Abstract
TiN and WS2 + hBN reinforced Ni-based alloy self-lubricating composite coatings were fabricated on TC4 alloy by laser cladding using TiN, NiCrBSi, WS2, and hBN powder mixtures. Energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffractometry (XRD), and optical microscopy (OM) were adopted to investigate the microstructure. The wear behaviors of the self-lubricating composite coatings were evaluated under large contact load in room temperature, dry-sliding wear-test conditions. Results indicated that the phases of the coatings mainly include γ-Ni, TiN, TiNi, TiW, WS2, and TiS mixtures. The average microhardness of the composite coating is 2.3–2.7 times that of the TC4 matrix. Laser cladding TiN/WS2 + hBN/NiCrBSi self-lubricating composite coatings revealed a higher wear resistance and lower friction coefficient than those of the TC4 alloy substrate. The friction coefficient (COF) of the coatings was oscillating around approximately 0.3458 due to the addition of self-lubricant WS2 + hBN and hard reinforcement TiN. The wear behaviors testing showed that the wear resistance of the as-received TC4 was significantly improved by a laser cladding TiN/WS2 + hBN/NiCrBSi self-lubricating composite coating.
Highlights
TC4 alloy is extensively applied in the fields of aeronautics and astronautics, petrochemistry, shipbuilding, biomedical, etc
Self-lubricating coatings have been widely used to fabricate components operating under extreme conditions, and solid self-lubricating composites exhibit prominent tribology, stabilizing chemical properties, broad temperature range, and pro-environment properties, which are capable of generating prominent self-lubricating effects in friction
The decomposition and evaporation of sulfide as a lubrication phase occurs, limiting it to be industrially applied in laser clad self-lubricating composite coatings
Summary
TC4 alloy (Ti–6Al–4V) exhibits low density, large specific strength, high Young’s coefficient, good anti-corrosive quality, and prominent biocompatibility, which are considered its advantages. NiCrBSi powder refers to a self-melting alloy powder with a low melting point (1027 ◦ C); the content of oxygen is zero, and the wettability is prominent. Bowen et al, based on laser cladding, processed the surface of TC4 alloy to prepare an NiCrBSi wear-resistant composite coating. Weng et al, based on laser cladding, delved into the synthesis of the Co/TiN/Y2 O3 composite coatings on TC4 alloy surface; the average microhardness (1197.9HV0.2 ) reached nearly. The decomposition and evaporation of sulfide as a lubrication phase occurs, limiting it to be industrially applied in laser clad self-lubricating composite coatings. In this study, based on laser cladding technology, a self-lubricating composite coating of TiN, TiNi, TiW, TiS, and an hBN lubrication phase was precast on TC4 alloy substrate. A prominent composite self-lubricating coating was achieved with TiS and hBN lubrication, and the synergy was achieved between rigid titanium intermetallic compounds
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
