热轧Ni_(47)Ti_(44)Nb_9形状记忆合金板材的织构及其对拉伸和恢复性能的影响  

Texture and its influence on tensile and recoverable properties of hot-rolled Ni_(47)Ti_(44)Nb_9 shape memory alloy sheet

作　　者：颜莹[1] 金伟[2] 周亭俊[1] 

机构地区：[1]东北大学材料物理与化学研究所,沈阳110004 [2]中国科学院金属研究所,沈阳110016

出　　处：《中国有色金属学报》2010年第11期2148-2153,共6页The Chinese Journal of Nonferrous Metals

基　　金：核燃料及材料国防科技重点实验室基金资助项目(51481130101ZK0601)

摘　　要：采用XRD、SEM和拉伸试验机对热轧Ni47Ti44Nb9形状记忆合金板材的织构及其对拉伸和恢复性能的影响进行研究,以便为改善该合金的力学和记忆性能提供理论依据。热轧板材的织构主要为{001}<uv0>和{111}<uvw>丝,沿轧向(RD),{001}<uv0>丝织构中强组分向{001}<010>靠近,{111}<uvw>丝织构中的{111}<112>和{111}<165>组分较强;沿横向(TD),强织构组分为{001}<010>和{111}<132>;热轧板材经高于再结晶温度热处理后,沿轧向,应力诱发马氏体相变临界应力最高,与轧向成45°角方向的临界应力最低,且沿横向拉伸断口表面出现很多微裂纹;经850℃热处理后,临界应力随着冷速的加快而降低,且该温度下退火板材的织构对可恢复应变的影响不明显,基本在7.0%～7.4%。The texture and its influence on tensile and recoverable properties of hot-rolled Ni47Ti44Nb9 shape memory alloy sheet were studied by XRD,SEM and tensile tester to provide theoretic basis for improving mechanical and memory properties of the alloy.The main textures of hot-rolled sheets are {001} uv0 and {111} uvw fibres.The strong components in {001} uv0 fibre approach to {001} 010 component,and {111} 112 and {111} 165 components are stronger in {111} uvw fibre along RD.The {001} 010 and {111} 132 are the strong components along TD;The critical stress of stress-induced martensite transformation along RD is the maximum and the minimum is along 45° to RD for hot-rolled sheet heat-treated at temperature higher than the recrystallization temperature,and some micro-cracks appear on the fracture surface of the specimen tensioned along TD.The critical stress decreases with increasing the cooling rate at 850 ℃,and texture has no obvious influence on the recoverable strain whose values are basically in the range of 7.0%-7.4% for sheet annealed at 850 ℃.

关 键 词：Ni47Ti44Nb9形状记忆合金 织构 拉伸性能 恢复应变 断裂 

分 类 号：TG146.4[一般工业技术—材料科学与工程] TG139.6[金属学及工艺—金属材料]