Effect of plasma immersion ion implantation and deposition on high temperature oxidation of titanium alloy IMI 834-aluminizing

Aluminium plays a significant role in high temperature construction materials and coatings. It helps to form continuous, protective and thermodynamically stable alumina oxide scale over their surfaces upon high temperature exposure and enhances their life significantly. However, the performance of coatings depends on the surface engineering technique that is used for application of coatings. In the present paper, plasma immersion ion implantation and deposition (PIII-D) was used to deposit aluminium coating on the titanium alloy IMI 834 under varying conditions. Subsequently, the oxidation behaviour of the alloy has been studied at elevated temperatures. The weight change data showed that the specimen that is aluminium coated followed by implantation exhibits minimum weight gain and extended period of oxide spallation when compared to uncoated and other coated specimens. XRD was used to identify the phases that formed during oxidation process. Oxide morphology was observed by SEM and the composition of oxide scales was analysed by EDS. A suitable degradation mechanism for Al coatings have been proposed based on the results obtained with different techniques.