Abstract:
Minimum quantity lubrication refers to the use of cutting fluids of only a
minute amount-typically of a flow rate of 50 to 500 ml/hour-:-which is about three
to four orders of magnitude lower than the amount commonly used in flood
cooling condition, where, for example, up to 10 liters of fluid can be dispensed
per minute. The concept of minimum quantity lubrication, sometimes referred to
as near dry 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 the airborne culling fluid particles on
factory shop floors. The minimization of cutting fluid also leads to economical
benefits by way of saving lubricant costs and workpiece/tool/machine cleaning
cycle time.
Significant progress has been made in dry and semidry machining
recently, and minimum quantity lubrication (Mal) machining in particular has
been accepted as a successful semidry application because of its
environmentally friendly characteristics. A number of studies have shown that
Mal machining can show satisfactory performance in practical machining
operations. However, there has been little investigation of the cutting fluids to be
used in Mal machining. In this regard the proposed research work has been
carried out with a view to study the effects of minimum quantity lubrication
(Mal) by vegetable oil-based cutting fluid on the cutting performance of AISI
x
9310 steel, as compared to completely dry and wet machining in terms of chiptool
interface temperature and tool wear reduction, tool life increment and
machined surface protection. An approach based on the process parameters
(speeds, feeds and depth of cut) has also been performed to identify the
suitable MQl nozzle position for better cooling action. In the study, the minimum
quantity lubrication will be provided with a spray of air and vegetable oil.
Compared to the dry or wet machining, MQl machining performed
much superior mainly due to substantial reduction in cutting zone temperature
enabling favorable chip formation and chip-tool interaction. It also provides
substantial reduction in tool wear, which enhanced the tool life, and surface
finish. Furthermore, it provides environment friendliness (maintaining neat, clean
and dry working area, avoiding inconvenience and health hazards due to heat,
smoke, fumes, gases etc. and preventing pollution of the surroundings) and
improves the machinability characteristics.
