热循环温度对Ti-6Al-4V合金组织和力学性能的影响

Influence of thermal cycling temperature on microstructure and mechanical properties of Ti-6Al-4V alloy

对上限温度为500、650、800℃高温短时热循环200次后的Ti-6Al-4V合金室温力学性能和组织进行了研究。结果表明:循环温度对合金强度影响较为明显,循环温度的升高使合金抗拉强度降低;分析认为:温度高于650℃,实验合金组织中β相逐渐分解碎化,β相含量减少和α晶粒逐渐长大是强度降低的主要原因。

Microstructure and tensile properties of Ti-6A1-4V alloy after thermal cycling in the temperature range of room temperature to 500 ℃ , 650 ℃ and 800 cC were studied. The results show that with increasing of thermal cycling temperature, tensile strength of Ti-6A1- 4V alloy decreases, β phase disintegrates and its volume fraction is reduced, and ct grain grows gradually. It is argued that when cycling temperature below 650 ℃ , the disintegration of β phase is responsible for the strength decreasing and when temperature above 650 ℃ , the strength decreasement is ascribed to the decrease of β phase amount and ot grains growth.