Performance Evaluation of Hard Turning for AISI M2 Die Steel with Coated and Non-Coated CBN Inserts

Abstract

Hard Finish Turning has been Widely Acknowledged as an Excellent Alternative for the Traditional Grinding, Especially it Enables many Intricate Machining Profiles Possible, in a Single Machining Set-up. Cubic Boron Nitride (CBN) Inserts are Usually Used for Hard Turning of Superior Hardened Steel Parts to Very High Degree of Accuracy, Geometry and Surface Texture. the Performance of CBN is of Significant Importance for Hard Finish Turning, because of the High Single Cutting Edge Cost. an Array of Experiments are Conducted with Two Different Types of Low Content CBN Insert Grades, 1) Tin Coated Insert CB7015, 2) Non Coated Insert BN250 by Using a Tool Holder MTJNL2525M16 in a LT20 Classic ACE Turning Centre. the Surface Roughness is Inspected by SJ201P Surfinish Mitutoyo Profile Tester. the Parameters Determined during the Experiments are MRR, Ra, and Tool Life in Minutes, Number of Parts Machined. A Satisfactory Match has been Reached by Comparing Mathematical Model Tool Life Using Experimental Data from the General Taylor’s Tool Life Equation and Experimentally Measured Tool Life. the Cost Analysis is Carried out by Gilbert’s Approach Indicates that the Cost Incurred per Part Produced is Lesser in Tin Coated Insert. the Proposed Methodology can Help to Optimise the Hard Finish Turning Process for AISI M2 Die Steel, and Also in Evaluating the Performance of CBN Tin Coated Insert over Non-Coated Insert.