ACCEPTED MANUSCRIPT
1
In luence o empe a u e on he biaxial s eng h o cemen ed ca bides
wi h di e en mic os uc u es
E. Chica di1*, R.Be mejo2, F. J. Go o 3, L.Llanes4 and Y. To es1.
1 Depa amen o de Ingenie ía y Ciencia de los Ma e iales y del T anspo e, Escuela
Poli écnica de Se illa (EPS). Uni e sidad de Se illa (US), Vi gen de A ica 7, 41011
Se illa, Spain.
2 Ins i u ue S uk u - und Funk ionske amik, Mon anuni e si ae Leoben, 8700
Leoben, Aus ia.
3 Ins i u o de Ciencia de Ma e iales de Se illa (US-CSIC), 41092 Se illa, Spain.
4 Depa amen de Ciència dels Ma e ials i Enginye ia Me allú gica, Uni e si a
Poli ècnica de Ca alunya, 08028 Ba celona, Spain.
* E-mail: [email p o ec ed]
Abs ac . The e ec o he empe a u e on he mechanical s eng h o WC-Co
cemen ed ca bides wi h di e en mic os uc u es (g ain size and binde con en ) was
e alua ed. Biaxial lexu al es s we e pe o med on h ee cemen ed ca bide g ades a
600°C using he ball-on- h ee-balls (B3B) me hod. Resul s we e in e p e ed by Weibull
s a is ics and compa ed o biaxial s eng h esul s a oom empe a u e. A de ailed
ac og aphic analysis, suppo ed by Linea Elas ic F ac u e Mechanics, was pe o med
o di e en ia e he na u e and size o c i ical de ec s and he mechanism esponsible o
he ac u e. A signi ican dec ease in he mechanical s eng h (a ound 30%) was
obse ed a 600ºC o all g ades o cemen ed ca bides. This ac was asc ibed o he
change in he c i ical law popula ion om sub-su ace (a oom empe a u e) o su ace
de ec s, associa ed wi h he selec i e oxida ion o Co. Addi ionally, an es ima ion o he
ac u e oughness a 600°C was a emp ed o he h ee cemen ed ca bides, based upon
he B3B s eng h esul s, he co esponding numbe o he es ed specimens agmen s
and he mac oscopic a ea o he B3B ac u e su aces. The ac u e oughness was no
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
2
a ec ed by he empe a u e, a leas up o 600ºC. In addi ion, he good ag eemen wi h
he Single Edge No ch Beam oughness da a sugges s he possibili y o employing his
app oach o ac u e oughness e alua ion o b i le ma e ials unde di e en es ing
condi ions.
Keywo ds: Cemen ed ca bides; empe a u e; Weibull s a is ics, biaxial lexu al
s eng h; Ball on h ee Balls.
1. In oduc ion
WC-Co cemen ed ca bides, also known as ha d me als, a e ce amic-me al
composi e ma e ials wi h excep ional combina ion o ha dness, s eng h, oughness,
elas ic modulus and wea esis ance [1, 2]. Such ema kable mechanical p ope ies
esul om he syne gic e ec o hei cons i uen phases, i.e., a ha d b i le ungs en
ca bide (WC) and a so duc ile me allic phase (Co) [3]. The mic os uc u e o WC-Co
cemen ed ca bides a e usually ace ed WC g ains, wi h ec angula o iangula
mo phology, embedded in a Co-based alloy ac ing as binde [4]. O he mino seconda y
ca bides (TiC, TaC, NbC, Mo2C, e c.) and me allic elemen s (Ni, V, C , e c.) a e added
o modula e he mic os uc u e, he chemical s abili y and he mechanical beha io o
hese ma e ials [5-7]. Mo eo e , he use o ine WC pa icles is also ano he op ion o
imp o e hei mechanical p ope ies [8].
