高温形变热处理对Ti-1300合金组织及硬度的影响

Effect of High Temperature Thermomechanical Treatment on Microstructure and Hardness of Ti-1300 Titanium Alloy

摘要:

采用光学显微镜、扫描电子显微镜、Gleeble-3800热模拟试验机以及IMVS-1000JMT2数显维氏显微硬度仪研究了等温变形条件下形变热处理对Ti-1300合金组织及硬度性能的影响。结果表明：高温形变热处理可以明显的细化Ti-1300合金的显微组织，并在一定程度上提高合金的力学性能。热轧态合金的组织中粗大块状和长条状α相经高温压缩变形后具有明显的等轴均匀化趋势，然后分别经过淬火时效和固溶时效处理后合金的组织主要由板条状初生α相，针状次生α相以及β相组成，初生α相和次生α相主要分布于晶界和β基体上。与淬火时效态相比，固溶时效态合金的硬度随初生α相板条厚度和含量的增加而降低，最后对影响的机理进行探讨和分析。

Abstract:

Effects of high temperature thermomechanical treatment on microstructure and hardness of Ti-1300 alloy under isothermal deformation condition were investigated by means of optical microscope (OM), scanning electron microscopy (SEM), thermal simulation testing machine (Gleeble-3800) and Vickers hardness tester (IMVS-1000JMT2). The results show that high temperature thermomechanical treatment can markedly refine the microstructure and improve the mechanical property of Ti-1300 alloy. Microstructure observation of the hot rolled and hot compressed samples indicates that the tendency of the coarse and elongated grains recovering to equiaxed shape is more obvious, and the microstructure of Ti-1300 alloy after quenching plus aging and solution plus aging treatment is composed of a mixture of primary α phase (αp), secondary α phase (αs) and β phase. The αp phase is mainly distributed in the grain boundary, but the αs phase is mainly in the β matrix after aging treatment. The hardness of the alloy under quenching plus aging is increased due to the growth of αs phase and the remarkable refining of αp phase in width.