W–Cu composites with excellent comprehensive properties

Abstract

Excellent mechanical and physical properties are usually mutually exclusive in W–Cu composites, which makes it challenging to achieve outstanding comprehensive performance. In the present work, improved copper connectivity and uniformly dispersed ultrafine tungsten particles were achieved in the ultrafine grained (UFG) W–Cu composites. The as-prepared UFG W–Cu composites exhibited enhanced combination of hardness, compressive strength and electrical conductivity compared with those reported in the literature. Specifically, the UFG W–30Cu composite showed a compressive strength over 1200 MPa (2.1 times that of the coarse grained counterpart), a hardness of 357 HV and an electrical conductivity of 48.6%IACS. The strengthening mechanisms of the presented W–Cu composites were quantitatively discussed in terms of grain refinement, stress transfer and dislocations strengthening. This study provides a novel approach for the synthesis of W–Cu composites with excellent comprehensive properties. W–Cu composites with an interconnected copper network structure and a uniform distribution of the ultrafine tungsten particles were synthesized by a novel approach integrating modified electroless plating and spark plasma sintering. The prepared materials show excellent combination of mechanical and electrical properties as compared with the reported counterparts in the literature. The strengthening and failure mechanisms of the presented W–Cu composites were disclosed. This study provides a new strategy for design and fabrication of bimetal composites with outstanding comprehensive mechanical and physical properties. • Improved Cu connectivity and uniformly dispersed ultrafine W particles are achieved in the UFG W–Cu composites. • The prepared UFG W–Cu composites exhibit enhanced combination of hardness, compressive strength and electrical conductivity. • Dislocations strengthening contributes the most to the strength improvement of the prepared UFG W-Cu composites.