铸态Ti-6Al-4V-0.1B合金的热变形行为及加工图

在Gleeble-1500热模拟试验机上进行高温压缩试验,研究了变形温度为1000～1100℃,初始应变速率为0.01～1 s-1的铸态Ti-6Al-4V-0.1B合金的变形行为。基于动态材料模型建立了加工图,并观察了变形组织。结果表明:该合金为热敏感和应力敏感型合金,热变形的最佳变形参数为1050～1100℃,应变速率在0.1～1 s-1之间。铸态大变形区组织为沿着变形方向拉长的原始β晶粒,晶粒组织内部出现针状马氏体,TiB相在变形的过程中出现折断,并沿着加工流线分布。

Hot deformation behavior and processing map of as-cast Ti-6Al-4V-0. 1B alloy

Hot deformation behavior of as-cast Ti-6Al-4V-0.1B alloy was investigated through isothermal compression tests from 1000 ℃ to 1100 ℃ in the strain rate range of 0.01-1 s-1 on a Gleeble-1500 machine.The processing map was established based on dynamic materials model.The results show that the peak flow stress and steady stress are sensitive to the strain rate and temperature.The optimum parameters for deformation temperature and strain rate are determined to be in the range of 1050-1100 ℃ and 0.1-1 s-1,respectively.Microstructural observation shows that prior beta grains are elongated along the deformation direction and needle martensite appears within grains.TiB phase are broken off under the compression stress and distributed along the processing flowing line.