(1. 陜西理工學院 材料科學與工程學院，漢中 723003；
2. 陜西理工學院 圖書館，漢中 723003)
摘 要: 用示差掃描熱分析儀、光學顯微鏡、X射線衍射儀和拉伸實驗研究退火態(tài)Ti-50.8Ni-0.5V(摩爾分數(shù)，%)形狀記憶合金的相變行為、顯微組織和循環(huán)形變特性。結果表明：400、500和600 ℃退火態(tài)合金的相變類型分別為A→R/R→A、A→R→M/M→R→A和A→M/M→A(A—母相B2，R—R相，M—馬氏體)，合金的室溫組成相為B2和R相。400、500和600 ℃退火態(tài)合金的顯微組織形態(tài)分別呈纖維狀、纖維狀和等軸狀。Ti-50.8Ni-0.5V合金在室溫下呈超彈性特性，600 ℃退火態(tài)合金的應力誘發(fā)M臨界應力(σM)高于400和500 ℃退火態(tài)合金的。400 ℃退火態(tài)合金的應力—應變的循環(huán)特性穩(wěn)定，超彈性特性優(yōu)異，經一次循環(huán)后合金即可呈現(xiàn)完全非線性超彈性；500和600 ℃退火態(tài)合金的應力—應變的循環(huán)穩(wěn)定性較差。隨循環(huán)次數(shù)增加，合金的σM降低，循環(huán)耗能減小。隨循環(huán)應變量增大，合金的循環(huán)耗能增加，而循環(huán)穩(wěn)定性有所降低。
關鍵字: Ti-Ni-V合金；形狀記憶合金；循環(huán)形變；超彈性
（1. School of Materials Science and Engineering, Shaanxi University of Technology, Hanzhong 723003, China;
2. Library, Shaanxi University of Technology, Hanzhong 723003, China）
Abstract:The transformation behavior, microstructure and cyclic deformation characteristics of annealing Ti-50.8Ni-0.5V (mole fraction, %) alloy were investigated by differential scanning calorimetry, optical microscopy, XRD and tensile test. The results show that the transformation types of the 400, 500 and 600 ℃ annealed alloys are A→R/R→A, A→R→M/M→R→A and A→M/M→A (A—parent phase, R—rhombohedral phase, M—martensite phase) upon cooling/heating, respectively. The constituent phases of the alloy at room temperature are B2 and R phases. The microstructure morphology of the 400, 500 and 600 ℃ annealed alloys are fibrous, fibrous and equiaxed, respectively. Ti-50.8Ni-0.5V alloy shows superelasticity at room temperature. The critical stress for inducing martensitic transformation (σM) of the 600 ℃ annealed alloy is higher than those of the 400 and 500 ℃ annealed alloys. The stress—strain cycling characteristics of the 400 ℃ annealed alloy is stable, the superelasticity is excellent, and the alloy shows completely nonlinear superelasticity after one stress—strain cycle. The stress—strain cycling stability of the 500 and 600 ℃ annealed alloys are poor. With increasing cyclic number, the σM and the cyclic energy dissipation of the alloy decrease. With increasing cyclic strain, the cyclic energy dissipation increases, while the cyclic stability decreases in the alloy.
Key words: Ti-Ni-V alloy; shape memory alloy; cyclic deformation; superelasticity
