Tungsten is a dense, robust metal that has a number of valuable applications, particularly in the chemical industry thanks to its corrosion resistance. Its hardness and extremely high melting point, however, have made it a difficult material to 3D print. In a paper entitled “Effect of processing parameters on the densification, microstructure and crystallographic texture during the laser powder bed fusion of pure tungsten,” a group of researchers addresses those challenges.
“This work looks to extend its [laser powder bed manufacturing’s] use to refractory metals, such as those considered in this paper where the behaviour of pure tungsten powder is investigated,” the researchers explain. “A strategy for fabricating high density parts was developed by creating a process map in which the effect of laser energy density was studied. The process quality was assessed using different techniques including light optical microscopy, XCT, SEM and EBSD. The results showed that the laser energy density was adequate to process tungsten to produce functional parts.”
Depending on the process conditions, the bulk density and optically determined densities of the tungsten ranged from 94 to 98%, but the parts showed micro cracks and defects due to micro- and macro-scale residual stress.