The effect of small amounts of ag, se, and sn on the recrystallization of copper
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T H E e f f e c t o f i m p u r i t y e l e m e n t s o n the r e c r y s t a l l i z a t i o n of c o p p e r h a s b e e n o f i n t e r e s t t o c o p p e r p r o d u c e r s and metallurgists for many y e a r s . Impurity e l e m e n t s w h e n p r e s e n t in c o p p e r generally r a i s e i t s recrystallization temperature and consequently c a u s e undesirable s t i f f n e s s in c o p p e r wire used f o r m o t o r a r m a t u r e s and s i m i l a r electrical equipment. T h e r e s e a r c h d e s c r i b e d in t h i s p a p e r d e a l s w i t h the e f f e c t o f s m a l l a m o u n t s o f s i l v e r , s e l e n i u m , tin, silver/selenium, and tin/selenium o n t h e r e c r y s t a l l i z a t i o n of c o p p e r . T h e f i r s t s y s t e m a t i c s t u d y of t h e e f f e c t s o f i m p u r i t y e l e m e n t s on t h e r e c r y s t a l l i z a t i o n of h i g h p u r i t y copp e r at c o n c e n t r a t i o n s c o m m o n l y f o u n d in r e f i n e d c o p p e r w a s r e p o r t e d by S m a r t a n d S m i t h1-3 w h o s t u d i e d t h e e f f e c t s of s m a l l a m o u n t s of i r o n , n i c k e l a n d c o b a l t . Subsequently, o t h e r investigators further q u a n t i z e d t h e e f f e c t s o f i m p u r i t i e s by d e t e r m i n i n g the c h a n g e i n a c t i v a t i o n e n e r g y f o r r e c r y s t a l l i z a t i o n 4,~ due t o the i m p u r i t y a d d i t i o n s . L a t e r a t h o r o u g h s t u d y of the effect of a n u m b e r of impurities and combinations of i m p u r i t i e s i n c o p p e r w a s m a d e by P a w l e k . 6-12 P a w lek utilized p o w d e r metallurgy techniques t o produce h i g h p u r i t y a l l o y s a n d a l s o s t u d i e d t h e e f f e c t s of c o m b i n a t i o n s o f i m p u r i t i e s . T a y l e r a n d P i t t 1~ r e p o r t e d d a t a o n t h e e f f e c t o f the i n t e r a c t i o n of s i l v e r a n d s e l e n i u m i n c o p p e r on t h e a c t i v a t i o n e n e r g y f o r r e c r y s t a l l i z a t i o n . T h i s p a p e r e x t e n d s t h e w o r k of T a y l e r a n d P i t t to d i f f e r e n t p r e - a n n e a l i n g t e m p e r a t u r e s a n d to t h e i m p u r i t i e s t i n a n d s e l e n i u m .
L a b o r a t o r y of K e n n e c o t t C o p p e r C o m p a n y by m e l t i n g t h e c o p p e r a n d a l l o y i n g m e t a l t o g e t h e r in a e v a c u a t e d a n d s e a l e d q u a r t z tube at a p p r o x i m a t e l y 1 1 7 0 ° C . T h e m e l t w a s s t i r r e d by r o c k i n g t h e q u a r t z t u b e s . T h e a l l o y s w e r e d i r e c t i o n a l l y s o l i d i f i e d by w i t h d r a w i n g t h e m f r o m the f u r n a c e a t 1 i n . p e r m i n . T h e f i n a l c a s t p i e c e s w e r e a p p r o x i m a t e l y 0.5 i n . i n d i a m . T h e c a s t rods were s w a g e d t o 0 . 1 2 5 i n . diam a n d f u r t h e r r e d u c e d t o 0 . 0 4 0 i n . d i a m by d r a w i n g t h r o u g h t u n g s t e n c a r b i d e wire d r a w i n
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