Ni60 self-lubricated anti-wear composite coatings were successfully precipitated on the 35CrMoV substrate by laser cladding technology. The effects of heat treatment on the macro-morphology, microstructure, precipitated phase, microhardness, and wear properties of the composite coatings with different heat treatment temperatures (25 °C, 500 °C, 600 °C, and 700 °C for 1 h) were investigated systemically. The macro-morphology, microstructure, precipitated phases, and elements distribution of laser cladding layers were detected by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS), respectively. The mechanical and tribological properties of the cladding layers were tested using a microscopic Vickers hardness tester and friction and wear tester, respectively. The results show that the main phases of Ni60 coatings are composed of γ-(Ni, Fe), Cr₇C₃, Cr₂₃C₆, CrB, CrFeB, and Cr₂Ni₃. In particular, the micro-structure and mechanical properties reach the best levels after heat treatment at 600 °C. The micro-hardness, average friction coefficient, and wear volume of the cladding layer are 771.4 to 915.8 HV₁ and 0.434 and 2.9546 × 10⁻⁵ mm³, respectively. In conclusion, the micro-structure and mechanical properties of the cladding layer are greatly improved by the proper heat treatment temperature.

The creep behaviour of hot hammer forged Ti-6Al-4V alloy under different forging temperatures has an essential influence on their high-temperature service performance. In this article, the high-temperature mechanical property and creep behaviour of Ti-6Al-4V alloy forging at different forging temperatures were first investigated experimentally. Then, in view of the critical effect of microcracks and other defects on the service life of components in forging, the creep characteristics at the tip of a 2 mm crack were characterized by the finite element method. The results show that when the Ti-6Al-4V alloy was forged at 1000°C, the high-temperature mechanical property was improved, and the steady-state creep rate and creep residual deformation were significantly reduced. In addition, the creep strain and creep rate at the crack tip were decreased apparently during creep, and the creep strain gradient in the crack tip region was also significantly reduced. This indicates that the creep deformation of Ti-6Al-4V alloy can be controlled by an appropriate forging temperature during hot hammer forging process and might delay the crack propagation to improve the service life of components.