~t~. d~,~ ~g and ~~cuum sinten~g. I~e le ~ canbe ~ hc~ to form p~liclcs in the rangc of ~om about 20 to 300 .~ 0!''- t~ ~ Altema~i~rely, WC ~nd Co ~ .t~,.., can be mixet uiti~ a ~ c binder in ~ atlTitor or ball mill and pellets in the range of ~!0 to 300 ~c.~ s ~si~ ter ~ t .~ ncd ~m the ..~1 Oversize and !~ pelle~ a~c .~_1~1 to achieve the desired parliclc size range. The pellets are d~,w~..d and ~b,.~d and then br~ n up as n~-.d to ~.~,.;de 20 to 300 m~ t~
pellet~. These pellets catl ~hen ~e ~onned into a double CC....~A;I~; by any of the four above--n-l-~ plo~ e~ ~e Pelle~ are blnn~l~d with the ~ tuc~le binder phase 2~
and ~is ser~ ~e is pr~sed into a desired shape, such as the shape of a ro11er cone rock 20 bil ins~ and thc likc. The p~essed sl~es are then Li~nid Phase Si.~t~
Ihe sccond ~;nt~ir~e of the pressed shapes may be done by liquid phax si~rt .i~c where the dc~uble C~ A car'oide CQ~ ;t-iS heatet abo~e the n~ point of ~he ductile metal or binder phase, or by ~ Iiquid phase eint~lnp whe~e ~he double c~,~. t~t~.1 carbide 25 ~o~ ~~ll¢ is heated above the solidus ~ d~ ofthe ductile binder phasc or above an alloy col..~s;tjon fonned by com~ of the ductile metal phase and binder in the pellets, but belo~v the fi~ c ~ ---r - 'n e. An &d~ of liquid phasc cint~!tmE~ over other cv~ csi fom~ng yl~ ~ s is its relali~ely lo~ cost, ant the fact that it is well suited for mass ~ J~ .n A disad~antage of liquld phase ~;rt~;~gisthat its use limiLs ~e s~kc~ of alloy sy~tems to those whe~e the bindcr alloy can folrn a liquid ~t a t- "~ below the liquid-fG.. i.. g ~f."~ 1"' of the hard phase pcllcts. Fo~ e~m~l~, WC-Co hard phase pelle~s have a1jnnt~ Gofi~ Y;~ y 1,280 C,thustheliquitphases~nteringt~ p~.8 for ~e double ce~ a~d t~ .. c~rbide c..,..~ of ~is ~ve.lt;ol~ 1~ to be below 1,280~t~.
Melting d~ ~-t cl~ such as Si, B or C have to be uset in comhin~;nnwlth ~e steels, 35 nickel, or cobal~ metal ;n orde~ to fonn a liquid during sintenng. Ho~vever, the l,.v~.li~.s of liquid ph~e Sint~ CO~ ~Sil~t~ri~l~Will~ di~n~ fi om ~u~ of ~loys without mel~ing poin~ deples~u ~

07/31/97 T~U 22:28 [TX/RX N0 6304]

