热循环对预应变NiTi记忆合金丝/铝基复合材料马氏体逆相变的影响

The Effect of Thermal Cycling on the Reverse Martensitic Transformation of Prestrained TiNi Alloy Fibers/Al Matrix Composite

采用热压法将 0 .2 6 mm的 Ni Ti合金丝复合于铝中 ,利用 SEM,DSC,热膨胀仪等实验手段研究了热循环对预应变为 4%的 Ni Ti合金丝 /铝基复合材料马氏体逆相变的影响。结果表明 :在第一次加热过程中 ,马氏体逆转变开始温度明显升高 ;第二次加热过程中逆转变开始温度比未预应变样品略有降低 ,随热循环次数增加 ,逆相变开始温度降低 ;当循环次数超过 30次后 ,逆转变温度几乎保持不变。

TiNi SMA fibers with 0 28mm in diameter were embedded in aluminum matrix by hot pressing method Scanning electron microscope (SEM), differential scanning calorimeter (DSC) and electric resistance strain gauge were used to study the effect of thermal cycling on the reverse martensitic transformation of TiNi alloy fibers/Al composite after 4% prestrain The results showed that, the reverse transformation temperatures increases obviously in the first heating process In the second heating process, the reverse transformation temperatures decreases, and are almost the same as that of the un prestrained specimen In further thermal cycling process, the reverse temperatures decreases a little and keeps constant after 30 thermal cycling The matensitic transformation behavior during thermal cycling was discussed