CAJ | 학술논문

采用 TEM 和拉伸实验研究经300、400和500℃分别时效0.5~100 h 后,时效温度和时效时间对Ti-50.8Ni-0.5V(摩尔分数,%)形状记忆合金室温显微组织和超弹性(SE)的影响.结果表明,时效温度对合金析出相形貌和SE特性的影响比时效时间显著.随时效温度的升高,合金中Ti3Ni4析出物形态由颗粒状向针状再向粗片状演变,合金的应力诱发马氏体相变临界应力(σM)降低,SE特性变差.300℃时效态合金的σM最大,SE最好;500℃时效态合金的σM最小,SE最差.随时效时间的延长,300℃时效态合金的SE特性稳定,σM和超弹性能耗降低;400和500℃时效态合金的超弹性残余应变增加,SE特性逐渐消失.
채용 TEM 화랍신실험연구경300、400화500℃분별시효0.5~100 h 후,시효온도화시효시간대Ti-50.8Ni-0.5V(마이분수,%)형상기억합금실온현미조직화초탄성(SE)적영향.결과표명,시효온도대합금석출상형모화SE특성적영향비시효시간현저.수시효온도적승고,합금중Ti3Ni4석출물형태유과립상향침상재향조편상연변,합금적응력유발마씨체상변림계응력(σM)강저,SE특성변차.300℃시효태합금적σM최대,SE최호;500℃시효태합금적σM최소,SE최차.수시효시간적연장,300℃시효태합금적SE특성은정,σM화초탄성능모강저;400화500℃시효태합금적초탄성잔여응변증가,SE특성축점소실.
The effects of aging temperature and aging time on the microstructure and superelasticity (SE) at room temperature of Ti-50.8Ni-0.5V (mole fraction, %) shape memory alloy aged at 300, 400 and 500 ℃ for 0.5?100 h, respectively, were investigated by TEM and tensile test. The results show that the effects of aging temperature on the precipitate morphology and SE property are more outstanding than those of aging time. With increasing aging temperature, the morphology of Ti3Ni4 precipitates in the alloy changes from the fine particle-shape to the needle-shape and then to the plate-shape?the critical stress for inducing martensitic transformation (σM) decreases?and the SE property becomes poor. TheσM is the largest and the SE property is the best for the alloy aged at 300℃, and theσM is the smallest and the SE property is the worst for the alloy aged at 500℃. With increasing aging time, the SE property is stable, theσM and the superelasticity energy dissipation decrease for the alloy aged at 300℃?the residual strain of the superelasticity increases and SE property disappears gradually for the alloy aged at 400 and 500℃.