半固态加工Ti−Cu合金的显微组织和力学行为

Microstructure and mechanical behavior of Ti−Cu alloys produced by semisolid processing

研究触变成形Ti−Cu合金的力学性能。Ti−Cu(25%,27%,29%Cu,质量分数)锭的制备流程为:先进行电弧熔炼,再在950℃均匀化处理24 h,然后在900℃热锻,最后在1035℃热处理300 s后以8 mm/s的速度触变成形。结果显示,触变成形合金表现出良好的力学强度,但其在拉伸载荷下的塑性一般,在压缩载荷下的塑性尚可。随着Cu含量的增加,包晶Ti_(2)Cu相(转变液相区)的体积分数增加,与α+Ti_(2)Cu相区(转变固相区)相比,其力学强度和塑性更低,导致合金的力学强度和塑性降低。这些结果表明,Ti−Cu合金的力学性能和半固态加工性之间的平衡主要取决于Cu含量。

The mechanical properties of Ti−Cu alloys processed via thixoforming were evaluated.Ti−Cu(25,27,and 29 wt.%Cu)ingots were produced via arc melting,homogenization at 950℃ for 24 h,and hot-forging at 900℃,followed by thixoforming at a speed of 8 mm/s after isothermal heat treatment at 1035℃ for 300 s.The thixoformed alloys exhibited good mechanical strength,limited plasticity under tensile loading,and reasonable plasticity under compressive loading.The mechanical strength and plasticity decreased as the Cu content increased as a result of the increasing volume fraction of the peritectic Ti_(2)Cu phase(transformed liquid),which exhibited a lower strength and plasticity than theα+Ti_(2)Cu regions(transformed solid).These findings indicated that the trade-off between the mechanical properties and semisolid processability is largely governed by the Cu content.