LAUSR

Abstract In situ heterogeneous Cu/TiB2 composites with a harmonic structure, where the soft domains of pure Cu are completely surrounded by the hard TiB2 enrichment domains, were fabricated by hot pressing. By controlling the ratio of the Cu powders during ball milling and vibrational blending, composites with different degrees of heterogeneity were obtained. The results of tensile testing show that the composites with proper degrees of heterogeneity possess an excellent combination of strength and ductility. In light of the loading–unloading–reloading tensile test and microstructure analysis results, the strengthening and toughening mechanisms of the heterogeneous composites are discussed. The high strength is attributed to back-stress hardening resulting from plastic incompatibility. The back-stress hardening associated with the strain partitioning results in an enhanced ductility.