The Ni60-SiC-CeO2 strengthening layer with deep remelting pools was constructed on the surface of 7075 aluminum alloy using the laser remelting-cladding processing method, and a soft and hard interphase was prepared on the matrix by the interval of laser remelting, which was inspired by soft-hard interphase structure with excellent crack inhibition performance from the natural world. The microstructure and microhardness of the remelting region and the remelting-cladding region of the strengthening layer were studied. The tensile characteristics of two distinct strengthening layers were investigated in the laboratory. The results showed that the grain size of remelting pools is finer, and the microhardness is higher than that of the matrix, which makes crack propagation more difficult. In addition, the results show that the strengthening layer has compact and flawless microstructure and has been metallurgically integrated with the matrix, and the microhardness of the regions treated by laser cladding and laser remelting-cladding has been improved obviously. Toughness has improved, as has the problem of toughness reduction after cladding ceramic particles. The sample's strength is also significantly greater than that of the untreated sample.
Keywords: 7075 aluminum alloy; laser remelting-cladding; strengthening layer.