…94· 北京科技大学学报 1997年第1期 partial crystallization of amorphous phase producing Ti,Si,phase;the second is crystalliza- tion of the rest amorphous phase producing the corresponding titanium aluminides accord- ing to the relative amount of Ti and Al in the elemental mixture;and the last one is grain growth of all the phase in powders.The crystallization result in formation of Ti,Al, TiAl and Al,Ti according the powder composition.Ti,Si,is the only silicide produced by crystallization reaction.The annealing treatment (less than 800 C for A3,A4 and A5,and 750 c for A6)shows that the grain size of all the phases fall in nanometer range. KEY WORDS mechanical alloying,nanocrystalline intermetallics,composite,Ti-Al-Si (上接88页) Crystallogrphic Orientation and Magnetostrictive Properties of Directionally Solidified Laves-phase TboDyo(Fe,M)195 Alloys Zhang Maocai Jiang Chengbao Zhao Qing Gao Xuexu Shi Zhenhua State Key Laboratory of Advanced Metals and Materials,UST Beijing,Beijing 100083,China ABSTRACT The crystallographic orientation,morphologies and the relationship between the orientation and magnetostrictive properties of directionally solidified Laves-phasee Tb,Dy?(Fe,M)1 alloys by zone melting with high thermal gradient G wre studied. With increasing in Laves-phase growth vilocity at a high G given,it is shown that the solidification structure of alloys are from planar to cellular and to final dentritic structure, and meanwhile the crystallographic orientation of the Laves-phase are various correspondent- ly.The optimum magnetostrictive properties of the alloys with perfect <112>axial orienta- tion are obtained. KEY WORDS crystallographic orientation,magnetostrictive properties,directional solidifi- cation· 9 4 · 北 京 科 技 大 学 学 报 19 97 年 第 l 期 p art i a l c 可s at lli atZ i o n o f am o rp h o u s p h as e p r o d u c in g T i s s i 3 p h a s e : ht e s e c o n d i s c 珍s at lli z a - it o n o f ht e r e s t am o rp h o u s Ph a s e P r o d u c in g ht e c o er s P o n d in g ti atn i u m a l u m in i d e s ac e o dr - in g ot ht e r e lat i v e am o un t o f T i an d A I i n ht e e l e m e n at l m i x trU e : an d ht e las t o n e 1 5 脚in 歹o w ht o f a ll ht e p h as e i n p o w d e r s · T h e c 叮s at lli z a t i o n er s u lt in fo mr a t i o n o f T i , A I , T认1 an d A 1 3 T i ac c o dr in g ht e p o w d e r c o m Po s it i o n · T i s s i 3 1 5 t h e o n l y s ili C id e p or d u c e d b y e 叮s at lli z iat o n r e ac t i o n . T h e an e a lin g etr a it n e n t ( l e s s ht an 8 0 0 oC fo r A 3 , A 4 an d A S , an d 7 5 0 oC fo r A 6 ) s h o w s ht a t ht e g r a i n s i z e o f a ll ht e Ph a s e s fa ll in n an o m e t e r r an g e . K E Y W O R D S m e e h an i e a l a ll o y in g , n an o e yr s at llin e in t e mr e at lli e s , e o m P o s it e , T i 一 A I 一 5 1 (上 接 8 8 页 ) C yr s t a ll o g pr h i e O r i e nt at i o n a n d M a g n e t o s tr i e t i v e P r o P e rt i e s o f D ir e e t i o n a l ly s o li d iif e d L va e s 一 p h a s e T b o . 3 D y o . 7 ( F e , M ) 1 . 9 5 A ll o y s hZ a n g M O o c a i iaJ n g hC e n沙 a o hZ a o Qin g G a o Xu xe u hS i hZ e n h u a S at 记 K e y L ab o ar t o yr o f A d v an c de M e alt s an d M at e ir al s , U S T B e ij in g , B e ij in g 10 0 0 8 3 , C h in a A B S T R A C T T h e e ry s at ll o gr aP h i c o ir e n at i o n , m o rp h o l o g i e s an d ht e r e l iat o n s h iP b e wt e e n ht e o ir e n at it o n an d m a g n e ot s itr e t i v e P r o P e rt i e s o f d i er e t i o n a lly s o li d iif e d L va e s 一 Ph a s e e Tb o 3 D y 。二 ( F e , M ) , . 9 , a ll o y s b y z o n e m e l int g w iht h i g h ht e mr a l 歹ad i e n t G L w er s ut d i e d . W i ht in c r e as in g in L a v e s 一 p h as e g or w ht v il o c iyt a t a h i g h G L g i v e n , it 1 5 s h o w n ht at ht e s o li d iif e iat o n s utr e tUr e o f a ll o y s aer for m Plan ar t o e e lin lar an d t o fm a l d e n itr t i e s trU e tUr e , an d m e an w h il e ht e c yr s at ll o g r a Ph i e o ir e n at t i o n o f ht e L va e s 一 Ph a s e aer v iar o u s e o r e s P o n d e nt - l y . T h e o Pt im u m m a gn e t o s itr e t i v e P r o P e rt i e s o f ht e a ll o y s w iht P e fer e t < 1 12 > ax i al o ir e n at - it o n 肛e o b at in e d . K E Y W O R D S e yr s at ll o g r ap h i e o ir e n at i o n , m a g n e t o s itr e t i v e P r o P e rt i e s , d ir e e t i o n a l s o lid iif - e at i o n