Note: Descriptions are shown in the official language in which they were submitted.
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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
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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
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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;
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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.
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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~.
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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
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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
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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
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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
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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
-10-
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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 ~
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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
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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
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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
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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--
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3 0760/GTL/S6 1
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
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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
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