New nano-lamellar eutectic high-entropy alloy coating by laser cladding.

A novel Al 27 Cr 25 Ti 18 Nb 18 Zr 12 eutectic high entropy alloy (EHEA) coating with BCC/B2 and Laves phase has been developed by laser cladding on Ti–6Al–4V alloys. The average microhardness of EHEA coating was ∼697.6HV 0.3 , which significantly surpasses the values reported for most eutectic high-entropy alloy coatings. The strengthening effect and additional strain hardening sources generated by the intersecting nanometer-spaced stacking faults and Lomer-Cotrell locks which found in BCC/B2 phase are important reasons for the superior hardness. And the adhesive problem of Ti–6Al–4V alloy was ameliorated by the EHEA coating with lower friction coefficient (83.05 % of the Ti–6Al–4V alloy) and volumetric loss (27.75 % of the Ti–6Al–4V alloy). • A novel eutectic high entropy alloy (EHEA) coating consisting of BCC/B2 and Laves phases was firstly reported. • A large number of intersecting nanometer-spaced lattice imperfections were found inside the BCC/B2 phase. • Due to the rigid eutectic phases and lattice imperfections, microhardness in this work exceeds the majority of EHEAs. • The adhesive problem of Ti–6Al–4V alloy was ameliorated by this coating and the effect mechanism was investigated. [ABSTRACT FROM AUTHOR]