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Ultra high strength sintered ferrous components
S t r n c t u r e a n d t h e r m a l s t a b i l i t y of t h e mille(l p()w(ters w e r e d e t e r m i n e d by eh~ctrnn microscopy, X ray difli'action and differentiai s c a n n i n g calorimetk~" a n d gas a b s o r b t i o n by p r e s s u r e r e d u c t i o n in t h e mill. h was found thai large a m o u n t s of N a r c a b s o r b e d d u r i n g m i l l i n g in a N c o n t a i n i n g a t m o s p h e r e a c ( o l n p a n i e d bv s t r u c t u r a l refinement a n d a m o r p h i s a t i o n CreN was forlne(t oil a n n e a l i n g . A m o r p h i z a t i o n did not occur on milling inAr or Ar 0 m i x t u r e s . Art e x p l a n a l i o n in t e r m s of t h e r m o d y n a n l i c s is given
Cobalt SINTERING CHARACTERISTICS ULTRAFINE COBALT POWDER
OF
Y Sakka, (National I~'esearch inst.ilute for Metals, ,lapan). J. Less Commo'** Metals.
tqd 168, No 2, 1991, 2772,S'7. The s i m e r i n g of u l t r a l i n e ( n powders in vacuunl an(t t[ was nlorlilored hv s t r u c t u r a l a n d d i m e n s i o n a l changes. The p r e s e n c e of i n c l u ( t e d o x i d e s h i n d e r s s i n l e r i n g il, vacuunl but in H t h e o x i d e s are reduced and significant (tensifi(:ation occurs. Gases are evolve(I d u r i n g ~ a c u u m s i n t e r i n g a n d t h e s e were identified as Co e, CO, tie a n d lift). Surface condit;ions are d i s c u s s e d by c o n s i d e r a t i o n of t h e (h~sort)tion sl)ectra.
Copper FACTORS INFLUENCING THE QUALITY OF E L E C T R O I N T I C C O P P E R P O W D E R A. I)urisinova, (Sh)vak A(:a(lemy of Sciences, K(,sice C z e c h o s h ) v a k i a ) , P o w d e r
Metallurgy, Vol 33, No 2, 199l. 139 141. The eflbcts of tint(! of growlh, current d e n s i l y , eleci r o l y t e c o m p o s i t i o n a n d len~l)eralure pll. c i r c u l a l i o n ()I" t h e electrolyte a n d l h e p r e s e n c e of i m p u r i t i e s on the quality of e l e c t r o l ~ i c Cu p o w d e r s have heen stu(lied. C h a n g e s in p o w d e r properties were delermined and the powders were e x a m i n e d microscopically.
Iron a n d S t e e l THE WORKABILITY OF POROUS STEEL PREFORMS A. El I)omialy, M. Shaker. (Suez Canal University, Egypt), ,L Materials Processin.q
Technology, Vol 25, No 2, 1991, 2 2 9 233. A t t e n t i o n is drawn to a m a j o r limitation of powder forging of steel, cracking in t h e (tie. A m e t h o d of c h a r a c l e r i s i n g workability h a s been developed for w r o u g h t m e t a l s a n d applied to p o r o u s metals. Workability limits for s i n t e r e d Fe-0.2%C-0.5%Mo-0.04%S0.04%P w i t h d i f f e r e n t p o r o s i t i e s w e r e d e t e r m i n e d a n d it w a s d e d u c e d t h a t porosity is the m a i n p a r a m e t e r controlling workability of p o r o u s materials.
EFFECT OF SINTERING CONDITIONS ON ISOTHERMAL DECOMPOSITION OF AUTENITE IN SINTERED STEELS V.N. Antsiferov et al, Stal', No 12, 1990, 84-
ferro-alloys are u s e d in p r o d u c t i o n of steels. The p a p e r r e p o r t s on how ferro-alloys influence properties structure and sintering charaeleristics of s i n t e r e d ferrous alloys.