Cemen ed ca bides a e widely used as cu ing ools, among o he indus ial
applica ions. As he cu ing speed inc eases, he ope a ing condi ions become mo e
demanding in e ms o he mo-mechanical s esses ha o en endange hei eliabili y
in se ice. In his ega d, cemen ed ca bides exhibi low oxida ion esis ance and
damage ole ance a he high empe a u es ha can be eached on he ool/chip in e ace
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
3
while in se ice [1-4]. I has been epo ed ha he o ma ion o de ec s a high
empe a u e as a esul o oxida ion and he g ow h o he p e-exis ing laws a e he
main causes o he loss o s i ness, mechanical s eng h and ac u e oughness du ing
se ice [9-12]. These de imen al e ec s begin o be signi ican a empe a u es abo e
600ºC [13], and in he 800-900ºC ange, depending on he binde con en , ha d me als
each ull oxida ion [14]. Accha e al. [8] ound a la ge loss in mechanical s eng h
om 600ºC and Fan ozzi e al. [15] epo ed ha he Young`s modulus and he
mechanical s eng h dec eased wi h empe a u e, which was pa icula ly impo an
beyond 500ºC. Howe e , a small inc ease in ac u e oughness has been epo ed
be ween 600-700ºC associa ed wi h elas ic-plas ic ansi ion [15, 16], al hough his
e ec is only empo a y since om 700ºC-800ºC he ac u e oughness diminishes
again because o oxida ion [15]. Mo eo e , he mechanical beha io o cemen ed
ca bides a high empe a u e no only depends on he wo king a mosphe e (oxygen
pa ial p essu e) and he exposu e ime, bu also on he na u e, con en and pa icle size
o he cons i uen phases [9, 14, 17] as well as he inhe en laws associa ed wi h he
manu ac u ing p ocess, such as po es, ce amic agglome a es, coa se ce amic pa icles,
e a phases, e c. [18, 19].
A oom empe a u e, cemen ed ca bides show de ec con olling ac u e s eng h,
which is associa ed wi h he size o he la ges (o c i ical) de ec in he ma e ial. The
ype o in insic de ec s in hese ma e ials anges om po es o non-me allic inclusions,
as well as abno mally la ge ca bides o binde less ca bide agglome a es, among o he
mic os uc u al he e ogenei ies [20]. This can di e om specimen o specimen (o
componen o componen ) [18, 19]. The e o e, s eng h canno be desc ibed uniquely by
a single numbe , bu as a dis ibu ion unc ion ( ela ed o he de ec size dis ibu ion),
whe e a p obabili y o ailu e can be de ined as he p obabili y ha ac u e occu s a a
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
4
s ess equal o o lowe han a gi en alue, acco ding o Weibull s a is ics [21, 22]. The
p obabili y o ailu e inc eases wi h he magni ude o he load (i.e.

) and he size o he
specimens (i.e. V). The size e ec on s eng h is he mos p ominen consequence o he
s a is ical beha io o s eng h in b i le ma e ials, i.e., la ge specimens ha e highe
p obabili y o ailu e han smalle specimens unde he same load applied.
In a p e ious wo k, he s eng h dis ibu ion o h ee cemen ed ca bide g ades
wi h di e en mic os uc u e was e alua ed and compa ed unde uniaxial ( ou -poin
bend, 4PB) and biaxial (ball-on- h ee-balls, B3B) bending a oom empe a u e [23].
Cha ac e is ic s eng hs anging om 2200 MPa o 3000 MPa we e measu ed unde
4PB, while highe alues be ween 3300 MPa and 4200 MPa we e ob ained unde
B3B. This could be explained acco ding o he size e ec on s eng h in b i le
ma e ials, as p edic ed by he Weibull heo y; ex apola ion o he 4PB esul s o
e ec i e su ace showed good ag eemen wi h he B3B expe imen al alues. A highe
Weibull modulus was measu ed in he WC-Co g ade wi h p onounced R-cu e unde
bo h 4PB and B3B, associa ed wi h he subc i ical g ow h o ini ial de ec s. The
ques ion a ises, whe he a simila beha io is o be expec ed a ele a ed empe a u es o
he h ee g ades.
The aim o his wo k was o e alua e he in luence o empe a u e on he s eng h
dis ibu ion o WC-Co cemen ed ca bides wi h di e en mic os uc u es, i.e., g ain size
and binde mean ee pa h. Biaxial lexu al es s we e pe o med a 600°C using he
B3B me hod and he esul s we e compa ed o hose a oom empe a u e. A de ailed
ac og aphic analysis was pe o med o in e p e he mechanism esponsible o he
ac u e. Addi ionally, he ac u e oughness o he es ed cemen ed ca bides was
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
5
es ima ed based upon he s eng h da a, he co esponding numbe o agmen s o he
es ed specimens, and he mac oscopic a ea o he ac u e su aces.
2. Expe imen al
2.1. Ma e ials
Th ee WC-Co cemen ed ca bide, named as 16F, 16M and 27C, acco ding o a
p e ious published wo k [3] and wi h di e en composi ion and/o mic os uc u al
pa ame e s, we e s udied. In able 1, he mass pe cen age o cobal , he WC a e age
pa icle size, he binde mean ee pa h and he Vicke s ha dness o he h ee di e en
cemen ed ca bides a e shown, as cha ac e ized in p e ious wo k [24].
