TA15钛合金挤压薄壁型材拉伸性能及差异性研究

针对"直接热挤压"和"热挤压+脉冲锻打"TA15钛合金薄壁型材的室温力学性能及差异开展实验研究。通过对型材不同位置切取的试样进行拉伸试验,获得了型材抗拉强度和屈服强度分布规律,并对性能数据分布的均匀性和一致性进行深入分析。结果表明,"直接热挤压"态型材的抗拉强度和屈服强度数值分布较分散,强度离散系数大于3.5%;而"热挤压+脉冲锻打"态型材的抗拉强度和屈服强度数值分布相对集中,不同批次型材之间的力学性能一致性较好,强度离散系数均小于3%。进一步分析表明,2种状态型材之间的性能差异与型材表面状态、表面细晶层和截面尺寸有关。脉冲锻打能够改善型材表面细晶层分布的均匀性和截面尺寸精度,从而改善型材力学性能分布的均匀性和一致性。

Difference Research on Tensile Properties of TA15 Titanium Alloy Thin Profile Prepared by Hot Extrusion

The room temperature mechanical properties of TA15 titanium alloy thin profiles which prepared by "direct hot extrusion"(DE) and "hot extrusion + pulse forging"(EF) process were studied by tensile test. The distribution regulation of tensile strength and yield strength were obtained by using the samples cut from different locations of profile. Then,the regulation of data distribution was analyzed. The results show that the values of tensile strength and yield strength distribute more scattered and the dispersion coefficient is larger than 3. 5% for DE profiles; By contrast,their distribution are more homogeneous and concentrated for EF profiles. Among different production lots,its distribution of test data is consistent and the dispersion coefficient is lower than 3%. By further analysis,the performance difference between two type profiles is related to surface states,fine grain layer and section size. Pulse forging process can uniform the thickness of fine grain layer and regulate section size,which are benefit for improving mechanical performance of the profile.