JUL 31'97 ZZ:36 FR CHRISTIE PRRKER ~HRLE 18 577 8800 TO 916046814081 P.14/3' 1 3O76OIGIIJS6l HOtF~ U~
Ale ~ ~C~ he;~J~J ~ nnay be hol pre~d t~ a des~ed shape in a closed tie a~ a t~ J~ below ~he solitus ~ .h~ of ~he ductile bindcr pbase for bnnding by .v ~ Hot ~. ~ ~L be ~ " ..I~"~ t~ ~ w~th or wi~o~t a liquid phase to ~chieve filll density. Dunng the hot pressing p~cess, green powder ~..p.~t or loose paclced powder i9 place~l ~n a ~vc.p~.~ die a~d is hcated by the die to a desiret ~ t-.., T~e green po~rder ~"'1- 1 or loose packed powter is pr~ at ehe desiset t ~ fl~ under a p~essure of about 10 one to ten Icsi for a~ t~ d lengt~ of titne, e~g., 30 ~o 60 ~ t~ ~ Ihe hot pLe~i~
process ~ a ~Qable ~.~lu~l;o.~ loO,~ for double c~ ~ vr~tn~ catbidlc co~ ~~;~s of this i...e~i.~n w~ ~ ~ d to 1i~d phase ~ t~" ~ ~ecause i-c use pc~ts a greater ~ lc~ n of binderalloyr t ' ' T~ ctorsofthehotp~processfor~ includethehigh cost ~e~;slte~ vith L~ p?-i~ mold ~.r~ nr., a~ ~ ~t ~ flç1r~ y with ~espect ~o Hot Tso ~"t;c p~F~
The Hot isos~s~c press (Em~) proces is anoUher option for ,.. ~"l5,eh~ doubleh~ carbide c~ ..r~ :t~COft~ig Lnvention. I~e powder miy~ ofthe hard phase particles ant the ductile metal phase powder a~e fi~t e~ .v~ in a soft ~etal case (5teel in m~n~
~, F' - tior c) under a vacuum. During HIP~, tlle powder blend ~r ~p ~ Ul the me~al case i~ corc~ Rted by ~n inert ~ ~g gas ~uch as a~on Ih.~ h the meral case at a pred~ .;n~ t~ c for iII the range of ~m about 30 ~ ', to ~ hou~ he HIP
IJ1~: is usually in the ~ange of fiom about 10 to 3n ~ Ihe enrire heating and cooling cycle for the H~P proeess is ~.~ ~ . ~ '.y 15 to 20 houIs in a ~.~u~ ~io ~ Lh~;L~ t -tOuasi~ s There are othcr quasi-HlP process that can also ~ et for ~ t ri~ double Cf~.--~ J ca~bide~ ssit-softhisinvention. A~ ofsuchquasi~DlNGprocès~is the r~ ~ ~ process as A C~ ill U.S. Patent ~Jo. 4,1;73,549, which is incc.~ t~i herein by l~h.~llcc. Thc Cr~); on p~occss is ~ pseudo hot ;c.~ t;~ ~ug u~ le~ whe~ the shape Is ~re;,inte.~d and ~ eO fi~er cc l~a tjon by hot ~ c pl~;~;n~ )I~G3 orquasi-HIDI~IG ph~ce~ whcre syh~ ,hile g~n~e~ are used as a ~ a~, t- ~ ;r.l~ media.
Ra~id Ol..nic~ ti~n.~l Co~ tiQn Aylef~ e~is~ef~Todt~as~idnrnni~;~cti~n~ , tinn (ROC). F.Y~
ROC ~ruc~s arc descnbed in U.S. Paten~s 4,945,073; 4,744,943; 4,656,002; 4,428,906;
4,341,557 and 4,142,888, wh;ch are hereby in.c.. ~ .d b~ l~f~.~.. ce. Broa~ly, the process involves fi~ g a ~ of pellets and a powder of a ductile ~netal binder, alonE~ with b ~ wax binter. Ihe ~iAlU-C iS pressed in a closed dic ~08 desin~d shape, such ~; a rock 07/31/97 T~U 22: 28 [TX/RX N0 63041 ~UL 31'97 22:36 FR CHRISTIE PRRKER ~HRLE 18 577 8e00 TO 916046814081 P.15/3' bit insert. The rff~llt~ g~en~ is va¢uum d.,~ ~.,d a~ ;nt~.~ci at a relatively low to achieve a dengity ~..,ciably below filll theoretical de~sicy. l~e ~ t .h~s is only s~lfficier-t to pcnnit ~ ~lin~ ofthc inse~t for ~ ~ c cqin~, This green ir~rt is ~ .~1 in 8 first ~,or~t~ and is then placed in seco~d C~ t~ P r made of a hi8h t- "1~ -c ~igh p~c3;~ self-sealing LF~ ~pt~riAI The second co~lT ~
is filled with 8 speci81 gla~s powder ant the gre¢n parts ~l;cp~$~ ~vithin the first co.~t~ . are e~ l in tho glass powder. Thc glass po~der has a lower m~lt;n~ po~IIt t~ that of the green pa~t, o~ of th.~ die. l~e seeond ~ - . is placet i~ a fi~naco to raise it to the tesi~edr~ t ~ at isdso abovethe~ gpointoftheglas~. For~ u~
for a WC-Co hard phase pellet~obalt ductile metal phasc system, the conc~
is in ~e range of ~om l,OOO~C to 1,500~C. Ttle heated secont e.n~ wit~ thc molrFn ~s and~enpar~si-,-",. I~inside~placediI~ahydmulicp~ssha~gaclosedcylil~;e~l diesnd mm tbat presse-s into the dle. Molten glas5 and ~he grecn pa~ts a~ ~ubj~_ted to hi~ ~. in the ~ealed celamic ,..---1A; .- - . Tlle pslts ~re ic.,~ 1y p~es~ by tl~c liqu~d glass to ~G~
as high as 120 Icsi ~e tempeIature r~p~t iliy of ~e entire p~cess can bc as hi~h as 1,X00~C.
Ihe hig~ ple~., is applied for a shorT penod of ~ime, e.g, less than about fi~e - ~ ! and one to two min~ C and isostatically c ~ ~ the ~n pa~s to cssert~ y 100 20 percent density.
ll~e ROC p~Dces~ has the follou/in~ ad~antages wllen cot~lp~cd against tl~ ,.oc~s~
(1) ~e ~ is a liquid ~e~ Than a ~s, thereby allowin~ one to start wieh a shaped ~reen pa~ lather ~ ing lo start ~i~ a powder blend that must be both e~ ps~llo~-d and ev_- ' ~fore HmDnNG; (2) it pennies near net-shapc m~ufach~ng ~ehout ~ ~t is .;~I.e~ flexible in K~ , unlike ~n~lG that .~ . post ~ , and is not suitable for small indi~ridual cu-~ t manufhclu--l.g, (3) it o~~Ar!4 a~ au~ as hig~ as 120 ksi, ra~her ehan ae lo~ HlDlNG p~ S of less than about 30 ksi; (4) it ~ ,t~, at high .~ atu,~, of up to about 1,800~C, rathcr than at HIDlNG t~ ~r ~ c~ of less than abou~
1.500~C; (5) it has a ~hort ~ n~ ~ime of about one to two ~ s at pressure ~nd the h~t;n~ aod cooling oF~iorc ar ,"~ om the acmal ROC proces~c, rather than havin~ a longH~)I~Gp~cesctimeof30to 120 m .d a~k,.~ ,and ~J~ . thatr~ e~long penod fo~ p.e~ and 1....~.~ ~ ~np up, pro~viding a typical cycle time of 10 eo 20 hour, ~6) it do~ not pl re a limit on thç co~n~it~ ange for lfu~ n~li~5-t;c.n ~ ~ ~1~ the L~ Je,..~
high ~,ress~c callses a large arnount of plas ic ~Pft~tior~, unlike HrDlNG that limits thc 3 5 ca bite C~ -, . if solid stat~ cnnen~ n is re~wred, ~ s the c~ncnlid~tion . . .~ F ~ n dcpends on crccp and solid s~ate diffi.lsioni and (7) it l,.~lu.~ a full~ consolidated product having less micro defecu such as micro yo.u;,il~, unlike HIDING whe~e the p.~lu l;or of a 07/31/97 T~U 22:28 [TX/RX N0 6304]

