Infiltrated W–Cu composites with combined architecture of hierarchical particulate tungsten and tungsten fibers

• W-fibers reinforced W–Cu composites were fabricated by sintering and infiltration.
• The sputtered Cr onto Wf has dissolved into adjacent Wf and Wp during fabrication.
• The intact interfaces of Wf/Wp and Wf/Cu confer enhanced strength and ductility.
• Tensile strength and hardness improve by 23.6% and 9.3% after interface tuning.

In this article, novel W–Cu composites reinforced with topologically-inserted tungsten fibers (Wf) have been fabricated by hot-press sintering and infiltration method. By pre-sputtering of ~ 100 nm thick chromium layer onto the surface of Wf, the contiguity or connectivity between Wf and neighboring tungsten particles (Wp) or Cu after sintering and infiltration was enhanced. Combined SEM, TEM and STEM techniques confirmed that the intact interfaces of Wf/Wp and Wf/Cu free from precipitates, impurities and porosities would provide desirable strength and ductility. Further mechanical tests also validated its superior compressive strength and plasticity at various temperatures, together with significantly improved tensile strength (by 23.6%) and hardness (by 9.3%) for the W–Cu composite after reinforcement with Cr-coated Wf, which promotes the engineering application of the composite greatly.