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.
