Study of Solid Particle Erosion Behaviour of Uncoated Superalloys of Turbine Application

Superalloys such as Ti-31 and Superco-605 are extensively used material for gas-turbine component. Most of these gas-turbine components such as compressors, blades and vanes work under very high temperature condition. The residue results after combustion of fuel consists of solid particles such as coal ash and unburned carbon particle. These solid particles travelling at very high speed when hit the component lead to the erosion wear. The damage caused to the component due to erosion wear has significant effect on the service life of the component. Thus, in present investigation effort has been made to conduct solid particle erosion wear test on Ti-31 and Superco-605 superalloys. The test was conducted as per ASTM G76 standard with the help of Air jet Erosion test rig. The test was performed at an air pressure of 1 Bar at different impact angles of 30°, 60°, and 90°. Steady state volumetric rate of erosion is calculated to analyse the erosion under different impact angles. Further, micrograph of eroded surface was taken using scanning electron microscope to analyse the mechanism of material removal. From the result, it was observed that loss of material is higher in Superco-605 in comparison to Ti-31 superalloy. Micrograph reveals that in case of Superco-605, the material removal takes place mainly through brittle fracture whereas ductile mode of erosion was observed in case of Ti-31 superalloy.