Forces and wear in high-speed machining of granite by circular sawing

In stone sawing process, the most adopted tool type is the circular diamond blade, whose duration and performance are influenced by various elements. These factors can be grouped into four categories: the mineralogical characteristics of the material to be machined; the working conditions, such as the depth of cut, the feed rate and the cutting speed; the production process of the diamond segment and the characteristics of both the matrix and the diamond, such as the size, the type and the concentration of the diamonds and the metal bonding formulation hardness. A key factor to increase productivity and reduce processing costs is cutting speed. In fact, the current trend is to adopt ever higher cutting speeds in order to reduce production times and costs. The purpose of this work is to evaluate over time the efficiency of the granite cutting process using diamond discs according to the cutting speed. The analysis was carried out for cutting speeds higher than the parameters conventionally used in the industrial field which is about 25 m/s. The efficiency of the processing was assessed by measuring the forces and wear of the tool according to the main process parameters for different working stages. In particular, the impact of working parameters modifications on the cutting operation of an ornamental stone was studied by experimental tests carried out on a CNC working centre equipped with a data acquisition system, suitable for the registration of all the three components of the cutting force.