Microstructure and Properties of AlCoCrFeNiTi High-Entropy Alloy Coating on AISI1045 Steel Fabricated by Laser Cladding

AISI1045 steel is widely used in mechanical engineering. In spite of the favorable toughness and strength, the surface properties of AISI1045 steel, such as hardness, wear resistance and corrosion resistance, are not ideal. Therefore, surface modification of AISI1045 is necessary, especially for the parts suffering severe work condition. Laser cladding is a promising surface modification technology. In this work, the AlCoCrFeNiTi high-entropy alloy (HEA) coatings were prepared on the AISI1045 steel to improve its surface properties. Metallurgical bonding is obtained between the coating and the substrate. The microstructure and surface properties of the coating were characterized by scanning electron microscope, energy-dispersive spectrometry, x-ray diffraction, electrochemical workstation, microhardness tester and pin-on-ring wear tester. The microstructure of the coating produced by laser cladding is dendritic. The AlCoCrFeNiTi HEA coating is mainly composed of disordered body-centered cubic phase (Fe-Cr), ordered B2 phase (AlNi) and intermetallic phase (Ti-rich). The coating shows excellent abrasion resistance and corrosion resistance in comparison with the substrate. The maximum microhardness of the coating reaches approximately 865 HV, which is 4.5 times of AISI1045 steel.