Experimental investigation of mechainability in milling of ductile cast iron ggg-70 using minimum quantity lubrication technique

Within the scope of thesis study, the effects of minumum amount of lubrication(MQL) conditions on machinability were investigated in milling operations which are important in machining operations. In this context, MQL mixed with nano-sized solid lubricant MoS2 and then GGG70 spheroidal graphited cast iron have milled. Surface roughness, tool wear and chip geometry and specially the effect of nano-MOS2 were investigated. Milling experiments were performed at a cutting speed of 300 m/min, a rate of feed of 0,2 mm/rev and a cutting depth of 4 min. The surface roughness(Ra,Rz), cutting tool wear and chip formation were investigated which were obtained under conditions of dry cutting, convntional cooling, MQL and 3 different rate of nano- MoS2 mixed with MQL. In the MQL system, 3 different pressures and 2 different flow rates were defined variably. Some statistical analysis were carried on like analysis of variance, Dunnet and Tukey tests for determination of the results of Ra and Rz and their relation to experimental parameters. In the MQL system, positive results were obtained from the nano-MoS2 mixed with fluid to improve lubricaiton and cooling properties. The lowest Ra value was measured as 0,47 µm at 5 bar pressure 160 ml/min flow rate and MQL+ 0.5% MoS2 spraying conditions. An improvement of around 45% was achieved under these conditions. The mixing nano-MOS2 has been effected in imroving surface roughness and tool wear. Keywords: MQL, Milling, Tool wear and surface roughness