中国物理B ›› 2021, Vol. 30 ›› Issue (1): 18104-.doi: 10.1088/1674-1056/abcf9b

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  • 收稿日期:2020-09-25 修回日期:2020-11-03 接受日期:2020-12-02 出版日期:2020-12-17 发布日期:2020-12-30

Numerical research on effect of overlap ratio on thermal-stress behaviors of the high-speed laser cladding coating

Xiaoxi Qiao(乔小溪)†, Tongling Xia(夏同领)†, and Ping Chen(陈平)‡   

  1. School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China
  • Received:2020-09-25 Revised:2020-11-03 Accepted:2020-12-02 Online:2020-12-17 Published:2020-12-30
  • Contact: These authors contributed equally to this work. \raisebox\ht\strutbox \hypertargetcauthor Corresponding author. E-mail: chenp@ustb.edu.cn
  • Supported by:
    Project supported by the National Key Research and Development Program of China (Grant No. 2018YFC0810500), the National Natural Science Foundation of China (Grant No. 51975042), and the Fundamental Research Funds for the Central Universities, China (Grant No. FRF-TP-19-004A3).

Abstract: High-speed laser cladding technology, a kind of surface technology to improve the wear-resistance and corrosion-resistance of mechanical parts, has the characterizations of fast scan speed, high powder utilization rate, and high cladding efficiency. However, its thermal-stress evolution process is very complex, which has a great influence on the residual stress and deformation. In the paper, the numerical models for the high-speed laser cladding coatings with overlap ratios of 10%, 30%, and 50% are developed to investigate the influence rules of overlap ratio on the thermal-stress evolution, as well as the residual stresses and deformations. Results show that the heat accumulation can reheat and preheat the adjacent track coating and substrate, resulting in stress release of the previous track coating and decreased longitudinal stress peak of the next track coating. With the overlap ratio increasing, the heat accumulation and the corresponding maximum residual stress position tend to locate in the center of the cladding coating, where the coating has a high crack susceptibility. For a small overlap ratio of 10%, there are abrupt stress changes from tensile stress to compressive stress at the lap joint, due to insufficient input energy in the position. Increasing the overlap ratio can alleviate the abrupt stress change and reduce the residual deformation but increase the average residual stress and enlarge the hardening depth. This study reveals the mechanism of thermal-stress evolution, and provides a theoretical basis for improving the coating quality.

Key words: high-speed laser cladding, overlap ratio, thermal-stress evolution, residual stress and deformation, numerical simulation

中图分类号:  (Laser-assisted deposition)

  • 81.16.Mk
75.40.Mg (Numerical simulation studies)