87. In R~ssian. The isothermal decomposition of A u s t e n i t e in PM steels c o m a i n i n g either 1.0 to 1.5%C a n d 3%Cu or" 1.0%C a n d 1.0%Mn was investigated with respect to the s i n t e r i n g a t m o s p h e r e . The s t r u c t u r e s were e x a m i n e d a n d it was l o u n d t h a t on s i n t e r i n g in s t a g n a n t a t m o s p h e r e s a e e m t i t e network w a s f o r m e d a n d t h e r e were g r a p h i t e i n c l u s i o n s w h i c h n u c l e a t e d the b r e a k d o w n of A u s t e n i t e t h i s r e d u c i n g the. i n c u b a t i o n period. It w a s found t h a t t h e C-Cu steel required a double heat treatmenl aud requench quench from 860 C a n d t e m p e r i n g at 300~C to a t t a i n greater s t r e n g t h . EFFECTS OF PRODUCTION PARAMETERS ON STRUCTURE AND PROPERTIES OF REDUCED AND ATOMISED IRON POWDERS 1.P. Argent'seva et al, (Moscow Evening Metallurgical Institute, USSR), Stal', No 11,
1990, 87-92. b~ Ru,ssiar~. The s t r u c t u r e a n d p r o p e r t i e s of r e d u c e d a n d a t o m i s e d Fe powders were investigated. Powder surface morpholog5 ~ a n d O c o n t e n t in relation t.o compactibility are d i s c u s s e d with respecl to t h e f o r m a t i o n of interparticle c o n t a c t s d u r i n g p r e s s i n g a n d s t r e n g t h a n d d e n s i t y of t h e c o m p a c t s . ULTRA HIGH STRENGTH FERROUS COMPONENTS
SINTERED
O. Durukimi et al, (Kawasaki Steel Corporation, Kawasaki, J a p a n ) , D~t J. P o w d e r
Metall,Jrgy, Vol 27, No 4, 1991, 331-337. A newly developed steel c o n t a i n i n g 2%Ni a n d l%Mo with tensile s t r e n g t h 1500 MPa, impact s t r e n g t h 21J, r o t a t i n g b e n d fatigue s t r e n g t h 460 MPa a n d c o m p a c t fatigue s t r e n g t h 2560 MPa is described. It w a s r e p o r t e d t h a t p r o p e r t i e s couM be i n c r e a s e d by double pressing, resintering, h a r d e n i n g a n d tempering. The i n c r e a s e d s t r e n g t h s are a t t r i b u t e d to a s t r a i n i n d u c e d m a r t e n s i t i c t r a n s f o r m a t i o n in t h e r e t a i n e d Austenite.
ENHANCED SINTERING AND PROPERTY IMPROVEMENTS IN SINTERED FERROUS COMPONENTS D.S. Madan, (Elkem D e v e l o p m e n t Centre, Sewiekley, P e n n s y l v a n i a , U S A ) , I n t J.
P o w d e r Metallurgy, Vol 27, No 4, 1991, 339-345. M o d e l s of e n h a n c e d s i n t e r i n g a r e reviewed a n d t h e role of a d d i t i o n s of ferro-alloys to PM steels is discussed. The m e c h a n i c a l a n d p h y s i c a l p r o p e r t i e s of w a t e r a t o m i s e d DFe p o w d e r alloyed with h i g h p u r i t y f e r r o - p h o s p h o r o u s or ferroboron are described. The p r o p e r t i e s are shown to be s u p e r i o r w h e n high p u r i t y
IMPROVED PROPERTIES AND P E R F O R M A N C E O F LOW ALLOY S T E E L PARTS THROUGH HIGH TEMPERATURE SINTERING K. S h i m a d a , (Tokyo Sintered Metals Corporation, Tokyo, .Japan), [nt J. P o w d e r
