Enhanced wear resistance of Ti(N, B)/AISI431 composite coating via exothermic in-situ reaction by ultra-high speed laser cladding

In order to enable efficient and cost-effective rehabilitation of surface-worn hydraulic supports, the synthesis and characterization of a novel Ti(N, B)/AISI431 composite coating formed on the surface of 27MnSi steel are explored via an exothermic in-situ reaction using the ultra-high speed laser cladding (EHLA in German) technique in combination with direct reaction synthesis (DRS). The aim is to mitigate the high residual stress and interfacial stress gradient in the remanufactured AISI431 coating on 27SiMn steel substrate and enhance surface wear resistance. The microstructure, phase composition and interface characteristics are carefully investigated. Much improved wear performance of the composite coating is revealed, mainly attributed to the in-situ formed Ti(N, B) precipitates, refined microstructure, broadened interface zone and reduced residual stress, benefited from the exothermic in-situ Ti(N, B)-reaction. The potential of combining ultra-high speed laser cladding with DRS is demonstrated to create coatings with tailored properties, providing valuable insights for developing advanced wear-resistant materials for industrial applications using EHLA.