In manufacturing the need for process monitoring is increasing due to increases in quality demand and cost pressure. Forces are suitable data sources for process monitoring. An approach to circumvent additional sensors is the use of sensory machine components. Strain gauges are integrated to measure the elastic strain caused by force. The application of conventional strain gauges is a manual and labour-intensive task. The direct deposition of strain gauges, using a sputtering process offers a high potential for automation in the manufacturing of sensory machine components. Sensory machine components are necessary for structure-integrated measurements. To manufacture functioning sensors through the sputtering process, high requirements regarding the component's surface quality have to be met before insulation and sensor layers can be deposited. The literature indicates that the mean roughness depth Rz must be below 0.6 µm and the average roughness Ra must be below 0.1 µm in order to achieve functioning sensors. Manual polishing or chemical-mechanical polishing is used to achieve the required surface quality. While chemical-mechanical polishing (CMP) is a well-known and established process, in the manufacturing of wafers, it is not suitable for complex mechanical components.  

To achieve reproducible surface roughness on complex workpieces, an automated process adaption of the manual polishing process is investigated using an Ultrasonic 10 machine tool from Sauer and different types of polishing tools. The machine offers a spindle speed of up to 42,000 min-1 to achieve sufficient cutting speeds for the investigated polishing tools. The machine is also equipped with an integrated laser-based tool measurement system. This allows the machine control to consider the adjustment of the tool length automatically. For the experimental investigation, ground C45W steel specimens are used. The results show that the automation of the manual polishing process using a machine tool leads to a surface roughness suitable for sputter deposition of sensors.