Micro Grinding

Micro Grinding (ESR 7). State-of-the-art

Precision and micro grinding process enable the machining of parts with high accuracy and surface finish. However, the grinding of hard and brittle materials can cause a poor surface integrity including residual stresses or micro cracks. To avoid such damages, enhanced ductile grinding processes are necessary, which have been subject to several research investigations.

Crucial requirements for high surface integrity are knowledge and control of the critical machining parameters. The correlation of process monitoring parameters with surface integrity has been investigated for precision grinding of optical glasses, but is still considered as a research topic for micro grinding, e.g. of dental implants. Also, process monitoring techniques are still an exception for micro grinding. Apart from research approaches for tool wear monitoring, few investigations have addressed in-line or even in-process monitoring for micro grinding.

Fingerprint concept implementation
The micro grinding fingerprint is considered as changes of the surface integrity induced by the micro grinding process, such as residual stresses or cracks. The fingerprint will be correlated with critical influencing parameters of the grinding operation. Therefore, an in-line metrology will be implemented to monitor and ensure stable machining conditions to reduce the amount of defective parts.

Expected progress beyond current state-of-the-art
To implement the micro grinding fingerprint it is essential to gain knowledge about small scale surface integrity (e.g. residual stresses, cracks, roughness) depending on the removal rate of micro grinding processes. Due to the small scale of possible effects, this is a challenging task and still subject of current research efforts. A correlation of small scale surface integrity with in-process / in-line monitoring implemented for micro grinding will lead to a strongly enhanced, reliable and robust machining process. The micro grinding fingerprint will be validated on a micro dental implant system.