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近年来,新型钛基无镍合金以其良好的生物相容性、耐腐蚀性、低弹性模量、高相变温度等特性成为了形状记忆合金领域的研究重点。采用X射线衍射(XRD)、金相光学显微镜(OM)、透射电镜(TEM)、差示扫描量热分析(DSC)、压缩应力-应变实验等方法系统研究了TixZr100-x(x=20,30,50,70,80)合金的微观组织结构、相变特性、力学性能及形状记忆效应。结果表明:二元钛锆合金是一种典型的高温形状记忆合金,室温下为具有孪晶结构的单一hcp-α’马氏体相,晶格常数和晶胞体积都会随Zr原子含量增加而增大;合金具有从β母相到hcp-α’马氏体的可逆相变,相变温度随Zr原子含量增加先降低后增大,在Zr含量50%附近,马氏体相变开始温度最低,约为520℃;合金的屈服强度随Zr原子含量增加而增大,在Zr含量50%附近达到最大值(955 MPa),然后随Zr含量增加而下降;不同成分合金均具有形状记忆效应,其中Ti70Zr30合金的记忆效应最大,为1.7%。
In recent years, the new titanium-based nickel-free alloy has become a research focus in the field of shape memory alloys due to its good biocompatibility, corrosion resistance, low elastic modulus and high phase transition temperature. X-ray diffraction (XRD), optical microscope (OM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and compressive stress- 30,50,70,80) alloy microstructure, phase transition characteristics, mechanical properties and shape memory effect. The results show that the binary titanium-zirconium alloy is a typical high-temperature shape memory alloy with a single hcp-α ’martensite phase with twin structure at room temperature. The lattice constants and unit cell volume increase with increasing Zr content The phase transition temperature decreases first and then increases with the increase of Zr atom content. When the Zr content is about 50%, the martensite transformation start temperature The minimum is about 520 ℃. The yield strength of the alloy increases with the increase of the Zr atom content, reaches the maximum (955 MPa) around 50% of Zr content, and then decreases with the increase of Zr content. All alloys have shape memory effect , Of which Ti70Zr30 alloy memory effect of the largest, 1.7%.