Evaluation of Superhard Abrasive Grains by Overcut Fly-Milling Test

Abstract

In this study, an overcut fly-milling test with inclined workpiece has been performed to accurately evaluate the cutting and wear characteristics of superhard abrasive grains(diamond, CBN) in related to work material. The milling experiment was carried out on a surface grinder, and the cutting tests were made mainly at a speed of 38m/s(cutter diameter 202mm) and a feed of 4.0 m/min. The maximum depth of cut 110μm, which corresponds to a chip thickness of about 45μm. Test was made both in dry and wet. The work materials(10mm thick and 100mm long) are hardened SUJ 2 steel, cemented carbide(P20), and sintered alumina. The abrasive grains used are natural diamond, CBN, green SiC, and regular alumina. The grit size was #12 with an exception of the CBN grain(#14-20). Thus, a quantitative evaluation of the chipping and attritious wear was made for each grains by tracing across the grooves with a stylus instrument and determining the wear or depth of cut between successive grooves by an abrasive grain. The data obtained has been treated statistically.