金属热处理 ›› 2020, Vol. 45 ›› Issue (3): 11-14.DOI: 10.13251/j.issn.0254-6051.2020.03.003

• 组织与性能 • 上一篇    下一篇

TC4钛合金表面B-Al复合渗层的组织和性能

高顺, 田晓东, 张梦瑶   

  1. 长安大学 材料科学与工程学院, 陕西 西安 710064
  • 收稿日期:2019-09-29 出版日期:2020-03-25 发布日期:2020-04-03
  • 通讯作者: 田晓东,副教授,博士,主要从事材料表面改性方面的研究,E-mail:tianxd@chd.edu.cn
  • 作者简介:高 顺(1993—),男,硕士研究生,主要从事材料耐磨改性研究,E-mail:1551669068@qq.com。

Microstructure and properties of B-Al composite coatings on TC4 titanium alloy

Gao Shun, Tian Xiaodong, Zhang Mengyao   

  1. School of Materials Science and Engineering, Chang'an University, Xi'an Shaanxi 710064, China
  • Received:2019-09-29 Online:2020-03-25 Published:2020-04-03

摘要:

采用固体粉末包埋渗两步法,在TC4钛合金表面先1050 ℃渗硼 4~6 h再950~1050 ℃渗铝 4 h制备出B-Al复合耐磨渗层。利用X射线衍射仪(XRD)、扫描电镜(SEM)、波谱仪(WDS)和能谱仪(EDS)、显微硬度仪和摩擦磨损试验机对复合渗层的物相组成、显微组织、微区成分、表面硬度和摩擦因数进行测试和分析。结果表明:B-Al复合渗层厚为37~115 μm,主要由TiB2相和TiAl3相组成,外层是弥散分布TiB2的TiAl3层,向内依次形成厚度较小的TiAl2、TiAl及Ti3Al等Ti-Al金属间化合物层。B-Al复合渗层表面硬度为1041.7~1429.4 HV0.1,约为TC4钛合金硬度的3.03~4.16倍;经1050 ℃×6 h渗B后1050 ℃×4 h渗Al,其摩擦因数约为0.3,较TC4钛合金基体下降约25%。

关键词: TC4钛合金, B-Al复合渗层, 摩擦因数, 耐磨性能

Abstract:

B-Al composite coatings were prepared on the surface of TC4 titanium alloy by boronizing at 1050 ℃ for 4-6 h and subsequent aluminizing at 950-1050 ℃ for 4 h through a two-step pack cementation process. The constituent phases, microstructure, composition, hardness, friction coefficient of the composite coatings were analyzed by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), wavelength dispersive spectrometer (WDS) and energy dispersive spectrometer (EDS), microhardness tester, and friction and wear tester. The results show that the thickness of the B-Al composite coatings is in the range of 37-115 μm, and the coatings mainly consist of TiB2 and TiAl3 phases. The outer layer is TiAl3 layer with dispersed TiB2; and TiAl2, TiAl and Ti3Al intermetallic compound layers with smaller thickness are formed inward in turn. The surface hardness of the B-Al composite coatings is in the range of 1041.7-1429.4 HV0.1, which is about 3.03-4.16 times of the TC4 alloy. By boronizing at 1050 ℃ for 6 h followed by aluminizing at 1050 ℃ for 4 h, the friction coefficient of the B-Al composite coating is about 0.3, lower than that of TC4 alloy by about 25%.

Key words: TC4 titanium alloy, B-Al composite coatings, friction coefficient, wear resistance

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