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US tungsten producers suspend OMA petition
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UPDATE
Sintering technique expands scope of FGMs A SINTERING t e c h n i q u e u n d e r development in Japan could allow the production of functionally gradient materials (FGM) from combinations of materials t h a t are impossible to process using conventional routes. Hot isostatic p r e s s i n g (HIP) is usually used to form FGMs, but this does not work with some materials c o m b i n a t i o n s . Even w h e n HIP is applicable it is complicated and costly. The new process uses electrical pulses to create a p l a s m a charge among the p o w d e r particles, h e a t i n g the m i x t u r e to a high temperature instantaneously, reports Nikkei Weekly. Sumitomo Coal Mining has used this process to create an FGM combining metal a n d glass. Because t h e s e materials have very different thermal-expans i o n c o e f f i c i e n t s , it h a s been difficult to combine t h e m using s t a n d a r d sintering techniques. With the electrical method, however, the powders are h e a t e d so quickly t h a t they are sintered into an integrated whole before t h e r m a l e x p a n s i o n has a chance to ruin things. Sumitomo Coal has fabricated FGMs from glass and stainless steel a n d from glass and silicon, it is now developing applications.
US tungsten producers suspend OMA petition THE REFRACTORY Melals Association (RMA) says that it is to stop p e t i t i o n i n g the I'S g o v e r n m e n t to negotiate an Orderly Marketing Agreement (OMA) to curtail sharply rising imports of Chinese tungsten products. The association says l hat its decision was based on a lack of support from govern ment agencies to proxq(te relief lor US producers of tungsten products. There was said to be no h o p e of the administra-
16 MPR June 1993
Meanwhile, researchers at t h e N a t i o n a l Defence Academy's have used t h e t e c h n i q u e to c o n s t r u c t FGMs from a titanium-aluminium alloy and a zirconium alloy -- two materials with vastly different melting points. The titanium-aluminium alloy melts at 1200°C, and the zirconium alloy a t 1600°C. G r o u p leader Hiroshi Kimura was able to bridge the t e m p e r a ture differential by putting the powders into a convex graphite mould. When a strong current was applied to the mould, the current was m o s t d e n s e at the apex, producing a higher t e m p e r a t u r e in t h a t area. A 1200 a m p current can create a t e m p e r a t u r e differential of at least 900°C between the powder at the top and the b o t t o m of the mould. The electrical m e t h o d makes it possible to sinter the material in about six minutes, says Kimura. The s t a n d a r d technique would take more t h a n six hours. Speed and low cost are two huge advantages of the electrical sintering method, agrees Toshio Hirai, an FGM e x p e r t from Tohoku University. Most exciting of all the technique could potentially be u s e d to develop new materials.
l i o n ' s p o s i t i o n c h a n g i n g in the near future. T h e RMA h a d r e c o m mended quantitative restraints on a range of tungsten intermediates. Some 93% of such p r o d u c t s imported by the US in 1992 came from China. The growing d e p e n d e n c e on C h i n e s e p r o d u c t s could put the domestic tungsten i n d u s t w at risk, claims the RMA. China controls more the half the world's tungsten reserves. Rqfi'actoKt] Metals Assoc~ia lion: tel: + 1-609-452-7700: j ¢ r : 4- I~609 987 8523.
Japanese firms collaborate on MIM TWO DIVISIONS of Sumitomo have joined forces to run a metal injection moulding (MIM) business. Sumitomo Cement and Sumitomo Special Metals plan to produce p a r t s for communications and office a u t o m a t i o n e q u i p m e n t m a d e from highp e r f o r m a n c e m a t e r i a l s such as low heat e x p a n s i o n alloys, malleable magnetic materials, and heat and corrosion resist a n t alloys.
Osprey gets quality approval OSPREY Powder Group claims to be the only gas atomized metal powder p r o d u c e r in the world to gain accreditation to the ISO 9001 qualiW management s t a n d a r d for both manuf a c t u r i n g and r e s e a r c h and d e v e l o p m e n t . The firm says t h a t this underlines its comm i t m e n t to t h e s u p p l y of p o w d e r s tailored specifically to its customers needs. The group is p a r t of Osprey Metals Ltd of Neath, UK, and concentrates on gas atomized powder production, s u p p o r t e d by- ongoing research and develo p m e n t into atomizer design. It was successfully assessed to ISO 9001 by SGS Yarsley Ltd earlier this year. R. Howells, Osprey Metals Ltd; tel: + 4 4 - 6 3 9 - 6 3 4 1 2 1 ; foa': + 44-639-630100.
