Optimization of ZrB2 content in CoCrNiFeAl high-entropy alloy coatings: experimental and simulation study of microstructure and wear resistance

• CoCrNiFeAl coatings with varying ZrB 2 contents were additively made; microstructure and wear studied. • The best hardness, grain refinement and excellent friction properties were obtained with the addition of 20 wt% ZrB 2 . • The addition of 30 wt% ZrB 2 triggers ceramic agglomerations, leading to stress concentrations and uneven surface wear. • FE simulation accurately captured stress distribution, matching well with experimental wear depth. CoCrNiFeAl high-entropy alloy (HEA) composite coatings with various ZrB 2 contents (10 wt%, 20 wt%, and 30 wt%) were fabricated on 316 stainless steel substrates using additive manufacturing. The effects of ceramic phase content on the phase composition, grain size, hardness, and tribological behavior of the coatings were systematically investigated. XRD, EBSD, and SEM characterizations revealed that ZrB 2 addition promoted the FCC-to-BCC phase transition and significantly refined the grain structure. Tribological tests showed that the 20 wt% ZrB 2 coating had the most stable coefficient of friction and the highest wear resistance. However, excessive ZrB 2 (30 wt%) content resulted in ceramic particle agglomeration, localized stress concentrations, and interfacial degradation. Finite element modeling using the Digimat/ANSYS platform confirmed the stress amplification effect in agglomerated regions. Overall, according to observed mechanical properties, 20 wt% ZrB 2 content was identified as the optimal reinforcement level for this system.