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Laser cladding is a powerful surface treatment technique that can significantly enhance the properties of metal alloys. This study delves into the liquid phase separation behavior of Cu-Fe-Cr alloys under the rapid solidification conditions inherent in laser cladding and evaluates the influence of 4% Mo and 2% B4C additions on the resulting alloy characteristics. The intensive undercooling characteristic of the laser cladding process facilitates the alloy's entry into the liquid-phase immiscibility gap, prompting pronounced phase separation. Our investigation reveals the emergence of Fe-rich regions, exhibiting a variety of shapes, set against a continuous Cu-rich matrix. The incorporation of Mo and B4C was found to modulate the mixing enthalpy and entropy, thereby refining the phase distribution: Mo was observed to prevent the agglomeration of Fe cores, resulting in a dispersion of isolated Fe cores throughout the Cu-rich matrix, while B4C promoted a more uniform compositional distribution. This study further enumerates the enhancements in microhardness, wear resistance, and magnetic properties of the alloys. Notably, the Cu-Fe-Cr-Mo-B4C alloy demonstrated a microhardness exceeding 600 HV, a low coefficient of friction around 0.15, high saturation magnetization, and reduced coercivity. These results underscore the efficacy of laser cladding in tailoring the microstructure and properties of Cu-Fe alloys, providing insights for the controlled manipulation of phase separation to optimize surface characteristics for engineering applications. [ABSTRACT FROM AUTHOR]

To improve the wear resistance of Fe-based cladding, NbC particles with different morphology are generated in situ by adding Nb, Cr 3 C 2 and C with different content. The composition of samples and the morphology of NbC particles generated in situ are revealed by XRD, SEM and EDS. The wear resistance is studied by a reciprocating friction and wear testing machine. The wear mode and the wear mechanism of each sample are investigated. The results show that although NbC particles are generated in situ in samples with different Nb, Cr 3 C 2 and C content, the morphology of NbC particles is varied. The wear resistance of samples containing cross-shaped NbC particles is more outstanding than that of samples containing only rectangular NbC particles. In addition, changing Nb, Cr 3 C 2 and C content does not result in a change in wear mode, but leads to the formation of continuous lattice structure of Cr 0.19 Fe 0.7 Ni 0.11 and Cr 23 C 6 compounds at grain boundaries and a change in the wear resistance. When the additions of Nb, Cr 3 C 2 and C are 11.2 wt%, 8.6 wt% and 0.2 wt% respectively, the coefficient of friction of the sample is the lowest, and the wear resistance is the most outstanding. [ABSTRACT FROM AUTHOR]

• Laser remelting tests were conducted on the Fe-based clad layer under different remelting time and remelting power conditions. • The morphological characteristics of the Fe-based clad layer after remelting under different remelting time and remelting power conditions were investigated. • The microhardness of the Fe-based clad layer after remelting under different remelting time and remelting power conditions was investigated. • The wear resistance, wear rate and wear mechanism of the Fe-based clad layer after remelting under different remelting time and remelting power conditions were investigated. • When the remelting time is 1 and the remelting power is 650 W, the clad layer has high microhardness and outstanding wear resistance. Laser remelting is a processing technique to improve the quality of forming. The remelting power and the remelting time are the key factors affecting its processing quality. Laser remelting tests were conducted on Fe-based clad layers with different remelting power and remelting time, and the morphological characteristics of each clad layer was investigated by laser microscopy. The microhardness, wear resistance and wear mechanism of each clad layer were investigated by Vickers microhardness tester and reciprocating friction and wear tester, respectively. The results show that an increase in remelting power or remelting time leads to a decrease in clad height and an increase in melting pool depth, clad width and dilution rate. When the remelting time is 1 and the remelting power is 650 W, the clad height is higher than that of YCF102 clad layer, although the melting pool depth, clad width and dilution rate of the clad layer are greater than that of YCF102 clad layer. In addition, an increase in remelting power or remelting times leads to a decrease in the microhardness of the clad layer and a deterioration in the wear resistance, which leads to an increase in the wear rate, but does not change the trend of microhardness, wear resistance and wear rate. Neither the increase in remelting power nor the remelting time leads to a change in the wear form, but causes the wear between the clad layer and the grinding ball to become more intense. The clad layer with 1 remelting time and 650 W remelting power has higher average microhardness and more outstanding wear resistance than the YCF102 clad layer. [ABSTRACT FROM AUTHOR]

The aim of this paper is to investigate the effect of laser re-melting on the morphology and mechanical properties of cladding layer under different laser power conditions. In this study, the laser re-melting tests were performed on YCF102 cladding layer with different laser power, and the morphology and microstructure of each cladding layer were researched by optical microscopy. Meanwhile, the microhardness and wear resistance of YCF102 cladding layer after laser re-melting with different laser power were studied. The results show that laser re-melting can not only improve the morphology of cladding layer, but also improve the microhardness and wear resistance of cladding layer. However, the excessive re-melting laser power leads to the increase of the number of defects in the cladding layer and the deterioration of the mircrohardness and wear resistance of cladding layer. When the re-melting laser power is 650 W, the cladding layer not only has a small surface roughness and no defects, but also has good mechanical properties. • Laser re-melting can reduce the number of defects in the cladding layer. • Laser re-melting can improve the surface morphology and mechanical properties. • Excessive re-melting laser power causes degradation of the mechanical properties. • Re-melting laser power is related to surface morphology and mechanical properties. [ABSTRACT FROM AUTHOR]