Tungsten and molybdenum slump in Japan THE SLUMP in J a p a n e s e production of t u n g s t e n and molybdenum p r o d u c t s continued in 1992, says Roskill's Letter f r o m Japan. This was reflected in tungsten powder s h i p m e n t s which fell by more t h a n 20% to 2635 tonnes. In contrast, s h i p m e n t s of molybdenum powder actually rose 8%, to 92.43 tonnes. But the rise in s h i p m e n t s of molybdenum powder was insufficient to offset the drop in d e m a n d for m a n u f a c t u r e d molybdenum products. Total shipm e n t s of molybdenum powder and manufactured products fell by 5% from 426 t o n n e s in 1991 to 404 t o n n e s in 1992, the lowest level for five years.
Pr<)ducLion began at the end (>f March, using equipm e n t installed at a Sumitomo Cement plant in Chiba prefecture. Sales will be handled by both firms and are e x p e c t e d to reach ¥ 3 0 0 million in the first year, increasing to ¥ 3 billion a year in fiw~ years. S u m i t o m o C e m e n t ; tel: + 81-3-3296-9600; f ~ r : + 8I3-3295-5156; Samitomo Special Metals; tel: + 81-6-2208850; fax: + 81-6 2208885. (c)
Xform develops process thanks to grant XFORM Inc of Cohoes, New York, is to commercialize its intermetallic p r o d u c t s and exp a n d its r e a c t i v e s i n t e r i n g manufacturing capabilities thanks to a $300 009 grant from two local authorities. F o u n d e d in 1990, Xform produces nickel and titanium aluminide powder using a proprietary reactive sintering process. E l e m e n t a l p o w d e r s are p r o c e s s e d t h r o u g h an exothermic reaction to form special materials ti)r further processing. The powders are t h e n c o n s o l i d a t e d into products by conventional pressing a n d s i n t e r i n g o r h o t p r e s s i n g . The p o w d e r s can also be used for plasma spray ing, says the Pal Technology Ne~wsletten The f i n n says t h a t t h e powders offer good compactibility, high green s t r e n g t h and can be sintered to fllll density. They compete u i t b atomized materials, it claims. E n d - p r o d u c t s include chemically resistant dies, d i a m o n d b o n d s and carbide and filters. Xform h~c: tel: * 1-518233-7249; fia~': ~ 1-518-2331846.
Items m a r k e d (c) are Copyright o f COMLINE International Corp. COMLINE News Service © 1993
UPDATE
Sintering technique expands scope of FGMs A SINTERING t e c h n i q u e u n d e r development in Japan could allow the production of functionally gradient materials (FGM) from combinations of materials t h a t are impossible to process using conventional routes. Hot isostatic p r e s s i n g (HIP) is usually used to form FGMs, but this does not work with some materials c o m b i n a t i o n s . Even w h e n HIP is applicable it is complicated and costly. The new process uses electrical pulses to create a p l a s m a charge among the p o w d e r particles, h e a t i n g the m i x t u r e to a high temperature instantaneously, reports Nikkei Weekly. Sumitomo Coal Mining has used this process to create an FGM combining metal a n d glass. Because t h e s e materials have very different thermal-expans i o n c o e f f i c i e n t s , it h a s been difficult to combine t h e m using s t a n d a r d sintering techniques. With the electrical method, however, the powders are h e a t e d so quickly t h a t they are sintered into an integrated whole before t h e r m a l e x p a n s i o n has a chance to ruin things. Sumitomo Coal has fabricated FGMs from glass and stainless steel a n d from glass and silicon, it is now developing applications.
US tungsten producers suspend OMA petition THE REFRACTORY Melals Association (RMA) says that it is to stop p e t i t i o n i n g the I'S g o v e r n m e n t to negotiate an Orderly Marketing Agreement (OMA) to curtail sharply rising imports of Chinese tungsten products. The association says l hat its decision was based on a lack of support from govern ment agencies to proxq(te relief lor US producers of tungsten products. There was said to be no h o p e of the administra-
16 MPR June 1993
Meanwhile, researchers at t h e N a t i o n a l Defence Academy's have used t h e t e c h n i q u e to c o n s t r u c t FGMs from a titanium-aluminium alloy and a zirconium alloy -- two materials with vastly different melting points. The titanium-aluminium alloy melts at 1200°C, and the zirconium alloy a t 1600°C. G r o u p leader Hiroshi Kimura was able to bridge the t e m p e r a ture differential by putting the powders into a convex graphite mould. When a strong current was applied to the mould, the current was m o s t d e n s e at the apex, producing a higher t e m p e r a t u r e in t h a t area. A 1200 a m p current can create a t e m p e r a t u r e differential of at least 900°C between the powder at the top and the b o t t o m of the mould. The electrical m e t h o d makes it possible to sinter the material in about six minutes, says Kimura. The s t a n d a r d technique would take more t h a n six hours. Speed and low cost are two huge advantages of the electrical sintering method, agrees Toshio Hirai, an FGM e x p e r t from Tohoku University. Most exciting of all the technique could potentially be u s e d to develop new materials.
