不同热处理工艺对Ti6Al4V钛合金微观结构和力学性能影响

The Effect of Different Heat Treatments on Microstructure and Mechanical Properties of Ti6Al4V Titanium Alloy

摘要:

通过对Ti6Al4V钛合金进行不同工艺的热处理，分析了不同工艺处理后的显微组织，进行了拉伸试验、示波冲击试验测试。研究固溶时效处理对Ti6Al4V钛合金显微组织、力学性能和冲击韧性的影响。利用金相显微镜、环境扫描电镜（ESEM）进一步分析了钛合金的组织、冲击断口特征与力学性能间的关系。结果表明随固溶温度增加，钛合金屈服强度和抗拉强度得到显著提高，塑韧性先增加后降低。优化热处理工艺后，Ti6Al4V钛合金经960 ℃ WQ和500℃ × 4 h AC处理，获得优良综合性能，σ0.2为1050MPa，σb为1120 MPa，Ak为46.22 J。钛合金固溶时效后的组织由β基体和析出的α相组成，片层状β相和小针丛状α相组织提高合金综合性能。

Abstract:

This paper analyzed the microstructure of Ti6Al4V titanium alloy after different heat treatments. The tensile experiment and instrumented impact test were done. It was studied that the microstructure, mechanical properties and impact toughness of Ti6Al4V titanium alloy were affected by the solution and aging treatment. The relationship among the microstructure, impact fracture characteristic and mechanical properties was analyzed by metallurgical mi-croscope and environment scanning electron microscope (ESEM). The results showed that the yield strength and ul-timate tensile strength were improved remarkably. The ductile increased firstly, then it decreased. The good compre-hensive properties can be gotten when the Ti6Al4V titanium alloy was treated in the condition of 960 ℃×1h WQ and 500 ℃×4h AC. The σ0.2 is 1050 MPa. The σb is 1120 MPa and Ak is 46.22 J. The microstructure of the tita-nium alloy after solution and aging treatment was consisted of the β matrix and the precipitation of the α-phase. The lamellar β-phase and the α-phase structure of the small needle plexiform can enhance comprehensive properties.