A novel procedure to predict cumulative tool wear in turning based on experimental analysis

Tool wear is one of the most challenging issues in manufacturing. In cutting processes, tool-life testing procedures are defined by ISO standards. These standards give the guidelines to perform tool-life testing in terms of workpiece material, tool geometry, tool material, cutting fluid, tool wear assessment, and tool-life evaluation. For determining the useful tool-life, the standards recommend running several tool-life tests at constant cutting speed till reaching a specified value of tool wear, as defined by the selected tool-life criterion. But, in industrial applications, the approach is different. The same tool is often used to make different geometrical features on the same component using different process parameters, depending on the desired geometry and surface quality. Therefore, it is possible to state that the tool accumulates wear over the working time under different cutting conditions. In other words, the tool is subjected to cumulative tool wear. This paper aims to deepen the knowledge about cumulative tool wear, which means the tool wear generated by a combination of different process parameters. An innovative experimental procedure is proposed to determine the useful tool-life when machining a part with the same tool at different process parameters. Cumulative tool flank wear tests were performed on AISI 1045 samples by changing the cutting speed, keeping the other cutting parameters constant. The experimental cumulative flank wear evolution was compared with the theoretical one. Four different machining cycles were tested to simulate different industrial cases. The comparison revealed a good agreement between the prediction and the experimental data.