The Influence of Surface Pre-Treatment on the Integrity of Alumina Scales on MA956Funded under: FP4-BRITE/EURAM 3
Quasi-isothermal and cyclic oxidation experiments at 1100degrees celsius in air have been performed on the ODS alloy MA 956 in order to investigate the effects of prior surface treatments on the integrity of the alumina scales formed. The oxidation behaviour of samples with 800 grit SiC ground surfaces has been compared with that of samples exposed (I) in the as-received condition and (ii) with lathe turned surfaces. Effects of these surface treatments on the growth kinetics of the scales, their morphologies, defect structures and spallation behaviour have been studied for exposure times up to 5000h and 3500h. Assessment of the scale failure mechanisms revealed that deleterious effects resulted mainly from geometrical surface irregularities and that scale defects had no obvious influence. Defects at the scale-substrate interface appeared to play a more important role in the long term exposure regime.
Bibliographic Reference: Article: The Just of Materials (1999)
Record Number: 199911750 / Last updated on: 2000-01-30
Original language: en
Available languages: en