Experimental investigations into turning of AerMet 100 alloy using uncoated and TiAIN coated inserts

The purpose of this paper is to investigate and compare the performance of TiAIN coated carbide inserts with the uncoated carbide inserts while machining AerMet 100 alloy. Orthogonal and oblique cutting tests were conducted using three different types of uncoated and TiAIN coated inserts at different cutting conditions. The effect of tool geometry and coating was studied. The results indicate that the tool-wear is significantly reduced when TiAIN coated inserts are used. The inserts with larger nose radius increase cutting forces and the inserts with positive rake angle generate lower cutting forces. The SEM analysis showed smearing of work-material, formation of built-up-edge, and chipping of the insert at various speed and feed. Optical images of a longitudinal cross-section of the chip show heavily disturbed metal and very fine serrations on the non-tool side of the chip. TiAIN coated CNMG 432 insert used at higher feed and speed provide superior performance.