The effect of laser power and scanning speed on forming structure in selective laser melting process

Abstract

With the continuous development of ship technology, the usage environment of some parts has changed, with higher requirements for materials and preparation technology being put forward. Some traditional structural materials have do not meet the actual working conditions of ships, which necessitates development of new materials and research on their preparation technology. Owing to its high strength and stable mechanical properties at high temperature, molybdenum base alloy is expected to replace nickel base alloy and aluminum base alloy the primary structural material in the development of ships. Under the conventional method, the impurity elements is quite complex and there are limitations in the shape of the formed parts. This experiment uses spherical pure molybdenum powder as raw material. The effects of laser power, powder thickness, scanning speed and scanning distance on the microstructure of formed parts during selective laser melting process were studied and the optimum process parameters were determined. Laser power and scanning speed can seriously affect the quality of the forming parts. In this experiment, by comparing the density and internal holes of the forming parts under different process parameters, the best preparation process for the forming parts was determined: laser power 325 watts, scanning speed 400 mm s−1, powder thickness 30 μm, scanning distance 40 μm. Meanwhile, the forming workpiece density is the largest, up to 94.92%.