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Powder forging of gears by the Laminated composite process
Porous materials HOMOGENEITY OF POROUS STRUCTURES U N D E R COMPACTION AND SINTERING OF POWDER MATERIALS
L.V. Lunin, A~G. Korstornov (Academy of Sciences of t h e Ukraine, Kiev, Ukraine), Poroshkovaya Metallurgiya, No 12, 1992, 92-95. (In Russian). An i n v e s t i g a t i o n of h o m o g e n e i t y of porosity in c o m p a c t e d a n d sintered m e t a l powders is described. It is r e p o r t e d t h a t sintering t e m p e r a t u r e is t h e most effective factor in controlling t h e d i s t r i b u t i o n of porosity in p o r o u s alloys.
P M components HEAT TREATMENT OF PM MATERIALS
C. Fang (Dongfeng Automobile Co, Danjiangkou, China), PM Technology, Vol l l , No 2, 1993, 110-114. (In Chinese). The role of h e a t t r e a t m e n t in t h e p r o d u c t i o n of m e d i u m to high s t r e n g t h sintered s t r u c t u r a l p a r t s is discussed with reference to materials selection, choice of h e a t t r e a t m e n t procedures a n d properties of parts. DEVELOPMENT OF PM S P E E D A D J U S T E R WEIGHTS
X. Liping (Nan County PM Factory, Hunan, C h i n a ) , PM Technology, Vol 11, No 3, 1993, 193-195, 110-114. (In Chinese). The p r o d u c t i o n of a d j u s t e r weights by PM is described a n d discussed with regard to design, materials selection a n d process parameters. It is r e p o r t e d t h a t p a r t quality is controlled in order to m a x i m i z e wear resistance. POWDER FORGING OF GEARS BY THE LAMINATED COMPOSITE P R O C E S S
W. K5nig et al (RWITI, Aachen, Germany), Umformtechnik, Vol 25, No 6, 1992, 426430. (In G e r m a n ) . T h e u s e of p o w d e r f o r g i n g in t h e p r o d u c t i o n of a p a r t with high density is discussed with respect to t h e a d v a n t a g e s of c o m b i n i n g t h e a b i l i t y of s i n t e r i n g to produce homogeneous material with precision forging a n d cost savings. The d r a w b a c k of s i n t e r i n g is s a i d to b e residual porosity w h i c h is overcome by powder forging.
Miscellaneous THE POWDER METALLURGY INDUSTRY AND P R O G R E S S IN CHINA
I~ Wang et al (Central S o u t h University of Technology, Hunan, China), Int J Powder Metallurgy, Vol 30, No 1, 1994, 21-30. The d e v e l o p m e n t of PM in t h e t h e n
40 MPR October 1994
People's Republic of C h i n a is reviewed. The c u r r e n t s i t u a t i o n a n d recent d e v e l o p m e n t s in scientific research, sintering iron a n d steel, h i g h p e r f o r m a n c e PM m a t e r i a l s , r e f r a c t o r y m e t a l s , c u t t i n g t o o l alloys, friction a n d anti-friction materials, nonferrous alloys, e l e c t r o n i c a n d m a g n e t i c materials a n d t h e p r o d u c t i o n of fine a n d ultra-fine powders are considered.
pM2TEC'94. The a b s t r a c t s w h i c h follow are of p a p e r s which were p r e s e n t e d a t t h e 1994 I n t e r n a t i o n a l Conference on Powder Metallurgy a n d Particulate Mat e r i a l s w h i c h w a s h e l d in T o r o n t o , Canada, from 8 t h to l l May 1994.
