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Laser cladding technology can obtain a cladding layer with good metallurgical bonding with the substrate and excellent performance. In situ growth of hard phase can effectively solve the problem of uneven distribution of reinforcements directly doped with hard particles. In this paper, 45# steel was adopted as the matrix material, WO3, B4C, Al, and Ni60 powder were used to prepare laser cladding and in situ synthesized WC (Tungsten Carbide) hard phase reinforced Ni‐based cladding layers. The effects of different laser cladding parameters, powder particle size, hard phase content on the microstructures and electrochemical properties of in situ synthesized WC hard phase reinforced Ni‐based cladding layer were analyzed. The results revealed that when the (WO3 + B4C + Al) mixed powder content was 25%, the bulk particles of WC phase in the cladding layer were most uniformly distributed in the cladding layer, which enhances the mechanical properties of the cladding layer. When the B4C particle size was 5 μm, the microhardness of the cladding layer was significantly higher than other cladding layers, and the enhancement mechanism of hardness by B4C is due to the Orowan strengthening caused by too small particle size of B4C. [ABSTRACT FROM AUTHOR]

A kind of wear‐resistant diamond‐like carbon (DLC) films doped with Ni, N, and multiwalled carbon nanotubes (MWCNTs) are synthesized on Ti–6Al–4V titanium alloy by a combined method of pulsed electrodeposition and liquid‐phase electrodeposition. The effect of different concentrations of MWCNTs on the microstructure and friction mechanism of Co‐DLC films is investigated. The results show that the polydimethyl diallyl ammonium chloride (PDDA)‐MWCNTs complex tend to deposit parallel to the substrate. Benefiting from the "bridging" effect of the MWCNTs between the cluster structures, it effectively reduces the protrusions on the surface of the films. When the concentration of MWCNTs is 0.06 g L−1, the surface microstructure of the films is uniform and dense, and the films present a low ID/IG value (0.57) and a high sp3‐C content. The Raman and X‐ray photoelectron spectroscopy patterns reveal that the Ni/N/MWCNTs‐DLC films are typical amorphous carbon films. Furthermore, the micro‐indentation hardness of the Co‐DLC films reaches 513.24 HV. The lubricated Ni/N/MWCNTs‐DLC films significantly improve the frictional wear properties of the titanium alloy surface, which is mainly attributed to the homogeneous and dense structure and the low friction coefficient (0.146) and wear loss (1.40 × 10−5 kg m−1). [ABSTRACT FROM AUTHOR]