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Characteristics and sintering mechanics of two copper-lead alloy powders
POWDER P R O D U C T I O N
PRESSING
STRUCTURE AND P R O P E R T I E S OF ELECTROLYTIC TITANIUM-IRON INTERMETALLICS
TOOLING FOR PM GEARS
L.J. Zarubitskaya and Y.V. Korobka. Poroshkoyaya Metallugiya, No 3, 1991, 1-3 (in Russian). Properties of Ti-Fe intermetallic powders produced by electrolysis and solid phase synthesis are compared. The intermetallic TiFe was produced by electrolysis of molten salt solutions. The powder was shown to have a fine structure, a high specific surface and the ability to absorb hydrogen.
No 3, 1991, 25-42. The paper presents a discussion of the tool design for the production of PM gears. The factors, powder properties, part shape, size and density, lot size and tool materials are considered as design parameters.
PRODUCTION OF COPPER POWDER GALVODYNAMIC ELECTROLYSIS
Z. Xiadong, (Beijing Friction Material Works, Beijing, China.), PM Technology, Vol 9, No 2, 1991, 96-100. (In Chinese). Differential equation theory has been applied to the design of dies for the p r o d u c t i o n of c u r v e d f r i c t i o n plates. C o n c o r d a n c e of t h e o r y w i t h p r a c t i c a l design was demonstrated. Friction in the dies was taken into account. Assembly of the mould was discussed.
P o t a p o v e t a~l,, P o r o s h k o v a y a Metallurgiya, No 3, 1991, 3-8 (In Russian). D.A.
Galvanodynamic electrolytic production of Cu powder is described. Measurements of process variables show the process is close to potentiostatic. It is shown t h a t the cathode over voltage has significant effects on p o w d e r p r o p e r t i e s a n d on p o s t electrolysis treatment. COATING T E C H N I Q U E S FOR POWDERED MATERIALS FOR USE IN COMPOSITES
M. Uda. (Nisshin Steel Co. Ltd., Ichikawa Chiba, Japan.), Powder Metallurgy Science and Technology, Vol 2, No 2, 1991, 38-42. Two new methods of particle coating, m a g n e t r o n dry powder sputtering and fluidized bed galvanization, are discussed with regard to their usefulness. Application to a range of metallic and non-metallic m a t e r i a l s is c o n s i d e r e d including t h e production of high alloy steel and fine grain materials. PREPARATION OF ULTRAFINE ALUMINIUM NITRIDE BY GAS PHASE REACTION
M. Yokota et al, J, Japan Soc, Powder and Powder Metallurgy, Vol 38, No 3, 1991, 382385, (In Japanese). The production of ultrafine AlN powder by a reaction between A1 and NH3 at 1175°C is d e s c r i b e d . S a m p l e s w e r e characterized by electron microscopy and X-ray diffraction. The effects of process variables were investigated and it was found t h a t increasing the ammonia supply gave a more uniform particle size distribution.
52 MPR November 1991
relationships were determined for the two alloys and a method of improving the properties was presented.
FUNDAMENTALS
S.D.K. Saheb and K. Gopinth, Powder Metallurgy Science and Technology, Vol 2,
D E S I G N AND CALCULATION FOR A CURVED TYPE OF DIE FOR A CURVED FRICTION PLATE
SINTERING TRANSFORMATION OF POROUS STRUCTURE OF T U N G S T E N POWDER COMPACTS IN INITIAL STAGES OF SINTERING
G o s t e v e t al, P o r o s h k o v a y a Metallurgiya, No 3, 1991, 23-26, (In
Y.V.
Russian). The use of mercury pore measurements to monitor porosity changes in the sintering of W powder compacts is described. It is shown that in the first stages of sintering there is a reduction in surface size and i n c r e a s e s in p r o b e c h a n n e l size a n d porosity, the change being greater when there is a great proportion of particles less than 1.5 ~m in the initial powder.
