Microstructure, mechanical and tribological properties of W–AlFeCoCrNi2.1 composites fabricated by laser direct energy deposition

Micron W particle reinforced W–AlFeCoCrNi 2.1 composites were additively prepared by laser direct energy deposition (LDED). The effect of W particle content on microstructure, mechanical and tribological properties of the W–AlFeCoCrNi 2.1 composites was studied. The results showed that the W particles partially dissolve in the AlFeCoCrNi 2.1 matrix, not only generating μ nanogranules at the phase interface of the FCC/BCC lamellas but also inducing the formation of the BCC-dominated flower-like structures. The heterogeneous distribution of the remained W particles results in the anisotropy of tensile properties. The tensile properties along the horizontal direction are better than that along the vertical direction. Planes with the densest W particles preferentially act as the easy-path of fracture. Owing to the synergistic effects of the solution strengthening of the matrix, precipitation strengthening of the μ nanogranules and phase strengthening of the BCC phase, along with the load-bearing strength of the W particles, the increasing W particle content improves the microhardness but deteriorates the tensile properties. The wear resistance is significantly improved by the increasing W particle content, attributed to the improvement of the hardness and the restriction of microcracks formation and oxide flakes spalling by the μ nanogranules and adhered W particles. The friction coefficient and wear rate achieve the minimum values of 0.75 and 4.36 × 10 −5 mm 3 /(N⋅m), respectively.