Influence of PVD AlCrN Coating and Surface Treatments on Characteristics and Performance of Cutting Tools during Machining of Incoloy 825

Abstract

With the increasing levels technology, advanced engineering materials have been developed regularly to fulfill the dedicated application effectively. These are categorized under difficult-to-cut materials owing to their peculiar properties. The machining of these advanced superalloys demands the cutting tools with superiority in various physical, mechanical properties and functional attributes. Although coated tools are there to serve this purpose, still there is significant scope to augment the properties and performance of coated tools in environment friendly dry machining. One of the possible ways to enhance the properties of coated tools is by surface treatment. The current work employed microblasting prior to and after the coating deposition owing to it’s promising results as a surface treatment. AlCrN coating is deposited on cemented carbide tool insert by physical vapor deposition (PVD) with prior as well as post treatment to recommend an optimal treatment technique. Critical examination of physical and mechanical characteristics such as surface morphology, microstructure, chemical composition, crystallite size, lattice strain, surface roughness and residual stress has been made to reveal the influence of micro-blasting prior and after the coating deposition on PVD coated tools. Evaluated the machining performance of coated tools with surface treatment during dry turning of Incoloy 825 in terms of cutting force, machined surface roughness and tool wear. Uncoated tool considered as reference to compare the machining performance. The results of the work witnessed the superior performance of AlCrN coated tool with pre-treatment only because its stronger adhesion and higher wear resistance in dry turning.