2.2. E alua ion o he mechanical s eng h
The mechanical s eng h o 16F, 16M and 27C cemen ed ca bides was e alua ed
by biaxial lexu al es s using he B3B me hod [25, 26]. This me hod is widely used o
b i le ma e ials (e.g. glasses, ce amics) [27-29], and has also been applied o cemen ed
ca bides [23, 30, 31], and e en me al alloys [32], due o some ad an ages compa ed o
he mos common s anda dized es s, such as 3-poin and 4-poin bending. Speci ically,
he main ad an ages include ease p epa a ion o es samples, high ole ance o some
ou o la ness o he disc and/o misalignmen , much lowe ic ion han in he o he
common es s, possibili y o using small es specimens (e en wi h i egula shape and
close o he eal wo kpiece geome y), absence o ensile loaded edges, among o he s
[23, 25, 27, 28, 33]. The main disad an age o he B3B me hod is ha he load is
concen a ed in a e y small loca ion o he sample and, hus, la ge c i ical de ec s may
no be sampled du ing he es s.
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
6
Fou alumina balls (3 mm o diame e ) we e used o he es s; h ee balls placed
on he op and he ou h ball cen e ed unde he disc specimen. This geome ic
a angemen du ing loading gua an ees a well-de ined h ee‒poin con ac . Wi h his
con igu a ion, a biaxial ensile s ess s a e a he midpoin o he disc su ace opposi e
he loading ball (down su ace) is gene a ed du ing loading, which is used o he
biaxial s eng h e alua ion. Mo e de ails abou he es and a schema ic ep esen a ion
can be ound elsewhe e [23, 33].
A leas en discs (13 mm o diame e and 0.7 – 1.3 mm o hickness) o each
cemen ed ca bide g ade we e es ed. The su aces we e ca e ully g ound and polished
( inal s ep wi h suspension diamond powde o 3 µm) o p e en su ace damage and
ensu e he same su ace quali y in all specimens. The B3B es s we e ca ied ou by an
elec omechanical uni e sal es ing machine (Model 5505, Ins on L d.) in ambien ai ,
unde load con ol a a a e o 100 N/s, coupled o a spli u nace (Ene gon S.L) wi h
e ac o y Molybdenum clamps (m.p. = 2623 ºC). The assembly o he de ice and disc
was ini ially made a oom empe a u e. Then, a 10 N p e-load was applied in o de o
gua an ee he con ac be ween he ou balls and he disc du ing he hea ing s ep. The
empe a u e was inc eased up o 600 ºC (2 h we e necessa y o each he empe a u e),
always con olling and holding he imposed 10 N p e-load.
In he B3B es , he ac u e load, F (in N), is used o calcula e he maximum
biaxial lexu al s eng h, σmax, acco ding o he ollowing equa ion [25]:
max 2


F
(1)
whe e (in mm) is he disc hickness and a non-dimensional ac o , which depends on
he specimen geome y and posi ion o he balls, he Poisson's a io o he ma e ial, and
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
7
he special ea u es o he load ans e om he clamps o he disc. In his wo k, he
alues o anged be ween 1.1 and 1.5 as de e mined om he equa ion by Bö ge ,
Supancic and Danze [25], due o he di e en specimen hicknesses.
The ac u e s eng h was s a is ically analyzed as a unc ion o s ess, which was
ela ed o a ce ain ailu e p obabili y, P , using a wo-pa ame e Weibull dis ibu ion.
Assuming an homogeneous c ack-size equency densi y unc ion [34], he ollowing
ailu e p obabili y unc ion, P , can be de ined [22]:
 
00
, 1 exp





   



m
V
PV V
(2)
whe e σ0 and m a e he cha ac e is ic s eng h and he Weibull modulus, espec i ely.
The Weibull modulus, m, desc ibes he sca e o he s eng h da a, and he cha ac e is ic
s eng h,

0, is he s ess a which, o specimens o olume V=V0, he ailu e
p obabili y is: P (

0, V0) = 1-exp(-1) ≈ 63%. The de e mina ion o he Weibull
dis ibu ion was pe o med acco ding o he s anda d EN 843-5 [35]. In addi ion, he
90% con idence in e als (CI) we e calcula ed o

0 and m, which ep esen he ange
whe e he ue Weibull pa ame e s (i.e. om he pa en dis ibu ion) can be ound wi h a
90% p obabili y and ha e lec he in luence o he sampling p ocedu e. They we e
de e mined acco ding o he s anda d EN 843-5 [35].
