Mechanical and thermal properties of Gyroid-based W[sbnd]Cu composites produced via laser powder bed fusion assisted by infiltration

Abstract

Plasma-facing components for thermonuclear fusion reactors require the introduction of new materials due to outstanding demands in mechanical, thermal, and thermal cycle fatigue resistivity properties. One promising solution is the WCu composite material or multimaterial that combines the properties of both components. In the present work, WCu samples were obtained by laser powder bed fusion (LPBF) consolidation of a tungsten porous matrix followed by copper infiltration. A design of structures with ordered porosity was achieved by translation of skeletal gyroid unit cell (triply periodic minimal surface). A relative density of 96.7% was achieved for solid pure tungsten samples with optimized LPBF process conditions. As-built W gyroid samples had a 15–20% ultimate compressive strength (UCS) of the solid sample. After the infiltration with copper, the ductility of WCu composites increased drastically, i.e. the samples did not fracture at a strain of 35%. It was found that UCS, yield strength (YS), and thermal diffusivity were sensitive to gyroid unit cell size. The sample with the smallest cell size of 2 mm had superior YS of 626 MPa and thermal diffusivity of 76.4 mm2/s. The obtained results will shed light on the possibilities for further development of WCu manufacturing technology based on the LPBF method combined with subsequent infiltration.