Additive manufacturing of high density pure tungsten by electron beam melting

• DOI: 10.1016/j.nme.2021.101046
• Publication Date: 2021-07-22T23:28:31Z
• Authors: D. Dorow-Gerspach; A. Kirchner; Th. Loewenhoff; G. Pintsuk; T. Weißgärber; M. Wirtz
• Keywords: Hot isostatic pressing; Brittleness

Tungsten is an outstanding material and due to its properties like highest melting point tensile strength of all natural metals high thermal conductivity it a prime candidate for being used in very harsh environments challenging applications X-ray tubes or as plasma facing (PFM) fusion reactors. Unfortunately, brittle ductile transition temperature hardness represent great challenge classic manufacturing processes. Additive (AM) tungsten could overcome these limitations resulting design restrictions. However, AM also poses challenges particular related the production density mechanical stability. Using selective electron beam base 1000 °C powder, we were able produce with theoretical 99 % without need any post-treatment second step redensification by e.g. hot isostatic pressing (HIP). The surface morphology, microstructure, hardness, stability against severe transient heat loads investigated respect relevant building parameters compared recrystallized standard W. Besides simple test geometries more sophisticated ones monoblocks successfully realized illustrating potential fusion.