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molydenum carbide tool materials with and without nitrogen
of Mo2FeB~. A block-on-ring dry wear t e s t w a s c a r r i e d o u t to a s s e s s t h e w e a r properties of Mo2FeB,~ against alloy steels a n d to make a c o m p a r i s o n with c e m e n t e d carbides, b ) t h e borides a ) t h e boride base m a t e r i a l s s h o w e d less w e a r t h a n t h e cemented carbides, b)the borides e x h i b i t e d non-adhesive (oxidative) wear up to a sliding speed of 0.94 m / s e e above which adhesive wear occurred. The c o m p a r a b l e f i g u r e for t h e c e m e n t e d carbides was 0.62 m/see. DIFFERENCE BETWEEN CERMET CONTAINING TITANIUM CARBONITRIDE AND TITANIUM CARBIDE AND NITRIDE N.Tsuchiya et al. ( ~ j i Die Co, Ltd., Tokyo, J a p a n . ) J . J a p a n Soc.Powder a n d Powder Metallurgy, Vol 38, No 5, 1991,605-609. (In Japanese.) A c o m p a r i s o n b e t w e e n Ni b o n d e d cermet cutting tools containing either Ti(C,N) or TiC a n d TiN is reported. The alloys studied were TiC-18wt%TiN-
20%M02C-20%Ni a n d Ti(C,N)-20%Mo2C20%Ni. The Ti(C,N) were e q u i v a l e n t to e i t h e r 30 or 50% of t h e nitride. It is reported that withincreased nitride c o n t e n t t h e s t r u c t u r e became finer int he case of t h e c a r b o n i t r i d e cermets. The m i x e d nitride/carbide materials had finer s t r u c t u r e s t h a n t h o s e of t h e c a r b o n i t r i d e ones. C o - e x i s t a n c e of c o a r s e a n d fine carbides and carbonitrides in the s t r u c t u r e s is noted.
P R O D U C T I O N AND C H A R A C T E R I S T I C S OF H I G H S P E E D HOLLOW BAR BY BINDER ASSISTED EXTRUSION H.Nakamura, Y.Mochida. (Hitachi Metals Ltd., Yasugi, J a p a n . ) J . J a p a n Soc.Powder and Powder Metallurgy, Vol 38, No 5, 1991, 689-693. (In J a p a n e s e . ) Binder assisted e x t r u s i o n of hollow high speed steel (HSS) tool blanks is described, It is r e p o r t e d t h a t t h e t e c h n i q u e may also be u s e d to p r o d u c e solid b l a n k s n o t possible by h o t rolling or forging. Full density can he a t t a i n e d by sintering a n d the s t r u c t u r e s are as fine as gas a t o m i s e d or HIP materials b u t with improved cutting p e r f o r m a n c e . An o u t l i n e of o p t i m u m process conditions is given. COMPARISON OF C U T T I N G P E R F O R M A N C E O F NICKEL CEMENTED TUNGSTEN CARBIDE/ MOLYBDENUM CARBIDE TOOL MATERIALS WITH AND W I T H O U T NITROGEN M.Ueki, H.Suzuki. (Toshiba ~lhngaloy Co. Ltd., Kawasaki, J a p a n . ) J . J a p n Soc.Powder and Powder Metallurgy, Vol 38, No 6, 1991, 718-722. (In J a p a n e s e . ) The effect of a 10% a d d i t i o n of TiN on the mechanical properties and cutting performance of TiC-10vol%Mo2C-10%Ni is described. The effects of grain size, 1.0, 1.5
a n d 2.5 ~m, was also studied. It is r e p o r t e d t h a t flank wear was less in the nitride free materials at equivalent grain sizes for low cutting speeds, less difference was n o t e d for high cutting speeds. The need for f u r t h e r work on t h e s e m a t e r i a l s was emphasised. F A B R I C A T I O N AND P R O P E R T I E S O F SINTERED YTTRIA/ZIRCONIA R E I N F O R C E D TITANIUM B O R I D E S.Trizuku, H.Nishio, (NKK C o r p o r a t i o n , Kawasaki,Japan.) J.Japan Soc.Powder a n d Powder Metallurgy, Vol 38, No 6, 1991, 723-728. (In Japanese.) Glass e n c a p s u l a t e d 1HIP was used to fabricate TiB2 w i t h 2mol%Y210a-Zrt02, a c o m p a r i s o n of t h e m e c h a n i c a l p r o p e r t i e s for this with TiBz containing ZrO2 alone is reported. The p r e s e n c e of Y203 is r e p o r t e d to be more effective in increasing b o n d s t r e n g t h a n d h a r d n e s s b u t t h e r e was a r e d u c t i o n in f r a c t u r e t o u g h n e s s . T h e differences in properties are a t t r i b u t e d to differences in t h e C c o n t e n t of monoclinic ZrO2 in t h e sintered material, EFFECT OF METHOD OF ADDING N I T R O G E N ON P R O P E R T I E S O F TITANIUM CARBIDE BASED C E R M E T S