THERMOMECHANICAL DEFORMATION OF PM POROUS ALUMINIUM - - EVOLUTION OF PORE STRUCTURE
P.T. Wang and M.A~ Zaidi. (Alcoa Labora t o r i e s , P e n n s y l v a n i a , U S A ) , Powder Technology, Vol 66, No 1, 1991, 9-19. The paper describes a study of pore morphology changes during deformation of porous Al compacts with initial porosities in the range 0 to 20%. Compacts were d e f o r m e d in c o m p r e s s i o n at e l e v a t e d temperature and at strain rates of 0.01 to 10 per second. Pore structures and sizes were examined, at room temperature after v a r i o u s a m o u n t s of d e f o r m a t i o n , by electron microscopy with image analysis. The mechanisms of pore deformation were discussed. THERMOMECHANICAL DEFORMATION OF PM POROUS ALUMINIUM - - CONSTITUTIVE MODEL INCLUDING DENSIFICATION HARDENING
P.T. Wang, (Alcoa Laboratories, Pennsylvania, USA), Powder Technology, Vol 66, No 1, 1991, 21-32. A model describing the deformation of porous Al is evaluated. The model involves Gurson's yield function, matrix stain rate, matrix effective stress and void fraction. Activation energy, matrix steady state flow stress and a non-linear equation describing evolution of p o r o s i t y can be derived. Experimental results of pore morphology analysis are used to link the model with microstructural features of deformed pores. The model is used to describe close die compaction and HIP and is applicable to other mechanical working processes for porous materials.
CHARACTERISTICS AND SINTERING MECHANICS OF TWO COPPER-LEAD ALLOY POWDERS
SURFACE E N E R G I E S OF SOLIDS FROM ULTRASONIC S T U D I E S OF POWDER ASSEMBLIES
L. Yong et al. (Zheejiang Univ, China), PM Technology, Vol 9, No 2, 1991, 101-196, (In Chinese). Sintering processes in two Pb bronzes have been studied with regard to powder characteristics and sinter-rolling process variables. Structure and property
K. Kendal.
(ICI, Runcorn, UIO, Powder Technology, Vol 66, No 1, 1991, 101-104.
The surface energy of assemblies of particles is discussed with regard to the natural attraction between solid surfaces and m e a s u r e m e n t s w e r e m a d e u s i n g ultrasonic wave propagation. The cohesion
PRESSING
STRUCTURE AND P R O P E R T I E S OF ELECTROLYTIC TITANIUM-IRON INTERMETALLICS
TOOLING FOR PM GEARS
L.J. Zarubitskaya and Y.V. Korobka. Poroshkoyaya Metallugiya, No 3, 1991, 1-3 (in Russian). Properties of Ti-Fe intermetallic powders produced by electrolysis and solid phase synthesis are compared. The intermetallic TiFe was produced by electrolysis of molten salt solutions. The powder was shown to have a fine structure, a high specific surface and the ability to absorb hydrogen.
No 3, 1991, 25-42. The paper presents a discussion of the tool design for the production of PM gears. The factors, powder properties, part shape, size and density, lot size and tool materials are considered as design parameters.
PRODUCTION OF COPPER POWDER GALVODYNAMIC ELECTROLYSIS
Z. Xiadong, (Beijing Friction Material Works, Beijing, China.), PM Technology, Vol 9, No 2, 1991, 96-100. (In Chinese). Differential equation theory has been applied to the design of dies for the p r o d u c t i o n of c u r v e d f r i c t i o n plates. C o n c o r d a n c e of t h e o r y w i t h p r a c t i c a l design was demonstrated. Friction in the dies was taken into account. Assembly of the mould was discussed.
P o t a p o v e t a~l,, P o r o s h k o v a y a Metallurgiya, No 3, 1991, 3-8 (In Russian). D.A.
