金属热处理 ›› 2020, Vol. 45 ›› Issue (2): 166-174.DOI: 10.13251/j.issn.0254-6051.2020.02.032

• 工艺研究 • 上一篇    下一篇

热处理温度对TC4ELI合金组织与性能的影响

毛江虹, 杨晓康, 罗斌莉, 魏芬绒   

  1. 西北有色金属研究院 西安赛特思迈钛业有限公司, 陕西 西安 710200
  • 收稿日期:2019-08-15 出版日期:2020-02-25 发布日期:2020-04-03
  • 作者简介:毛江虹(1974—),高级工程师,硕士,主要研究方向为钛相关技术与工艺,联系电话: 029-86962225,E-mail:mjh2323@126.com。
  • 基金资助:

    陕西省科技计划项目(2018ZDXM-GY-138)

Effect of heat treatment temperature on microstructure and mechanical properties of TC4ELI alloy

Mao Jianghong, Yang Xiaokang, Luo Binli, Wei Fenrong   

  1. Northwest Institute for Nonferrous Metal Research, Xi'an Saite Simai Titanium Industry Co., Ltd., Xi'an Shaanxi 710200, China
  • Received:2019-08-15 Online:2020-02-25 Published:2020-04-03

摘要:

为揭示TC4ELI合金随热处理温度的不同,显微组织、力学性能及相组成的变化规律,研究了TC4ELI钛合金经700~1000 ℃热处理并空冷的组织演变,进行了室温力学性能测试与XRD分析。结果表明:800 ℃热处理后,合金实现了再结晶,α相均匀等轴化,体积含量达到最大值。XRD图谱未出现β相的衍射峰,均为α相的衍射峰。700~800 ℃热处理时可以获得良好的综合性能,满足相关标准要求。850~950 ℃温度范围内,TC4ELI合金有二次针状α相析出,属于双态组织。随着温度的升高,由于合金中β相的晶粒粗化与含量增加,使得强度与弹性模量下降。1000 ℃热处理后,立方马氏体α′相具有较强的(002)α′、(101)α′衍射峰,其它晶面的衍射峰能量很弱,合金的弹性模量达最大值110 GPa。通过显微组织观察,推断TC4ELI合金α+β→β转变的开始温度处于850~870 ℃,终了温度处于950~970 ℃。

关键词: 钛合金, TC4ELI, 热处理, 显微组织, 力学性能, 弹性模量, 相组成

Abstract:

In order to reveal the microstructure evolution, mechanical properties and phase composition of TC4ELI alloy with different heat treatment temperatures, the microstructure of TC4ELI alloy heat treated at 700-1000 ℃ with air-cooling conditions was studied, and the room temperature mechanical properties and XRD of the samples were tested. The results show that the alloy achieves crystallization when heat treated at 800 ℃. The α phase is homogeneous and equiaxial, and its volume fraction reaches the maximum. There are all diffraction peaks of the α phase in the XRD pattern but for the β phase. In the range of 700-800 ℃, the alloy can obtain the good comprehensive performance, and meet the requirement of related standards. In the temperature range of 850-950 ℃, the TC4ELI alloy is the bimodal microstructure with the precipitation of the secondary needle-like α phase. As the temperature increases, the strength and elastic modulus decrease due to the increase of grain size and volume fraction of the β phase in the alloy. After heat treated at 1000 ℃, the cubic martensite phase has strong (002)α' and (101)α' diffraction peaks, and the diffraction peak energy of other lattice orientations is very weak, and the elastic modulus of the alloy reaches a maximum of 110 GPa. Through microstructure observation, the start temperature of α+β→β transformation is in the range of 850-870 ℃, and the finish temperature of that is in the range of 950-970 ℃.

Key words: titanium alloy, TC4ELI, heat treatment, microstructure, mechanical properties, elastic modulus, phase composition

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