金属热处理 ›› 2021, Vol. 46 ›› Issue (3): 135-139.DOI: 10.13251/j.issn.0254-6051.2021.03.028

• 材料研究 • 上一篇    下一篇

Al/Si比例对TC4合金表面激光熔覆Ti-Al-Si涂层组织与摩擦性能的影响

刘冉1, 高苑1, 吴韬2   

  1. 1.北方工业大学 机械与材料工程学院, 北京 100144;
    2.浙江机电职业技术学院, 浙江 杭州 310053
  • 收稿日期:2020-11-22 出版日期:2021-03-25 发布日期:2021-05-08
  • 通讯作者: 吴韬,讲师,E-mail:627322800@qq.com
  • 作者简介:刘冉(1984—),女,助理研究员,博士,主要研究方向为激光表面改性,E-mail:liuran@ncut.edu.cn。
  • 基金资助:
    北京市教委科研计划一般项目(KM201910009006);北方工业大学科研启动基金;北方工业大学毓优人才项目

Effect of Al/Si ratio on microstructure and wear resistance of Ti-Al-Si coating onTC4 alloy by laser cladding

Liu Ran1, Gao Yuan1, Wu Tao2   

  1. 1. College of Mechanical and Materials Engineering, North China University of Technology, Beijing 100144, China;
    2. Zhejiang Institute of Mechanical & Electrical Engineering, Hangzhou Zhejiang 310053, China
  • Received:2020-11-22 Online:2021-03-25 Published:2021-05-08

摘要: 以不同Al/Si比例的Ti-Al-Si复合粉末为原料,采用激光熔覆技术在TC4合金表面制备Ti-Al-Si涂层,研究了Al/Si比例对涂层物相、微观组织、显微硬度及摩擦磨损性能的影响。结果表明,单道熔覆的涂层中没有发现明显的裂纹及气孔,涂层与基体之间呈现良好的冶金结合。不同Al/Si比例涂层中组织均以熔断的枝晶为主,枝晶的成分主要为α-Ti,增强相为板条状的Ti5Si3及Ti7Al5Si12,枝晶间主要是TiAl、Ti3Al、TiAl3金属间化合物。Si元素含量越高,涂层中原位生成的增强相的含量越多,涂层的显微硬度也比较高,最高可达1194 HV0.1,约为基体的4.1倍,但增强相过多会使涂层的脆性增加,耐磨性降低。Al元素含量较多时,组织细化效果明显,增强相对硬度和耐磨性能的影响比晶粒细化的作用更强。

关键词: 激光熔覆, Ti-Al-Si涂层, Al/Si比例, 微观组织, 显微硬度, 摩擦磨损性能

Abstract: Ti-Al-Si coating was prepared on the surface of TC4 alloy by laser cladding and using Ti-Al-Si composite powder with different Al/Si ratio as raw material. Effect of Al/Si ratio on phase composition, microstructure, microhardness and friction and wear properties of the coating was investigated. The results show that there is a good metallurgical bonding between the coating and the substrate, and no obvious cracks and pores are found in the single pass coating. The main structures of the coatings with different Al/Si ratio are mainly the dendrite, which has the main component of α-Ti, the reinforcing phase is lamellar Ti5Si3 and Ti7Al5Si12, and TiAl, Ti3Al and TiAl3 phases are distributed among the dendrite. The higher the content of Si element, the more the content of in-situ reinforcing phase is in the coating. The highest microhardness of the coating is 1194 HV0.1, which is about 4.1 times of that of the substrate. However, the brittleness of the coating increases and the wear resistance decreases with the increase of the content of Si element. It is also found that the effect of reinforcing phases on hardness and wear resistance is stronger than that of grain refinement when the coating has more Al element.

Key words: laser cladding, Ti-Al-Si coating, Al/Si ratio, microstructure, microhardness, wear resistance

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