-JUL 31'97 22:36 FR CHRISTIE PRRKER ~H~LE 1~ 577 e800 TO 916046el4081 P.16~3' 30760/G~IJS6 1 pofosilr-free ~h~el~4~ is d~ d~v ~t on ~e type of c.~."Y~ '1;,... e g., the higher tlle carbide - rt the hi~ber the p~bal~ r for rnic~ pO~uail~r.
Double~ arbide. .,~ ~ of~is............ ~ .Pbetter~ ~t~odand ~i r ~ 1 With l~f~ cc to the following ~

Exam~le 1 - Double c~ /t~ t~ carbide. c~ ~ed bv ~nfi~ on Process Mim~s 200 mesh 5~ WC-6Co ~i-lt~ -~l pellets v~ in a ~ e mold to the desi~d ~hape of an i~sert for use w~th a rot~r cone rock bi~ Tne pelleta ha~rc an average pa~ticle si~e ~sl the r~nge of from about 40 to 50 .- ~~ .."rt.~ The pellcts ~e p.~ t~.~l in the mold in a ~ ~-tn at about 1,300~C for i, r~ 30 mr ~ "~,tL.~ insen~
wete tben infi1- I withNi~ t;.~ LM, a nickel ~ -3d infiltration alloy 1- ~7-~ -v~ by Wall Colmonoy, l:nc. ~he infilhation le p ~ ~ e ~as cont~lled at , ~ 050~C for a 15 ~od of app¢~ .y 30 .: ~ s For thc ~rles used for infilh~ n, -~y~v~ ly 30 percent by weig~t oft~ Ni~...l~,~ LM material was used ~o chargc the mold IIo~/~.", due to exce~ ;nfilt~-lt piIe ~ on ~e top and bottom of the r ' S, about 40 percent by volume (26 percent by weight) of nickel alloy wa~ in the final as-infil- ~t ~ ~ samples.

20 r ~ 2 - D ~ouble c-- . .- .t~ n~n carbide c.,~ t~ p.~ u ..1 b~r ~ot P~ss P~ces~
Sph ~1 WC~Co si~e ~.d pellets having an ~ , p_rticle size of appr~Yimq-~ly 40 ~O 50 ~ f~ t~.~ were bl~ d ~nth a low~bon ductile ~eel (i.e., the duc~leb~nderphase ;1),such~sC~adeAlOOOC,--~-,--r ~ by H~ C~y~rn~iOn A~.v..;...~tely 36 pe~ent by volwne (i.e., less than 2~ percem by weight) ofthe ductilc steel w~s used Ihe ~.h. . :. A1 pelletc were minus 200 mesh. i.e. they p~sed ~ Ju~L a ~ d 200 mesh screen. I~e bl~P~ powdet was paelced into a ~,it~ mold that was coated w~th I~BN, ~ndthenhot pressedat~pr~-Yil "a~~ 200~C foronehourata~ cof;~y.~ ~ ~t:'ysix ksi.

