利用光学显微镜、DSC差热分析仪和X-射线衍射仪，研究了Ni47Ti44Nb9合金锻棒、热挤压管和不同条件下冷轧管材的组织、织构和相转变，以便为该合金冷轧管材在工程上的应用提供理论依据。结果表明：锻棒中的B2相呈较宽的纤维状，主要的织构组分接近{112}〈111〉和{110}〈111〉；热挤压管纤维组织变细且发生碎化，多数晶粒的{111}取向接近管材的轴向；冷轧管相组成为B2、 β-Nb和(Ti,Nb)4Ni2O，纤维组织发生严重碎化，抑制了马氏体相变的进行， {111}〈110〉和{112}〈110〉成为主要的织构组分。随热处理温度升高，冷轧管硬度下降，相转变温度区间变窄，转变峰升高，主要织构{111}〈110〉和{112}〈110〉显著增强。当温度达到850℃，再结晶晶粒明显长大，热滞和硬度显著下降，织构组分偏离{111}〈110〉和{112}〈110〉，这对于希望在管材的径向方向 具有高的力学性能和恢复应变是不利的。
The microstructure, texture and phase transformation of forged bar, hot-extruded tube and cold-rolled tubes at different conditions of Ni47Ti44Nb9 alloy were investigated in terms by optical microscope，DSC and X-ray technique，in order to provide theoretical data for application of cold-rolled tubes in engineering. The results show that B2 phase presents broad fibred shape in the forged rod, and major textures are close to {112}〈111〉and {110}〈111〉; Fibred microstructure in hot-extruded tube becomes fine and fibres have broken, at the same time, {111} orientation of many grains is close to axis direction of tube; Microstructure in cold-rolled tube consists of B2,β -Nb and (Ti,Nb)4Ni2O phases, fibres has heavily broken, which restrains phase transformation during cooling and heating. And {111}<110〉and {112}〈110〉become the major texture components; As the result of the increase of heat treatment temperature, hardness decreases, temperature interval of phase transformation becomes narrow, transformation peak rises, the primary {111}〈110〉and {112}〈110〉textures markedly enhance. Recrystallization grains have grown at 850℃, thermal hysteresis and hardness obviously drop. The primary texture components depart from {111}〈110〉and {112}〈110〉.These are disadvantageous to expect to obtain greater mechanical properties and restoration strain along radial direction of tube.
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