Hot corrosion behavior of Yb2Zr2O7 ceramic against V2O5 and Na2SO4 + V2O5 (molar ratio = 1:1) was investigated at temperatures of 900-1100 degrees C for 2 h in air. YbVO4 was identified due to chemical interactions of these two corrosive agents with Yb2Zr2O7 ceramic. Although YbVO4 formed in these two hot corrosion reactions has the same crystallographic structural characteristic, its morphologies exhibit significant difference. YbVO4 evolved from hot corrosion of V2O5-coated Yb2Zr2O7 is particle-shaped, while it is rod-like in the (Na2SO4 + V2O5)-coated Yb2Zr2O7. A model describing the formation process of the hot corrosion products was presented and the growth mechanism of YbVO4 crystal was proposed on the basis of the hot corrosion model. (C) 2013 Elsevier B.V. All rights reserved.