Powder production PROTECTION OF INDUCTION M E L T E D STAINLESS S T E E L IN PRODUCTION OF POWDERS
Till et al (Liquid Air Corp, Countryside, Illinois, USA). The use of a n Ar cover to p r o t e c t m o l t e n stainless steel from o x i d a t i o n to reduce inclusion c o n t e n t a n d to e x t e n d crucible life w a s r e p o r t e d . I n d u c t i o n m e l t i n g procedures, t e s t methods, economics a n d overall process a d v a n t a g e s were discussed. OPTIMIZATION OF P R O P E R T I E S OF WATER ATOMIZED CARBON S T E E L POWDER BY EXPERIMENTAL D E S I G N
G-H. Shiau et al ( C h i n a Steel Corp). The u s e of s t a t i s t i c a l e x p e r i m e n t a l design to optimize process conditions for t h e p r o d u c t i o n of c a r b o n steel powders was described. Powder p r o p e r t y i m p r o v e m e n t s were accomplished by Taguchi m e t h o d s of analysis. The predicted o p t i m u m conditions were validated experimentally. Effects of a d d i t i o n s of mill scale to t h e m o l t e n m e t a l on c o m p a c t i o n of t h e steel were also described. PRODUCTION OF SUB-MICRON POWDERS BY A PLASMA Q U E N C H TECHNIQUE
J.W. Sears et al (E.G. a n d G, Idaho, USA). The p r o d u c t i o n of s u b - m i c r o n m e t a l powders by dissociation of a m e t a l halide in a p l a s m a a t 5000°C, in presence of H, followed by q u e n c h cooling, was described. The halogen combines with t h e H. The design of t h e e q u i p m e n t was described. The q u e n c h w a s r e p o r t e d t o p r e v e n t rec o m b i n a t i o n of m e t a l a n d halogen. Results for A1 a n d Ti powders were given. PRODUCTION OF HIGH QUALITY INTERMETALLIC POWDERS BY A NOVEL PROCESS
S.K. G u h a et al (MER Corp, USA). Production of aluminides of Ti, Nb a n d
Ni was discussed with regard to properties, applications a n d e c o n o m i c s . It w a s reported that a process had been d e v e l o p e d for t h e p r o d u c t i o n of fine powders of high quality. Data concerning physical a n d chemical characteristics were presented. ATOMIZATION OF LEAD POWDER WITH A NEW TYPE OF NOZZLE
S. Wang, C.Y. Chow ( N a t i o n a l Inst. of Technology, Taiwan). It was r e p o r t e d t h a t a new type of nozzle h a d been developed for t h e a t o m i z a t i o n of m o l t e n Pb. The nozzle comprised a central a n d two concentric a n n u l a r o p e n i n g s which w a s i m m e r s e d in t h e m o l t e n Pb. A i r pressure through the inner and outer openings caused a t o m i z a t i o n of t h e metal. Results of e x p e r i m e n t s on t h e effects of process variables were presented.
Compaction RELATIONSHIPS B E T W E E N COMPACTION PARAMETERS AND ELASTIC MODULI IN G R E E N COMPACTS
M. Aesoph, ~ Gurson ( C o n c u r r e n t Technologies Corp, Inc., USA). The effects of c o m p a c t i o n p r e s s u r e , l u b r i c a n t , zinc s t e a r a t e , c o n t e n t a n d relative m e t a l density on densification of steel powder were investigated. Relationships with elastic moduli of t h e g r e e n c o m p a c t s were d e d u c e d . It was reported that the lubricant aided densification a t low densities b u t n o t at high densities a n d also reduced t h e elastic moduli. APPLICATION O F A GENERAL COMPACTION EQUATION TO METAL AND CERAMIC POWDERS
I. Shapiro (Universal Chemical Systems, Inc., USA). The study described h a d t h e objective of establishing a general c o m p a c t i o n e q u a t i o n applicable to all types of metallic a n d nonm e t a l l i c p o w d e r s a n d c o r r e l a t i o n of equation constants with powder c h a r a c t e r i s t i c s . Good a g r e e m e n t of t h e model with experimental results was reported. The relationships between powder characteristics and equation c o n s t a n t s were discussed. P R E S S E S FOR ISOSTATIC P R E S S I N G AT HIGH P R E S S U R E S
F.X. Z i m m e r m a n (ABB Autoclave Systems Inc., Erie, Pennsylvania, USA). T h e p r e s s u r e s u s e d f o r CIP w e r e discussed with refere,lce to t h e need to use high pressure for some types of m a t e r i a l in o r d e r to a t t a i n h i g h d e n s i t y a n d p r o b l e m s of fatigue in t h e machinery. The p a p e r showed h o w a wire w o u n d pre-
L.V. Lunin, A~G. Korstornov (Academy of Sciences of t h e Ukraine, Kiev, Ukraine), Poroshkovaya Metallurgiya, No 12, 1992, 92-95. (In Russian). An i n v e s t i g a t i o n of h o m o g e n e i t y of porosity in c o m p a c t e d a n d sintered m e t a l powders is described. It is r e p o r t e d t h a t sintering t e m p e r a t u r e is t h e most effective factor in controlling t h e d i s t r i b u t i o n of porosity in p o r o u s alloys.
