的相變特性
(陜西理工學(xué)院 材料科學(xué)與工程學(xué)院，漢中 723003)
摘 要: 用示差掃描量熱儀研究了退火溫度、退火時(shí)間和時(shí)效溫度、時(shí)效時(shí)間對(duì)Ti-50.2Ni(摩爾分?jǐn)?shù))形狀記憶合金絲相變特性的影響，給出了退火、時(shí)效工藝對(duì)該合金R、M相變溫度和熱滯的影響規(guī)律。結(jié)果表明：350~550℃退火態(tài)合金冷卻/加熱相變類型為A→R→M/M→A(A－母相，R－R相，M－馬氏體)，600~800 ℃退火態(tài)為A→M/M→A，400 ℃長時(shí)間退火態(tài)相變類型為A→R→M/M→R→A；隨時(shí)效時(shí)間延長，300 ℃時(shí)效態(tài)合金的相變類型經(jīng)過A→M/M→A到A→R→M/M→A再到A→R→M/M→R→A的轉(zhuǎn)變，400 ℃時(shí)效態(tài)相變類型經(jīng)過A→M/M→A到A→R→M/M→A的轉(zhuǎn)變，500 ℃時(shí)效態(tài)相變類型則保持A→M/M→A不變。
關(guān)鍵字: Ti-50.2Ni合金; 形狀記憶合金; 相變溫度; 熱滯
Ti-50.2Ni shape memory alloy
heat-treated in different processes
（School of Materials Science and Engineering, Shaanxi
University of Technology,Hanzhong 723003, China）
Abstract:The effects of annealing temperature, annealing time, aging temperature, and aging time on the transformation characteristics of Ti-50.2Ni (atomic percentage) shape memory alloy wire were investigated by differential scanning calorimetry. The effect regularity of annealing and aging processes on the R, M transformation temperature and temperature hysteresis were given out. The results show that the cooling / heating transformation type of 350−550 ℃ annealed Ti-50.2Ni alloy is A→R→M/M→A (A is parent phase, R is R phase, M is martensite ), that of 600−800 ℃ annealed alloy is A→M/M→A, and that of the alloy annealed at 400 ℃ for long time is A→R→M/M→R→A. With increasing aging time, the transformation type of 300 ℃ aged alloy changes from A→M/M→A then A→R→M/M→A to A→R→M/M→R→A, the one of 400 ℃ aged alloy changes from A→M/M→A to A→R→M/M→A, and the one of 500 ℃ aged alloy keeps as A→M/M→A.
Key words: Ti-50.2Ni alloy; shape memory alloy; transformation temperature; temperature hysteresis
