Microstructure and superelasticity control by rolling and heat treatment in columnar-grained Cu-Al-Mn shape memory alloy-猫眼课题宝

柱状晶Cu-Al-Mn形状记忆合金轧制和热处理的显微组织和超弹性控制

DOI：

10.1016/j.msea.2017.04.085

发表时间：

2017-06

期刊：

Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing

影响因子：

6.4

通讯作者：

中科院分区：

材料科学1区

文献类型：

作者：

Ji-Li Liu;Zhi Hong Chen;Hai You Huang;Jian-xin Xie

研究了轧制和热处理工艺对柱状晶Cu 71 Al 18 Mn 11形状记忆合金显微组织和超弹性的影响。采用了两种不同的轧制策略：（i）多道次高温轧制（HR）;（ii）单道次HR后多道次冷轧（HR+nCR）。结果表明，对于第一种轧制策略，在800 °C下进行单道次HR，压下量大于80%时，仍能保留柱状晶组织，且随着HR次数的增加，会发生再结晶。通过800 °C退火控制组织，多道次HR试样的超弹性应变可达5.9%。对于第二轧制策略，在具有80%压下量的第一道次HR和在550 °C下退火之后，可以在室温下以50- 70%的总压下量对合金进行冷轧。冷轧后的合金组织仍为柱状晶组织，由β1+α两相组成。再结晶退火后，HR+nCR合金倾向于<011>沿轧制方向形成沿着织构，有利于获得高的超弹性。最后，采用晶粒长大热处理进一步提高冷轧合金的超弹性。经过2-3次晶粒异常长大热处理后，合金的晶粒直径可由几百微米长大到1厘米以上，沿轧制方向仍具有较强<011>的沿着织构，使合金的超弹性应变高达7%左右。

The effects of rolling and heat treatment on the microstructure and superelasticity of columnar-grained Cu71Al18Mn11shape memory alloy were investigated in this paper. Two different rolling strategies were adopted: (i) multipass high-temperature rolling (HR); (ii) one-pass HR followed by several-pass cold rolling (HR+nCR). For the first rolling strategy, the results showed that columnar-grained microstructure was reserved after one-pass HR at 800 °C with rolling reduction of above 80%, and recrystallization would occur if more HR processes were applied. The superelastic strain could reach 5.9% in multipass HR sample through microstructure control by annealing at 800 °C. For the second rolling strategy, after the first pass HR with the reduction of 80% and annealing at 550 °C, the alloy could be cold rolled at room temperature with total reduction of 50–70%. The columnar-grained microstructure still existed in the cold-rolled alloy which consisted of two phases (i.e. β1+α). After recrystallization annealing, the HR+nCR alloy tend to form <011> texture along the rolling direction, which was helpful to obtain high superelasticity. Finally, the grain growth heat treatment was used to further improve the superelasticity of the cold-rolled alloy. After 2–3 times abnormal grain growth heat treatment, the grains of the alloy could grow up from several hundred micrometers to more than one centimeter in diameter; they still had strong <011> texture along the rolling direction, which enabled the superelastic strain of as high as about 7%.