TEM Studies of High Temperature Corrosion Behaviour of TiAl Intermetallics with Surface Modifications

✍ Scribed by H. L. Du; S. R. Rose; Z. D. Xiang; P. K. Datta; X. Y. Li

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 568 KB
• Volume: 34
• Category: Article
• ISSN: 0933-5137
• DOI: 10.1002/mawe.200390087

✦ Synopsis

The oxidation/sulphidation behaviour of a Ti-46.7Al-1.9W-0.5Si alloy with a TiAl 3 diffusion coating was studied in an environment of H 2 /H 2 S/H 2 O at 850 o C. The kinetic results demonstrate that the TiAl 3 coating significantly increased the high temperature corrosion resistance of Ti-46.7Al-1.9W-0.5Si. The SEM, EDX, XRD and TEM analysis reveals that the formation of an Al 2 O 3 scale on the surface of the TiAl 3 -coated sample was responsible for the enhancement of the corroison resistance. The Ti-46.7Al-1.9W-0.5Si alloy was also modified by Nb ion implantation. The Nb ion implanted and as received sampels were subjected to cyclic oxidation in an open air at 800 o C. The Nb ion implantation not only increased the oxidation resistance but also substantially improved the adhesion of scale to the substrate.