F.Y~m~1e 3. - Double c~ r~1 n~ t, .. carbide CUIn~_ tr.. ~rc;v_~d bY ROC: Prlxess S~Pn~l W C-6cosiAte~ pelle~ havmg an average pa~icle size of ~ri~ st~ly 40 ~O 501~iCnJ~ t~,;.;~ werc Wct milled to~ether wi~h AIOOOC lo~r~arbon tuctilc steel powder in heptane fluid, and ~p~A' ~ 1 t~o percent by weigllt l~ wax ~as added thereto.
Ap~J~u~;...~t~ly 36 percent by volume (i e., less than 25 percent by wei~ht) of ~he ductile s~eel was uset. ARer milli-l~ the powter was dried ant it wa3 pressed in~o green inselts on a uni-axial press ~o a spccifir ~li...- ,..-:on The green insert was then presinte~:d in a vacuum a approxim~ly 950~C for 30 r~in~ 5 The p.~, 3~tc-~ inxls was tllen subject to a rapid 07/31/97 THU 22:28 [TX/RX N0 6304]

JUL 31'97 ZZ:37 FR CHRISTIE PRRKER &HRLE 18 577 8800 TO 916~46814081 P.17/35 30760/GT~IS61 ~.mni~ ctinn~l c~r~ctiQr~ p~ocess at ~p~ t.l~ 1,100~C uri~ 120 ksi pl.~3_~. Other ductile metal alloy binde~i were also lJsed to 1~ t~ ~ using the ROC process. Ihe ,~ f ~rere then ev~luated for l.,ic,~,l,~lu.~ and ~ - - !.,-,~;~1 l~n-~ I; .~

E~n~' 9 4 to 9 - ~urth~ Double c~ ..t~ t~ ~ carl~ide ~...~ s~ el bY E~OC
Prlx~
Fulther double c~ d ~ c~ite cc ~ ' ~ were y~y~ in a manna~ similar tO ~at ~1F ~ ~) aboYe for ExaIslple 3, exeep~ ~at ~e type of ductile binder phsse mater~al sDt its ~ .,.I;or~ was ~aried in the following ll,&hn_.. ~ ,1~ 4 - app.o~ ~t~l~ 36 perceM by volume (i.c., less thar4 ~5 pe~cent by wcig~t) Gmte 4650 s~el; ~ !.e 5 - ~pp.~ . . t.~ 30 p~ .t by volume (i.e., le~s tha~ 2~ perccnt by weight) G~alle 4650 steel; F ,)!s 6 -a~lo~ t~ 38 percent by volume Seah~ ~e-Ni-Co alloy, Example 7 - ~p,~;." -t,ly 3015 pen~ent by .rolume Sealvar, r~ 8 - &yy~u.~ t~l~ 38 per~ent b~r ~olume cobalt; ~nd FY~rle 9 - ~yy.u~..~ely 30 percent by volume cobalt. In each of ~ese o t~l'3, the ~,ph~, iç~l pellets were minw 200 mesh EXa~DIe 10- Double~ . .t~ 1nçarbite ~ n.~ swi~ epl~;va~1bY ROC
20 Pro~
A double ~ t~ clrbide co~ ite was ~ t in a ~,~.,. simil_r to '~hat described above for F~ mpl~ 3? except tl~at the tuctilc binder phase mRtrriRl was cobalt and i~cluded an additive of WC particles. Sper;fi~lly, the c ~-r cc..~r~ approximalely 38 percent by ~olume tuctile binder phas .-- .T~ l and atdidve, based on ~e total weight of the 25 co,.~ , s3nd a~ ....s~t~ Iy 10 percent by volume WC ~ddi~ve, baset on the total wci~t of the ductile binder phase mQteriQl and the adLliv~. The ad~ , W53~ ~n the fonn of fine ~n WC, having an ave~age pa~icle ss2e in the tange of ~om about 10 ~o 15 ...;~ The sphencal pellets of c- ~ .- .~'ed t~ 1 c3rbide had ~n average p~ticle si~ in the ~nge of f~om abou~ l S0 to 200 nuc.o. t~
Ibe double c- ~.~ d l~ t~ ~~ carbide CO!~rc;t~s l,~pd~cd ~-~: di.-~ to ~ r~lP c 6 to lO ~rere testect for such ' ier~ ,~nies ~ I~.e~, f~a~ tou~nPsc~ ~ld wear e H~n~c w s ~ ,~u~ uslng a Ro~ w 'I A standard ~IRa)~ f;~ t~e tou~hn~sC was . ,.~,l by using a KlC (~csi~in 2) ~k"~l lest acc~ to ASTM B7~ I -87, and wear r~ n~e 3 5 w~ rep~l r-,d as a wear nurnber ( l ,000 rev/cm3) as cor~ to ASlM B-6 1 1-~5. llle test results are set forth in the Tabte below.

