Study on the tungsten bulk materials prepared by selective laser melting

The tungsten bulk materials were prepared by selective laser melting (SLM) in this paper. The effects of SLM processing parameters on surface morphology, microstructures, and density of tungsten parts were investigated. The results indicate that, the number of internal pores in SLM samples is reduced with the increase of input laser energy density. The density is increased with the improvement of laser power and the decrease of laser scanning speed. The pure tungsten block sample with a relative density of 97% is prepared in the laser power of 300 W at the scanning speed of 200 mm·s^-1. However, when the laser power raises to 350 W, the density of bulk tungsten sample decreases due to the enhancement of cracks. The grain is enlarged and elongated along the height direction in additive manufacturing with the increase of input laser energy density. The inside pores are increased and distributed along the height direction in additive manufacturing by using laser scanning strategy 2 (laser power 200 W and scanning speed of 200 mm·s^-1). Moreover, some of grains inside sample prepared by laser scanning strategy 2 are elongated along the height direction in additive manufacturing.