Novel eutectic high-entropy alloy surfacing of flower-pot structure with outstanding wear resistance manufactured by laser cladding

Abstract

Eutectic-high entropy alloys (EHEA) have been a hot topic of study in recent years due to their excellent thermal stability and great potential for industrial applications. In this study, a novel “flowerpot-seed” structure 19Al-24Cr-19Ti-37Ni-1Y eutectic high-entropy surfacing, which was manufactured by laser cladding successfully, is reported. The structure of EHEA surfacing consists of stable Heusler-type order phase (L21 phase) and B2 phase (interlamellar spacing of ∼320 nm). The structure near the interface resembles a "flowerpot-seed" with a large number of uniform rod-like nanoprecipitates inside the "seed", while the structure away from the interface resembles a "flower". The nanoprecipitates and low lattice misfit eutectic-phase interface with a lattice misfit of only 2.51% has the effect of strengthening and improving the hardness and wear resistance (WR) of EHEA surfacing. This alloy displays higher hot hardness and WR than most reported high-entropy alloys, EHEAs, and conventional Ni- and Co-based alloys widely used in industry.