Studies on Erosion of Atmospheric Plasma Sprayed NiCrBSi/Mo/Flyash Coating Nagabhushana N Senior Assistant Professor, New Horizon College of Engineering, Bangalore-560103, India Dr. Rajanna S Associate professor, Government Engineering College, Kushalnagar-571234, India Dr. M.R Ramesh Associate Professor, National Institute of Technology, Suratkal-575014, India Padmini B.V Assistant Professor, Sambhram Institute of Technology, Bangalore-560097, India Abstract - In the current work, the erosion behavior of plasma sprayed NiCrBSi/Mo/Flyash cenosphere coating deposited on Super Ni76 steel was studied. The coating was characterized using a scanning electron microscope (SEM). Microhardness, porosity, fracture toughness and ductility of the coating were quantified. The solid particle erosion test was carried out at room temperature using alumina powder at 30° and 90° impact angles. The erosion resistance of the coating was observed to be higher at lower impact angles. The stability of the molybdenum, alumina and oxide layers helps to improve the corrosion resistance of the coating. The eroded coating surface morphology reveals a brittle pattern of material removal. Key words: Substrate, Coating, Erosion, Plasma spray 1. INTRODUCTION Aircraft engines operating in sandy environments are severely damaged by sand on compressor blades, vanes, or impeller blades/wheels. Damage may occur on these components due to the pitting and cut of the leading edge, the trailing edge becoming thinner and the blade chord length shortening. Physical changes in blade geometry due to erosion affect the dynamic response characteristics of the compressor airfoil, and the column results in increased fuel consumption and reduced life of the hot portion of the engine. A large amount of material removal not only leads to further aerodynamic losses, but also leads to weakening of the structure of the blade. When the damage is too large, component integrity and aircraft safety are affected. Due to excessive corrosion of the compressor blades, some helicopters were removed from the site early. Replacing parts with corrosion damage limitations has been costly and can lead to logistical problems with engine availability. There are several ways to minimize corrosion damage in gas turbine engines, including the use of air intake filtration, improved engine design, optimized intake positioning, and the application of corrosion resistant coatings on component surfaces. Integral transition metal nitride coatings such as TiN, CrN, TiAlN and TiSiN have been investigated as corrosion resistant coatings for engine components. TiN coatings were first implemented by Russia during its military involvement in Afghanistan, where sand erosion severely limited the life of helicopter turbine engines. Although it provides excellent protection against erosion of the compressor blades at low sand impact angles, it is susceptible to cracking and spalling from the substrate due to its brittleness, particularly when impacted by high velocity particles at high angles. A CrN coating having a higher toughness than TiN is disadvantageous as a candidate for corrosion resistance applications because it is insufficient to effectively resist particle removal materials by micro-cutting. In general, coatings with high hardness and toughness can withstand impact loads and resist crack formation, resulting in excellent resistance to solid particle erosion. Although monolithic binary transition metal nitrides are often difficult to achieve such a combination of mechanical properties, they can be achieved by introducing alloying elements, changing the microstructure and structure of the coating, or using a combination of the two. Coatings with a multilayer structure may be harder and tougher than a uniform coating of the same material because the layered structure hinders dislocation slip and crack propagation. The toughening of the multilayer structure is attributed to the effect of the interface on the dissipation of fracture energy and deflection cracks. The nano- layered coating consists of nano-scale multilayer alternating materials with a modulation period between a few nanometers and a few hundred nanometers. It is also expected to achieve high hardness and toughness due to interface toughening. Therefore, it has been reported that the improved erosion performance of some nanolayer and multilayer coating systems is not surprising. Erosion is a phenomenon of material removal caused by solid particles hitting a target surface. Solving corrosion of components operating at high temperatures becomes negligible and complex, as in gas and steam turbines, jet engine components, coal-fired power plant boiler tubes, and the like. The nickel and stainless steel alloys used in these components provide good mechanical strength. However, they lack better erosion, wear and corrosion resistance, resulting in a shorter service life. The corrosion resistance of these components can be enhanced by suitable surface modification International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 Published by, www.ijert.org NCRAEM - 2019 Conference Proceedings Volume 7, Issue 09 Special Issue - 2019 1