Ni47Ti44Nb9形状记忆合金冷轧管材的组织、织构和相变  

MICROSTRUCTURE,TEXTURE AND PHASE TRANSFORMATION OF Ni_(47)Ti_(44)Nb_9 SHAPE MEMORY ALLOY COLD-ROLLED TUBE

作　　者：颜莹[1] 金伟[2] 曹名洲[2] 

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：《金属学报》2008年第2期139-144,共6页Acta Metallurgica Sinica

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：利用OM、DSC和XRD,研究了Ni_(47)Ti_(44)Nb_9合金热锻棒、热挤压管材和不同热处理条件下冷轧管材的组织、织构和相变.结果表明:热锻棒中的B2相呈较宽的纤维状,主要织构接近{112}〈111〉和{123}〈111〉;热挤压管材纤维组织变细且发生碎化,多数晶粒的取向靠近{111}〈UVW〉;冷轧管材的B2相纤维组织发生严重碎化,抑制了冷却过程中马氏体相变的进行,{111}〈110〉和{112}〈110〉成为主要织构.随淬火温度的升高,冷轧管材硬度下降,M_s和A_s点升高,热滞减小.冷轧管材经600℃/90 min退火,{111}〈110〉和{112}〈110〉织构显著增强,经850℃退火,再结晶晶粒明显长大,M_s点显著提高,热滞和硬度下降,晶粒取向偏离{111}〈110〉和{112}〈110〉.The microstructures, textures and phase transformations in forged bar, hot-extruded tube, and cold-rolled tubes at different heat-treated conditions of Ni47Ti44Nb9 alloy were investigated by OM, DSC and XRD. The results show that B2 phase in the forged rod has broad fibred shape, and main textures are close to {112} 〈111〉 and {123} 〈111〉; Fibred microstructure in the hot-extruded tube is refined, and the orientations of many grains are close to {111} 〈UVW〉; B2 phase fibres in the cold-rolled tube have been heavily broken, which restrains martensitic phase transformation during cooling, and {111}〈110〉 and {112} 〈110〉 become the major textures. With the increase of quenching temperature, hardness of the cold-rolled tube decreases, Ms and As points increase, thermal hysteresis drops. The above textures in the cold-tube annealed at 600 23 for 90 min markedly enhance. When the annealing temperature is 850 23, the recrystallized grains in the cold-rolled tube obviously grow, Ms point markedly increases, thermal hysteresis and hardness decrease, the main textures depart from {111} 〈110） and {112} 〈110）.

关 键 词：Ni47Ti44Nb9形状记忆合金 冷轧管 组织 织构 相变 

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]