Selection of Optimal Tool Geometry and Cutting Conditions in End Milling With Graphite as a Solid Lubricant

Abstract

Coolants dissipate the heat generated during machining and hence improve productivity, machinability, etc. However, the use of cutting fluids in machining operations may seriously degrade the quality of environment. So, in recent years researchers have started machining with the use of solid lubricants with the aim of improving machining performance and overcome some of the limitations that arise with the use of cutting fluids or while machining dry. This paper deals with an investigation on using graphite as a solid lubricant to reduce the heat generated at the milling zone for improving the surface roughness of the machined AISI 1045 steel. An experimental setup has been developed to maintain constant flow rate of graphite powder continuously on to the workpiece and tool interface zone. The experimental studies have been conducted to see the effect of tool geometry (radial rake angle and nose radius) and cutting conditions (cutting speed and feed rate) on the machining response such as surface finish in solid lubricant assisted machining using four fluted solid TiAlN coated carbide cutters. Results indicate that there is a considerable improvement in the performance of milling AISI 1045 steel using graphite as a solid lubricant when compared with machining with cutting fluids. An attempt has also been made to select optimum tool geometry and cutting conditions in end milling with graphite as a solid lubricant by using the prediction model obtained from these experimental results.