中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 31 No. 9 September 2021 |
（1. School of Mechanical and Electrical Engineering, Nanchang University, Nanchang 330031, China;
2. Nanchang Key Laboratory of Light Alloy Preparation & Processing, Nanchang 330031, China;
3. School of New Energy Vehicles, Nanchang Institute of Science & Technology, Nanchang 330108, China）
Abstract:The microstructure, microhardness, and corrosion resistance of laser cladding Ni-WC coating on the surface of AlSi5Cu1Mg alloy were investigated by scanning electron microscopy, X-ray diffraction, microhardness testing, immersion corrosion testing, and electrochemical measurement. The results show that a smooth coating containing NiAl, Ni3Al, M7C3, M23C6 phases (M=Ni, Al, Cr, W, Fe) and WC particles is prepared by laser cladding. Under a laser scanning speed of 120 mm/min, the microhardness of the cladding coating is 9-11 times that of AlSi5Cu1Mg, due to the synergistic effect of excellent metallurgical bond and newly formed carbides. The Ni-WC coating shows higher corrosion potential (-318.09 mV) and lower corrosion current density (12.33 μA/cm2) compared with the matrix. The crack-free, dense cladding coating obviously inhibits the penetration of Cl- and H+, leading to the remarkedly improved corrosion resistance of cladding coating.
Key words: laser cladding; Ni-WC coating; AlSi5Cu1Mg; mechanical properties; corrosion resistance