The ac u e su aces o he es ed discs we e analyzed by Scanning Elec on
Mic oscopy (SEM) using a Hi achi S-4800 SEM-Field Emission Gun mic oscope and
he Image Analysis so wa e Image-P o Plus 6.2 (Media Cybe ne ics Inc., USA). These
ac og aphic analyses allow he de e mina ion and e alua ion o he na u e and size o
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
8
he laws causing he ailu e, and (in many cases) he (mic o)-mechanism ha may has
been esponsible o he ac u e. In addi ion, he WC, Co and O con en s in he WC-Co
cemen ed ca bides we e measu ed using an ene gy dispe si e X- ay spec ome y
(XEDS) de ec o coupled o he SEM mic oscope.
Finally, he measu emen s o he o al a ea o he ac u e su ace, S , and he
numbe o disc agmen s associa ed wi h he ac u e p ocess, Ni, was ca ied ou on a
ep esen a i e numbe o discs o each g ade o cemen ed ca bides using a Nikon
Epipho op ical mic oscope coupled wi h a Jenop ik P og es C3 came a and he analysis
so wa e Image-P o Plus 6.2.
3. Resul s and discussion
3.1. In luence o empe a u e on he biaxial s eng h
Fig. 1 shows he p obabili y o ailu e e sus he co esponding ailu e s ess
(Weibull plo s) o he h ee comme cial cemen ed ca bides g ades (16F, 16M and 27C)
a oom empe a u e (RT) and 600°C. The calcula ed σ0 and m alues a e p esen ed in
able 2, oge he wi h he co esponding 90% CI. A de imen al e ec o empe a u e on
he mechanical s eng h o he h ee cemen ed ca bides is e idenced in Fig. 1 (see
cha ac e is ic alues in able 2). The dec ease o app ox. 30% in s eng h a 600ºC
compa ed o RT may be mainly a ibu ed o oxida ion phenomena, as was di ec ly
obse ed a i s sigh on he su ace o he discs a e es ing. As epo ed in he
li e a u e, he o ma ion o oxida ion p oduc s begins o be app eciable a 600°C [10]. In
ac , p e ious wo ks ha e shown a signi ican educ ion o he mechanical s eng h o
cemen ed ca bides only a e 10 min a 700ºC [36]. The e o e, i is no su p ising ha an
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
9
oxida ion p ocess was associa ed wi h he es ing p ocedu e, since he samples we e
hea ed du ing 2 h o each he es ing empe a u e o 600°C.
In addi ion o he loss o mechanical s eng h a 600ºC, an appa en inc ease o he
Weibull modulus, m, was obse ed o he 16F and 16M g ades ( he mean alue o m
inc easing om 8 o 10, and 7 o 13, o he wo g ades espec i ely). A highe m may
be associa ed wi h he subc i ical g ow h o p eexis ing p ocessing laws, hus yielding a
highe amoun o de ec s o simila (la ge ) size. Ano he possibili y migh be he
appea ance o new laws wi h a mo e homogeneous size dis ibu ion and loca ion. In he
case o g ade 27C, i seemed no o be an in luence o he empe a u e on he Weibull
modulus (m=10 a RT e sus m=9 a 600°C). I is wo hy poin ing ou ha he 90% CI
o m do o e lap o he h ee WC-Co g ades. In o de o ein o ce he hypo hesis
men ioned abo e o 16F and 16M ma e ials on he change o law dis ibu ions wi h
empe a u e, mo e expe imen s would be equi ed ha may na ow he 90% CI, and
hus e eal s a is ically signi icance di e ences in m. This aspec will be discussed in
mo e de ail in he ollowing sec ion, suppo ed by ac og aphic conside a ions.
The e ec o he mic os uc u e on he mechanical s eng h o he cemen ed
ca bides is illus a ed in Fig. 2a and 2b a RT and a 600ºC, espec i ely. I can be
obse ed how he in luence o he mic os uc u e on he p obabili y o ailu e o he
specimens was di e en o bo h e alua ed empe a u es. A RT and lowe mechanical
s eng h alues, co esponding o la ge inhe en laws (Fig. 2a), all h ee g ades seem o
ha e same beha io . In addi ion, a de ia ion om he expec ed Weibull beha io was
obse ed in he 16M and 27C g ades. In hese wo g ades, he ob ained cu es using 2-
pa ame e Weibull dis ibu ion do no i he s eng h da a; he e seems o be an appa en
“ h eshold s ess”, a app ox. 2800 MPa, below which he ma e ial does no ail.
