Integrating thin wall into block: A new scanning strategy for laser powder bed fusion of dense tungsten

Abstract

• A novel scanning strategy to manufacture pure tungsten with less defects was developed in this study using laser powder bed fusion (LPBF). Dense pure tungsten samples from the novel strategy present a nice brick-stacking structure. • The report on thermal properties of pure tungsten processed by LPBF is rather limited. In this study, their thermal contributions, electrical properties and thermoelectric figure of merit (zT) were firstly reported. • Although the temperature dependence of samples fabricated by different strategies was similar, phonon contribution to the total thermal conductivity varied significantly, which could be interpreted by the higher grain boundary thermal resistance in the brick-stacking tungsten builds. By integrating thin-wall into block (ITWB), a novel scanning strategy to manufacture dense tungsten with few cracks was developed in this study using laser powder bed fusion (LPBF). Different from the S-shaped grains observed from the other LPBFed tungsten, samples fabricated by the ITWB strategy present a pore-free microstructure composed of stacked columnar grains. The thermal conductivities of tungsten parts manufactured by the different strategies were compared. Although their temperature dependence was similar, phonon contribution to the total thermal conductivity varied significantly, which could be primarily interpreted by the differences on the grain boundary thermal resistance.