Comparative evaluation of performance of cold sprayed and bare N06601 superalloy in medical waste incinerator at 900 °C

Waste Incinerators and waste-to-energy (WTE) plants are viable sources to compensate for the energy (thermal/heat and electricity) requirements, especially in developing countries which are facing shortage of energy. However due to highly corrosive waste these plants are running at low temperature and hence at low efficiency. Since there is no possibility of removal or selection of corrosive waste/fuel as the waste management/disposal is the primary requirement of these plants, therefore in this study efforts are made for comparative performance study of new materials to raise the working temperature of these plants. The present study was planned to test uncoated/bare N06601 superalloy and the effect of surface modification (50%Ni-50%Cr) by cold spray process in the real service medical waste based incinerator environment at 900 °C for 1000 h. The performance has been characterized via surface morphology, phase composition and element concentration using the combined techniques of XRD, SEM/EDX, BSEI and Elemental X-Ray analysis. The chlorine based incinerator environment is found to be so aggressive that corrosive species are able to penetrate through the N06601superalloy specially designed for high temperature applications. Highly corrosive 'Active-Oxidation' reaction mechanism is observed in the case of bare alloy, which is not observed in modified alloy.