时效Ti_(49)Ni_(51)合金的显微组织与双程形状记忆效应

Microstructure and two way shape memory effect of agedTi_(49)Ni_(51) alloy

采用弯曲试验和透射电镜分析研究了时效Ti4 9Ni51合金的显微组织与双程形状记忆效应 .结果表明 ,5 0 0℃ ,1h时效处理试样中Ti3Ni4 相呈透镜片状 ,周围有较强的应变场衬度 ,而 5 0 0℃ ,30h时效试样中 ,Ti3Ni4 相已聚集长大成粗片状 ,与基体失去共格 .5 0 0℃ ,1h时效处理试样在训练后可获得较好的双程形状记忆效应 .时效Ti4 9Ni51合金中Ti3Ni4 相粒子周围的共格应变场和训练时位错交互作用可以产生有效内应力场 ,从而诱发双程形状记忆效应 .

Presents the systematic investigation of the microstructure and two way shape memory effect of aged Ti 49 Ni 51 alloy by means of bending test and transmission electron microscopy (TEM), discusses the experimental results that the lenticular like Ti 3Ni 4 phase precipitate when Ti 49 Ni 51 alloy is aged at 500 ℃ for 1 h and there is a strong strain contrast around Ti 3Ni 4 precipitates; Upon aging at 500 ℃ for 30 h, Ti 3Ni 4 precipitates grow to coarse plates and their coherence with the matrix gradually disappears; after thermal cycling training, the Ti 49 Ni 51 alloy exhibits excellent two way shape memory effect for specimens aged at 500 ℃ for 1 h, concludes that the strain contrast around Ti 3Ni 4 precipitates interacts with dislocations induced during training generate the effective internal stress for TWSME.