Ternary phases with TiFeSi and ordered Fe 2 P type structures
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Ternary Phases with TiFeSi and Ordered Fe2 P Type Structures WOLFGANG J E I T S C H K O A r e c e n t s u r v e y on t e r n a r y e q u i a t o m i c t r a n s i t i o n m e t a l s i l i c i d e s and g e r m a n i d e s T L T R M * showed the *TL ... transition metalfrom the left side of the periodictable (Ti, V, Crgroup elements), TR ... transitionmetalfrom the right side (Fe, Co, Ni group elements), and M... Si or Ge. f r e q u e n t o c c u r r e n c e of the T i N i S i - s t r u c t u r e ( o r d e r e d PbC12 type). ~ C o m p e t i n g with it is the o r d e r e d FezP type s t r u c t u r e which has b e e n found for NbMnSi, 2 NbMnGe, 3 TiCoGe, 4 and a d i s t o r t e d v e r s i o n of that type, found f o r T i F e S i and T i F e G e . 4 In the p r e s e n t c o m m u n i c a t i o n the e x i s t e n c e of s o m e m o r e FezP type and T i F e S i type s t r u c t u r e s is r e p o r t e d . Experimental. Alloy specimens were prepared from the e l e m e n t a l c o m p o n e n t s (all of p u r i t y h i g h e r than 99.9 pct) by a r c m e l t i n g u n d e r a r g o n (99.996 p c t A t ) . All s a m p l e s w e r e t u r n e d o v e r and r e m e l t e d at l e a s t t w i c e to en h an ce h o m o g e n e i t y . Weight l o s s e s w e r e in a l l c a s e s l e s s than 1 pct, with the e x c e p t i o n of s a m p l e s in the s y s t e m T i - M n - S i , w h e r e the r e l a t i v e l y high v a p o r p r e s s u r e of m a n g a n e s e r e s u l t e d in weight l o s s e s of up to 5 pct. T h e s e w e r e p a r t i a l l y c o m p e n s a t e d f o r by s t a r t i n g with s l i g h t l y h i g h e r m a n g a n e s e c o n c e n t r a t i o n s . The s a m p l e s w e r e e n c a p s u l a t e d in e v a c u a t e d W. JEITSCHKO, formerly Research Associate, University of Illinois, Urbana, II1., is at the Central Research Department, Experimental Station, E. I. du Pont de Nemours,& Co., Wilmington, Del. 19898. Manuscript submitted May 15, 1970. METALLURGICALTRANSACTIONS
f o r d i s l o c a t i o n s to r e m a i n c o p l a n a r in c r y s t a l l o g r a p h i c p l a n e s . C a s s a a l s o o b s e r v e d that d i s l o c a t i o n s tend to l i e along c l o s e - p a c k e d d i r e c t i o n s in Ti-9A1 and his o b s e r v a t i o n is c o n f i r m e d h e r e . The a u t h o r s w i s h to e x p r e s s thanks to T i t a n i u m M e t a l s Co r p . of A m e r i c a who s u p p o r t e d this w o r k . Thanks a r e a l s o due to M r s . E l i z a b e t h Bo n d u r an t of T I M E T who p r o v i d e d the f o i l and to P r o f e s s o r C. R. B a r r e t t of Stanford U n i v e r s i t y f o r heipful c o m m e n t s .
1. P. R. Swarm:Electron Microscopy and Strength of Crystals, p. 131, Interscience,NewYork,.1962. 2. P. B. Hirsch,R. W.Home, and M. J. Whelan:Dislocations andMechanicalProperties of Crystals, pp. 106-08,John Wiley& Sons,New York, 1957. 3. Fourdeux and Berghezon:Solid State Physics Supp. 6, p. 364, AcademicPress, NewYork, 1964. 4. J. W. Edington, Referencedby
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