Influence of laser energy input on fabricating pure tungsten thin wall grids by selective laser melting

Abstract

Pure tungsten thin wall grids were fabricated by selective laser melting. The effects of laser energy on formability, surface evenness, thickness, thickness deviation, relative density and microhardness of the fabricated grids were investigated and discussed. It was indicated that the grids were fabricated successfully with the linear energy density El in the range from 0.35 to 0.80 J mm−1. A higher or lower laser power and scanning rate increased the surface evenness of grids. For the design wall thicknesses of 0.15 and 0.20 mm, the fabricated grids with the thinnest wall thickness were about 0.27 and 0.32 mm, respectively. The thickness deviation of the grids reached a minimum of 0.02 mm. The relative density of the grid reached the maximum of 95.13%. The microhardness of the grid reached the maximum of 477.66 HV. El played an important effect on formability, surface evenness, thickness, thickness deviation, relative density and microhardness of the grids. Both a lower and higher El increased the thickness deviation, and decreased the microhardness and relative density of fabricated grids.