ABSTRACT

High-temperature shape memory alloys (HTSMAs) show enormous potential for applications as energy conversion devices, actuators and sensors in automotive, aerospace, and energy exploration industries, but they suffer from strength decrease and microstructural instability at elevated temperatures, rendering it difficult to achieve satisfactory high-temperature superelasticity. Here, a novel Ti₂₀Hf₁₅Zr₁₅Cu₂₅Ni₂₅ high-entropy HTSMA exhibiting large superelasticity with a fully recoverable strain of 4.0% at temperatures up to 285°C is designed with the high-entropy alloy concept by employing the sluggish diffusion and severe lattice distortion effects to suppress thermal softening. This work illuminates the design of novel high-performance functional materials for high-temperature applications.

摘要

高温形状记忆合金（HTSMAs）在汽车，航空航天和能源勘探行业中作为能量转换设备，致动器和传感器具有巨大的应用潜力，但它们在高温下会出现强度降低和微结构不稳定性的问题，难以实现令人满意的高温超弹性。在这里，一种新型的Ti ₂₀ Hf ₁₅ Zr ₁₅ Cu ₂₅ Ni ₂₅采用低熵扩散和严重的晶格畸变效应来抑制热软化，采用高熵合金概念设计了在高达285°C的温度下具有4.0％的完全可恢复应变的超弹性HTSMA。这项工作阐明了用于高温应用的新型高性能功能材料的设计。