The microstructure and properties of Ti-enhanced AlCoCrFeNiTix coatings prepared by laser cladding

Abstract

The B2 phase in AlCoCrFeNi coatings prepared by conventional techniques is quite large, which hampers the attainment of desirable strength and plasticity. In this research, AlCoCrFeNiTi_x coatings were prepared by the laser cladding technique. The ideal content of Ti enhances both the strength and plasticity of the coatings. The results show that increasing the Ti content does not greatly change the phase composition of the coating. A significant leftward shift in the diffraction peaks related to the FCC matrix and the B2 phase is noted. The B2 phase in the coating experiences a gradual process of refinement and homogenization, which can greatly enhance the strengthening effect on the FCC matrix. There have been notable improvements in the coating’s hardness and wear resistance. The tensile strength of the coating shows a steady increase, with the AlCoCrFeNiTi_0.3 coating reaching a tensile strength of 1297 MPa, which is higher than the 1179 MPa recorded for the AlCoCrFeNi coating. Initially, the elongation of the coating rises before it starts to decline, with the AlCoCrFeNiTi_0.15 coating achieving a peak elongation of 13.5 %. This behavior is mainly due to the refinement of the B2 phase and the higher concentration of Ti in solid solution.