D E V E L O P M E N T O F HARD WEAR RESISTANT COMPOSITE COATINGS Z.Yizhe, (Central Iron a n d Steel Research Ins., China.) P M Technology, Vol 9, No 4, 1991, 233-237. (In Chinese.) The s t r u c t u r e s of interfaces, coherent, semi-coherent and incoherent with a t r a n s i t i o n a l zone, between coatings a n d hard material substrates are outlined. C u r r e n t research into composite coatings for cutting tool m a t e r i a l s is discussed. THERMAL SHOCK R E S I S T A N C E O F CEMENTED CARBIDES I~Tokumoto et al. (Nippon T u n g s t e n Co. Ltd., Fukuoka, J a p a n . ) N i p p o n Tungsten Rev/ew, Vol 23, 1990m 59-66. The d e v e l o p m e n t of surface cracks on c e m e n t e d carbides caused by t h e r m a l shock a n d severe sliding friction is described. Thermal shock resulted in t h e generation of a n e t w o r k or cracks r u n n i n g in all d i r e c t i o n s a n d t h e s l i d i n g r e s u l t e d in c r a c k i n g p e r p e n d i c u l a r to t h e s l i d i n g direction. ~NTBRM~TALL~C
MNeki et al. (Toshiba Tungaloy Co. Ltd.,
MA'~BR~LS
Kawasaki, J a p a n . ) J . J a p a n S o t . P o w d e r a n d Powder Metallurgy, Vol 38, No 6, 1991, 729-932. (In J a p a n e s e . ) N was a d d e d to TiC b a s e d c e r m e t sin t h e form of e i t h e r Ti n i t r i d e (TIN) or Ti c a r b o n i t r i d e Ti(C,N). It is r e p o r t e d t h a t the hardness of the carbide/nitride m a t e r i a l is h i g h e r t h a n t h a t o f t h e carbonitride material at ambient and elevated t e m p e r a t u r e s . This is a t t r i b u t e d to a f i n e r s t r u c t u r e . O t h e r p r o p e r t i e s , including transverse rupture strength, creep a n d c o m p o s i t i o n s of b i n d e r a n d h a r d p h a s e s were found to be similar for b o t h types of material,
.....:-:::-::..............~:::::::---:- :_.::--.........::::::--:------::::~
OXIDATION BEHAVIOUR O F SILICON CARBIDE W H I S K E R R E I N F O R C E D ALUMINA/ZIRCONIA COMPOSITES
PRODUCTION OF HIGH MELTING POINT INTERMETALLIC COMPOUNDS BY MECHANICAL ALLOYING
P.Wang et al. (Dalmler-Benz AG, UlmB5fingen, Germany.) Powder Metall. Int., Vol 23 No 6, 1991, 370-375. A study of t h e o x i d a t i o n of AI2OJZrO2 reinforced with SiC whiskers is described. It is r e p o r t e d t h a t t h e o x i d a t i o n resistance of t h e composite is good up to 1000°C. Above 1000°C t h e o x i d a t i o n resistance is reduced due to preferential oxidation of SiC a n d reaction between o x i d a t i o n p r o d u c t s a n d the matrix. The thermodynamics and kinetics a n d m e c h a n i s m s of t h e o x i d a t i o n are discussed. The o x i d a t i o n follows a parabolic rate law. Details are given of t h e p h a s e s formed, including crystalline a n d a m o r p h o u s a l u m i n o - s i l i c a t e s , s u c h as mullite, and the time-temperature
A~P.Radinski, A~Calka. (Australian National University, Canberra, Australia.) Materials Science a n d Engineering A, Vol A134, 1991, 1376-1379. Metal/metalloid mixtures were s u b j e c t e d t o m e c h a n i c a l a l l o y i n g to synthesize high melting points intermetallic compounds. Systems c o n t a i n i n g Fe, Ti, Ni, V, W, Si, B a n d C were studied. F o u r r e a c t i o n routes are described, direct formation of t h e c o m p o u n d , f o r m a t i o n of a m o r p h o u s phases, n a n o s t r u e t u r e s a n d simple mixing of t h e powders followed by recrystallization of annealing at t e m p e r a t u r e s below t h e melting points. X-ray diffractometry was used to m o n i t o r t h e reactions.
