Investigation on the influence of calcium Fluoride and Barium Fluoride on cutting performance during hard turning with minimal fluid application

Abstract

Recently the concept of minimal fluid application has gained attention in metal cutting industry as it has the ability to resemble pure dry turning and at the same time free from all the problems related to large scale use of cutting fluid as in conventional wet turning. Since a very small quantity of cutting fluid is doing cooling and lubrication in minimal fluid application, there must be some performance enhancers to improve the efficiency of utilization of the cutting fluid and to facilitate uninterrupted operation. In this research work, an effort is made to investigate the effect of semi-solid lubricants such as grease in pure form and as a mixture with graphite, barium fluoride and calcium fluoride on cutting performance during hard turning of AISI 4340 steel with minimal fluid application using hard metal inserts with sculptured rake face using a special semi-solid lubricant applicator developed for this purpose. Semi-solid assisted machining is a novel concept to control cutting force, cutting temperature, tool wear and to improve surface finish. From the results it was observed that the use of semi-solid lubricant grease and calcium fluoride combination applied at the tool-chip interface along with minimal fluid application provides better results when compared to other lubricant combinations. The present study illustrates the use of semi-solid lubricants along with minimal fluid application as a viable alternative for hard turning with minimal fluid application, dry and wet turning. It is also a possible environmental friendly alternative for effective control of heat generated at the machining zone.