Rapid Growth of TiNi intermetallic compound within undercooled Ti_(50)Ni_(50)alloy under electrostatic levitation condition  

作　　者：P.F.Zou C.H.Zheng L.Hu H.P.Wang 

机构地区：[1]School of Physical Science and Technology,Northwestern Polytechnical University.Xi'an,710072,China

出　　处：《Journal of Materials Science & Technology》2021年第18期82-89,共8页材料科学技术（英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.51734008,51522102 and 51327901);the National Key R&D Program of China(Grant No.2018YFB2001800);the Shannxi Key Industry Chain Program(Grant No.2019ZDLGY05-10)。

摘　　要：The undercooling dependence of the solidification mechanism was systematically explored by the electrostatic levitation(ESL)facility.During the experiments,the maximum undercooling reached up to 406 K(0.26 T_L)and the growth velocity of the primary TiNi phase was in-situ determined at various undercoolings.At the initial increase of alloy undercooling,the value of growth velocity sluggishly rose followed by a power function.In this case,the primary TiNi phase preferentially developed as the equiaxed dendrite,then the remnant liquid participated as Ti_(2)Ni andα-Ti phases on the grain boundary.Once the undercooling exceeded the critical value of 350 K,the growth velocity of the primary phase displayed a sharply increase tendency.Meanwhile,the TEM results demonstrated that the precipitation of the intermetallic Ti_(2)Ni compound was gradually restrained during the rapid solidification and the R-phase existing in the TiNi matrix at large undercooling implied that the martensitic transformation was incomplete.

关 键 词：UNDERCOOLING Ti-Ni alloy SOLIDIFICATION Growth kinetics 

分 类 号：TG139.6[一般工业技术—材料科学与工程]