Yongzhe Fan

Influences of Si on corrosion of Fe–B alloy in liquid zinc

Abstract Influences of silicon content on the microstructure and corrosion resistance of a Fe–2·5 wt-%B alloy have been investigated by using scanning electron microscopy, X-ray diffraction and energy dispersive spectroscopy. Si can change the microstructure from hypereutectic to eutectic and furthermore, enhance the corrosion resistance of the alloy in molten zinc. The high corrosion resistance of the alloy was mainly attributed to the eutectic phase increase and solubility of Si in α phase enhancement. The corrosion of these alloys in liquid zinc was controlled by the diffusion mechanism. The reaction products are FeZn6·67, Fe5SiB2 and FeSi. The reaction layer further prevents the diffusion of zinc atoms into the base material and delays the reaction between the substrate and the molten zinc efficiently.

Effect of Si addition on the stability of Al-10Ti-5Cu-xSi alloy/SiC interface

Abstract The effect of Si addition on the interfacial stability of Al-10Ti-5Cu-xSi (x = 0, 5, 10, 15) alloy/SiC is investigated. SiC and the Al-10Ti-5Cu-xSi alloys were compacted to obtain a stable interface with 10 wt% Si. Analysis of the processing conditions and the microstructures indicated that an excellent Ti3SiC2 phase had been formed and the deleterious Al4C3 phase had been eliminated successfully by the addition of 10 wt% Si to the Al-10Ti-5Cu alloy. Formation of Ti3SiC2 increased at first and then decreased, while the formation of Al4C3 was gradually inhibited with increasing Si content. Ti3SiC2 possesses good chemical stability, and flexibility. However, Al4C3 degrades within few days, in composites exposed to ambient conditions. The presence of Ti3SiC2 at the interface and the elimination of Al4C3 together ameliorate the bonding of Al-10Ti-5Cu-xSi alloy to SiC, thereby improving the interfacial stability of Al-10Ti-5Cu-xSi/SiC.

Corrosion behaviour of stoichiometric Fe3Si alloy in liquid zinc

Abstract The corrosion behaviour of stoichiometric Fe3Si alloy in a liquid zinc bath for 3 and 62 h at 500°C was examined. The corrosion products at the Fe3Si/liquid zinc interface were investigated by using scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). The corrosion process was controlled by the diffusion of iron and zinc atoms. There were scarcely any silicon atoms diffusing at Fe3Si/liquid zinc interface from the matrix to liquid zinc. The phase transition process of the stoichiometric Fe3Si alloy in liquid zinc was Fe3Si, α, α+ FeSi+δ, FeSi+δ, and the main corrosion products were periodic array of FeSi and δ phase.