Tool Wear and Surface Roughness in Machining AISI D2 Tool Steel

Abstract

Background: Along with the recent developments in hard milling technology, tool wear and surface integrity has become a very important consideration in order to achieve optimum cutting conditions. The purpose of this research paper is to study the tool wear and surface roughness while machining American Iron Steel Institute (AISI) D2 tool steel using coated carbide tool. Method: A series of cutting tests have been carried out to verify the change in surface roughness of the workpiece due to increasing tool wear. The tests have been done under various combinations of speed and feed in the dry condition. The machined surface was evaluated in terms of surface roughness. Findings: Mechanical wear or abrasion is typically dominant during the initial cutting. Thermal wear is dominant at higher cutting speeds due to high cutting temperature. Majority of the tool wear modes were due to flank face wear and excessive chipping on the tool edge. The results also reveal that the variation in cutting speed and feed would not significantly change the surface roughness of the machined surface. Generally, surface produced are very smooth with Ra values in the range of 0.1 μm to 0.37 μm. Conclusions: Roughness values (Ra and Rmax) were found to be almost constantly with the progression of the flank wear under all cutting conditions. It indicates that surface roughness did not play a significant role in limiting tool life.