--lS--07/31/97 T~U 22:28 [TX/RX NO 6304]

-JUL 31 ' 97 22: 37 FR CHR I ST I E PRRKER ~HRLE 18 577 88~0 TO 916046814081 P.le~3C

Table of Me sure Mech~icsl F'r. ,a l lies Sampl~ lD HardneuFract~lro Touglu-e~s, Kk Wear 1;'~ t~ e~
O-,rer~(k~,i-ill-Z) (1,000 1e./~ ') F~ 6 77 27 2 F le'7 81 23 2 ~,~r~8 82 29 2 r , I 9 _ 83 22 r ~ 10 N/A 40 3.8 .
A~ eed in ehe ~able, the double c~ I tungsten Qtbide ~u ~p~,;t, of Examplcs 6 to 10 each tispla~ chlre b u~ ,~ (Kle) ~er than 20 ksi~in 2, and had a ~earnumber ~reaeerdlan 1.5 (1,000 rl:V~cm3~11t, mon~ ly of ~ F u~ t~ l~r 2 (1,000 rcv/cm3). Each of ehc r ~ - 6 to l O double c~ tungsrer~ carl~ide ~ f ehis y ' a fiacb Ie t~!.~A- c~ of . .r ~ r 2~ or g~ter, a~d some ~ high ~c 27, 29 and 40.
FIG. S ~-~ly r~ e ~ or~cl~ip ~n ~ L~l~ t~ s alld wcar }Pcict5-n-~ for both col~v~ t;~ c~ ¢~vA t~ cu~ite ms-t~n~l~, and for the doublç
~,,",~ . ,t. ~ . ca~ide cc~ , of ~eg 6 to 9. As ill~ .t. d ill ~IG. 5, the fiscn~e ~oug}-n~c for ~o.~ ~ n~l cemented t~ carbite m~t~-lC., ha~i~g a u~ar nu--.~. of ~p~u~ateb two or more i~ no g~eater ~an about 18 ksi-in-2, and ~nore ~ A~ly is ~ithin the lange of fi~m about I 1 to 18. According to dle tcst dal~, double c ~ h~n~t carbide 25 composites of this i..~_~o~ have improved ~lo~.l c5 of r.~ to~ ss~of at least 22 percent and 0s high as 60 percent) when CC ~I~p~ to conv~ ntion~J e~ d ~ r~ carbide ms~--on~lc w~thouts~ .;rl-~~wear ~L ~ e ~he i~ d firactuIe lo~ss providet by double ~ d t~ ct~ cart~ide cc,...~ ;tes of this invention is a le~ult of the special a.c~ t~ ~, of the micro~cmTe~
3 0 ~ o~ u ~e h~r~d phase ~ r ~ that act to control the wear rate of the cc r ~;t~ a~ tct by the duc~le binder phase t~at p~ides a crack blunt~ng, i.e., a ~acture ener~ so.bi~g~ effcc~
to thereby improve the ~acrure to~J~hnrcs of the CO~
Double cer- ~t.~ carbide cc.l..~ of this i~ tio~, ean be used in a number ofdif~erenl applirs~tinn~, such as ~ools for D~inin~ and cons~uction aF~ ti~ whel~e ~ A~
35 p~u~lies of high La-:n~ ougJln~, we~ ~ , ~d h~ are highly dcsircd Doublc~ . ". ~ ~t. ~ cart~ite c~ of ~is inven~ion can be used to form wear and cuning c~ t~
~n such tools ~s roller cone bits, ~lssion or h~ r bits, drag bits, and a number of different 07/31/97 THU 22:28 [TX/RX NO 6304]