Metallurgy, Vol 27, No 4, /991, 357-361. S u p e r i o r s t r e n g t h , fatigue p r o p e r t i e s a n d w e a r r e s i s t a n c e are r e p o r t e d to have been a t t a i n e d in low alloy st,eel PM p a r t s by s i n t e r m g at 1250:C, carburising, h a r d e n i n g a n d tempering. The p r o p e r l y i m p r o v e m e n t s a r e a t t r i b u t e d to p o r o s i t y r e d u c t i o n , s p h e r o i d i s a t i o n of r e s i d u a l p o r e s a n d increased neck growth d u r i n g sintering. A u t o m o t i v e a p p l i c a t i o n s a r ( discussed. NEW SINTERED STEELS CONTAINING HARD PHASES FOR WEAR RESISTANT APPLICATIONS F. Thfimmler, C. Gutsfeld. (University ol Karlsruhe, Karlsruhe, G e r m a n y ) , P o w d e r
Metall. Int, Vol 23, No 5, /991, 285-290. T h e p r o d u c t i o n of Fe b a s e d m e t a l m a t r i x c o m p o s i t e s (MMC', c o n t a i n i n g 10 to 30vo>,; of h a r d plrases NbC. TiC of AI~O:~, u s i n g m e c ' h a n i c a l a l l o y i n g (MA) to incorporate the hard phase and sintering at 128()"C in H is d e s c r i b e d The a d d i t i o n of C or P to create a liquid ptmse d u r i n g s i n t e r i n g resulted in d e n s i t i e s of 97 to 99?,; a n d a u n i f o r m d i s t r i b u t i o n of t h e h a r d particles was d u e to t h e ~se of MA. The mechanical properties and wear c h a r a c t e r i s t i c s were, shown to d e m o n s t r a t e t h e p o t e n t i a l of t h e m a t e r i a l s lot u s e in wear resistant applications
PROPERTIES OF WATER ATOMISED IRON POWDER CONTAINING PHOSPHOROUS AND CARBON OR BORON AND SILICON T. Sato et al, J. Materials Science, Vol 26,
No 9, 1991, 2329-2336. The mierostructure and powder p r o p e r t i e s of w a t e r a t o m i s e d Fe-P-C a n d Fe-B-Si a l l o y s w e r e i n v e s t i g a t e d w i t h respect to glass f o r m i n g conditions. The metallic glass p o w d e r s h a d not flowability. It w a s also found t h a t p a r t i c l e s b e c a m e m o r e irregular as t h e size increased. In crystalline powders both ~ and intermetallic p h a s e s were found in hypoa n d hyper-eutectic ;alloys.
STRUCTURAL CHARACTERISTICS ATOMISED WHITE CAST IRON POWDER
OF
A.P. Gulyaev et al, Metalloved. Term. Obrab
Met, No 1, 1991, 34-35. I~ R u s s i a n .
MPR February 1992 57
Cobalt SINTERING CHARACTERISTICS ULTRAFINE COBALT POWDER
OF
Y Sakka, (National I~'esearch inst.ilute for Metals, ,lapan). J. Less Commo'** Metals.
tqd 168, No 2, 1991, 2772,S'7. The s i m e r i n g of u l t r a l i n e ( n powders in vacuunl an(t t[ was nlorlilored hv s t r u c t u r a l a n d d i m e n s i o n a l changes. The p r e s e n c e of i n c l u ( t e d o x i d e s h i n d e r s s i n l e r i n g il, vacuunl but in H t h e o x i d e s are reduced and significant (tensifi(:ation occurs. Gases are evolve(I d u r i n g ~ a c u u m s i n t e r i n g a n d t h e s e were identified as Co e, CO, tie a n d lift). Surface condit;ions are d i s c u s s e d by c o n s i d e r a t i o n of t h e (h~sort)tion sl)ectra.
Copper FACTORS INFLUENCING THE QUALITY OF E L E C T R O I N T I C C O P P E R P O W D E R A. I)urisinova, (Sh)vak A(:a(lemy of Sciences, K(,sice C z e c h o s h ) v a k i a ) , P o w d e r
Metallurgy, Vol 33, No 2, 199l. 139 141. The eflbcts of tint(! of growlh, current d e n s i l y , eleci r o l y t e c o m p o s i t i o n a n d len~l)eralure pll. c i r c u l a l i o n ()I" t h e electrolyte a n d l h e p r e s e n c e of i m p u r i t i e s on the quality of e l e c t r o l ~ i c Cu p o w d e r s have heen stu(lied. C h a n g e s in p o w d e r properties were delermined and the powders were e x a m i n e d microscopically.
