Stress-induced martensitic transformation of Cu50Zr50 shape memory alloy optimized through microalloying and co-microalloying
Stress-induced martensitic transformation of Cu50Zr50 shape memory alloy optimized through microalloying and co-microalloying
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DOI：
10.1016/j.jallcom.2018.12.099
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发表时间：
2019-04
影响因子：
6.2
通讯作者：
F. D. Luca;P. Nnamchi;A. Younes;A. T. Fry;S. González
中科院分区：
文献类型：
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作者：
F. D. Luca;P. Nnamchi;A. Younes;A. T. Fry;S. González
研究了Cu 50 Zr 50 at. %的形状记忆合金，通过微合金化和共微合金化对形状记忆合金进行了调整。微合金化元素Co或Ni单独或组合（即，Co-微合金化）进行了研究，并在宏观和纳米尺度上进行了比较。从纳米压痕实验，（P/h）-h曲线的斜率的变化，塑性指数和恢复率退火后进行了研究：部分取代Cu的1at。%的Ni促进孪晶形成，而1at. % Co时，孪晶倾向降低，采用0.5at. %的Co和Ni具有中间效果。Cu 50 Zr 50合金在400 ℃退火5 min后，由400 ℃退火5 min后的残余晶界的体积变化计算的回复率，在Cu替代1at. %的Ni。这些结果，在纳米尺度上得到的，是在协议与宏观尺度的测试观察，即差示扫描量热法和X-射线衍射。因此，微合金化为开发更具成本效益的CuZr合金开辟了可能性，以期在不久的将来开发可取代昂贵的NiTi合金的商业致动器。
The stress-induced martensitic transformation of Cu50Zr50at. % shape memory alloy was tuned through microalloying and co-microalloying. The effect of microalloying elements Co or Ni individually or combined (i.e., co-microalloying) was investigated and compared at the macro- and nanoscale. From nanoindentation experiments, change in the slopes of (P/h)-h curves, plastic index and recovery ratio after annealing were investigated: partial replacement of Cu by 1 at. % Ni was observed to promote twinning while for 1 at. % Co the twinning propensity decreased and co-microalloying using 0.5 at. % Co and Ni had an intermediate effect. The recovery ratio of the Cu50Zr50alloy, calculated from the volume change of a residual indent after annealing at 400 °C for 5 min after annealing at 400 °C for 5 min increased from 15.6% to 19.5% when substituting Cu by 1 at. % Ni. These results, obtained at the nanoscale, are in agreement with macroscale test observation, namely, differential scanning calorimetry and x-ray diffraction. Therefore, microalloying opens up possibilities for the development of more cost-effective CuZr alloys, with a view to develop commercial actuators that could replace costly NiTi alloys in the near future.