JUL 31'97 ZZ:37 FR CHRISTIE PRRKER ~H~LE 18 577 ~800 TO 916046el40el P.19~35 1 30760/GllJS61 cuKing and ~ ;n~ too~. Fo~ ex~ple. ref~Lo~ to FIG. 6, touble C~ t.,~ carbide con ~rl~ ~it~ g of ~ ivn ca~ be uset to fonn a mil~ing or tnll bit insert 24. Refe ring to FIG.
1, such an ins~ 24 can be used w1~h a roller cone drill bit 26 C-~ ';gi~ a bod~r ~8 ha~ng three legs 30, and a cut~er cone 3Z .-.~ d on a lower end of each leg. ~ach roller cone bi~ insert 24 can be r~ ~ d ar ~ 8 to one of the ..~ .h.~. descnbet above. The inserts 24 are l.rv ~ided in the ~u.r~,c~ of the cutter cone 32 for b~ on a rock f~ being drillet.
R.e~ - .; g to FIG. 8, inserts 24 forInod f~vm touble c- ~--o ~t~ carbide ca--~ ~ ~ ~ of this i~ ntivu can also b~u~ed wi~ a p~ ,.- or ~ . bit 34, co ~r; - g a hollow stcel body 36 having a 1~icd pin 38 on an end of the body for ~bl~ the bit onto a drill s~ing ~not shown) for drillirlg oil wells and the lil~e. A pluraliy of ~he ir~serts 24 re t..~.~.;ded in the ~urface of a head 40 of tlle body 36 for bearing on the 5~ t~ n f ~- ... ~';An belIlg drilled.
R~ f~.~;r~ to FIG. 9, doubb c~ t~1 carbidc cn,~ ;t~ 5 of t~ iv.l can also be 15 used to fonn PCI:) ~hear cutters 42 tha~ a~e used, for example, ~rith a d~g bit for dnlling subt~ f~ ~ More ~ y, double L~ t~ car~ide c~ ~, of this invention can bc used to fo~n a shear cuttcr ~~ ~f 44 that is used to ca~Ty a layer of polyc~alline .Ijh~ ~n~ (PCD) 46 that i~5 s~-~d thereto. 12~f~i~g to FIG. lO, ~ d~ag bit 48 CC-~ Q a plurali~ of such PCD shesr cut~r~s 42 that are each ~ e1 ~d to blades 50 ~t extent 20 fi~om a head 52 of the d~ag bit for cutting aga~nst ~e su~ ,-- ."5~h- ~-- oeing drilled.
Although, limitet Pmki 1i~ r~i of touble cr-....~t '1 carbide co.~ it~ c Of mal~ng the same, and n~l j~ 3~ for ~e same. haYc been described and ill-~ t~ herein, many t;.~l,C ~1l be ~ ,.lt to those skilled in the ~t Ac~o~dingly, it is to ~e t~ -od that w~thin the scope of the r~ d claims, double c~ t~ ~ carbide . u~ e 25 according to ~ ,le s of this i~ tion may be e"-ho~ d other t~an as ~ lly ~.it~d hcreirL

07/31/97 TIIU 22:28 [TX/RX No 6304l

Claims

1. A composite cermet material comprising:
a plurality of first regions, each region comprising a composite of grains and a first ductile phase bonding the grains, wherein the grains are selected from the group of carbides consisting of W, Ti, Mo, Nb, V, Hf, Ta, and Cr carbides, wherein the first ductile phase is selected from the group consisting of Co, Ni, Fe, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, Si and Mn;
a second ductile phase separating the first regions from each other, the second ductile phase being selected from the group consisting of Co, Ni, W, Mo, Ti, Ta, V, Nb, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, and Mn.

2. The composite material as recited in claim 1 comprising in the range of from about 40 to 95 percent by volume first regions, and less than about 60 percent by volume second ductile phase based on the total volume of the composite.

3. The composite material as recited in claim 2 comprising in the range of from about 60 to 80 percent by volume first regions and in the range of from about 20 to 40 percent by volume second ductile phase based on the total volume of the composite.

4. The composite material as recited in claim 1 having a Kie fracture toughness of greater than 20 ksi~in-2, and a wear number of at least 1.5(1,000 rev/cm3).

5. An insert for use in roller cone and percussion drill bits formed from the composite material of claim 1.

6. A polycrystalline diamond shear cutter substrate formed from the composite material of claim 1 and layer of polyerystalline diamond on a face of the shear cutter substrate.

7. The composite material as recited in claim 1 wherein the second ductile phase further comprises an additive selected from the group consisting of carbides, nitrides, borides, and mixtures thereof.

8. The composite material as recited in claim 7 wherein the additive is selected from the group consisting of WC, VC, NBC, TIB2, TIC, MoC, Cr3-C7, polycrystalline diamond, and cBN.

9. The composite material as recited in claim 7 wherein the additive has an average particle size of less than about 20 micrometers.

10. The composite material as recited in claim 7 comprising less than about 30 percent by volume of the additive based on the total volume of the second ductile phase.

11. The composite material as recited in claim 1 wherein the first regions comprise tungsten carbide grains a cobalt first ductile phase, and wherein the second ductile phase is cobalt.

12. The composite material as recited in claim 1 wherein the first regions comprise spherical pellets embedded in the second phase.

13. The composite material as recited in claim 1 wherein in the event that the second ductile binder is an alloyed steel, the steel comprises less than about 0.8 percent by weight carbon and has a total alloy content of less than five percent by weight based on the total weight of the second ductile binder.

14. The composite material as recited in claim 13 having a Kie fracture toughness of greater than 20 ksi.in-2, and a wear number of at least 1.5 (1,000 rev/cm3).

