Mold copper plates (Cr–Zr–Cu alloy) frequently fail due to severe wear under high-temperature conditions during continuous casting. To solve this problem, Inconel 718 coatings were prepared on the plate surface via laser cladding to enhance its high-temperature wear resistance. The results demonstrate that the coatings exhibit a defect-free structure with metallurgical bonding to the substrate. The coating primarily consists of a γ-(Fe, Ni, Cr) solid solution and carbides (M₂₃C₆ and M₆C). Notably, elongated columnar Laves phases and coarse Cr–Mo compounds were distributed along grain boundaries, significantly enhancing the coating’s microhardness and high-temperature stability. The coating exhibited an average microhardness of 491.7 HV_0.5, which is approximately 6.8 times higher than that of the copper plate. At 400 °C, the wear rate of the coating was 4.7 × 10⁻⁴ mm³·N⁻¹·min⁻¹, significantly lower than the substrate’s wear rate of 8.86 × 10⁻⁴ mm³·N⁻¹·min⁻¹, which represents only 53% of the substrate’s wear rate. The dominant wear mechanisms were adhesive wear, abrasive wear, and oxidative wear. The Inconel 718 coating demonstrates superior hardness and excellent high-temperature wear resistance, effectively improving both the surface properties and service life of mold copper plates.

Laser cladding is a new technology to fabricate a coating on the surface of a metal substrate. The properties on copper substrates are usually not very good due to the high thermal conductivity and reflectivity. The appropriate preheating temperature is helpful to fabricate coatings with good quality and properties, especially for copper substrates. In order to investigate the effect of different preheating temperatures, four coatings with different preheating temperatures (100, 200, 300 and 400 °C) were fabricated via a laser on a copper substrate. The microstructures and properties of four coatings were investigated using SEM, XRD, EDS, a Vickers microhardness meter, a wear tester and an electrochemical workstation. The results show that the elements from Ni-based alloy powder were uniformly distributed among the binding region, which obtained a good metallurgical bonding. The microstructure was mainly composited of cellular, dendrite and plane crystals, and the main reinforced phases were γ (Fe, Ni), Cr_0.09Fe_0.7Ni_0.21, WC and Ni₃B. The values of average microhardness of the four coatings were 614.3, 941.6, 668.1 and 663.1 HV_0.5, respectively. The wear rates of the four coatings were 9.7, 4.9, 12.5 and 13.3 × 10⁻⁵ mm³·N⁻¹·m⁻¹, respectively, which were less than that of the copper substrate (4.3 × 10−3 mm³·N⁻¹·m⁻¹). The decrease in wear rate was due to the existence of the reinforced phases, such as WC, Ni₃B, M₇C₃ (M=Fe, Cr) and Cr_0.09Fe_0.7Ni_0.21. The fine crystals in the coating preheated at 200 °C also improved the wear resistance. Additionally, the minimum values of corrosion current density were 3.26 × 10⁻⁵, 2.34 × 10⁻⁷, 4.02 × 10⁻⁶ and 4.21 × 10⁻⁶ mA·mm⁻², respectively. It can be seen that the coating preheated at 200 °C had higher microhardness, lower wear rates and better corrosion resistance due to the existence of reinforced phases and fine and uniform crystals.

Based on laser cladding technology, six composite coatings with different amounts of Inconel 718 and 0~5% CeO₂ were successfully prepared on the 316L stainless steel substrate. The effect of different amounts of CeO₂ particles was investigated and discussed, such as microstructure, phases, elemental distribution, microhardness, wear resistance and corrosion resistance. The results show that the phases are composed of γ~(Fe, Ni), Ni₃Nb, (Nb_0.03Ti_0.97)Ni₃, and MC_X(M = Cr, Nb and Mo). When the amount of CeO₂ particles is higher than 1%, some Ce₂O₃ compounds can be detected in coatings. The average microhardness values of N0~N5 are 604.6, 754.5, 771.6, 741.4, 694.5 and 677.3 HV_0.2, respectively. There is a trend that the microhardness increases firstly and then decreases, because an appropriate amount of CeO₂ can improve the solid solution strength. The average wear rate values of N0~N5 are 2.97 × 10⁻⁵, 1.22 × 10⁻⁵, 0.94 × 10⁻⁵, 1.53 × 10⁻⁵, 1.81 × 10⁻⁵ and 2.26 × 10⁻⁵ mm³∙N⁻¹∙min⁻¹, respectively. The N2 coating has the smallest corrosion current density of 2.05 × 10⁻⁴ A·cm⁻², which is about 56% of the N0 coating. When the amount of CeO₂ particles is 2%, the coating has the best wear resistance and corrosion resistance due to fine grains and Cr, Nb and Mo compounds.

In order to improve the high-temperature wear resistance of mold copper plates, this study used laser cladding technology to prepare a high-wear-resistant composite coating with Inconel 718 and WC(Tungsten carbide) particles. The phase composition, microstructure, microhardness, and tribological properties at 400 °C were systematically analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Vickers microhardness tester, and high temperature friction and wear tester. The results indicate that the Inconel 718/WC coating is free of pores and cracks and exhibits a metallurgical bond with the substrate. Its phases mainly consist of a γ-Ni solid solution and various hard carbide reinforcing phases, such as MC, M₃W₃C, and W₂C. The average microhardness of the coating reaches 851.7 HV_0.5, which is 11.5 times than that of the substrate (74 HV_0.5). At 400 °C, the wear rate of the coating is 3.48 × 10⁻⁴·mm³·N⁻¹·m⁻¹, only 35.7% of the substrate’s wear rate. The dominant wear mechanism is abrasive wear, accompanied by oxidative wear. The outstanding performance of the coating is attributed to the combined effects of grain refinement strengthening, solid solution strengthening, and second-phase strengthening induced by the various hard carbides.