Thermal and mechanical modeling of single metallic powder layer for laser micro sintering

Abstract

Three-dimensional model for the evolution of residual stress within a single metallic layer formed on the powder bed using different process parameters such as laser beam diameter, laser power and laser scan speed in laser micro sintering (LMS) has been proposed. The finite element model allows for the transition from powder to solid, the adoption of μMKS system of units, the utilization of element birth and death technique and implementation of moving laser beam power with a Gaussian distribution. It is found that, during the laser multi-track, the maximum residual stress resulting from the non-uniform temperature distribution increases with the laser power and the scan speed in the beam scanning direction. Moreover, it indicates the stress to be tensile with large magnitudes at the beginning side of the sintering part, then compressive close to the end side.Three-dimensional model for the evolution of residual stress within a single metallic layer formed on the powder bed using different process parameters such as laser beam diameter, laser power and laser scan speed in laser micro sintering (LMS) has been proposed. The finite element model allows for the transition from powder to solid, the adoption of μMKS system of units, the utilization of element birth and death technique and implementation of moving laser beam power with a Gaussian distribution. It is found that, during the laser multi-track, the maximum residual stress resulting from the non-uniform temperature distribution increases with the laser power and the scan speed in the beam scanning direction. Moreover, it indicates the stress to be tensile with large magnitudes at the beginning side of the sintering part, then compressive close to the end side.