高温氧化对钛合金超塑性能的影响

Influence of High Temperature Oxidation on the Superplastic Ability of Ti-6Al-4V Alloy

研究了Ti-6Al-4V合金在800℃、850℃和900℃高温条件下进行拉伸试验时空气氧化对超塑性能的影响。通过光学显微镜、扫描电镜和X射线衍射分析了该钛合金氧化层的微观形貌和成分组成,并研究其在高温拉伸下的氧化机理。结果表明,高温氧化导致该合金在高温拉伸过程中表面产生氧化层,而在拉伸应力作用下氧化层断裂并向基体扩展,从而严重降低了Ti-6Al-4V合金的超塑性,但不会影响其抗拉强度及屈服强度。

The influence of oxidation on the superplastic ability of Ti-6Al-4V alloy was investigated by performing elevated temperature uniaxial tensile tests at 800℃, 850℃ and 900℃. The mass gain was measured and the oxidation kinetics curves were determined. Optical microscope, SEM and XRD were used to study the microstructure, composition and morphology of the oxidized layer. It is showed that high temperature oxidation at the surface of the alloy can induce cracks and degrade the ductility of Ti-6Al-4V alloy, but has little effect on its tensile strength and yield strength.