Corrosion behaviors of Ti₃SiC₂/Cu composites in molten salts

Abstract

The corrosion behaviors of Ti3SiC2/Cu composites synthesized by spark plasma sintering technique were investigated at 900°C in three molten salts including NaCl, Na2SO4, and Na2CO3, and the related corrosion mechanism was discussed. The morphology and composition of the composites after corrosion were characterized by scanning electron microscopy and X‐ray photoelectron spectroscopy. The results indicated that the weight gain per unit surface area of the composites was negative in molten Na2CO3, while it was positive and relatively small in molten NaCl and Na2SO4. The high weight loss of the composites in molten Na2CO3 was owing to that in molten Na2CO3, an oxidation layer of the composites was dissolved, and oxygen diffused through the layer to corrode the substrate inside. Thus, in the molten Na2CO3, the composites exhibited a worse corrosion resistance. However, in molten NaCl and Na2SO4, an oxidation layer containing SiO2 and TiO2 was formed on the surface of the composites, inhibiting its further corrosion. Conclusively, the composites showed better corrosion resistance in molten NaCl and Na2SO4.