P M components HEAT TREATMENT OF PM MATERIALS
C. Fang (Dongfeng Automobile Co, Danjiangkou, China), PM Technology, Vol l l , No 2, 1993, 110-114. (In Chinese). The role of h e a t t r e a t m e n t in t h e p r o d u c t i o n of m e d i u m to high s t r e n g t h sintered s t r u c t u r a l p a r t s is discussed with reference to materials selection, choice of h e a t t r e a t m e n t procedures a n d properties of parts. DEVELOPMENT OF PM S P E E D A D J U S T E R WEIGHTS
X. Liping (Nan County PM Factory, Hunan, C h i n a ) , PM Technology, Vol 11, No 3, 1993, 193-195, 110-114. (In Chinese). The p r o d u c t i o n of a d j u s t e r weights by PM is described a n d discussed with regard to design, materials selection a n d process parameters. It is r e p o r t e d t h a t p a r t quality is controlled in order to m a x i m i z e wear resistance. POWDER FORGING OF GEARS BY THE LAMINATED COMPOSITE P R O C E S S
W. K5nig et al (RWITI, Aachen, Germany), Umformtechnik, Vol 25, No 6, 1992, 426430. (In G e r m a n ) . T h e u s e of p o w d e r f o r g i n g in t h e p r o d u c t i o n of a p a r t with high density is discussed with respect to t h e a d v a n t a g e s of c o m b i n i n g t h e a b i l i t y of s i n t e r i n g to produce homogeneous material with precision forging a n d cost savings. The d r a w b a c k of s i n t e r i n g is s a i d to b e residual porosity w h i c h is overcome by powder forging.
Miscellaneous THE POWDER METALLURGY INDUSTRY AND P R O G R E S S IN CHINA
I~ Wang et al (Central S o u t h University of Technology, Hunan, China), Int J Powder Metallurgy, Vol 30, No 1, 1994, 21-30. The d e v e l o p m e n t of PM in t h e t h e n
40 MPR October 1994
People's Republic of C h i n a is reviewed. The c u r r e n t s i t u a t i o n a n d recent d e v e l o p m e n t s in scientific research, sintering iron a n d steel, h i g h p e r f o r m a n c e PM m a t e r i a l s , r e f r a c t o r y m e t a l s , c u t t i n g t o o l alloys, friction a n d anti-friction materials, nonferrous alloys, e l e c t r o n i c a n d m a g n e t i c materials a n d t h e p r o d u c t i o n of fine a n d ultra-fine powders are considered.
pM2TEC'94. The a b s t r a c t s w h i c h follow are of p a p e r s which were p r e s e n t e d a t t h e 1994 I n t e r n a t i o n a l Conference on Powder Metallurgy a n d Particulate Mat e r i a l s w h i c h w a s h e l d in T o r o n t o , Canada, from 8 t h to l l May 1994.
