固溶处理温度对TC4钛合金组织和性能的影响

Effect of solution treatment temperature on microstructure and properties of TC4 titanium alloy

在不同温度下对TC4钛合金进行固溶处理,随后通过拉伸试验机、扫描电镜和光学显微镜等手段分别测试和观察TC4钛合金的力学性能、拉伸断口的形貌和显微组织,以研究固溶温度对其微观组织和断裂行为的影响。结果表明,随着固溶温度的升高,TC4钛合金的抗拉强度和规定塑性延伸强度持续增加,收缩率和伸长率逐渐降低,说明固溶处理有效提高了钛合金的强度,但却伴随着塑性的降低。经固溶处理后α相占比增加,且随着固溶温度升高β相逐渐向α相转变,α相强度更高,因而钛合金强度得以提高。断口的宏观形态呈暗灰色,且观察不到放射区;根据断口微观形态照片存在的大量韧窝,可以判断出其拉伸后断裂机制为韧性断裂。

TC4 titanium alloy was treated at different solution treatment temperatures,the mechanical properties,morphologies of tensile fracture and microstructure of the alloy were tested or observed by means of tensile tester,SEM and OM,respectively,and the effect of solution treatment temperature on the microstructure and fracture behavior of TC4 titanium alloy was studied.The results show that with the increase of solution treatment temperature,the tensile strength and proof strength,plastic extension of TC4 titanium alloy increase continuously,while the shrinkage and elongation decrease gradually,which means that solution treatment can effectively improve the strength of the titanium alloy,but the plasticity is decreased.With the increase of solution treatment temperature,βphase transforms gradually intoαphase,the proportion ofαphase increases and becomes stronger after solution treatment,so the strength of the titanium alloy is enhanced.The macro morphology of the fracture is dark gray,and no radiation area can be observed.According to a large number of dimples observed in the micromorphological fracture photograph,the tensile fracture mechanism can be judged as ductile fracture.