Optimization of machining conditions with D type cutting tools using Taguchi technique

Abstract

In the present study a commercial grade D2, D3 and HSS steel tool materials have been forged and heat treated to induce better hardness. The microstructures of the forged and heat treated tools were seen using metallurgical optical microscopy. The hardness of the cutting tools was recorded with the OMNITECH micro Vickers hardness tester. The D2 tool with 20% forged & heat treated, D3 tool with 20% forged & heat treated and HSS tool exhibited the VHN 629, 610 and 846 respectively. The machining of brass, aluminum and aluminum metal matrix composites were observed with respect to chip generation and materials surface roughness. The machining was carried out at different conditions of work piece rotational speed (300, 540 & 720 m/min), cutting tool feed rate (0.1 & 0.15 mm/rev) and depth of cut (0.3, 0.5 &1 mm). As Taguchi technique helps in simplifying experimental design, data analysis, and prediction of optimum results, it has been employed for the optimization of machining parameters. It is noticed that lower cutting speed resulted discontinuous and segmented chips and larger surface roughness. The larger cutting speeds resulted semi continuous chips with saw toothed tip and comparatively good surface roughness.