α+β钛合金不同条件下力学行为和微观组织研究

Research on Mechanical Behavior and Microstructure ofα+βTitanium Alloy under Different Conditions

采用配置环境温箱的万能材料试验机、扫描电子显微镜,研究α+β钛合金在不同温度和应变率条件下的力学行为和微观组织。研究结果表明,α+β钛合金在热轧状态下的显微组织表现出明显的双态组织特点。初生αp相的体积分数和等效直径与温度和应变率成正相关。次生αs相的长宽比与温度和应变率成负相关。在所有温度和应变率条件下,α+β钛合金均表现出负应变率敏感性和负温度敏感性。α+β钛合金均发生断裂,总体呈现韧脆混合的断裂机制。

The mechanical behavior and microstructure ofα+βtitanium alloy at different temperatures and strain rates were studied by means of a universal material testing machine equipped with an ambient temperature chamber and a scanning electron microscope.The result shows that the microstructure ofα+βtitanium alloy exhibits obvious bimodal characteristic in the hot-rolled state.The volume fraction and equivalent diameter of the primaryαp phase are positively correlated with temperature and strain rate.The aspect ratio of the secondaryα,phase is negatively correlated with temperature and strain rate.Under all the temperature and strain rate conditions,α+βtitanium alloy exhibits negative strain rate sensitivity and negative temperature sensitivity.α+βtitanium alloy undergoes fracture,and exhibits an overall ductile brittle hybrid fracture mechanism.