Diffusion Study of Al-8%Si Alloy Double-Coating on Steel
Al-8%Si alloy double-coating on Q235 steel were produced, Then the samples were executed diffusion at high temperatures protecting with flowing argon gas. Scanning electron microscope (SEM), optical microscope (OM), and energy dispersive X-ray spectroscope (EDS) were employed for microstructure observation of cross-sectional, surface and compositional analysis of coating. The diffusion mathematical model was established with the finite element method. The results show that good quality Al-8%Si coating is made; after heat-diffusion treatment, the new phases FeAl and Fe3Al presents; Silicon atoms in Al-8%Si alloy can hinder the diffusion of aluminum atoms into steel substrate at high temperature; Al-8%Si alloy double-coating sample’s high-temperature oxidation resistance is higher than Q235 steel. This material is hopefully used in the engine exhaust manifold.
Zhengyi Jiang, Shanqing Li, Jianmin Zeng, Xiaoping Liao and Daoguo Yang
Y. H. Lu et al., "Diffusion Study of Al-8%Si Alloy Double-Coating on Steel", Advanced Materials Research, Vols. 189-193, pp. 1080-1084, 2011