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Preparation of ultrafine powders by nanopowder process
POWDER P R O D U C T I O N STUDY OF METAL POWDER ANNEALING M E T H O D S
D. Jianzong, (Mechanical a n d Electrical Design Institute, Shanghai, China), Powder Metallurgy Technology, Vol 8, No 764, 1990, 213-215. In Chinese. Methods for a n n e a l i n g high p r e s s u r e w a t e r a t o m i z e d p o w d e r s are c o m p a r e d with respect to reduction in O c o n t e n t a n d energy consumption. The use of infra-red heating is recommended. PREPARATION OF Cu/A1203 COMPOSITE POWDERS
H. Kaga, et al, J. Japan Soe. Powder and Powder Metallurgy, Vol 37, No 7, 1990, 9951000. In Japanese. A process by which Cu powders, 30 p m in diameter, are coated with A120 ~ particles 0.5 # m in d i a m e t e r , is described. The process involves v a c u u m mechano-fusion. The m i x e d p o w d e r s are t u m b l e d in a r o t a t i n g kiln a t a p r e s s u r e less t h a n 10-ZPa a n d t e m p e r a t u r e s 100-200°C. The effects of process variables on the pick-up of a l u m i n a particles by t h e c o p p e r was studied.
PREPARATION OF ULTRAFINE POWDERS BY NANOPOWDER PROCESS
M. Nishida, et al, J.Japan Soc. Powder and Powder Metallurgy, Vol 37, No 6, 1990, 827831. In Japanese. Effects of milling rates and c o n t a m i n a t i o n of powders by a b r a s i o n of t h e milling bodies was investigated in t h e p r o d u c t i o n of ultrafine powders of piezoelectric ceramic materials. It was found t h a t milling rates increased a n d t h e r e was less c o n t a m i n a t i o n with smaller milling balls. 1 ttm powder could be reduced to 0.2 # m on milling for 7 m i n u t e s a n d to 19 n m after 90 m i n u t e s w h e n using 0.4 m m balls.
PRODUCTION AND P R O P E R T I E S OF HIGHLY-DISPERSED N i POWDERS
K h a r i t i n y c h , et al, Poroskovaya Metallurgia, No 5, 1990, 1-4. In Russian. N.E.
The p r o d u c t i o n a n d p r o p e r t i e s of highly dispersed Ni powders, with a n d w i t h o u t a plastic protective coating of polycaproamide h a s been investigated. The p o w d e r s w e r e p r o d u c e d by t h e r m a l decomposition of Ni formate. Particle size, density a n d specific surface were found to d e p e n d on d u r a t i o n of heating. A process route a n d conditions are suggested for t h e p r o d u c t i o n of highly dispersed Ni powders w h o s e s u r f a c e is p r o t e c t e d against oxidation by a plastic film.
PRODUCTION OF U L T R A D I S P E R S E D Pb BY THERMOLYSIS OF COMPLEX COMPOUNDS
PRODUCTION OF Ti POWDERS BY CALCIO-THERMIC R E D U C T I O N OF TiO2
Varavko, et al, P o r o s k o v a y a Metallurgia, No 5, 1990, 4-8. In Russian.
K.Ono, (The University , Kyoto, J a p a n ) , J. Iron and Steel Inst. of Japan, Vol 76, No 1, 1990, 568-575. In Japanese. The reduction of TiOe to m e t a l p o w d e r u s i n g Ca v a p o u r a n d l i q u i d Call2 is described. The powders were characterized a n d O~ contents, which were in t h e range 1000-2000 ppm, measured. The particle s i z e s w e r e in t h e r a n g e 1-10 # m . Thermodynamics was used to show t h a t t h e d e o x i d a t i o n limit is 500 ppm.
I.A.
