Optimisation of the wear resistance properties of laser cladded T-800 coatings

摘要

Taguchi design of experiments (DoE) was employed to determine appropriate laser cladding (LC) parameters for optimising microstructural and anti-wear properties of Tribaloy (T-800) coatings. The nature of wear mechanism was also explored with scanning electron microscopy (SEM). Statistical analysis established that both microhardness and wear rates were primarily dependent on powder feed rates and scanning speeds while coefficient of friction (COF) is significantly influenced by spot diameter. Variation in wear morphology, across the samples, could be explained by presence or absence of surface defects; sizes of surface defects, distance between the surface defects as well as the nature of evolving microstructure within the clad samples. Optimum samples were imparted with microhardness (900 HV), COF (0.0743) and specific wear rate (0.0071 mm(3)/N/m), and these compared favourably well with the predicted values. Samples fabricated with optimum LC parameters are suitable for wear application in mining industries.