Machinability studies on IN 800 nickel alloy using different tool inserts and cutting environments

Abstract

Machining of Nickel-based alloys is quite difficult due to the higher amount of friction and heat generation at the cutting zone which greatly affects the surface quality, tool wear and material removal rate. IN-800 (Incoloy 800) alloy is a Nickel-Iron super alloy commonly used in nuclear, petrochemical industries mainly for its superior high-temperature strength and excellent corrosion resistance properties. It is superior to austenitic stainless steel but at the same time more difficult to machine owing to its low capability to transfer heat, high hot-hardness and chemical affinity to the cutting tool materials. Large volume of water-based cutting fluids is generally applied to the cutting zone to lower the friction and dissipate the heat generated during cutting. This involves huge consumption of water for preparing the cutting fluid, high disposal costs, health and environmental issues. In the present investigation, a high-pressure minimum quantity lubrication (MQL) system without compressed air, has been developed to evaluate the machining performances of TiAlN PVD (Titanium Aluminium Nitride physical vapor deposition) coated carbide tool and uncoated carbide tool inserts in face turning IN-800 alloy (Incoloy 800) alloy under different cutting environments, namely dry, flood coolant, MQL and nano fluid based MQL (N-MQL). Aluminum oxide (Al2O3) nano cutting fluid was deployed with minimum quantity lubrication in this study. The influence of cutting environment and cutting parameters in the face turning output characteristics, such as surface roughness (Ra and Rz), cutting force (Fz), specific cutting energy, material removal rate, tool wear, surface morphology, chip morphology, and micro hardness were studied in detail. newline