Investigation of use of cubic boron nitride (cBN) as alternative abrasive in natural stone cutting tools

In this study, all the sockets containing of cBN and/or diamond, in which designed for natural stone cutting were produced in hot-press by powder metallurgy method. 85-15 CuSn bronze powder was choosen as a matrix material into which 30/40 and 40/50 US mesh grain size of diamond and/or cBN grains was added with a concentration of 30 %. The production of sockets used in this investigation was carried out under 35 MPa pressure at 600, 650, 700 °C sintering temperature for 3 minutes. The cutting performance of each socket welded around a circular cutting disc with a diameter 300 mm was measured.In this natural stone cutting process, Ankara-Andezit stone with a dimension of 30x150x1500 mm was used. The wear values of the sockets after the cutting process were measured with a digital calliper with a precision of 0.01 mm. Each socket was inspected for its chemical composition and microstructure properties by using a scanning electron microscope (SEM), X-ray diffraction spectrometer (XRD) and Energy-dispersive X-ray spectroscopy (EDS).The results of the experimental studies show that the bending strength of diamond cutting tools is less than cBN cutting tools about 30% and cutting performance of diamond cutting tools were found two and a half times higher than cBN cutting tools. The SEM photographs show that the micro-plowing and matris tail are formed on wear surface. Besides, it is obtained that the cBN grains were worn more than diamond grains.