l i o n ' s p o s i t i o n c h a n g i n g in the near future. T h e RMA h a d r e c o m mended quantitative restraints on a range of tungsten intermediates. Some 93% of such p r o d u c t s imported by the US in 1992 came from China. The growing d e p e n d e n c e on C h i n e s e p r o d u c t s could put the domestic tungsten i n d u s t w at risk, claims the RMA. China controls more the half the world's tungsten reserves. Rqfi'actoKt] Metals Assoc~ia lion: tel: + 1-609-452-7700: j ¢ r : 4- I~609 987 8523.
Japanese firms collaborate on MIM TWO DIVISIONS of Sumitomo have joined forces to run a metal injection moulding (MIM) business. Sumitomo Cement and Sumitomo Special Metals plan to produce p a r t s for communications and office a u t o m a t i o n e q u i p m e n t m a d e from highp e r f o r m a n c e m a t e r i a l s such as low heat e x p a n s i o n alloys, malleable magnetic materials, and heat and corrosion resist a n t alloys.
Osprey gets quality approval OSPREY Powder Group claims to be the only gas atomized metal powder p r o d u c e r in the world to gain accreditation to the ISO 9001 qualiW management s t a n d a r d for both manuf a c t u r i n g and r e s e a r c h and d e v e l o p m e n t . The firm says t h a t this underlines its comm i t m e n t to t h e s u p p l y of p o w d e r s tailored specifically to its customers needs. The group is p a r t of Osprey Metals Ltd of Neath, UK, and concentrates on gas atomized powder production, s u p p o r t e d by- ongoing research and develo p m e n t into atomizer design. It was successfully assessed to ISO 9001 by SGS Yarsley Ltd earlier this year. R. Howells, Osprey Metals Ltd; tel: + 4 4 - 6 3 9 - 6 3 4 1 2 1 ; foa': + 44-639-630100.
Tungsten and molybdenum slump in Japan THE SLUMP in J a p a n e s e production of t u n g s t e n and molybdenum p r o d u c t s continued in 1992, says Roskill's Letter f r o m Japan. This was reflected in tungsten powder s h i p m e n t s which fell by more t h a n 20% to 2635 tonnes. In contrast, s h i p m e n t s of molybdenum powder actually rose 8%, to 92.43 tonnes. But the rise in s h i p m e n t s of molybdenum powder was insufficient to offset the drop in d e m a n d for m a n u f a c t u r e d molybdenum products. Total shipm e n t s of molybdenum powder and manufactured products fell by 5% from 426 t o n n e s in 1991 to 404 t o n n e s in 1992, the lowest level for five years.
Pr<)ducLion began at the end (>f March, using equipm e n t installed at a Sumitomo Cement plant in Chiba prefecture. Sales will be handled by both firms and are e x p e c t e d to reach ¥ 3 0 0 million in the first year, increasing to ¥ 3 billion a year in fiw~ years. S u m i t o m o C e m e n t ; tel: + 81-3-3296-9600; f ~ r : + 8I3-3295-5156; Samitomo Special Metals; tel: + 81-6-2208850; fax: + 81-6 2208885. (c)
Xform develops process thanks to grant XFORM Inc of Cohoes, New York, is to commercialize its intermetallic p r o d u c t s and exp a n d its r e a c t i v e s i n t e r i n g manufacturing capabilities thanks to a $300 009 grant from two local authorities. F o u n d e d in 1990, Xform produces nickel and titanium aluminide powder using a proprietary reactive sintering process. E l e m e n t a l p o w d e r s are p r o c e s s e d t h r o u g h an exothermic reaction to form special materials ti)r further processing. The powders are t h e n c o n s o l i d a t e d into products by conventional pressing a n d s i n t e r i n g o r h o t p r e s s i n g . The p o w d e r s can also be used for plasma spray ing, says the Pal Technology Ne~wsletten The f i n n says t h a t t h e powders offer good compactibility, high green s t r e n g t h and can be sintered to fllll density. They compete u i t b atomized materials, it claims. E n d - p r o d u c t s include chemically resistant dies, d i a m o n d b o n d s and carbide and filters. Xform h~c: tel: * 1-518233-7249; fia~': ~ 1-518-2331846.
Items m a r k e d (c) are Copyright o f COMLINE International Corp. COMLINE News Service © 1993