摘要 钛合金具有非常好的综合力学性能，在众多领域得到了广泛应用。最近几年，国内 外高度重视钛合金性能的改善。 

本课题主要研究的是在不同热处理条件下对 5 vol。% (TiC+TiB )/Ti-6Al-4V 材料的组 织和相变的影响，首先，对钛基复合材料在 1080℃下淬火；之后进行不同温度和不同时 间的回火转变研究，研究回火温度、回火时间对钛基复合材料的组织和性能的影响；随 后，又对化后的试样在不同温度下进行盐浴实验，盐浴保温时间为 1 小时。最后对所 有热处理的试样进行了组织观察和拉伸力学性能测试。通过这些不同的热处理，观察金 相组织变化，结合硬度及拉伸力学性能，对 5 vol。% (TiC+TiB )/Ti-6Al-4V 相变研究进行 分析。得到以下结论：淬火后的组织是针状马氏体，回火后，马氏体向 α 转变，α 相随 着温度的升高由针状向片状转变，而且有变粗变大的趋势。同一温度下随着时间增长， α 相逐渐变粗，不过回火时间对 α 相变化的影响没有温度显著。盐浴后的主要组织是 α 相，随着盐浴温度的升高，可以明显看到 α 相逐渐变短变粗。而不管在回火后还是盐浴 后，5 vol。% (TiC+TiB )/Ti-6Al-4V 都是以解理断裂为主的脆性断裂。78082

毕业论文关键词 钛基复合材料；热处理；相变 

Abstract It is well known that titanium alloy combine excellent mechanical properties，it has been widely used in many fields。 In recent years, the domestic and foreign people have attached great importance to the performance modification of titanium alloy。

This paper is to study the heat treatment of 5 vol。% (TiC+TiB )/Ti-6Al-4V material and phase transformation of the organization。 First of all, quenching of titanium matrix composite for 1080℃。  Then  we  tempering  to  the  samples  at  the  different  temperatures  and  the  same

temperature for different times, Research the change of microstructure and mechanical properties of titanium matrix composites in different tempering temperature and tempering time。 Then making the salt bath to the sample indifferent temperature, the holding time of salt

bath for 1 hour。 Finally，we observe microstructure and test the tensile properties to all  these

samples。 Through these different heat treatment to observe the metallographic structure change, combined with hardness and tensile mechanical properties to analysis of 5 vol。% (TiC+TiB )/Ti-6Al-4V phase transition。 Finally we came to the following conclusion: The microstructure after quenching is a needle like martensitic, after tempering, martensitic transform to α, with the increase of the temperature, the α phase is gradually increasing and there is a tendency to become thick。 at the same temperature, as time grows, the α phase becomes thick too。 However, the effect of tempering time on the phase change of α phase was not significant。 The main microstructure is the α phase after salt bath。 With the increase of salt bath temperature, we can obviously see that α phase gradually become short and thick。 No matter in tempering or salt, 5 vol。% (TiC+TiB )/Ti-6Al-4V is cleavage fracture。

Keywords : Titanium matrix composite；Heat treatment；Phase transition

目录

第一章 绪论 1

1。1  引言 1

1。2  钛合金概况 2

1。2。1  钛合金的分类 2

1。2。2 钛合金显微组织 3

1。3  钛合金的热处理