Production of Pb powder by t h e r m a l decomposition of organo-lead c o m p o u n d s has been studied. The c o m p o u n d s were completely d e c o m p o s e d to spherical Pb particles, 0.2-0.8/~m in size, at 240°C. CENTRIFUGAL PNEUMATIC D I S P E R S I O N OF ALLOYS m PRODUCTION AND PROPERTIES OF Sn AND Sn ALLOYS
S.M. S h e i k h a l i e v , e t al, Poroskovaya Metallurgia, No 5, 1990, 8-11. In Russian. C e n t r i f u g a l - p n e u m a t i c spraying of Sn a n d Sn alloys, for p r o d u c t i o n of powders, h a s been investigated with reference to t h e gas used a n d t h e properties of t h e powders produced. Mean particle sizes a n d bulk densities found were (a) for He spraying: 15 #m, 2.62g/cm ~, (b) with use of Ar:17 # m 4.33g/cm 3 a n d (c) N2:18 # m m e a n particle size a n d 4.7g/cm 3 density. Reasons for t h e differences are discussed. ELECTROLYTIC NICKELIZING OF ALUMINIUM POWDER
L.M. K u r v y a k o v a , et al, Poroskovaya Metallurgiya, No 6, 1990, 12-15. In Russian. The coating o f A1 p o w d e r by e l e c t r o p l a t i n g w i t h Ni is d e s c r i b e d . A sulphate/chloride electrolyte with a d d i t i o n s of boric acid, 1.4 butynediol, formalin a n d saccharine at a pH of 4.5-5.0 was used a n d this gave a n electrodeposit of good quality. Optimum operating conditions were determined. CLADDING OF A1 AND WC POWDERS WITH Ni
K a n a s h v i l i , e t al, P o r o s k o v a y a Metallurgiya, No 6, 1990, 16-18. In Russian.
R.S.
A1 a n d WC powders were coated with Ni by a n autoclave process a n d t h e properties of t h e Ni-A1 a n d WC-Ni powders examined. It is shown t h a t the m a x i m u m yield of coated powders w i t h a c o n t i n u o u s film of Ni is a c h i e v e d i n s o l u t i o n s w h e r e t h e c o n c e n t r a t i o n of Ni does not decrease a n d at 150°C a n d 1.5 MPa pressure.
CHARACTERIZATION OF INERT GAS ATOMIZED SUPERALLOY POWDERS
M. Kumar, et al, (Defence Metallurgical Laboratories, India), J. Materials Science Letters, Vol 9, No 2, 1990, 147-151. Auger electron spectroscopy h a s been used to characterize t h e oxide film on a powdered superalloy containing Ni, Co, Cr, Mo, A1, Ti, C, B a n d Zr.
WATER ATOMIZATION OF AI-5Cr-2Zr1Mn
G.Staniek, et al, ( G e r m a n A e r o - S p a c e Research E s t a b l i s h m e n t , Cologne, Germany), Powder Metallurgy International, Vol 22, No 4, 1990, 7-9. An A1 powder alloy, A1-5Cr-2Zr-lMn, h a s been p r o d u c e d by i m p i n g e m e n t of a s t r e a m of molten metal on to a rapidly r o t a t i n g m e t a l disk covered with a w a t e r film. The powder was collected with t h e cooling w a t e r a n d sieved. The powders were c o m p a c t e d by e x t r u s i o n . P r o p e r t i e s of p o w d e r s a n d compacts were c o m p a r e d with those of air a n d He atomized powdered materials.
PRODUCTION OF Fe POWDER FROM WASTE S T E E L PICKLING LIQUOR
D-S.Yoon, Y-S.Kim, (Dong-A University, Busan, Korea), J.Korean Inst. of Metals, Vol 28, No 6, 1990, 538-544. In Korean. The p r o d u c t i o n of Fe powder from waste s t e e l p i c k l i n g l i q u o r is d e s c r i b e d . Fe h y d r o x i d e is p r e c i p i t a t e d from the solution at pH 12-13. This is filtered off a n d reduced to Fe by heating at 750°C for 1 h o u r in H 2. Particles 1-5 p m in size are produced.
KINETICS OF U L T R A F I N E TiN POWDER PREPARATION BY HIGH FREQUENCY PLASMA
L.Zhu, S.Zou, (Chengdu University of Science a n d Technology, Chengdu, China), Aeta MetallurFica Sinica (English E d n ) , Series B, Vol 3, No 4, 1990, 271-276. A m o d e l of r e a c t i o n k i n e t i c s f o r synthesis of ultraYine TiN powder from t h e v a p o u r p h a s e system TiC14-NH3-H2-N 2 is proposed. The factors influencing reaction rate are analysed as a basis for i m p r o v e m e n t s in q u a l i t y of t h e TiN p o w d e r a n d o p t i m i z a t i o n of t h e p l a n t design.