Powder production PROTECTION OF INDUCTION M E L T E D STAINLESS S T E E L IN PRODUCTION OF POWDERS
Till et al (Liquid Air Corp, Countryside, Illinois, USA). The use of a n Ar cover to p r o t e c t m o l t e n stainless steel from o x i d a t i o n to reduce inclusion c o n t e n t a n d to e x t e n d crucible life w a s r e p o r t e d . I n d u c t i o n m e l t i n g procedures, t e s t methods, economics a n d overall process a d v a n t a g e s were discussed. OPTIMIZATION OF P R O P E R T I E S OF WATER ATOMIZED CARBON S T E E L POWDER BY EXPERIMENTAL D E S I G N
G-H. Shiau et al ( C h i n a Steel Corp). The u s e of s t a t i s t i c a l e x p e r i m e n t a l design to optimize process conditions for t h e p r o d u c t i o n of c a r b o n steel powders was described. Powder p r o p e r t y i m p r o v e m e n t s were accomplished by Taguchi m e t h o d s of analysis. The predicted o p t i m u m conditions were validated experimentally. Effects of a d d i t i o n s of mill scale to t h e m o l t e n m e t a l on c o m p a c t i o n of t h e steel were also described. PRODUCTION OF SUB-MICRON POWDERS BY A PLASMA Q U E N C H TECHNIQUE
J.W. Sears et al (E.G. a n d G, Idaho, USA). The p r o d u c t i o n of s u b - m i c r o n m e t a l powders by dissociation of a m e t a l halide in a p l a s m a a t 5000°C, in presence of H, followed by q u e n c h cooling, was described. The halogen combines with t h e H. The design of t h e e q u i p m e n t was described. The q u e n c h w a s r e p o r t e d t o p r e v e n t rec o m b i n a t i o n of m e t a l a n d halogen. Results for A1 a n d Ti powders were given. PRODUCTION OF HIGH QUALITY INTERMETALLIC POWDERS BY A NOVEL PROCESS
S.K. G u h a et al (MER Corp, USA). Production of aluminides of Ti, Nb a n d
Ni was discussed with regard to properties, applications a n d e c o n o m i c s . It w a s reported that a process had been d e v e l o p e d for t h e p r o d u c t i o n of fine powders of high quality. Data concerning physical a n d chemical characteristics were presented. ATOMIZATION OF LEAD POWDER WITH A NEW TYPE OF NOZZLE
S. Wang, C.Y. Chow ( N a t i o n a l Inst. of Technology, Taiwan). It was r e p o r t e d t h a t a new type of nozzle h a d been developed for t h e a t o m i z a t i o n of m o l t e n Pb. The nozzle comprised a central a n d two concentric a n n u l a r o p e n i n g s which w a s i m m e r s e d in t h e m o l t e n Pb. A i r pressure through the inner and outer openings caused a t o m i z a t i o n of t h e metal. Results of e x p e r i m e n t s on t h e effects of process variables were presented.
Compaction RELATIONSHIPS B E T W E E N COMPACTION PARAMETERS AND ELASTIC MODULI IN G R E E N COMPACTS
M. Aesoph, ~ Gurson ( C o n c u r r e n t Technologies Corp, Inc., USA). The effects of c o m p a c t i o n p r e s s u r e , l u b r i c a n t , zinc s t e a r a t e , c o n t e n t a n d relative m e t a l density on densification of steel powder were investigated. Relationships with elastic moduli of t h e g r e e n c o m p a c t s were d e d u c e d . It was reported that the lubricant aided densification a t low densities b u t n o t at high densities a n d also reduced t h e elastic moduli. APPLICATION O F A GENERAL COMPACTION EQUATION TO METAL AND CERAMIC POWDERS
I. Shapiro (Universal Chemical Systems, Inc., USA). The study described h a d t h e objective of establishing a general c o m p a c t i o n e q u a t i o n applicable to all types of metallic a n d nonm e t a l l i c p o w d e r s a n d c o r r e l a t i o n of equation constants with powder c h a r a c t e r i s t i c s . Good a g r e e m e n t of t h e model with experimental results was reported. The relationships between powder characteristics and equation c o n s t a n t s were discussed. P R E S S E S FOR ISOSTATIC P R E S S I N G AT HIGH P R E S S U R E S
F.X. Z i m m e r m a n (ABB Autoclave Systems Inc., Erie, Pennsylvania, USA). T h e p r e s s u r e s u s e d f o r CIP w e r e discussed with refere,lce to t h e need to use high pressure for some types of m a t e r i a l in o r d e r to a t t a i n h i g h d e n s i t y a n d p r o b l e m s of fatigue in t h e machinery. The p a p e r showed h o w a wire w o u n d pre-