Surface Integrity of Inconel 825 When Turning With Uncoated and CVD Coated Carbide Inserts

Abstract

During the machining of any materialit is very important to analyse these variables i.e. cutting force, shear angle and surface integrity etc. These are depends on workpiece material, tool material and its geometry, cutting parameters like cutting speed, feed rate and depth of cut.Nature and condition of surface region of a component is defined by a term known as surface integrity. During the machining of nickel-based super alloy surface defects such as surface drag, material pull out/cracking, feed marks, adhered material particle, debris of chips, surface plucking, deformed grain surface cavities and slip zone were found [1]. This type of failure generally depends on the surface quality. Study of surface characteristics has become very important. Nickel based super alloy is highly used in aerospace industry but nickel based super alloy has poor machinability. So it is very difficult to machine nickel based super alloy at high cutting speed with carbide tool. During the machining with higher production rate,cutting parameters play an important role.Higher cutting speed higher will be the production rate. Cutting speed is directly influenced on the surface integrity. So study of surface integrity analysis becomes very important. Among all nickel based super alloy lots of experiments were done on Inconel 718.Analysis of surface integrity characteristics of Inconel 718 with new and worn coated carbide and PCBN (Polycrystalline cubic boron nitride) tool were investigated. Machining with new cutting tool had better surface integrity than worn tool for both type of tools. PCBN tool performed better than coated carbide tooleven at high cutting speed.