Stability of a Ni-rich Ni-Ti-Zr high temperature shape memory alloy upon low temperature aging and thermal cycling
Stability of a Ni-rich Ni-Ti-Zr high temperature shape memory alloy upon low temperature aging and thermal cycling
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DOI：
10.1016/j.scriptamat.2016.06.029
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发表时间：
2016-11
影响因子：
6
通讯作者：
A. M. Pérez-Sierra;J. Pons;R. Santamarta;I. Karaman;R. Noebe
中科院分区：
文献类型：
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作者：
A. M. Pérez-Sierra;J. Pons;R. Santamarta;I. Karaman;R. Noebe
研究了Ni50.3Ti29.7Zr20在250 °C下在奥氏体中时效的热稳定性，以获得选定热处理后获得的三种不同的显微组织：无沉淀物和含有两种不同尺寸和密度的H相纳米沉淀物。马氏体相变在时效1-3周后受到抑制，这取决于初始显微结构，这是由于Ti + Zr亚晶格内短程原子重新排序形式的B2相不稳定性，被认为是H相沉淀的前体。热循环导致显着的变化，在转变温度，这强烈地依赖于起始的微观结构。
The thermal stability of Ni50.3Ti29.7Zr20with aging in austenite at 250 °C has been studied for three distinctive microstructures obtained after selected thermal treatments: precipitate free and containing two different sizes and densities of H-phase nanoprecipitates. The martensitic transformation is suppressed after 1–3 weeks aging, depending on the initial microstructure, due to a B2 phase instability in the form of short range atomic reordering within the Ti + Zr sublattice, considered to be precursor to the H-phase precipitation. Thermal cycling leads to notable changes in the transformation temperatures, which strongly depends on the starting microstructure.