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采用快速凝固工艺制取了不同规格的Cu—24.9Zn—4.5A1合金薄带,并通过应力—应变曲线、电阻—温度曲线、光学金相、X射线衍射、扫描电镜和透射电镜等方法研究了该合金的形状记忆性能、组织结构特征及随后热处理对它们的影响。结果表明:合金喷带室温组织是单一的β_1细晶(50μ厚带:～20μ晶粒);经720℃/10’水淬处理后,晶粒长大到100μ左右,室温下为(β_1+M)组织,该状态下可以获得合金最佳的形状记忆性能,且不引起粗晶脆化,在ε≤8％时均能实现完全的形状恢复。加载变形过程中试样表面形成的晶粒和马氏体浮雕所具有的可逆特性,是记忆过程相变本质的反映。
The Cu-24.9Zn-4.5A1 alloy ribbons with different sizes were prepared by rapid solidification. The stress-strain curves, electrical resistance-temperature curves, optical metallography, X-ray diffraction, scanning electron microscopy and transmission electron microscopy The shape memory properties of the alloy, the organizational structure and the subsequent heat treatment on them. The results show that the microstructure of the sprayed zone is single β_1 fine grain (50μ thick zone: ~ 20μ grain) at room temperature. The grain size grows up to 100μ after 720 ℃ / 10 ’ M). Under this condition, the best shape memory property of the alloy can be obtained without causing coarse grain embrittlement, and full shape recovery can be achieved at ε≤8%. The reversible properties of the grains and martensite relief formed on the specimen surface during the loading process are the reflection of the nature of the phase transition in the memory process.