15. A double cemented carbide composite that is prepared by combining:
hard phase particle comprising a carbide compound and a first binder material, wherein the carbide compound is selected from the group consisting W, Ti, Mo, Nb, V, Hf, Ta and Cr carbides and the first binder material is selected from the group consisting of Co, Ni, Fe, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, Si, and Mn, Wherein the hard phase particles have an average particle size of less than about 500 micrometers; with a ductile second binder material separating the hard phase particles from each other, the second ductile material being selected from the group consisting of Co, Fe, Ni, W, Mo, Ti, Ta, V, Nb, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, and Mn, and sintering the composite at a sufficient temperature for melting the second binder material;
wherein the composite has a kic fracture toughness of greater than 20 ksi-in-2, and a wear number of at least 1.5 (1,000 rev/cm3).

16. The double cemented carbide composite as recited in claim 15 wherein the hard phase particles are substantially spherical.

17. The double cemented carbide composite as recited in claim 15 comprising in the range of from about 40 to 95 percent by volume hard phase particles and less than about 60 percent by volume of the ductile second binder material based on the total volume of the composite.

18. The double cemented carbide composite as recited in claim 15 wherein the ductile second binder material further comprises an additive ingredient selected from the group consisting of carbides, nitrides, borides, and mixtures thereof.

19. The double cemented carbide composite as recited in claim 18 wherein the additive ingredient is selected from the group consisting of WC, VC, NbC, TiB2, TiC, MoC, Cr3C7, polycrystalline diamond, and cBN.

20. The double cemented carbide composite as recited in claim 19 comprising less than about 30 percent by volume of the additive ingredient based on the total volume of the ductile second binder material.

21. The double cemented carbide composite as recited in claim 15 wherein in the event that the second ductile binder material comprises an alloyed steel it comprises less than 0.8 percent by weight carbon and has a total alloy content of less than five percent by weight based on the total weight of the second ductile binder material.

22. A double cemented carbide composite comprising:
has particle of tungsten carbide cemented with a first cobalt binder, and a second cobalt binder surrounding the hard particles.

23. The double cemented carbide composite as recited in claim 22 wherein the hard particles are substantially spherical.

24. The double cemented carbide composite as recited in claim 22 comprising hardparticles in the range of from 60 to 80 percent by volume of the total composite.

25. The double cemented carbide composite as recited in claim 22 wherein the hard particles have an average particle size of less than about 500 micrometers.

26. The double cemented carbide composite as recited in claim 22 wherein the composite has a Kie fracture toughness of greater than 20 ksi~in2, and a wear number of at least 1.5 (1,000 rev/cm3).

27. The double cemented carbide composite as recited in claim 22 wherein the second cobalt binder further comprises additives selected from the group consisting of carbides, nitrides, borides, and mixtures thereof.

28. The double cemented carbide composite as recited in claim 28 wherein the additive is selected from the group consisting of WC, VC, NbC, TiB2, TiC, MoC, Cr3C7 polycrystalline diamond, and cBN.

29. A double cemented carbide composite comprising;
hard particles of tungsten carbide cemented with a first cobalt binder, and a second binder surrounding the hard particles formed from a material having a coefficient of thermal expansion less than about 8 µm/m-K.

30. A roller cone drill bit comprising:
a body having a number of legs that extend therefrom;
cutting cones rotatably disposed on an end of each leg;
a plurality of cutting inserts disposed in the cutting cones, wherein at least a portion of the cutting inserts are formed from a double cemented carbide composite comprising;
a plurality of first regions, each region comprising a composite of grains and a first ductile phase bonding the grains, wherein the grains are selected from the group of carbides consisting of W, Ti, Mo, Nb, V, Hf, Ta, and Cr carbides, wherein first ductile phase is selected from the group consisting of Co, Ni, Fe, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, Si, and Mn; and a second ductile phase separating the first regions from each other, the second ductile phase being selected from the group consisting of Co, Ni, Fe, W, Mo, Ti, Ta, V, Nb, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, and Mn.

31. The roller cone drill bit as recited in claim 31 wherein the event that the second ductile phase comprises an alloyed steel it comprises less than 0.8 percent by weight carbon and has a total alloy content of less than five percent by weight based on the total weight of the second ductile phase.

32. The roller cone drill bit as recited in claim 31 wherein the double cemented carbide composite comprises in the range of from about 40 to 95 percent by volume first regions, and less than about 60 percent by volume second ductile phase based on the total volume of the composite.

33. The roller cone drill bit as recited in claim 31 wherein the double cemented carbide composite comprises in the range of from about 60 to 80 percent by volume first regions and in the range of from about 20 to 40 percent by volume second ductile phase based on the total volume of the composite.

