Study of the behavior of the minimum quantity lubricant technique in grinding different steels

Abstract

Grinding process is characterized mainly by high specific energy requirement due to large negative rake and high cutting speed, which results in very high temperature. Such high temperature oftell leads to several problems like a large heat affected zone, challge in hardness and microstructure of the work piece, burning and its consequences and micro cracks. Application of conventional flUids reduced the above problems to some extent through cooling and lubrication of the grinding zOlle. On the other hand, the cOlwenlionai culling fluids utilized in grindll1g are considered a problem for manufacturers, since these substances can seriously damage human health and environment Hence environmentally friendly production techniques like Minimum Quantity Lubrication technique have become the focus of attention of researchers and technicians In the field of machining and grinding as an alternative to traditional fluids. In thiS technique, uses of cutting fluids of only a minute amount-tYPically of a flow rate 50 to 500 mllhour. The concept of minimum quantity lubncatlon some time referred to as near dry machining, The minimization of cutting flUids leads to economical benefits. In the present research work, attempts have been made to develop a minimum quantity lubricant delivery system to carry out grinding of different grades of steels (AISI-1040, AISI-4320 and AISIA140 steel) on a surface grinding machine by stalldard diamond coated grinding wheel at different infeeds and ellvlronmellt cOllditions The presellt minimum quaillity lubricallt delivery system enabled reduction In average chip-tool Illterface temperature upto 20% depending UPOIl cuttillg conditions alld evell such apparently small reductioll, unlike common belief, enabled favourable challge in the chip-tool alld work-tool illteractions, which helped in reduclllg frictloll, cutting force, bUilt-up edge formation, thermal distortion of the work and wear of the grindillg wheel tool. MOL system with the present technique has substalltially reduced flank wear alld hence is expected to improve tool life, Surface finish significantly improved by millimum qualltity lubricallt