Iron a n d S t e e l THE WORKABILITY OF POROUS STEEL PREFORMS A. El I)omialy, M. Shaker. (Suez Canal University, Egypt), ,L Materials Processin.q
Technology, Vol 25, No 2, 1991, 2 2 9 233. A t t e n t i o n is drawn to a m a j o r limitation of powder forging of steel, cracking in t h e (tie. A m e t h o d of c h a r a c l e r i s i n g workability h a s been developed for w r o u g h t m e t a l s a n d applied to p o r o u s metals. Workability limits for s i n t e r e d Fe-0.2%C-0.5%Mo-0.04%S0.04%P w i t h d i f f e r e n t p o r o s i t i e s w e r e d e t e r m i n e d a n d it w a s d e d u c e d t h a t porosity is the m a i n p a r a m e t e r controlling workability of p o r o u s materials.
EFFECT OF SINTERING CONDITIONS ON ISOTHERMAL DECOMPOSITION OF AUTENITE IN SINTERED STEELS V.N. Antsiferov et al, Stal', No 12, 1990, 84-
ferro-alloys are u s e d in p r o d u c t i o n of steels. The p a p e r r e p o r t s on how ferro-alloys influence properties structure and sintering charaeleristics of s i n t e r e d ferrous alloys.
87. In R~ssian. The isothermal decomposition of A u s t e n i t e in PM steels c o m a i n i n g either 1.0 to 1.5%C a n d 3%Cu or" 1.0%C a n d 1.0%Mn was investigated with respect to the s i n t e r i n g a t m o s p h e r e . The s t r u c t u r e s were e x a m i n e d a n d it was l o u n d t h a t on s i n t e r i n g in s t a g n a n t a t m o s p h e r e s a e e m t i t e network w a s f o r m e d a n d t h e r e were g r a p h i t e i n c l u s i o n s w h i c h n u c l e a t e d the b r e a k d o w n of A u s t e n i t e t h i s r e d u c i n g the. i n c u b a t i o n period. It w a s found t h a t t h e C-Cu steel required a double heat treatmenl aud requench quench from 860 C a n d t e m p e r i n g at 300~C to a t t a i n greater s t r e n g t h . EFFECTS OF PRODUCTION PARAMETERS ON STRUCTURE AND PROPERTIES OF REDUCED AND ATOMISED IRON POWDERS 1.P. Argent'seva et al, (Moscow Evening Metallurgical Institute, USSR), Stal', No 11,
1990, 87-92. b~ Ru,ssiar~. The s t r u c t u r e a n d p r o p e r t i e s of r e d u c e d a n d a t o m i s e d Fe powders were investigated. Powder surface morpholog5 ~ a n d O c o n t e n t in relation t.o compactibility are d i s c u s s e d with respecl to t h e f o r m a t i o n of interparticle c o n t a c t s d u r i n g p r e s s i n g a n d s t r e n g t h a n d d e n s i t y of t h e c o m p a c t s . ULTRA HIGH STRENGTH FERROUS COMPONENTS
SINTERED
O. Durukimi et al, (Kawasaki Steel Corporation, Kawasaki, J a p a n ) , D~t J. P o w d e r
Metall,Jrgy, Vol 27, No 4, 1991, 331-337. A newly developed steel c o n t a i n i n g 2%Ni a n d l%Mo with tensile s t r e n g t h 1500 MPa, impact s t r e n g t h 21J, r o t a t i n g b e n d fatigue s t r e n g t h 460 MPa a n d c o m p a c t fatigue s t r e n g t h 2560 MPa is described. It w a s r e p o r t e d t h a t p r o p e r t i e s couM be i n c r e a s e d by double pressing, resintering, h a r d e n i n g a n d tempering. The i n c r e a s e d s t r e n g t h s are a t t r i b u t e d to a s t r a i n i n d u c e d m a r t e n s i t i c t r a n s f o r m a t i o n in t h e r e t a i n e d Austenite.
