Shape recovery in high temperature shape memory alloys based on the Ru-Nb and Ru-Ta systems
Shape recovery in high temperature shape memory alloys based on the Ru-Nb and Ru-Ta systems
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基于 Ru-Nb 和 Ru-Ta 系统的高温形状记忆合金的形状恢复
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
R. Portier
中科院分区：
文献类型：
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作者：
A. Manzoni;K. Chastaing;A. Denquin;P. Vermaut;R. Portier
本文研究了三种RuTa合金和三种RuNb合金的高温行为。第一步是确定Ta或Nb含量如何影响MT温度。单斜相Ru50Ta50和Ru50Nb50合金在高温相场中经历了两次连续的位移转变：(B2)∆∂（四方）∆∂∂（单斜），而Ru45 Nb55、Ru45Ta55、Ru43Nb57和Ru43Ta57在冷却时表现出从立方到四方的单一转变。所有合金均表现出高度孪晶的（011）复合孪晶模式。∂∆∂∂变换的主要特征是形成分离平移变量的域边界，而不是形成新的孪生分离方向变量。通过在“∂or∂”阶段进行的压缩测试来研究形状记忆效应。根据马氏体晶格参数的演变，总形状恢复主要是由于“∂∆”转变，从单斜合金的约3%下降到43% Ru合金的约0.1%。
This work investigates the high-temperature behaviour of three RuTa alloys and three RuNb alloys. The first step was to determine how Ta or Nb content affects the MT temperatures. The monoclinic Ru50Ta50 and Ru50Nb50 alloys undergo two successive displacive transformations from the high temperature �� phase field: �� (B2) ∆ �� ∂ (tetragonal) ∆ �� ∂∂ (monoclinic) whereas Ru45 Nb55 , Ru45Ta55 , Ru43Nb57 , and Ru43Ta57 exhibit a single transition from cubic to tetragonal on cooling. All alloys exhibit a highly twinned microstructure with a (011) compound twinning mode. The main feature of the �� ∂ ∆ �� ∂∂ transformation is the formation of domains boundaries separating translation variants instead of formation of new twin separating orientation variants. The shape memory effect was studied through compression tests performed in the �� ∂ or �� ∂∂ phase. The total shape recovery is mainly due to the �� ∂ ∆ �� transformation and appears to decrease from about 3% for the monoclinic alloys to about 0.1% for alloys with 43% Ru in accordance with the evolution of the lattice parameters of martensites.