热处理对Ti-6Al-4V钛合金力学性能的影响研究

Investigation on Influence of Heat Treatment on Mechanical Property of Ti-6Al-4V Alloy

研究了不同热处理制度(固溶处理和时效处理)对Ti-6Al-4V钛合金力学性能的影响,并用金相显微镜、环境扫描电镜(ESEM)进一步分析了钛合金的组织、冲击断口形貌与力学性能之间的关系。结果表明:热处理改变了热轧态的纤维组织形态,获得的等轴状和针状混合状组织可使合金的综合性能匹配较好。由于有大量的弥散相析出,其强度和弹性模量得到显著提高,塑韧性明显降低。通过优化热处理制度对其进行960℃×1 h固溶(水冷)、550℃×6 h时效(空冷)处理,可以获得较好的综合性能。

The influences of different heat treatment （solution and aging treatment） on the mechanical properties of Ti-6Al-4V titanium alloy were studied. The relation between the microstructure, impact fracture images and mechanical properties were analyzed by metallurgical microscope and environment scanning electron microscope （ESEM）. The results show that the microstmcture of hot rolling state is changed by heat treatment. The obtained mixed tissue of equiaxed and acicular enables the comprehensive performance of the alloy better match. The strength and modulus of elasticity are significantly improved. And the plastic toughness significantly reduces because a large number of dispersion phases are precipitated. Good mechanical properties will be obtained by optimizing the heat treatment system. The better combination property can be gotten after treated at 960 ℃ for 1 h＋WC and then at 550 ℃ for 6 h＋AC.