Ti-2.5Cu合金应力时效析出行为及其力学性能研究

Precipitation Behavior and Tensile Properties of Stress-Aged Ti-2.5Cu Alloy

摘要:

对固溶处理后的Ti-2.5Cu合金施加大约200 MPa弹性压应力，同时进行时效处理。TEM观察结果表明：Ti-2.5Cu合金时效处理析出了片状的Ti2Cu强化相粒子；在未施加压应力常规时效的试样中出现了3种Ti2Cu片的变体；而在应力时效处理后的试样里，一些晶粒中只出现2种或1种Ti2Cu片的变体，即弹性应力导致了时效析出Ti2Cu粒子的变体选择效应。拉伸试验结果表明，时效析出相变体选择效应导致了合金材料的强度降低和延伸率升高。

Abstract:

Solution treated Ti-2.5Cu alloy was aged under a compressive stress of ~200 MPa. TEM investigations show that three variants of precipitated Ti2Cu plates are observed in conventionally aged samples without compressive stress. However, in the stress-aged samples, for most grains, one or two variants of Ti2Cu plates could be observed, which indicate the variant selection effect of precipitated Ti2Cu plates resulting from external compressive elastic stress. Lower yield strength and higher elongation is observed during subsequent tensile tests due to the variant selection effect.