Effect of machining parameters and lubrication on surface integrity and tool performance in turning Inconel 825

Nickel superalloy Inconel 825 is extensively used for manufacturing components in various industries, including nuclear, marine, chemical, oil and gas, and aerospace, due to its excellent thermal stability and resistance to corrosion. It contains nickel (Ni), iron (Fe), chromium (Cr), molybdenum (Mo), copper (Cu), and titanium (Ti) and is perfectly adaptable for use under high temperatures. However, because of its poor machinability index (15–20%), it is a ‘hard-to-cut’ material and causes issues like excessive cutting force, tool life, and surface integrity issues. Influence of machining conditions like cutting speed, feed rate, and lubrication (dry, flood, MQL) on responses like surface roughness, cutting force, vibration, and tool wear is investigated in this investigation according to a Taguchi L27 orthogonal array design. Experimental results concluded that in minimum quantity lubrication (MQL), the surface roughness was reduced to 1.52 µm, and the flank wear was minimised to 0.28 mm, compared to 2.63 µm and 0.4 mm, respectively, under dry cutting conditions. The results indicate the necessity for adjustments in the machining conditions and lubrication modes to achieve maximum performance and tool life in the machining of Inconel 825.