Optics & Laser Technology 167 (2023) 109595 0030-3992/© 2023 Elsevier Ltd. All rights reserved. Full length article Analysis of the sequentially coupled thermal–mechanical and cladding geometry of a Ni60A-25 %WC laser cladding composite coating Sha Wu a , Zenghua Liu a, * , Yu Gong a , Xiubing Liang b , Yufeng Wu a , Xin Zhao c a Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China b Defense Innovation Institute, Academy of Military Science, Beijing 100071, China c Faculty of Information Technology, Beijing University of Technology, Beijing 100124, China A R T I C L E INFO Keywords: Laser cladding Ni60A-25 %WC Sequentially coupled thermal–mechanical Residual stress Cladding geometry ABSTRACT In this research, a three-dimensional (3D) transient finite element model based on a sequentially coupled thermal–mechanical analysis (SCTMA) is proposed to simulate the evolution of the temperature field and stress field as well as the cladding geometry of the Ni60A-25 % WC laser cladding composite coating. Based on the thermo-physical properties of Ni60A-25 % WC powder and the design of the double ellipsoidal heat source model, a 3D finite element model of double-layer laser cladding with two channels is established. The evolution of the temperature field and the residual stress field at different laser process parameters are investigated to evaluate the quality of the cladding layer. The impact of different laser cladding process parameters on the cladding dimensions is investigated. The dimensions of the simulated molten pool are analyzed by fitting a polynomial curve. The simulation results show that the laser power is proportional to the temperature, and the temperature growth rate of the coating is significantly higher than that of the substrate. The scanning speed is inversely proportional to the temperature. The maximum temperature of the cladding is 1.5 times the maximum temperature of the substrate. The temperature growth rate of the cladding layer is twice that of the substrate. Due to the asymmetry of the heat source in the multi-pass cladding process, the laser energy absorption rate is not the same on both sides of the melted layer. The double ellipsoidal heat source model has a larger diffusion range in the un-melted powder, resulting in asymmetry in the width direction of the cladding layer. The analysis of the residual stresses in the cladding layer shows that the residual compressive stresses in all paths increase with the increasing laser power. The normal x residual compressive stress in the coating and the maximum residual compressive stress occur at the end of the laser beam scan. The residual compressive stress in all paths decreases as the scanning speed increases. The results show that the dimensions of the molten pool are proportional to the laser power and inversely proportional to the scanning speed. The cladding geometry can be calculated with polynomial fitting equations at a selected laser power (500 W–2800 W) and scanning speed (1 mm/s–8 mm/s). The error analysis of the simulation and the experimental results can validate the proposed finite element simulation model. The error in the molten pool size is less than 20 % for the simulation and experimental results. 1. Introduction Laser cladding is a new laser surface modification technology. By adding different composite powders, the surface properties of the matrix can be greatly improved by laser cladding. A laser cladding layer has the advantages of controlled heat input, high wear resistance, low distor- tion, a small heat-affected zone, and a low dilution rate [1–3]. Conse- quently, laser cladding has been introduced in the design of conductor damage tolerance in aerospace, the automotive and tool manufacturing industries, and food processing and medical applications [4–6]. Laser cladding has a high cooling rate, which leads to high residual stress generation. As a result, cracks appear in the cladding layer and reduce the cladding quality. In recent years, with the development of com- puters, many scholars have adopted the finite element method to simulate the process of laser cladding. Liu et al. [7] developed a 3D finite element model (FEM) to investigate the impact of dynamic preheating on the molten pool. The effect of dynamic preheating on the thermal behavior of multi-orbital and multi-layer laser cladding was explored by applying an additional heat source in a localized area in front of a moving melt pool. The results showed that the heat flux density, * Corresponding author. E-mail address: liuzenghua@bjut.edu.cn (Z. Liu). Contents lists available at ScienceDirect Optics and Laser Technology journal homepage: www.elsevier.com/locate/optlastec https://doi.org/10.1016/j.optlastec.2023.109595 Received 6 October 2022; Received in revised form 3 April 2023; Accepted 11 May 2023