High-strength materials containing dispersed Ti 3 Ni 4 particles (d ~ 800 nm) and exhibiting superelasticity (SE) in a wide temperature range from 200 to 450 K were designed by aging at 823 K, 1 h of nickel-rich [001]-oriented Ti–51.8 at.% Ni single crystals. The influence of the stress-assisted austenite aging in different regimes (temperature, applied stress, and time) on the stability of the shape memory effect (SME) and SE is studied. It is shown that the single crystals are stable to stress-assisted austenite aging in the entire SE temperature range at T < 523 K under a stress of 0.8σ cr . An increase in the temperature to 523–573 K for stress-assisted (1400 MPa) and stress-free aging time 1–10 h leads to precipitation of nanosized Ti 3 Ni 4 particles and changes the SE and SME evolution. The largest effect of increase in the M s temperature by 22–27 K during SME, decrease in the critical stress σ cr during SE (by 10–34%), and increase in the deformation hardening coefficient θ = dσ/dε and the coefficient of critical stress growth with temperature α = dσ/dT was observed after aging at 573 K for 10 h (0 and 1400 MPa).

中文翻译：

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高温和高应力辅助奥氏体时效对高强度 Ti – 51.8 ат.% Ni 单晶马氏体转变的影响

含有分散的 Ti 3 Ni 4 颗粒（d ~ 800 nm）并在 200 至 450 K 的宽温度范围内表现出超弹性（SE）的高强度材料是通过在 823 K、1 小时的富镍时效设计的 [001]取向 Ti–51.8 at.% Ni 单晶。研究了不同状态（温度、施加应力和时间）下应力辅助奥氏体时效对形状记忆效应 (SME) 和 SE 稳定性的影响。结果表明，在 0.8σ cr 应力下，在 T < 523 K 的整个 SE 温度范围内，单晶对应力辅助奥氏体时效是稳定的。在应力辅助 (1400 MPa) 和无应力时效时间 1-10 小时，温度增加到 523-573 K 会导致纳米尺寸的 Ti 3 Ni 4 颗粒沉淀并改变 SE 和 SME 演变。