Effect of sintering parameters on sawing performance of marble cutting tools with carbide

In this study, the diamond segments with Bronze-B4C matrice content used to cut marble were manufactured using powder metallurgy (PM) process. Boron carbide powder with an average grain size of 20 ?m powder was added to bronze as 2, 5 and 10 wt. % percents. The production of segments was made under 35 MPa pressure at 600, 650 and 700 °C sintering temperatures with a 3 minutes sintering time. The synthetic diamond grains with grain sizes of the 30/40 and 40/50 mesh with a final concentration of 30 were added to Bronze-B4C matrice prepared, and then the matrice and diamond were mixed by mixer. The diamond segments were produced by hot pressing of the Bronze-B4C/diamond mixture. The segments were welded to the steel disc with a diameter of 300 mm using the solder having wt. 40 % silver composition.The experimental and the relative density measurements were carried out with the Archimedes method. The hardness of matrices was measured using hardness tester with a ball of 2.5 mm diameter under the load of 62.5 kgs. The bending strength of segments was identified by a three-point bending tester. The cutting performance of segments with boron carbide was examined by cutting Ankara andesite stone in a marble cutting machine with PLC system. The amount of the wear was determined by measuring of diameters of saw blades with a digital caliper before and after the cutting process. Microstructure and chemical composition of segments were determined by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis.The results of the experimental studies show that the boron carbide particles formed in the bronze grain boundaries and it has a partially homogenous distribution. It was determined that the more boron carbide was added, the more pore formed and the porosity was inversely proportional to the sintering temperature. The hardness of the matrice increased with an increasing amount of boron carbide and sintering temperature. The addition of boron carbide decreased the experimental and relative densities of the segments. However, both of the densities increased as the sintering temperature increased. The boron carbide caused the bending strength of the segments to decreased, but the sintering temperatures increased the bending strength of the segments.The wear rate of each saw blade was calculated after the andesite stone cutting by diamond cutting tools with boron carbide. The wear rate of the segments decreased with increasing amount of boron carbide and sintering temperature. The lowest wear rate was obtained at wt.5 % B4C rate and 700 °C sintering temperature. Nevertheless, the addition of wt.10 % B4C rate increased the wear rate. The results were associated with the sintering parameters.