Journal of Mechanics Vol. 36, No. 1, February 2020 19 DOI : 10.1017/jmech.2019.30 Copyright © 2019 The Society of Theoretical and Applied Mechanics A SIMPLE AND ACCURATE 3D NUMERICAL MODEL FOR LASER CLADDING Shih-Kai Chien Kuo-Teng Tsai Laser and Additive Manufacturing Technology Center Industrial Technology Research Institute Tainan, Taiwan Yueh-Heng Li Department of Aeronautics and Astronautics National Cheng Kung University Tainan, Taiwan Yu-Ting Wu Department of Engineering Science National Cheng Kung University Tainan, Taiwan Wen-Lih Chen * Department of Aeronautics and Astronautics National Cheng Kung University Tainan, Taiwan ABSTRACT A simple numerical model has been proposed for laser cladding. The model does not involve complex techniques such as cell addition, moving mesh, or prescribing a clad profile with a certain polynomial function. Instead, a mass function has been introduced to register the clad mass deposition on substrate, and from which the clad-track height can be estimated. The model takes several operational parameters, laser power, laser-head speed, and clad powder feeding rate, into consideration and predicts clad-track geometry, dilution, and substrate temperature. Experiments using two different combinations of substrate and clad powder materials to lay single and multiple clad tracks were conducted to provide data for model validation. The results show that the present model returns good agreement with experimental clad profiles for single and multiple tracks. Keywords: laser cladding; numerical method; clad profile; dilution. 1. INTRODUCTION Laser cladding (shown in Fig. 1) is an innovative machining method which deposits layers of clad material on a substrate to repair surface cracks or to create a protective coating. The cladding process can be achieved by either pre-placed powder or blown-powder methods. During this process, laser melts the surface of substrate and forms a melt pool. The powder is then injected into the melt pool by a co-axial or off-axial nozzle using inert carrier gas. As the powder exits the nozzle, it forms a powder stream which impinges on the same substrate- surface spot where the laser beam is irradiated. The powder is melted and captured by the melt pool, where both the powder material and the substrate material are mixed to form metallurgical bonding between coating and substrate when the melt pool is solidified. Inert gas such as argon, nitrogen, or helium is often used as carrier gas * Corresponding author (wlchen@mail.ncku.edu.tw) Downloaded from https://academic.oup.com/jom/article/36/1/19/5950367 by guest on 29 November 2022