A review of tungsten fabricated via laser powder bed fusion

Tungsten and its alloys with high strength, thermal conductivity, and plasma radiation resistance are highly desirable for applications in medical, electronic and also nuclear facilities. However, the high melting point and high ductile–brittle transition temperature limit the fabrication of complex parts by using traditional methods, such as powder metallurgy. As a kind of additive manufacturing technology, laser powder bed fusion (LPBF) was used to fabricate tungsten and its alloys in recent years because of its high energy density and low action time. This paper reviewed the recent progress of LPBF fabricated tungsten. Two main challenges, which are the lack of density and cracking problem, are focused. The methods to solve these problems are reviewed. In terms of improving the density, decreasing oxygen content, optimizing the process parameter, and adopting spherical powder were proved effective. In terms of cracking problem, the method of alloying, such as adding secondary phase nanoparticles and alloy elements, could significantly reduce the cracking density. However, the crack problem has not been completely solved up to now. Finally, future developments and potential new research directions for LPBF tungsten are proposed.