Effect of cold rolling ratio on the microstructure and recovery properties of Ti-Ni-Nb-Co shape memory alloys
Effect of cold rolling ratio on the microstructure and recovery properties of Ti-Ni-Nb-Co shape memory alloys
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DOI：
10.1016/j.jallcom.2018.09.113
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发表时间：
2019-01
影响因子：
6.2
通讯作者：
Bo Cui;Jianmin Yao;Yeqiong Wu;W. Cai
中科院分区：
文献类型：
--
作者：
Bo Cui;Jianmin Yao;Yeqiong Wu;W. Cai
对不同冷轧比的Ti44. 5 Ni 44. 5 Nb 9 Co2合金进行650 °C退火处理，研究冷轧比对合金组织和回复性能的影响。冷轧比的变化显著影响β-Nb相的分布以及位错和析出物的密度。随着冷轧比的增加，位错密度增加，有利于Ti 2Co析出相的优先形核和长大。同时，高密度的位错和析出相阻碍了回复和再结晶过程。由于位错和纳米级析出相的强化作用，40%冷轧Ti44.5Ni44.5Nb9Co2合金在650 °C退火后，与典型的Ti-Ni-Nb合金相比，总回复应变提高了25%，回复应力提高了50%以上。
The Ti44.5Ni44.5Nb9Co2alloys with different cold rolling ratios were annealed at 650 °C to investigate the influence of cold rolling ratio on the microstructure and recovery properties. The change in cold rolling ratio remarkably affected the distribution ofβ-Nb phase and the density of dislocations and precipitates. The density of dislocations increased with the increase of cold rolling ratio, which facilitated preferential nucleation and growth of Ti2Co precipitates. Meanwhile, high density of dislocations and precipitates retarded the recovery and recrystallization process. Owing to the strengthening effect of dislocations and nanoscale precipitates, the 40% cold rolled Ti44.5Ni44.5Nb9Co2alloy annealed at 650 °C after 16% pre-strain exhibited 25% enhancement in the total recovery strain and over 50% improvement for the recovery stress compared to the typical Ti-Ni-Nb alloys.