Galvanodynamic electrolytic production of Cu powder is described. Measurements of process variables show the process is close to potentiostatic. It is shown t h a t the cathode over voltage has significant effects on p o w d e r p r o p e r t i e s a n d on p o s t electrolysis treatment. COATING T E C H N I Q U E S FOR POWDERED MATERIALS FOR USE IN COMPOSITES
M. Uda. (Nisshin Steel Co. Ltd., Ichikawa Chiba, Japan.), Powder Metallurgy Science and Technology, Vol 2, No 2, 1991, 38-42. Two new methods of particle coating, m a g n e t r o n dry powder sputtering and fluidized bed galvanization, are discussed with regard to their usefulness. Application to a range of metallic and non-metallic m a t e r i a l s is c o n s i d e r e d including t h e production of high alloy steel and fine grain materials. PREPARATION OF ULTRAFINE ALUMINIUM NITRIDE BY GAS PHASE REACTION
M. Yokota et al, J, Japan Soc, Powder and Powder Metallurgy, Vol 38, No 3, 1991, 382385, (In Japanese). The production of ultrafine AlN powder by a reaction between A1 and NH3 at 1175°C is d e s c r i b e d . S a m p l e s w e r e characterized by electron microscopy and X-ray diffraction. The effects of process variables were investigated and it was found t h a t increasing the ammonia supply gave a more uniform particle size distribution.
52 MPR November 1991
relationships were determined for the two alloys and a method of improving the properties was presented.
FUNDAMENTALS
S.D.K. Saheb and K. Gopinth, Powder Metallurgy Science and Technology, Vol 2,
D E S I G N AND CALCULATION FOR A CURVED TYPE OF DIE FOR A CURVED FRICTION PLATE
SINTERING TRANSFORMATION OF POROUS STRUCTURE OF T U N G S T E N POWDER COMPACTS IN INITIAL STAGES OF SINTERING
G o s t e v e t al, P o r o s h k o v a y a Metallurgiya, No 3, 1991, 23-26, (In
Y.V.
Russian). The use of mercury pore measurements to monitor porosity changes in the sintering of W powder compacts is described. It is shown that in the first stages of sintering there is a reduction in surface size and i n c r e a s e s in p r o b e c h a n n e l size a n d porosity, the change being greater when there is a great proportion of particles less than 1.5 ~m in the initial powder.
THERMOMECHANICAL DEFORMATION OF PM POROUS ALUMINIUM - - EVOLUTION OF PORE STRUCTURE
P.T. Wang and M.A~ Zaidi. (Alcoa Labora t o r i e s , P e n n s y l v a n i a , U S A ) , Powder Technology, Vol 66, No 1, 1991, 9-19. The paper describes a study of pore morphology changes during deformation of porous Al compacts with initial porosities in the range 0 to 20%. Compacts were d e f o r m e d in c o m p r e s s i o n at e l e v a t e d temperature and at strain rates of 0.01 to 10 per second. Pore structures and sizes were examined, at room temperature after v a r i o u s a m o u n t s of d e f o r m a t i o n , by electron microscopy with image analysis. The mechanisms of pore deformation were discussed. THERMOMECHANICAL DEFORMATION OF PM POROUS ALUMINIUM - - CONSTITUTIVE MODEL INCLUDING DENSIFICATION HARDENING
P.T. Wang, (Alcoa Laboratories, Pennsylvania, USA), Powder Technology, Vol 66, No 1, 1991, 21-32. A model describing the deformation of porous Al is evaluated. The model involves Gurson's yield function, matrix stain rate, matrix effective stress and void fraction. Activation energy, matrix steady state flow stress and a non-linear equation describing evolution of p o r o s i t y can be derived. Experimental results of pore morphology analysis are used to link the model with microstructural features of deformed pores. The model is used to describe close die compaction and HIP and is applicable to other mechanical working processes for porous materials.
CHARACTERISTICS AND SINTERING MECHANICS OF TWO COPPER-LEAD ALLOY POWDERS
SURFACE E N E R G I E S OF SOLIDS FROM ULTRASONIC S T U D I E S OF POWDER ASSEMBLIES
L. Yong et al. (Zheejiang Univ, China), PM Technology, Vol 9, No 2, 1991, 101-196, (In Chinese). Sintering processes in two Pb bronzes have been studied with regard to powder characteristics and sinter-rolling process variables. Structure and property
K. Kendal.
(ICI, Runcorn, UIO, Powder Technology, Vol 66, No 1, 1991, 101-104.
The surface energy of assemblies of particles is discussed with regard to the natural attraction between solid surfaces and m e a s u r e m e n t s w e r e m a d e u s i n g ultrasonic wave propagation. The cohesion