OPTIMIZATION OF COATING THICKNESS FOR VARIOUS PROPERTIES OF COMPOSITE TYPE THERMAL BARRIER COATED WITH INCONEL 718 ALLOY

In the past, continuous improvements were made in the gas turbines field using several methods such as increasing the efficiency of reheating, regeneration, and intercooling stages. This required either high thermal resistant alloys or surface modification of conventional material. The latter method is inexpensive and effective. Thermal barrier coating is one surface modification methods for improving the performance of gas turbines. Various studies have been carried out either by taking different coating materials and their thicknesses, or by implementing different processes. In the current work, atmospheric plasma spray coating technique is used for depositing the ceramic material (8%YSZ-Cr2O3). The coating thickness is also varied by using different proportions of YSZ (yttria-stabilized zirconia) and Cr2O3 (chromium oxide) and analyzing various properties. The optimum thickness of coating is found from the experimental results for maximum temperature gradient across the material to increase the efficiency of a turbine by reducing the stress levels.