MPR March 1991 51
D. Jianzong, (Mechanical a n d Electrical Design Institute, Shanghai, China), Powder Metallurgy Technology, Vol 8, No 764, 1990, 213-215. In Chinese. Methods for a n n e a l i n g high p r e s s u r e w a t e r a t o m i z e d p o w d e r s are c o m p a r e d with respect to reduction in O c o n t e n t a n d energy consumption. The use of infra-red heating is recommended. PREPARATION OF Cu/A1203 COMPOSITE POWDERS
H. Kaga, et al, J. Japan Soe. Powder and Powder Metallurgy, Vol 37, No 7, 1990, 9951000. In Japanese. A process by which Cu powders, 30 p m in diameter, are coated with A120 ~ particles 0.5 # m in d i a m e t e r , is described. The process involves v a c u u m mechano-fusion. The m i x e d p o w d e r s are t u m b l e d in a r o t a t i n g kiln a t a p r e s s u r e less t h a n 10-ZPa a n d t e m p e r a t u r e s 100-200°C. The effects of process variables on the pick-up of a l u m i n a particles by t h e c o p p e r was studied.
PREPARATION OF ULTRAFINE POWDERS BY NANOPOWDER PROCESS
M. Nishida, et al, J.Japan Soc. Powder and Powder Metallurgy, Vol 37, No 6, 1990, 827831. In Japanese. Effects of milling rates and c o n t a m i n a t i o n of powders by a b r a s i o n of t h e milling bodies was investigated in t h e p r o d u c t i o n of ultrafine powders of piezoelectric ceramic materials. It was found t h a t milling rates increased a n d t h e r e was less c o n t a m i n a t i o n with smaller milling balls. 1 ttm powder could be reduced to 0.2 # m on milling for 7 m i n u t e s a n d to 19 n m after 90 m i n u t e s w h e n using 0.4 m m balls.
PRODUCTION AND P R O P E R T I E S OF HIGHLY-DISPERSED N i POWDERS
K h a r i t i n y c h , et al, Poroskovaya Metallurgia, No 5, 1990, 1-4. In Russian. N.E.
The p r o d u c t i o n a n d p r o p e r t i e s of highly dispersed Ni powders, with a n d w i t h o u t a plastic protective coating of polycaproamide h a s been investigated. The p o w d e r s w e r e p r o d u c e d by t h e r m a l decomposition of Ni formate. Particle size, density a n d specific surface were found to d e p e n d on d u r a t i o n of heating. A process route a n d conditions are suggested for t h e p r o d u c t i o n of highly dispersed Ni powders w h o s e s u r f a c e is p r o t e c t e d against oxidation by a plastic film.
PRODUCTION OF U L T R A D I S P E R S E D Pb BY THERMOLYSIS OF COMPLEX COMPOUNDS
PRODUCTION OF Ti POWDERS BY CALCIO-THERMIC R E D U C T I O N OF TiO2
Varavko, et al, P o r o s k o v a y a Metallurgia, No 5, 1990, 4-8. In Russian.
K.Ono, (The University , Kyoto, J a p a n ) , J. Iron and Steel Inst. of Japan, Vol 76, No 1, 1990, 568-575. In Japanese. The reduction of TiOe to m e t a l p o w d e r u s i n g Ca v a p o u r a n d l i q u i d Call2 is described. The powders were characterized a n d O~ contents, which were in t h e range 1000-2000 ppm, measured. The particle s i z e s w e r e in t h e r a n g e 1-10 # m . Thermodynamics was used to show t h a t t h e d e o x i d a t i o n limit is 500 ppm.
I.A.
