| || Aluminide Coatings on Titanium-based Alloy IMI-834 for High Temperature Oxidation Protection
Author : Alam, Zafir;Das, Dipak K.
Source : Defence Science Journal ; Vol:61(2) ; 2011 ; pp 180-190
Subject : 620.1 Material Science and Technology
Keywords : Coatings;oxidation;Titanium;IMI-834 alloy;near-alpha titanium alloy;aluminide
Abstract : 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.
| || Reactions in Solids Phase II
Author : Singh, Kartar
Source : Defence Science Journal ; Vol:16(2) ; 1966 ; pp 27-52
Subject : 54 Chemistry
Keywords : Oxide film;Oxidation;Metals
Abstract : The productions of oxide film capacitors and protective coatings on metals involves controlled oxidation of metals. The reactions which may give homogeneous, dense and coherent films on oxidation of metals and semiconductors have been discussed in this paper. The present position regarding mechanisms of oxidation in space charge regions and in field free regions has been presented. The factors which control the rate of oxidation have been highlighted.