An analytical model for prediction of denudation zone width in laser powder bed fusion additive manufacturing

Abstract

Accurately modeling the physics of laser-powder interaction is needed for predicting the probabilities of performance-limiting defects in parts additively manufactured using laser powder bed fusion. In this paper, we present an analytical model for rapid prediction of denudation width in laser powder bed fusion additive manufacturing process. The model is based on the force balance analysis for a powder particle sitting on top of the powder bed. The model relates the laser power and laser scan speed to the vapor jet speed and consequently to the inward entrainment gas velocity. The effects of laser power and laser speed on denudation width are investigated and compared with experimental data. In addition, a criterion for the onset of denudation is presented which accounts for chamber gas, powder particle size and density. The results show that for a given laser power the denudation width increases as the laser speed decreases.