Using Cr₇C₃/Ni₃Al alloyed powder and Cr₃C₂/Ni₃Al mixed powder, laser cladding was carried out to prepare a Cr₇C₃ reinforced Ni₃Al composite cladding layer. The microstructure and tribological properties of the cladding materials were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and wear tests. The results indicate that the microstructure of the Cr₇C₃/Ni₃Al alloyed powder cladding layer contains mainly Ni₃Al, NiAl, and in situ-formed Cr₇C₃, whereas Cr₃C₂ occurs in the Cr₃C₂/Ni₃Al mixed powder cladding layer. The friction coefficient and wear loss of the alloyed powder cladding layer are about 0.1 and 0.75 mg, respectively, which are less than those of the mixed powder cladding layer (0.12 and 0.8 mg). Moreover, the alloyed powder cladding layer is much friendlier to its counterpart. The counterpart’s loss weight of the alloyed powder cladding layer decreases 42.2% than the mixed powder cladding layer. The reason can be attributed to the homogeneous distribution of fine in situ-formed Cr₇C₃ in the alloyed powder cladding materials, which can effectively separate the friction pair, improving the wear resistance of the cladding materials.

In this paper, an engine piston ring coating comprising composite material of Fe₃Al and Cr₃C₂ mixed powder was prepared by laser cladding onto carbon structural steel. The microstructure and tribological properties of the cladding materials were investigated through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and wear tests. The influence mechanism of the Cr₃C₂ content in cladding powder was studied. During the process of wear, the soft Fe₃Al/Fe₂AlCr matrix is first ground off, and the hard Cr₇C₃ phase initially supports the abrasive surface before being worn away into hard particles, resulting in abrasive wear. With the increase in Cr₃C₂ content, the hardness of the cladding layer increases, the proportion of the Cr₇C₃ phase increases, and the morphology changes from a sparse network to a dense floccule. Of the cladding layers with different Cr₃C₂ content, the 15 wt.% Cr₃C₂ cladding layer had the lowest friction coefficient, and the 25 wt.% Cr₃C₂ cladding layer had the lowest wear rate. The low wear rate of the 25 wt.% Cr₃C₂ cladding layer can be attributed to the fact that adhesive wear does not easily occur and the fine microstructure of the strengthening phase, which facilitates better separation in the grinding surfaces.

In this paper, a brake cylinder coating comprising composite material of Fe₃Al and Cr₃C₂ mixed powder was prepared by laser cladding onto carbon structural steel. The microstructure of the cladding materials was investigated through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The influence mechanism of the Cr₃C₂ content and process parameters on crack generation of Fe₃Al/Cr₃C₂ composites were studied. The crack is mainly caused by the mismatch between the plastic phase of Fe₂AlCr, the brittle phase of Fe₃Al, and Cr₇C₃ in the cladding layer. With the increase in Cr₃C₂ content, Fe₂AlCr and Cr₇C₃ in the cladding layer increased, while Fe₃Al decreased. When the content of Cr₇C₃ is low, the cladding layer mainly reflects the plastic increase brought by Fe₂AlCr; when the content of Cr₇C₃ is too much, the property of the cladding layer is reflected as the brittleness of Cr₇C₃. The number of cracks reached the lowest value at 15 wt.%. The process parameters mainly affect the dilution rate of the cladding layer and thus affect the content of Fe₂AlCr.