Cr12MoV has been widely used in the manufacture of stamping and drawing dies. In the present study, an attempt was made to improve the mechanical properties of Cr12MoV by laser cladding Ni60 alloy reinforced by WC. X-ray diffraction (XRD), scanning electron microscopy (SEM), a microhardness tester, and a friction and wear test prototype were used to analyze the macroscopic morphology, microstructure, and mechanical properties of the coating. The results showed that the coating mainly was composed of Cr-Fe-Ni, γ-(Fe, Ni), Cr₂₃C₆, Cr₇C₃, and W₂C phases. The cladding layer presented the dendritic eutectic structure enriched Cr, Fe, and Ni. Zigzag-shaped dendrites with thicknesses of 50~80 μm of the bonding zone ensured the strong metallurgical bonding. Due to solid solution strengthening, dispersion hardening, and grain refinement, the hardness of the coating reached 745 HV, which was 3.5 times that of the substrate. The wear volume of the coating was 14 × 10⁻³ mm³, which was 48% lower than that of the substrate (27 × 10⁻³ mm³). The coating had the abrasive wear; however, the substrate had the adhesive wear besides the abrasive wear.

Y₂O₃-reinforced Al-Si alloy coatings were prepared on the surface of a Mg alloy by the laser cladding technique. The microstructure, hardness, and wear resistance of the coatings were analyzed using an X-ray diffractometer, a scanning electron microscope, an energy spectrometer, a Vickers hardness tester, and a friction wear tester. The effect of different additions of Y₂O₃ on the microstructure and properties of the coatings was investigated. The results indicate that the addition of Y₂O₃ leads to a significant refinement of the grain size and a denser microstructure of the coatings. Coatings with a high Y₂O₃ content provide superior hardness and wear resistance. With a Y₂O₃ content of 7.5 wt.%, the coating exhibits the finest grain size, highest hardness, and smallest wear volume. Excessive amounts of Y₂O₃, however, cause a reduction in the surface properties of the coating.

Al-Si/7.5 wt.%Y₂O₃ coatings were prepared on Mg alloy with laser cladding to enhance the wear and corrosion resistance of substrate. The influence of laser power on the microstructure and properties of the coating were discussed. The results uncovered that the coatings consisted primarily of Mg₂Si, Mg₁₇Al₁₂, Mg₂Al₃, Al₄MgY, and α-Mg phases. Through calculation, it was observed that the crystal size decreased with the decrease in the laser power. Y₂O₃ gave the coating a better strengthening effect due to the fine-grain strengthening and hard-phase strengthening. The average hardness of the coating with laser power of 1100 W achieved 312 HV, which was approximately 4.2 times that of the substrate. The wear volume of the coating was 22.2% that of the substrate. Compared with Mg alloy, the self-corrosion potential of the coating increased by 1.09 V, and the self-corrosion current density decreased by three orders of magnitude.

To enhance high-temperature wear resistance of H13 steel, laser cladding was used to prepare a high-entropy alloy + carbide composite coating. The microstructure and high-temperature wear resistance of the composite coating were systematically analyzed. The results indicate that the FeCoCrNiAl + WC composite coating had a phase structure of BCC + FCC solid solutions, with a small amount of CFe15.1. The microstructure of the composite coating consisted of columnar and equiaxed grains. The microhardness of the FeCoCrNiAl + WC composite coatings was approximately 3.0–3.4 times that of H13. At wear temperatures of 823 K, compared with H13 steel, the wear volumes of composite coatings with different WC contents were reduced by 73.4%–80.2%. Among these, the FeCoCrNiAl + 10% WC composite coating showed the lowest wear volume. Furthermore, when wear temperatures increased from 623 K to 823 K, compared with H13 steel (108.37%), the increase in the wear volume of the FeCoCrNiAl + 10% WC coating was reduced to 90.82%, which indicates the FeCoCrNiAl + 10% WC coating had better high-temperature wear resistance. The wear mechanisms of the composite coating were abrasive and oxidative wear, while H13 steel exhibited abrasive wear, oxidative wear and fatigue wear.

This paper investigated the FeCoCrNiAl high-entropy alloy on H13 steel, prepared using laser cladding, to improve the elevated-temperature wear resistance of the alloy. The results revealed that FCC and BCC phases, in terms of the coating, produced a large dislocation density. The coating exhibited a columnar and equiaxed crystal microstructure. With the comprehensive effects of fine-grain strengthening, solid solution strengthening, and dislocation strengthening, the average hardness of the coating (500 HV_0.1) was improved by 150% compared with that of H13 steel (200 HV_0.1). The wear experiments were conducted at 623 K, 723 K, and 823 K. Compared with H13 steel, the wear volume of the coating decreased by 59.20%, 70.79%, and 78.20% under different temperatures. The wear forms impacting the coating were mainly abrasive wear and oxidation wear. However, H13 steel presented adhesive wear and fatigue wear, in addition to abrasive wear and oxidation wear.

The microstructure and properties of Al-matrix composites are directly determined by ceramic particles in the matrix, such as synthetic methods, morphologies, sizes, interface, etc., especially the distribution of particles. Hereinto, Al-matrix nanocomposites, which show brilliant, comprehensive properties, have been widely studied. How to give full play to its advantages in further applications in automotive and aerospace areas has attracted considerable attention from researchers. In this review, current development on the pre-distribution of reinforcement particles and deformation processes and microstructure, mechanical properties of Al-matrix composites reinforced with in-situ and ex-situ nanoparticles will be addressed. In addition, the corresponding development prospects and challenges of nanoparticles reinforced Al-matrix composites fabricated by a combination of pre-distribution and deformation were also summarised.