ENHANCED SINTERING AND PROPERTY IMPROVEMENTS IN SINTERED FERROUS COMPONENTS D.S. Madan, (Elkem D e v e l o p m e n t Centre, Sewiekley, P e n n s y l v a n i a , U S A ) , I n t J.
P o w d e r Metallurgy, Vol 27, No 4, 1991, 339-345. M o d e l s of e n h a n c e d s i n t e r i n g a r e reviewed a n d t h e role of a d d i t i o n s of ferro-alloys to PM steels is discussed. The m e c h a n i c a l a n d p h y s i c a l p r o p e r t i e s of w a t e r a t o m i s e d DFe p o w d e r alloyed with h i g h p u r i t y f e r r o - p h o s p h o r o u s or ferroboron are described. The p r o p e r t i e s are shown to be s u p e r i o r w h e n high p u r i t y
IMPROVED PROPERTIES AND P E R F O R M A N C E O F LOW ALLOY S T E E L PARTS THROUGH HIGH TEMPERATURE SINTERING K. S h i m a d a , (Tokyo Sintered Metals Corporation, Tokyo, .Japan), [nt J. P o w d e r
Metallurgy, Vol 27, No 4, /991, 357-361. S u p e r i o r s t r e n g t h , fatigue p r o p e r t i e s a n d w e a r r e s i s t a n c e are r e p o r t e d to have been a t t a i n e d in low alloy st,eel PM p a r t s by s i n t e r m g at 1250:C, carburising, h a r d e n i n g a n d tempering. The p r o p e r l y i m p r o v e m e n t s a r e a t t r i b u t e d to p o r o s i t y r e d u c t i o n , s p h e r o i d i s a t i o n of r e s i d u a l p o r e s a n d increased neck growth d u r i n g sintering. A u t o m o t i v e a p p l i c a t i o n s a r ( discussed. NEW SINTERED STEELS CONTAINING HARD PHASES FOR WEAR RESISTANT APPLICATIONS F. Thfimmler, C. Gutsfeld. (University ol Karlsruhe, Karlsruhe, G e r m a n y ) , P o w d e r
Metall. Int, Vol 23, No 5, /991, 285-290. T h e p r o d u c t i o n of Fe b a s e d m e t a l m a t r i x c o m p o s i t e s (MMC', c o n t a i n i n g 10 to 30vo>,; of h a r d plrases NbC. TiC of AI~O:~, u s i n g m e c ' h a n i c a l a l l o y i n g (MA) to incorporate the hard phase and sintering at 128()"C in H is d e s c r i b e d The a d d i t i o n of C or P to create a liquid ptmse d u r i n g s i n t e r i n g resulted in d e n s i t i e s of 97 to 99?,; a n d a u n i f o r m d i s t r i b u t i o n of t h e h a r d particles was d u e to t h e ~se of MA. The mechanical properties and wear c h a r a c t e r i s t i c s were, shown to d e m o n s t r a t e t h e p o t e n t i a l of t h e m a t e r i a l s lot u s e in wear resistant applications
PROPERTIES OF WATER ATOMISED IRON POWDER CONTAINING PHOSPHOROUS AND CARBON OR BORON AND SILICON T. Sato et al, J. Materials Science, Vol 26,
No 9, 1991, 2329-2336. The mierostructure and powder p r o p e r t i e s of w a t e r a t o m i s e d Fe-P-C a n d Fe-B-Si a l l o y s w e r e i n v e s t i g a t e d w i t h respect to glass f o r m i n g conditions. The metallic glass p o w d e r s h a d not flowability. It w a s also found t h a t p a r t i c l e s b e c a m e m o r e irregular as t h e size increased. In crystalline powders both ~ and intermetallic p h a s e s were found in hypoa n d hyper-eutectic ;alloys.
STRUCTURAL CHARACTERISTICS ATOMISED WHITE CAST IRON POWDER
OF
A.P. Gulyaev et al, Metalloved. Term. Obrab
Met, No 1, 1991, 34-35. I~ R u s s i a n .
MPR February 1992 57