Microstructure and high-temperature wear behaviour of Inconel 625 multi-layer cladding prepared on H13 mould steel by a hybrid additive manufacturing method

To improve the high-temperature performance of a hot-working mould, high-temperature wear-resistant multi-layer laser cladding was prepared on the forming surface of the mould by a hybrid additive manufacturing (HAM) method. First, an Inconel 625 multi-layer cladding was fabricated on the H13 mould steel by laser cladding. Then, the multi-layer laser cladding was milled by CNC. Finally, the milled multi-layer cladding was subjected to ultrasonic surface rolling (USR) treatment. The microstructure and high-temperature wear behaviour of the multi-layer cladding prepared by HAM were studied using SEM, EDS, and a high-temperature tribometer. The results show that the multi-layer laser cladding after USR has a smooth nanolayer. The surface roughness is below 0.15 μm. The multi-layer cladding has better high temperature wear resistance than the substrate. The microstructure of the multi-layer cladding from the surface to the substrate is composed of coaxial, columnar, and dendritic grains. After USR treatment, the dendritic grains are grown in the processing direction and significantly refined.