Investigation of the pulsed laser parameters for optimizing SLM processes in the manufacture of metal products with improved characteristics

Abstract

The application of ultrasound in laser fusion processes enhances the quality of manufactured items by improving metal surface characteristics and weld joint properties. This is achieved due to reduction of porosity and the formation of the fine-grained microstructure. This study investigates the technical feasibility of inducing cavitation bubble collapse through optoacoustic effects generated by a secondary pulsed laser under Selective Laser Melting (SLM) conditions. Numerical modeling was used to analyze the physical characteristics of the melt and the melt pool boundaries under simultaneous operation of continuous-wave and pulsed lasers. Based on computations, optimal laser parameters were identified to achieve cavitation bubble collapses in the resonant mode.