Comportamento di rettifica di mole diamantate a legante metallico con l’aggiunta di cromo come elemento formatore di carburi. Grinding behaviour of metal-bonded diamond grinding wheels with an additive of chromium as a carbide-forming element

Addition of carbide-forming elements to metal-bonded diamond grinding wheels can increase the grain retention through carbide formation at the grain-bond interface. In order to investigate the effect of chromium addition, bronzebonded diamond grinding wheels were fabricated through field assisted sintering technology. The resulting grinding layers were characterized by means of critical bond strength, hardness and density. At a sintering temperature of 720°C no carbide formation within the interface of diamond and bronze-bond was observable. The chromium particles with an average diameter of 10 µm remain unreacted und evenly distributed within the grinding layer after sintering, resulting in no significant increase in grain retention forces. Nevertheless, the chromium addition leads to a decrease of ductility of the bond, resulting in a grinding wheel surface topography were diamonds are more exposed and the bond is further recessed after machining. The thus emerging higher grain protrusion results in an improved grinding behaviour with a decrease of near 100% in process forces and increase of 446% in G-Ratio.