Howe e , o smalle inhe en laws (highe mechanical s eng h alues in Fig. 2a), he
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
16
c i ical de ec s due o he selec i e oxida ion o he binde phase. In addi ion, he
ac u e oughness o he h ee cemen ed ca bides was no a ec ed by he empe a u e,
a leas up o 600ºC.
The iabili y o he B3B biaxial lexu al es o es ing WC-Co was
demons a ed a ele a ed empe a u es, enabling he obse a ion o oxida ion
phenomena and hei consequence on s eng h by e ealing a new c i ical (su ace) law
popula ion compa ed o sub-su ace laws ound a oom empe a u e.
In addi ion, a di ec ela ionship be ween he numbe s o b oken agmen s a e
B3B es ing, he mechanical s eng h and he o al ac u e su ace a ea was obse ed.
This in e es ing p o ocol de eloped by Yanaba and Hayasaki [46] and co obo a ed he e
o he h ee cemen ed ca bides s udied, opens he possibili y o gene a e diag ams o
di e en b i le ma e ials, connec ing hei agmen numbe s a e mechanical es ing
wi h hei ac u e oughness. O special in e es is he applica ion o his p ocedu e
when he ac u e oughness es ing may become di icul .
Acknowledgmen s
This wo k was suppo ed by he Andalusian go e nmen (Spain) unde he
excellence p ojec no. P12-TEP-2622. Funding o his in es iga ion was also pa ly
supplied by he Spanish MINECO/FEDER unde G an No. MAT2015-70780-C4-3-P.
The au ho s wan o hank he echnician J. Pin o and M. Sánchez o hei assis ance
wi h mechanical es ing and mic os uc u al cha ac e iza ion.
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
17
Re e ences
[1] Ta agó JM, Jiménez-Piqué E, Schneide L, Casellas D, To es Y, Llanes L.
FIB/FESEM expe imen al and analy ical assessmen o R-cu e beha io o WC–Co
cemen ed ca bides. Ma e ials Science and Enginee ing: A. 2015;645:142-9.
[2] Ma i D, Bolognini S, Feusie G, Via e T, Benoi W. Expe imen al s a egy o s udy
he mechanical beha iou o ha dme als o cu ing ools. In e na ional Jou nal o
Re ac o y Me als & Ha d Ma e ials. 1999;17:209-25.
[3] Llanes L, To es Y, Anglada M. On he a igue c ack g ow h beha io o WC-Co
cemen ed ca bides: kine ics desc ip ion, mic os uc u al e ec s and a igue sensi i i y.
Ac a Ma e ialia. 2002;50:2381-93.
[4] La e gne O, Robau F, Hodaj F, Allibe CH. Mechanism o solid-s a e dissolu ion
o WC in Co-based solu ions. Ac a Ma e ialia. 2002;50:1683-92.
[5] Juhani K, Pi so J, Viljus M, Le uno i s S, Ta as e M. The In luence o C 3C2 and
VC as Alloying Addi i es on he Mic os uc u e and P ope ies o Reac i e Sin e ed
WC-Co Ce me s. Ma e ials Science-Medziago y a. 2012;18:79-83.
[6] Lee HR, Kim DJ, Hwang NM, Kim DY. Role o anadium ca bide addi i e du ing
sin e ing o WC-Co: Mechanism o g ain g ow h inhibi ion. Jou nal o he Ame ican
Ce amic Socie y. 2003;86:152-4.
[7] Zhang L, Xie M-w, Cheng X, Nan Q, Wang Z, Feng Y-p. Mic o cha ac e is ics o
binde phases in WC-Co cemen ed ca bides wi h C -V and C -V-RE addi i es.
In e na ional Jou nal o Re ac o y Me als & Ha d Ma e ials. 2013;36:211-9.
[8] Accha W, Gomes UU, Kaysse WA, Go ing J. S eng h Deg ada ion o a Tungs en
Ca bide-Cobal Composi e a Ele a ed Tempe a u es. Ma e ials Cha ac e iza ion.
1999;43:27-32.
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
18
[9] Basu SN, Sa in VK. Oxida ion beha io o WC-Co. Ma e ials Science and
Enginee ing a-S uc u al Ma e ials P ope ies Mic os uc u e and P ocessing.
1996;209:206-12.
