Aluminide Coatings on Titanium-based Alloy IMI-834 for High Temperature Oxidation Protection
Microstructural aspects and cyclic oxidation behaviour of plain aluminide and Pt-aluminide coatings on the near-a Ti-alloy IMI-834 have been studied. Both the coatings provide good oxidation resistance to the above alloy at 650 °C, 750 °C, and 850 °C. However, significant cracking develops in the coatings during coating formation as well as during cyclic oxidation exposure. The extent of cracking during oxidation is found to increase with the exposure temperature. Presence of through-thickness cracks in the coatings leads to localised oxidation damage of the underlying substrate at all the three temperatures. At 850 °C, such localised oxidation generates enough TiO2 so that this oxide phase grows through the cracks and emerges at the sample surface forming a clearly identifiable mud-crack pattern. The extent of such oxidation damage is comparatively much lower at 750 °C and 650 °C.
Defence Science Journal, 2011, 61(2), pp.180-190, DOI:http://dx.doi.org/10.14429/dsj.61.477
where otherwise noted, the Articles on this site are licensed under Creative Commons License: CC Attribution-Noncommercial-No Derivative Works 2.5 India