Production of Pb powder by t h e r m a l decomposition of organo-lead c o m p o u n d s has been studied. The c o m p o u n d s were completely d e c o m p o s e d to spherical Pb particles, 0.2-0.8/~m in size, at 240°C. CENTRIFUGAL PNEUMATIC D I S P E R S I O N OF ALLOYS m PRODUCTION AND PROPERTIES OF Sn AND Sn ALLOYS
S.M. S h e i k h a l i e v , e t al, Poroskovaya Metallurgia, No 5, 1990, 8-11. In Russian. C e n t r i f u g a l - p n e u m a t i c spraying of Sn a n d Sn alloys, for p r o d u c t i o n of powders, h a s been investigated with reference to t h e gas used a n d t h e properties of t h e powders produced. Mean particle sizes a n d bulk densities found were (a) for He spraying: 15 #m, 2.62g/cm ~, (b) with use of Ar:17 # m 4.33g/cm 3 a n d (c) N2:18 # m m e a n particle size a n d 4.7g/cm 3 density. Reasons for t h e differences are discussed. ELECTROLYTIC NICKELIZING OF ALUMINIUM POWDER
L.M. K u r v y a k o v a , et al, Poroskovaya Metallurgiya, No 6, 1990, 12-15. In Russian. The coating o f A1 p o w d e r by e l e c t r o p l a t i n g w i t h Ni is d e s c r i b e d . A sulphate/chloride electrolyte with a d d i t i o n s of boric acid, 1.4 butynediol, formalin a n d saccharine at a pH of 4.5-5.0 was used a n d this gave a n electrodeposit of good quality. Optimum operating conditions were determined. CLADDING OF A1 AND WC POWDERS WITH Ni
K a n a s h v i l i , e t al, P o r o s k o v a y a Metallurgiya, No 6, 1990, 16-18. In Russian.
R.S.
A1 a n d WC powders were coated with Ni by a n autoclave process a n d t h e properties of t h e Ni-A1 a n d WC-Ni powders examined. It is shown t h a t the m a x i m u m yield of coated powders w i t h a c o n t i n u o u s film of Ni is a c h i e v e d i n s o l u t i o n s w h e r e t h e c o n c e n t r a t i o n of Ni does not decrease a n d at 150°C a n d 1.5 MPa pressure.
CHARACTERIZATION OF INERT GAS ATOMIZED SUPERALLOY POWDERS
M. Kumar, et al, (Defence Metallurgical Laboratories, India), J. Materials Science Letters, Vol 9, No 2, 1990, 147-151. Auger electron spectroscopy h a s been used to characterize t h e oxide film on a powdered superalloy containing Ni, Co, Cr, Mo, A1, Ti, C, B a n d Zr.
WATER ATOMIZATION OF AI-5Cr-2Zr1Mn
G.Staniek, et al, ( G e r m a n A e r o - S p a c e Research E s t a b l i s h m e n t , Cologne, Germany), Powder Metallurgy International, Vol 22, No 4, 1990, 7-9. An A1 powder alloy, A1-5Cr-2Zr-lMn, h a s been p r o d u c e d by i m p i n g e m e n t of a s t r e a m of molten metal on to a rapidly r o t a t i n g m e t a l disk covered with a w a t e r film. The powder was collected with t h e cooling w a t e r a n d sieved. The powders were c o m p a c t e d by e x t r u s i o n . P r o p e r t i e s of p o w d e r s a n d compacts were c o m p a r e d with those of air a n d He atomized powdered materials.
PRODUCTION OF Fe POWDER FROM WASTE S T E E L PICKLING LIQUOR
D-S.Yoon, Y-S.Kim, (Dong-A University, Busan, Korea), J.Korean Inst. of Metals, Vol 28, No 6, 1990, 538-544. In Korean. The p r o d u c t i o n of Fe powder from waste s t e e l p i c k l i n g l i q u o r is d e s c r i b e d . Fe h y d r o x i d e is p r e c i p i t a t e d from the solution at pH 12-13. This is filtered off a n d reduced to Fe by heating at 750°C for 1 h o u r in H 2. Particles 1-5 p m in size are produced.
KINETICS OF U L T R A F I N E TiN POWDER PREPARATION BY HIGH FREQUENCY PLASMA
L.Zhu, S.Zou, (Chengdu University of Science a n d Technology, Chengdu, China), Aeta MetallurFica Sinica (English E d n ) , Series B, Vol 3, No 4, 1990, 271-276. A m o d e l of r e a c t i o n k i n e t i c s f o r synthesis of ultraYine TiN powder from t h e v a p o u r p h a s e system TiC14-NH3-H2-N 2 is proposed. The factors influencing reaction rate are analysed as a basis for i m p r o v e m e n t s in q u a l i t y of t h e TiN p o w d e r a n d o p t i m i z a t i o n of t h e p l a n t design.
MPR March 1991 51