C添加对近β钛合金显微组织及性能的影响

Effect of C Addition on Microstructure and Mechanical Properties of Near Beta Titanium Alloy

摘要:

本文研究了在不同热处理条件下C元素的添加对一种近β钛合金的微观组织及维氏硬度的影响。结果表明：C含量对近β钛合金在不同热处理条件下的微观组织都有显著影响。C元素的添加会导致β晶粒的细化。当C添加量由0 vol.% 增加到3 vol.%时，固溶处理后合金的β晶粒尺寸由137μm降低至25μm，且尺寸更加均匀。当C添加量持续增加时β晶粒开始长大。时效后，随着C含量的增加次生α相尺寸和体积分数都减小。此外，单级时效后晶界处的次生α相会随着C含量的增加而逐渐消失。由于受晶粒细化、TiC颗粒和次生α相的影响，随着C添加量的增加，在不同热处理条件下该合金的显微硬度有都明显提高。

Abstract:

In this paper, the effects trace carbon element on microstructure and micro-hardness of a forged near beat titanium alloy through solution and aging treatment were studied. The results show that the addition of carbon element has a significant effect on the refinement of beta grain. Through solution treated at single field, the size of beta grains decreases from 137μm to 37μm and becomes more uniform with the increasing of carbon from 0 vol.% to 3 vol.%. And beta grains began to grow as the C content continued to increase. After aging treatment, the size and volume fraction of secondary alpha phase decreases with the increasing of carbon. Additionally, with the increasing of carbon, grain boundary alpha phase reduces gradually through single-aging treatment. Due to the influence of grain refinement, TiC particles and secondary alpha phase, with the increase of carbon, the micro-hardness of the alloy increased significantly under different heat treatment conditions.