34. The roller cone drill bit as recited in claim 31 wherein the double cemented carbide composite has a K~~ fracture toughness of greater than 20 ksi*in-2, and a wear number of at least 1.5 (1,000 rev/cm3).

35. The roller cone drill bit as recited in claim 31 wherein the second ductile phase further comprises an additive selected from the group consisting of carbides, nitrides, borides, and mixtures thereof.

36. The roller cone drill bit as recited in claim 36 wherein the additive is selected from the group consisting of WC, VC, NbC, TiB2, TiC, MoC, Cr3C7, polycrystalline diamond, and cBN.

37. The roller cone drill bit as recited in claim 31 wherein the first regions comprise substantially spherical pellets of cemented tungsten carbide.

38. The roller cone drill bit as recited in claim 31 wherein the first regions comprise tungsten carbide grains and a cobalt first ductile phase, and wherein the second ductile phase is cobalt.

39. A percussion drill bit comprising:
a body having a head with a surface adapted to engage a subterranean formation during drilling;
a plurality of inserts disposed in head surface, wherein the inserts are formed from a double cemented carbide composite comprising:
a plurality of first regions, each region comprising a composite of grain and a first ductile phase bonding the grains, wherein the grains are selected from the group of carbides consisting of W, Ti, Mo, Nb, V, Hf, Ta, and Cr carbides, wherein the first ductile phase is selected from the group consisting of Co, Ni, Fe, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, Si, and Mn; and a second ductile phase separating the first regions from each other, the second ductile phase being selected from the group consisting of Co, Ni, Fe, W, Mo, Ti, Ta, V, Nb, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, and Mn.

40. The percussion drill bit recited in claim 40 wherein the first regions comprise substantially spherical pellets of cemented tungsten carbide.

41. A drag drill bit comprising:
a body having a head and having a number of blades extending away from a head surface, the blades being adapted to engage a subterranean formation during drilling;
a plurality of shear cutters disposed in the blades to contact the subterranean formation during drilling, each shear cutter comprising a substrate and a layer of cutting material disposed thereon, the substrate being formed from a double cemented carbide composite comprising:
a plurality of first regions, each region comprising a composite of grains and a first ductile phase bonding the grains, wherein the grains are selected from the group of carbides consisting of W, Ti, Mo, Nb, V, Hf, Ta and Cr carbides, wherein the first ductile phase is selected from the group consisting of Co, Ni, Fe, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, Si, and Mn; and a second ductile phase separating the first regions from each other, the second ductile phase being selected from the group consisting of Co, Ni, Fe, W, Mo, Ti, Ta, V, Nb, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, and Mn.

42. The percussion drill bit recited in claim 40 wherein the first regions comprise substantially spherical pellets of cemented tungsten carbide.

43. A method for forming a double cemented carbide composite comprising the steps of:
combining:
a plurality of hard particles, each comprising a composite of grains and a firstductile binder bonding the grains, wherein the grains are selected from the group of carbides consisting of W, Ti, Mo, Nb, V, Hf, Ta, and Cr carbides, wherein the first ductile binder is selected from the group consisting of Co, Ni, Fe, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, Si, and Mn; with a second ductile binder material selected from the group consisting of Co, Ni, Fe, W, Mo, Ti, Ta, V, Nb, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, and Mn to form a mixture, wherein in the event that the second ductile binder material is alloyed steel it comprises less than 0.8 percent by weight carbon and has a total alloy content of less than five percent by weight based on the total weight of the second ductile binder material; and consolidating the mixture at an elevated temperature for sufficient time to form a shaped part.

44. The method as recited in claim 42 wherein the step of consolidating is done by hot isostatic pressing process.

45. The method as recited in claim 42 wherein the step of consolidating is done by rapid omnidirectional compaction process.

46. The method as recited in claim 42 wherein the hard particles comprise grains of tungsten carbide bonded with a cobalt binder, and the second ductile binder is cobalt.

47. The method as recited in claim 42 wherein the hard particles comprise substantially spherical pellets of cemented tungsten carbide.

48. A method for forming a double cemented carbide composite comprising the steps of:
combining:
a plurality of hard particles each comprising carbide grains and a first ductilebinder bonded to the grains; with a second ductile binder selected from the consisting of metals and metal alloys to form a mixture;
pressing the mixture to form a shaped part;
placing the shaped part into a high-temperature ceramic container comprising glass powder disposed therein;
heating the ceramic container to consolidation temperature above a liquefaction temperature of the glass powder, and isostatically pressing the ceramic container within a close die a produce a double cemented carbide composite part.

49. The method as recited in claim 49 wherein the hart particles grains of tungsten carbide bonded with a cobalt binder, and the second ductile binder is cobalt.

50. The method as recited in claim 49 wherein the hard particle comprise substantially spherical pellets of cemented tungsten carbide.