[10] Voi o ich VB, S e del VV, Voi o ich RF, Golo ko EI. Oxida ion o WC-Co, WC-
Ni and WC-Co-Ni ha d me als in he empe a u e ange 500-800 deg ees C. In J
Re ac Me Ha d Ma e . 1996;14:289-95.
[11] A enas F, Ribas N, B i o J, Albo noz A, Cho SA. Examina ion o oxida ion
p oduc s in WC-Co ha d me als. B is ol: Iop Publishing L d; 1998.
[12] Lee G. Oxida ion Beha io o WC-Co Ha dme al. Jou al o Ko ean Powe
Me allu gy Ins i . 2004;11:111-7.
[13] Huang S, Xiong J, Guo Z, Wan W, Tang L, Zhong H, e al. Oxida ion o WC-TiC-
TaC-Co ha d ma e ials a ela i ely low empe a u e. In e na ional Jou nal o Re ac o y
Me als & Ha d Ma e ials. 2015;48:134-40.
[14] Babu ina TE, U a o a IV. E ec o he condi ions o oxida ion o lump was es o
WC-Co(Ni) ha d alloys on he dispe si y o he oxidized mix u es. Powde Me allu gy
and Me al Ce amics. 1997;36:107-10.
[15] Fan ozzi G, Mohand H, O ange G. High empe a u e mechanical beha iou o WC-
6 w .% Co cemen ed ca bide. Science o ha d ma e ials. 1986;20:699-712.
[16] Milman YV, Luyckx S, Goncha uck VA, No h op JT. Resul s om bending es s
on submic on and mic on WC-Co g ades a ele a ed empe a u es. In e na ional Jou nal
o Re ac o y Me als & Ha d Ma e ials. 2002;20:71-9.
[17] Bhaumik SK, Balasub amaniam R, Upadhyaya GS, Vaidya ML. oxida ion
beha io o ha d and binde phase modi ied WC-10Co cemen ed ca bides. Jou nal o
Ma e ials Science Le e s. 1992;11:1457-9.
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
19
[18] Da idge RW. Mechanical Beha iou o Ce amics. Camb idge: Camb idge
Uni e si y P ess; 1980.
[19] Danze R. Ce amics: mechanical pe o mance and li e ime p edic ion. Ox o d:
Pe gamon P ess; 1994.
[20] Fischmeis e H. De elopmen and P esen S a us o he Science and Technology o
Ha d Ma e ials. In: R.K. Viswanadham DJRaJG, edi o . P oc o ICSHM1 - 1s In Con
on he Science o Ha d Ma e ials. New Yo k: Plenum P ess; 1981. p. 1-45.
[21] Danze R. A gene al s eng h dis ibu ion unc ion o b i le ma e ials. J Eu
Ce am Soc. 1992;10:461-72.
[22] Weibull W. A s a is ical dis ibu ion unc ion o wide applicabili y. J Appl Mech.
1951;18:253.
[23] To es Y, Be mejo R, Go o FJ, Chica di E, Llanes L. Analysis on he mechanical
s eng h o WC-Co cemen ed ca bides unde uniaxial and biaxial bending. Ma e ials &
Design. 2014;55:851-6.
[24] To es Y, Casellas D, Anglada M, Llanes L. F ac u e oughness e alua ion o
ha dme als: in luence o es ing p ocedu e. In J Re ac Me Ha d Ma e . 2001;19:27-
34.
[25] Bö ge A, Supancic P, Danze R. The ball on h ee balls es o s eng h es ing o
b i le discs: S ess dis ibu ion in he disc. Jou nal o he Eu opean Ce amic Socie y.
2002;22:1425-36.
[26] Danze R, Ha e W, Supancic P, Lube T, Wang Z, Bö ge A. The ball on h ee
balls es -S eng h and ailu e analysis o di e en ma e ials. Jou nal o he Eu opean
Ce amic Socie y. 2007;27:1481-5.
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
20
[27] Be mejo R, Supancic P, Ald ian F, Danze R. Expe imen al app oach o assess he
e ec o me alliza ion on he s eng h o unc ional ce amic componen s. Sc ip a
Ma e ialia. 2012;66:546-9.
[28] Be mejo R, Supancic P, K au gasse C, Mo ell R, Danze R. Subc i ical c ack
g ow h in Low Tempe a u e Co- i ed Ce amics unde biaxial loading. Enginee ing
F ac u e Mechanics. 2013;100:108-21.
