Enhancement of Shape Memory Properties through Precipitation Hardening in a Ti-Rich Ti-Ni-Pd High Temperature Shape Memory Alloy
Enhancement of Shape Memory Properties through Precipitation Hardening in a Ti-Rich Ti-Ni-Pd High Temperature Shape Memory Alloy
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DOI：
10.2320/matertrans.mb201516
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发表时间：
2016-03
影响因子：
1.2
通讯作者：
Yuki Namigata;Y. Hattori;M. Khan;H. Y. Kim;S. Miyazaki
中科院分区：
文献类型：
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作者：
Yuki Namigata;Y. Hattori;M. Khan;H. Y. Kim;S. Miyazaki
研究了时效对Ti50Ni20Pd30和Ti52Ni18Pd30合金马氏体转变温度、显微组织和形状记忆特性的影响。对于 Ti50Ni20Pd30 合金，无论时效温度如何，时效后的显微组织和转变温度没有显着变化。另一方面，Ti52Ni18Pd30合金在673-1073K的时效温度范围内时效时形成细小的Ti2Pd型析出物。 Ti52Ni18Pd30 合金的转变温度敏感地依赖于时效温度。人们发现Ti2Pd型纳米级沉淀物对于增强形状记忆循环过程中的高温尺寸稳定性非常有效。 Ti52Ni18Pd30 合金在 673 和 773K 的较低温度固溶处理和时效后，由于形成细小致密的 Ti2Pd 型析出物，观察到优异的形状记忆性能，即使在 500MPa 下也具有较大的恢复应变和较小的塑性应变。 [doi:10.2320/matertrans.MB201516]
Effects of aging on martensitic transformation temperature, microstructure and shape memory characteristics were investigated for Ti50Ni20Pd30 and Ti52Ni18Pd30 alloys. There was no significant change in the microstructure and transformation temperature by aging, irrespective of aging temperature, in case of the Ti50Ni20Pd30 alloy. On the other hand, fine Ti2Pd type precipitates were formed upon aging in the Ti52Ni18Pd30 alloy within the aging temperature range of 673-1073K. The transformation temperature of the Ti52Ni18Pd30 alloy was sensitively dependent on the aging temperature. The Ti2Pd type nanoscaled precipitates were found to be very effective in enhancing the high temperature dimensional stability during shape memory cycling. Excellent shape memory properties with a large recovery strain and a small plastic strain even at 500MPa were observed in the Ti52Ni18Pd30 alloy solution treated and aged at lower temperatures of 673 and 773K owing to the formation of fine and dense Ti2Pd type precipitates. [doi:10.2320/matertrans.MB201516]