Hot corrosion of layered machinable ceramic Ti3AlC2 coated with 3.8+/-0.2 mg/cm(2) Na2SO4 in air at 700-1000degreesC has been investigated by means of thermogravimetric analysis, X-ray diffraction, Raman spectroscopy, and scanning electron microscopy/energy-dispersive spectroscopy. The hot corrosion of Ti3AlC2 was slight at low temperatures of 700 and 800degreesC, while Ti3AlC2 was severely attacked by fused sodium sulfate at 900 and 1000degreesC. No protective scales were observed on Ti3AlC2, and sulfur-rich layers were present at the Ti3AlC2 substrate/scale interface. The linear hot corrosion kinetics at 800 and 900degreesC demonstrated that electrochemical reactions of Ti3AlC2 with sodium sulfate at the substrate/scale interface dominated, while the parabolic kinetics at 1000degreesC implied that the rate-limiting step involved in the hot corrosion was the diffusion of hot corrosion medium through the scale formed. The hot corrosion behaviors were explained by a mechanism of electrochemistry coupled with basic dissolution-precipitation. (C) 2004 The Electrochemical Society.