APPLICATION OF THERMAL SPRAY TECHNOLOGY IN THE REFURBISHMENT OF AUTOMOTIVE CAMSHAFT COMPONENTS

Tóm tắt

This paper presents the research results on the application of High- Velocity Oxy-Fuel (HVOF) thermal spray technology for the refurbishment of automotive camshaft components manufactured from 40Cr steel using WC-12Co cermet coatings, as an environmentally friendly alternative to conventional hard chromium electroplating. The study employs the Taguchi experimental design method based on an L9 orthogonal array to evaluate the effects of key process parameters, including powder feed rate (m), rotational speed of the workpiece (n) and spray gun traverse distance (S), on the adhesion strength of the coating. The results indicate that the maximum adhesion strength of 72.8MPa was achieved under the optimal process conditions (m = 32g/min, n = 100rpm, S = 8mm/rev). Microstructural analysis using SEM confirms that the coating exhibits a dense lamellar structure with low porosity (< 1%), where the dominant bonding mechanism is mechanical interlocking combined with metallurgical diffusion at the coating-substrate interface. The study demonstrates the high feasibility of HVOF spraying technology in enhancing the service life and functional performance of refurbished camshafts, meeting the stringent requirements of the automotive industry.