[29] Wagne R, Ha e W, Danze R. Applica ion o he Ball on Th ee Balls Tes in he
De elopmen o a High S eng h Pa ially S abilised Zi conia Ce amic. C i-Ce amic
Fo um In e na ional. 2009;86:E50-E3.
[30] Chica di E, To es Y, Co doba JM, H izdos P, Go o FJ. E ec o an alum con en
on he mic os uc u e and mechanical beha io o ce me s based on (TixTa1-
x)(C0.5N0.5) solid solu ions. Ma e ials & Design. 2014;53:435-44.
[31] Chica di E, To es Y, Có doba JM, Sayagués MJ, Rod íguez JA, Go o FJ. E ec
o sin e ing ime on he mic os uc u e and mechanical p ope ies o (Ti,Ta)(C,N)-based
ce me s. In e na ional Jou nal o Re ac o y Me als and Ha d Ma e ials. 2013.
[32] Bena en e-Ma inez E, De esa F, Amigo V. Mechanical cha ac e iza ion o Ti-Nb
alloys by ball on h ee balls es . Re is a De Me alu gia. 2010;46:19-25.
[33] Bö ge A, Supancic P, Danze R. The ball on h ee balls es o s eng h es ing o
b i le discs: Pa II: Analysis o possible e o s in he s eng h de e mina ion. Jou nal o
he Eu opean Ce amic Socie y. 2004;24:2917-28.
[34] Be mejo R, Danze R. 2.09 - Mechanical Cha ac e iza ion o Ce amics: Designing
wi h B i le Ma e ials A2 - Sa in, Vinod K. Comp ehensi e Ha d Ma e ials. Ox o d:
Else ie ; 2014. p. 285-98.
[35] EN 843-5. Ad anced Technical Ce amics - Monoli hic Ce amics - Mechanical
Tes s a Room Tempe a u e - Pa 5: S a is ical Analysis. EN 843-51997. p. 40.
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
21
[36] Casas B, Ramis X, Anglada M, Salla JM, Llanes L. Oxida ion-induced s eng h
deg ada ion o WC-Co ha dme als. In e na ional Jou nal o Re ac o y Me als & Ha d
Ma e ials. 2001;19:303-9.
[37] I win GR. F ac u e. In: Flügge S, edi o . Handbuch de Physik. Be lin: Sp inge -
Ve lag; 1958. p. 551-89.
[38] Johannesson B, Wa en R. Subc i ical c ack g ow h and plas ic de o ma ion in he
ac u e o ha d me als. Ma e ials Science and Enginee ing: A. 1988;105-106:353-61.
[39] Sheikh S, M'Saoubi R, Flasa P, Schwind M, Pe sson T, Yang J, e al. F ac u e
oughness o cemen ed ca bides: Tes ing me hod and mic os uc u al e ec s.
In e na ional Jou nal o Re ac o y Me als & Ha d Ma e ials. 2015;49:153-60.
[40] Wang G, Wang YT, Liu YH, Pan MX, Zhao DQ, Wang WH. E olu ion o
nanoscale mo phology on ac u e su ace o b i le me allic glass. Applied Physics
Le e s. 2006;89:3.
[41] Riedle J, Gumbsch P, Fischmeis e HF. Clea age aniso opy in ungs en single
c ys als. Physical Re iew Le e s. 1996;76:3594-7.
[42] Ga cia-Rosales C, Lopez-Ruiz P, Al a ez-Ma in S, Cal o A, O das N, Koch F, e
al. Oxida ion beha iou o bulk W-C -Ti alloys p epa ed by mechanical alloying and
HIPing. Fusion Enginee ing and Design. 2014;89:1611-6.
[43] Gu W-H, Jeong YS, Kim K, Kim J-C, Son S-H, Kim S. The mal oxida ion
beha io o WC–Co ha d me al machining ool ip sc aps. Jou nal o Ma e ials
P ocessing Technology. 2012;212:1250-6.
[44] A is izabal M, Sanchez JM, Rod iguez N, Iba e a F, Ma inez R. Compa ison o
he oxida ion beha iou o WC–Co and WC–Ni–Co–C cemen ed ca bides. Co osion
Science. 2011;53:2754-60.
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
22
[45] Chen L, Yi D, Wang B, Liu H, Wu C. Mechanism o he ea ly s ages o oxida ion
o WC–Co cemen ed ca bides. Co osion Science. 2016;103:75-87.
