新型近β钛合金Ti-7333的高温不连续屈服行为（英文）

对一种新型近β钛合金Ti-7333在温度为770~845℃,应变速率为10-3~1 s-1条件下的高温不连续屈服行为进行了研究。结果表明:在试验温度范围内,当应变速率大于10-2 s-1时,Ti-7333合金高温变形过程中会出现不连续屈服现象。该合金的不连续屈服幅度随着应变速率的减小和温度的升高而逐渐增大,而且屈服的幅度对应变速率较温度更为敏感。通过对不连续屈服现象的显微组织观察可知,这是由于随着应变的增大,在晶界处生成的可动位错在塑性变形中向晶粒内部扩展传播所导致,晶界是这些可动位错的位错源。不连续屈服现象与位错源局部位错攀移开动传播、晶界迁移以及(或者)合金元素固溶重排过程有关。     

Microstructure and mechanical properties of new metastable β type titanium alloy

A new metastable β type titanium alloy called TB-13 with the combination of excellent strength and ductility was developed successfully.In order to develop a perspective on this new alloy,the influence of several commonly used heat treatments on the microstructure and properties was studied.In solution-treated and quenched samples,a low-temperature aging at 480°C results in the precipitation of finerαphase.The precipitation of coarserαphase plate at higher aging temperature(560°C)leads to the increase of tensile ductility but reduction of strength.During low-temperature aging at 300°C,quite homogeneous distribution of fine isothermalωphase particles was found.The isothermalωphase provides nucleation sites forαphase during two-step aging process and makesαphase extremely fine and disperse uniformly in β matrix.Thus,TB-13 alloy is strengthened and its mechanical properties are improved.     

High Temperature Discontinuous Yielding in a New Near β Titanium Alloy Ti-7333

对一种新型近β钛合金Ti-7333在温度为770~845℃,应变速率为10-3~1 s-1条件下的高温不连续屈服行为进行了研究。结果表明:在试验温度范围内,当应变速率大于10-2 s-1时,Ti-7333合金高温变形过程中会出现不连续屈服现象。该合金的不连续屈服幅度随着应变速率的减小和温度的升高而逐渐增大,而且屈服的幅度对应变速率较温度更为敏感。通过对不连续屈服现象的显微组织观察可知,这是由于随着应变的增大,在晶界处生成的可动位错在塑性变形中向晶粒内部扩展传播所导致,晶界是这些可动位错的位错源。不连续屈服现象与位错源局部位错攀移开动传播、晶界迁移以及(或者)合金元素固溶重排过程有关。