Machining, but Make It Better

As a key area of manufacturing science, machining is firmly anchored at Fraunhofer IPK – from macro to micro scale. It is not a discipline that produces groundbreaking innovations, but: »We support our customers with the hands-on challenges they are facing,« reports Ingmar Thiede, one of the institute's machining experts. Inquiries from companies often concern processes that are generally working but are supposed to be more productive or economical. 

The questions and issues are diverse. Often factors such as processing times or tool costs should be reduced while maintaining the same surface quality and dimensional accuracy. Or we receive requests for machining strategies with the appropriate tolerances for new products and materials, or our objective is to reduce the need for post-processing.

Solutions range from determining more suitable cutting parameters or adapting tool path strategies to tool optimization. »We always look at the overall process,« reports Thiede. »After all, what is the benefit of optimizing the process time during machining, but creating excessive burrs that require more post-processing?«

»The right milling strategy is particularly relevant for components that place extreme demands on the machined structures and surfaces in terms of planar parallelism or roughness,« says Muzaffer Dargin, who deals with ultra-precision machining. There is also a lot to consider when it comes to ultra-precision machining of complex components. When there are sharp directional changes during tool engagement, for example, the tool may stand still on the surface briefly, creating unsightly marks. »We optimize milling strategies so that these changes in direction become unnecessary or more continuous, thereby reducing their impact,« summarizes Thiede.

Certain materials offer potential for optimization as well – very hard materials, for example, result in longer process times and greater wear on tools. »We are improving tool properties and developing new cutting materials in response«, says Dargin. Milling tools made of diamond or cemented carbide, for example, are harder thanks to their composition and show fewer wear marks than conventional milling tools.

There are some areas in machining where real innovations are taking place – most of them separate from the actual cutting process. One example is automated CAM planning for the machining of used parts. Another is increasing energy efficiency by identifying consumers that can be avoided by adapting the milling strategy. And even seemingly exotic topics such as robotic milling are addressed at the institute.