Estimation of Heat Affected Zone in the Laser Surface Modification of Single-Crystal Nickel-Based Superalloy by Using a 3D Transient Heat Transfer Modelling

Abstract

This paper describes an estimation of the heat-affected zone (HAZ) in laser surface modification (LSM) of a 2nd generation, SC nickel-based superalloy. The study was conducted by using a continuous wave (CW) fiber laser through a DOE-based, L18 (orthogonal array) OA with different levels of laser power, laser beam diameter, and scanning speed under the conductive mode of heat penetration. A 3D finite element method (FEM) based model of transient heat transfer with a surface heat flux was developed in Abaqus/CAE™. The moving heat sources having modified Gaussian beam profiles, were implemented in the FEM model by using the DFLUX subroutines. Based on the quasi-steady state temperature distribution, the HAZ was calculated as the region above the temperature of 1200 °C and below the melting temperature of the alloy. The model was validated with the LSM experiments on SC superalloy. On average, the estimated HAZ depth ranging from 13 to 20% of the fusion zone depth. The statistical analysis reveals that the laser power, followed by scanning speed are significant factors in HAZ. The model helped in the evaluation of total damage depth for laser-induced surface damage of SC nickel-based superalloys for improving the machinability. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.