Three-dimensional connected W-Cu10Sn composites materials with high relative density (99.36%) were fabricated through selective laser melting (SLM). The densification process of the composite balanced the melting of W, evaporation of Cu/Sn and the spreading of melted a-Cu. Under the optimized SLM parameters,

high laser power (LP) melted the most of W powder, the adjacent laser scanning track with small hatch space (HS) could fuse Wphase together. With small HS and low scanning speed (SS), the spreading of melted a-Cu could fill up the pores caused by the evaporation of Cu/Sn. Finally, a three-dimensional connected structure is formed by W phase, and a-Cu phase occupied the gaps the gaps among W phase.