Abstract:
The generation of huge amount of heat in high production machining at high
cutting veloeit} and feed rate shortens the tool life and deterioratcs the job quality. 'l1,e
conventional cutting tluids arC not that effcctive in such high producti"n machining
particularly in continuous cutting of materials like steels, Becausc of these some
alternatives has been ',Ought to minimize or even avoid thc use of cutting fluid in
machining operation.l. One of these alternativcs is machining with minimum quantity
lubrication (MQL). It is a mixture of impinging of least amount of cutting fluid along with
highly compres,ed air through a small noalc result, in reducing thc heat produced during
metal cutting.
The effect, of MQI, on cutting performance, in respect of chip fonnation, chiptool
intcrface temperature, cutting forces, tool wear and tool life as well as product quality
i.e, dimensional deviation and surface roughncss have bccn studied using t"o different
uncoated carbide imerts (SNMM and SNMG) for three different steels viz (i) medium
carbon steel (ii) AISI 4140 steel and (iii) A1SI 4320 steel. The same experiments were
carried out on thc above under dry condition in order to compare the results \~ith those
obtained under MQL conditions.
The result indicated that the machining with minimum quantity lubrication
(MQL) perf"nned much better than dry or wel machining mainly duc to <ubstantial
reduction in culting zone temperature enabling favorable chip-tool interaction. Thi, also
facilitated the reduction in cutting forces and substantial reduction in tool wcar in leading
to cnhance tool life, dimensional accuracy and surface finish.
The overail results of the present investigation clearly rcvealed that proper
application of minimum quantity lubricants (MQL) method not only make the machining
environment mOre eco-friendly but also provide, substantial technological benefits and
hence cconOll1ical gain, which are the reasonable target, of the modern ll1achining
industries,