P R O C E S S I N G AND CONSOLIDATION O F BULK NANOCRYSTALLINE TITANIUM A L U M I N I D E T.Christman, M.Jain, (California I n s t i t u t e of Technology,) ScriptaMetall. Mater., Vo125, No 4, 1991, 767-772. Processing of the intermetallic c o m p o u n d TiA1 w i t h a d d i t i o n s of Nb is described. The powders were p r e p a r e d in a high energy a t t r i t i o n mill a n d consolidated by h o t rolling. The m e t h o d s u s e d are r e p o r t e d to have p o t e n t i a l for use in t h e fabrication of bulk n a n o - p h a s e materials.
relationships for t h e i r formation.
MPR April 1992 53
20%M02C-20%Ni a n d Ti(C,N)-20%Mo2C20%Ni. The Ti(C,N) were e q u i v a l e n t to e i t h e r 30 or 50% of t h e nitride. It is reported that withincreased nitride c o n t e n t t h e s t r u c t u r e became finer int he case of t h e c a r b o n i t r i d e cermets. The m i x e d nitride/carbide materials had finer s t r u c t u r e s t h a n t h o s e of t h e c a r b o n i t r i d e ones. C o - e x i s t a n c e of c o a r s e a n d fine carbides and carbonitrides in the s t r u c t u r e s is noted.
P R O D U C T I O N AND C H A R A C T E R I S T I C S OF H I G H S P E E D HOLLOW BAR BY BINDER ASSISTED EXTRUSION H.Nakamura, Y.Mochida. (Hitachi Metals Ltd., Yasugi, J a p a n . ) J . J a p a n Soc.Powder and Powder Metallurgy, Vol 38, No 5, 1991, 689-693. (In J a p a n e s e . ) Binder assisted e x t r u s i o n of hollow high speed steel (HSS) tool blanks is described, It is r e p o r t e d t h a t t h e t e c h n i q u e may also be u s e d to p r o d u c e solid b l a n k s n o t possible by h o t rolling or forging. Full density can he a t t a i n e d by sintering a n d the s t r u c t u r e s are as fine as gas a t o m i s e d or HIP materials b u t with improved cutting p e r f o r m a n c e . An o u t l i n e of o p t i m u m process conditions is given. COMPARISON OF C U T T I N G P E R F O R M A N C E O F NICKEL CEMENTED TUNGSTEN CARBIDE/ MOLYBDENUM CARBIDE TOOL MATERIALS WITH AND W I T H O U T NITROGEN M.Ueki, H.Suzuki. (Toshiba ~lhngaloy Co. Ltd., Kawasaki, J a p a n . ) J . J a p n Soc.Powder and Powder Metallurgy, Vol 38, No 6, 1991, 718-722. (In J a p a n e s e . ) The effect of a 10% a d d i t i o n of TiN on the mechanical properties and cutting performance of TiC-10vol%Mo2C-10%Ni is described. The effects of grain size, 1.0, 1.5
a n d 2.5 ~m, was also studied. It is r e p o r t e d t h a t flank wear was less in the nitride free materials at equivalent grain sizes for low cutting speeds, less difference was n o t e d for high cutting speeds. The need for f u r t h e r work on t h e s e m a t e r i a l s was emphasised. F A B R I C A T I O N AND P R O P E R T I E S O F SINTERED YTTRIA/ZIRCONIA R E I N F O R C E D TITANIUM B O R I D E S.Trizuku, H.Nishio, (NKK C o r p o r a t i o n , Kawasaki,Japan.) J.Japan Soc.Powder a n d Powder Metallurgy, Vol 38, No 6, 1991, 723-728. (In Japanese.) Glass e n c a p s u l a t e d 1HIP was used to fabricate TiB2 w i t h 2mol%Y210a-Zrt02, a c o m p a r i s o n of t h e m e c h a n i c a l p r o p e r t i e s for this with TiBz containing ZrO2 alone is reported. The p r e s e n c e of Y203 is r e p o r t e d to be more effective in increasing b o n d s t r e n g t h a n d h a r d n e s s b u t t h e r e was a r e d u c t i o n in f r a c t u r e t o u g h n e s s . T h e differences in properties are a t t r i b u t e d to differences in t h e C c o n t e n t of monoclinic ZrO2 in t h e sintered material, EFFECT OF METHOD OF ADDING N I T R O G E N ON P R O P E R T I E S O F TITANIUM CARBIDE BASED C E R M E T S
