材料期刊网

The uniform and dense Al(2)O(3) and Al(2)O(3)/Al coatings were deposited on an orthorhombic Ti(2)AlNb alloy by filtered arc ion plating. The interfacial reactions of the Al(2)O(3)/Ti(2)AlNb and Al(2)O(3)/Al/Ti(2)AlNb specimens after vacuum annealing at 750 degrees C were studied. In the Al(2)O(3)/Ti(2)AlNb specimens, the Al(2)O(3) coating decomposed significantly due to reaction between the Al(2)O(3) coating and the O-Ti(2)AlNb substrate. In the Al(2)O(3)/Al/Ti(2)AlNb specimens, a gamma-TiAl layer and an Nb-rich zone came into being by interdiffusion between the Al layer and the O-Ti(2)AlNb substrate. The gamma-TiAl layer is chemically compatible with Al(2)O(3), with no decomposition of Al(2)O(3) being detected. No internal oxidation or oxygen and nitrogen dissolution zone was observed in the O-Ti(2)AlNb alloy. The Al(2)O(3)/Al/Ti(2)AlNb specimens exhibited excellent oxidation resistance at 750 degrees C. (C) 2010 Elsevier B. V. All rights reserved.