抄録
PcBN cutting tools have excellent characteristics such as large hardness and low chemical reactivity, so they have the potential to replace high precision grinding of hardened steel with high precision cutting. However, there are some problems if diamond grinding is employed as forming method for PcBN cutting edge; such as chipping, falling a cBN particle off and forming pre-crack. In order to solve these problems, PLG (Pulse Laser Grinding) was adopted to form a PcBN cutting edge and performances which were demanded as a cutting tool were investigated. Firstly, the cutting edge was measured by contact-type profilometer. As a result, cutting edges processed by the PLG are similar or sharper than that by conventional diamond grinding. Secondly, the hardness of processing surfaces was measured by micro-Vickers hardness tester. The hardness increases by about 10 percent after PLG. Lastly, the frictional test was conducted by lateral force microscopy. Coefficient of friction of a PLG'ed surface decreases by half of the ordinary surface because of generation of hBN or TiB_2 during PLG Processing. Depending on these advantages of PLG, the tool processed by PLG can demonstrate a good performance rather than a tool processed by diamond grinding under the condition of high precision turning of hardened steel with 58HRC in hardness.
