Effects of minimum quantity of lubrication (MQL) on tool wear and surface roughness in turning AISI-1040 steel with uncoated carbide tool

Abstract

Minimum quantity lubrication (MOL) refers to the use of culling fluids of only a minute amount-typically of a flow rate of 50 to 500 mllhour which is aboul three to four orders of magnitude lower than the amount commonly used in flood cooling condition. The concept of minimum quanlily lubrication, sometimes referred to as near dl)' lubrication or micro lubrication, has been suggested since a decade ago as a means of addressing the issues of 'environmental intrusiveness and occupational hazards associated with theairborne cutting fluid panicles on faclory shop floors. The minimization of cutting fluid also leads to economical benefits by way of saving lubricant costs and workpiece/iool/machine cleaning cycle lime. During machining, the cutting tool generally undergoes both flank wear and crater wear. Flank wear generally causes an increase in the cutting forces, dimensional inaccuracy and vibration. Crater wear takes place on the rake face of the tool where the chip slides over the tool surface. This was aimed to study the role of culling fluid, tool and workpiece material, 1001geometry and cutting conditions on machinability. Proper selection and application of cutting fluid generally improves tool life. But surface finish did not improve significantly. Wearing of cutting tools not only causes ioss of the cutting edges or tips of the inserts but loss of the entire insert after wear of all Ihe corners. From an environmental perspective, therefore, the significant waste is not the portion of the tool worn away by the tool-work contact, but the remaining portion of the tooi that is disposed after its useful iile. Compared to the dry and wet machining, MOL machining performed many superiors mainly due to reduction in cutting zone temperature enabling favorable chip formation and chip-tool interaction. it also provides reduction in tool wear, which enhanced the tool life, dimensionai accuracy and product quality. Furthermore, it provides environment friendiiness and improves the machinability characteristics.