Enhancing Machinability of Nimonic 90 Alloy by Micro-Texturing Based Solid Lubricant on AlTiN Coated Carbides: A Sustainable Approach towards Commercialization

The manufacturing industry has a significant impact on the economy of a country. Therefore, carrying out necessary developments and modifications in manufacturing machine components is essential. Some materials, called superalloys, are challenging to machine, and they have a wide application in the turbine components of aerospace, submarines, oil, nuclear, steam, and other power generation industries. Due to the exceptional properties of these superalloys their machining becomes very difficult and time-consuming; They damage the cutting tool, and excessive use of lubricants eventually affect the material handling and cost. These problems lower down the sustainability and therefore an attempt has been made in the current research work to eliminate the use of cutting fluid by impinging solid lubricant on AlTiN coated tungsten carbide cutting tool by using pulsed direct current magnetron sputtering and cathodic arc physical vapour deposition techniques. The micro-texturing is first done on rake face of the milling insert such that graphite, which acts as a solid lubricant, can be then deposited in those micro-textures. The end milling of Nimonic 90, a superalloy, is done using the solid lubricant filled microtextured insert under compressed air environment, and the cutting forces, cutting temperature, tool wear, and surface roughness are analysed. It is found that there is a substantial decrease in the cutting forces and tool wear when compared with non-textured tool due to less friction and temperature at the machining zone. Sustainability of such solid lubricant based textured cutting tool has shown improvement when compared with non-textured cutting tool. The machinability of Nimonic 90 is increased by implementing the solid lubricant-based cutting tool, and therefore, it can be effectively utilised for the machining of superalloys soon.