( 1. 石油大學(xué) 材料科學(xué)與工程系, 北京102249;
2. 北京航空航天大學(xué) 材料科學(xué)與工程系, 北京100083)
摘 要: 研究了TiNi二元與TiNiCu三元形狀記憶合金的回復(fù)力特征, 并通過(guò)示差掃描量熱分析研究了合金的熱彈性馬氏體相變特征。 結(jié)果表明: 二元與三元合金在一定溫度范圍內(nèi)的最大回復(fù)力隨著預(yù)應(yīng)變的增大而升高, 但是當(dāng)預(yù)應(yīng)變達(dá)到或超過(guò)其最大可恢復(fù)變形極限時(shí)最大回復(fù)力反而減小。 對(duì)于TiNi合金, 回復(fù)力隨溫度增長(zhǎng)的速率隨著預(yù)應(yīng)變的增加而增加, 而TiNiCu合金的回復(fù)力隨溫度增長(zhǎng)的速率隨著預(yù)應(yīng)變的增加而減小。 通過(guò)對(duì)克勞修斯-克拉珀龍方程進(jìn)行修正, 分析了回復(fù)力和相變之間的關(guān)系。 結(jié)果表明： TiNi二元合金的冷變形應(yīng)變?cè)酱? 相變溫度區(qū)間越小, 其回復(fù)力隨溫度增長(zhǎng)的速率就越大； TiNi三元合金的冷變形越大, 相變溫度區(qū)間越大, 其回復(fù)力隨溫度增長(zhǎng)的速率就越小。
關(guān)鍵字: 形狀記憶合金； TiNi； TiNiCu； 回復(fù)力； 熱彈性馬氏體相變
（ 1. Department of Materials Science and Engineering, University of Petroleum, Beijing 102249, China;
2. Department of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China）
Abstract: The recovery stress characteristics of TiNi binary and TiNiCu ternary shape memory alloys were studied. Both the maximum recovery stresses of TiNi and TiNiCu alloys increase with increasing prestrain level. The recovery stress rate (dσ/dT) of the TiNi alloy increases with increasing prestrain level, but that of the TiNiCu alloy decreases with increasing prestrain level. By comparing the results of differential scanning calorimetry, analysis based on the modified Clausius-Clapeyron equation shows that the recovery stress characteristics have a close relation to the thermoelastic martensitic transformation characteristics. For TiNi binary alloys, the transformation temperature interval decreases with increasing prestrain level, resulting in the increase of the recovery stress rate. For TiNiCu ternary alloy, the transformation temperature interval increases with increasing prestrain level, resulting in the decrease of the recovery stress rate.
Key words: shape memory alloys； TiNi； TiNiCu； recovery stress； thermoelastic martensitic transformation
