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Interdiffusion analysis in multicomponent alloy systems plays a pivotal role in controlling various processes and in designing materials. Interdiffusion of elements also leads to changes in microstructure and properties during service, especially for the materials operating at elevated temperatures. The urge of increasing efficiency of gas turbine engines has led to the demand of higher service temperatures and longer life, which is achieved by the application of thermal barrier coatings (TBC) on Ni based superalloys. To prevent oxidation damage to the superalloy substrate, bond coats are used in which diffusion acts as a key factor influencing the stability and durability of the engine components. Over the last few decades, β-(Ni,Pt)Al coatings have been widely employed as bond coat materials because the presence of Pt enhances oxidation resistance by accelerating diffusion of Al to generate a continuously growing TGO (Thermally grown oxide) layer.

The effect of different cold- rolling and cryo-rolling routes on the strength and ductility of Al-6061 alloy was thoroughly investigated. Rolling decreased the grain size and increased the strength according to the Hall-Petch relationship. However subjecting the samples to ageing at different temperatures and for different time period increased the strength and improved the ductility. The ductility was improved due to the rearrangement and even decrease in dislocation density due to recovery and recrystallization during ageing while the strength was maintained due to ageing. Evolution of microstructure was investigated by optical microscopy, scanning electron microscopy. Preliminary hardness measurements coupled with tensile tests indicate the improvement of both yield strength and ductility. The disparity in ultimate tensile strength, yield strength and the elongation to failure with different ageing temperatures and for different time period is determined and discussed.