[46] Yanaba Y, Hayashi K. Rela ion be ween ac u e su ace a ea o a lexu al s eng h
specimen and ac u e oughness o WC-10mass%Co cemen ed ca bide and Si3N4
ce amics. Ma e ials Science and Enginee ing a-S uc u al Ma e ials P ope ies
Mic os uc u e and P ocessing. 1996;209:169-74.
[47] Danze R. On he ela ionship be ween ce amic s eng h and he equi emen s o
mechanical design. J Eu Ce am Soc. 2014;34.
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
23
Table 1. Mic os uc u al pa ame e s and mechanical p ope ies o he WC-Co cemen ed
ca bides s udied.
WC-Co g ade
w .% Co
dwc (µm)
Co (µm)
HV30 (GPa)
16F
10
0.50
0.25
15.5 ± 2.5
16M
10
1.06
0.30
14.0 ± 2.6
27C
16
1.66
0.76
11.2 ± 0.8
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
24
Table 2. In luence o he mic os uc u e and he empe a u e on he Weibull pa ame e s
(σ0 and m) o he h ee cemen ed ca bides s udied a oom empe a u e (RT) [23] and a
600 °C. The alues shown in squa e b acke s co espond o he 90% con idence
in e als o he Weibull pa ame e s.
WC-Co g ade
Cha ac e is ic s eng h, σ0 (MPa)
[90% CI]
Weibull modulus, m
[90% CI]
RT
600 °C
RT
600 °C
16F
4208 [3888-4567]
2978 [2787-3189]
8 [4-11]
10 [5-13]
16M
3281 [3012-3585]
2258 [2148-2377]
7 [4-10]
13 [7-17]
27C
3341 [3133-3571]
2331 [2156-2529]
10 [6-13]
9 [5-12]
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
25
Table 3. C i ical law sizes, 2ac: (i) es ima ed a RT and (ii) measu ed on ac u ed
specimens a 600 °C. F ac u e oughness alues, KIc, es ima ed a 600 °C using wo
di e en geome ic ac o s: Y=2/ as o sub-su ace laws, and Y=(2/)·21/2 as o
su ace laws con ac ing he su ace.
WC-Co
g ade
C i ical law sizes, 2ac
(µm)
Measu ed KIc
by SENB a
RT [24]
(MPam1/2)
Es ima ed KIc
by LEFM a
600ºC
(MPam1/2)**
Es ima ed KIc
by LEFM a
600ºC
(MPam1/2)***
@RT
(es ima ed)*
@600ºC
(measu ed)
16F
6–9
8-10
9.2 ± 0.6
7.1 ± 0.4
9.9 ± 0.4
16M
14–19
19-22
10.5 ± 0.8
8.1 ± 0.4
11.4 ± 0.4
27C
27–35
30-32
14.7 ± 1.0
10.1 ± 1.1
14.1 ± 1.1
* 2ac alues a RT es ima ed using LEFM om measu ed σ0 [23], KIc [24] and Y=(2/) (as o sub-su ace
laws [47])
** KIc alues @600°C es ima ed using LEFM om measu ed 2ac, σ0 and Y=(2/) (as o sub-su ace laws
[47])
*** KIc alues @600°C es ima ed using LEFM om measu ed 2ac, σ0 and Y=(2/)·21/2 (as o su ace laws
con ac ing he su ace [47])
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
32
3 µm
3 µm
27C_RT
27C_600ºC
W
W
Co
Co
O
O
Figu e 5
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
33
W
Co
O
27C_600ºC
Figu e 6
30 µm
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
34
Figu e 7
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
35
1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
0
5
10
15
20
Numbe o pieces
0 (GPa)
16F_RT
16F_600ºC
16M_RT
16M_600ºC
27C_RT
27C_600ºC
Figu e 8
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
36
0 1 2 3 4 5 6 7 8 9 10
0.0
0.4
0.8
1.2
1.6
2.0
2.4
2.8
3.2
16F Linea Fi
16M Linea Fi
27C Linea Fi
y = 356·x
y = 329·x
y = 378·x
0 (GPa)
16F
16M
27C
S
1/2 (mm)
Figu e 9
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
37
HIGHLIGHTS
 The e ec o he empe a u e on he WC-Co mechanical s eng h was de e mined.
 Biaxial lexu al es s we e pe o med a 600°C by he ball-on- h ee-balls me hod.
 A signi ican dec ease in he mechanical s eng h (30%) was obse ed a 600ºC.
 This ac was asc ibed o he change o sub-su ace o su ace c i ical laws.
 Addi ionally, he ac u e oughness was no a ec ed by he empe a u e.
ACCEPTED MANUSCRIPT