D E V E L O P M E N T O F HARD WEAR RESISTANT COMPOSITE COATINGS Z.Yizhe, (Central Iron a n d Steel Research Ins., China.) P M Technology, Vol 9, No 4, 1991, 233-237. (In Chinese.) The s t r u c t u r e s of interfaces, coherent, semi-coherent and incoherent with a t r a n s i t i o n a l zone, between coatings a n d hard material substrates are outlined. C u r r e n t research into composite coatings for cutting tool m a t e r i a l s is discussed. THERMAL SHOCK R E S I S T A N C E O F CEMENTED CARBIDES I~Tokumoto et al. (Nippon T u n g s t e n Co. Ltd., Fukuoka, J a p a n . ) N i p p o n Tungsten Rev/ew, Vol 23, 1990m 59-66. The d e v e l o p m e n t of surface cracks on c e m e n t e d carbides caused by t h e r m a l shock a n d severe sliding friction is described. Thermal shock resulted in t h e generation of a n e t w o r k or cracks r u n n i n g in all d i r e c t i o n s a n d t h e s l i d i n g r e s u l t e d in c r a c k i n g p e r p e n d i c u l a r to t h e s l i d i n g direction. ~NTBRM~TALL~C
MNeki et al. (Toshiba Tungaloy Co. Ltd.,
MA'~BR~LS
Kawasaki, J a p a n . ) J . J a p a n S o t . P o w d e r a n d Powder Metallurgy, Vol 38, No 6, 1991, 729-932. (In J a p a n e s e . ) N was a d d e d to TiC b a s e d c e r m e t sin t h e form of e i t h e r Ti n i t r i d e (TIN) or Ti c a r b o n i t r i d e Ti(C,N). It is r e p o r t e d t h a t the hardness of the carbide/nitride m a t e r i a l is h i g h e r t h a n t h a t o f t h e carbonitride material at ambient and elevated t e m p e r a t u r e s . This is a t t r i b u t e d to a f i n e r s t r u c t u r e . O t h e r p r o p e r t i e s , including transverse rupture strength, creep a n d c o m p o s i t i o n s of b i n d e r a n d h a r d p h a s e s were found to be similar for b o t h types of material,
.....:-:::-::..............~:::::::---:- :_.::--.........::::::--:------::::~
OXIDATION BEHAVIOUR O F SILICON CARBIDE W H I S K E R R E I N F O R C E D ALUMINA/ZIRCONIA COMPOSITES
PRODUCTION OF HIGH MELTING POINT INTERMETALLIC COMPOUNDS BY MECHANICAL ALLOYING
P.Wang et al. (Dalmler-Benz AG, UlmB5fingen, Germany.) Powder Metall. Int., Vol 23 No 6, 1991, 370-375. A study of t h e o x i d a t i o n of AI2OJZrO2 reinforced with SiC whiskers is described. It is r e p o r t e d t h a t t h e o x i d a t i o n resistance of t h e composite is good up to 1000°C. Above 1000°C t h e o x i d a t i o n resistance is reduced due to preferential oxidation of SiC a n d reaction between o x i d a t i o n p r o d u c t s a n d the matrix. The thermodynamics and kinetics a n d m e c h a n i s m s of t h e o x i d a t i o n are discussed. The o x i d a t i o n follows a parabolic rate law. Details are given of t h e p h a s e s formed, including crystalline a n d a m o r p h o u s a l u m i n o - s i l i c a t e s , s u c h as mullite, and the time-temperature
A~P.Radinski, A~Calka. (Australian National University, Canberra, Australia.) Materials Science a n d Engineering A, Vol A134, 1991, 1376-1379. Metal/metalloid mixtures were s u b j e c t e d t o m e c h a n i c a l a l l o y i n g to synthesize high melting points intermetallic compounds. Systems c o n t a i n i n g Fe, Ti, Ni, V, W, Si, B a n d C were studied. F o u r r e a c t i o n routes are described, direct formation of t h e c o m p o u n d , f o r m a t i o n of a m o r p h o u s phases, n a n o s t r u e t u r e s a n d simple mixing of t h e powders followed by recrystallization of annealing at t e m p e r a t u r e s below t h e melting points. X-ray diffractometry was used to m o n i t o r t h e reactions.
P R O C E S S I N G AND CONSOLIDATION O F BULK NANOCRYSTALLINE TITANIUM A L U M I N I D E T.Christman, M.Jain, (California I n s t i t u t e of Technology,) ScriptaMetall. Mater., Vo125, No 4, 1991, 767-772. Processing of the intermetallic c o m p o u n d TiA1 w i t h a d d i t i o n s of Nb is described. The powders were p r e p a r e d in a high energy a t t r i t i o n mill a n d consolidated by h o t rolling. The m e t h o d s u s e d are r e p o r t e d to have p o t e n t i a l for use in t h e fabrication of bulk n a n o - p h a s e materials.
relationships for t h e i r formation.
MPR April 1992 53