材料期刊网

对Ti55531合金棒材和锻件进行不同工艺的固溶和时效热处理，研究了热处理工艺对其显微组织和拉伸性能的影响。结果表明：随着固溶温度升高(575~650℃)，棒材中的初生α相由颗粒状变为条状或短棒状，直至全部变为β晶粒，室温抗拉强度和屈服强度明显增大，伸长率和断面收缩率大幅下降；随着时效温度降低，短棒状或条状α相逐渐溶解并球化析出α颗粒，室温抗拉强度和屈服强度明显增大，伸长率和断面收缩率显著降低；为使钛合金棒材的室温强度和塑性达到最佳匹配，固溶温度应控制在相变点以下，时效温度宜选择在600~620℃区间；固溶温度在相变点以下，时效温度为600℃时，锻件的强度和塑性可满足相关标准的要求。

Heat treatement processes with different solid-solution and aging temperatures were carried on Ti5 5 5 3 1 titanium alloy bar and forging,and the effects of heat treatment processes on microstructure and tensile properties were studied.Results show that,with the increase of solid-solution temperature from 575 ℃ to 650 ℃, primaryαphase in bar changed from granulated shape to strip or short bar-like,and until to change toβgrains.The tensile strength and yield strength at room temperature obviously increased,the elongation and reduction of area dropped sharply with the increase of solid-solution temperature.With the decrease of aging temperature,the strip or short bar-likeαphase gradually dissolved and precipitated with granulated shape,and tensile strength and yield strength at room temperature obviously increased and elongation and reduction of area sharply decreased.In order to obtain a best match between strength and plasticity for the bar,the solid-solution temperature should below the phase transition point and aging temperature within the range of 600 ℃ to 620 ℃.Strength and plasticity of the forging could meet the requiements of relavant standard when the solid solution temperature was below phase transition point and aging temperature was 600 ℃.