• Binder, Maximilian
• Müller, Alexander Von
• You, Jeong-Ha
• Yücel, Olgu
• Schlick, Georg
• Seidel, Christian
• Luca, Riccardo De
• Buschmann, Birger
• Fanelli, Pierlugi
• Bareth, Thomas

Abstract

The production of complex lattice structures made of pure tungsten can be of great interest for potential applications in various industrial sectors such as energy technology or medical devices. One example is the plasma-facing armour of so-called limiter components in nuclear fusion power reactors, where the tungsten lattice armour is supposed to withstand extreme heat flux loads up-on transient plasma events.. The reliability of the tungsten armour is hence an important requirement for the sustainable operation of fusion power reactors [1,2]. Tungsten is difficult to process to a satisfactory degree due to its high melting point, its hardness as well as its susceptibility to cracking. Therefore, this paper presents the manner in which tungsten can be processed into fine lattice structures by means of high- temperature laser-based powder bed fusion. It also explains to what extent the used metal powder and the laser-exposure strategy have an influence on pores and component defects. It is shown how particle size distribution and sphericity of the powders have a major impact on the basic processability of the material. Furthermore, it presents to what extent the laser exposure parameters, such as the laser hatch distance, can have an influence on the resulting density of the material and which methods are used to determine the actual material density of lattice cubes in the first place. Finally, measurements of the electrical conductivity of the fabricated AM structures are presented, as this is of interest with respect to many other areas of application.

Topics

• density
• impedance spectroscopy
• pore
• hardness
• selective laser melting
• susceptibility
• tungsten
• electrical conductivity