Detection of smallest differences in roughness

3D measuring offers 3D depth measurement and surface classification software

In the search for the right measuring method a hurdle had to be overcome. As this was a newly introduced process no suitable measurement or analysis methods were known that could have been used in production. In the end, they found what they were looking for in a Bruker Alicona 3D measuring device which in addition to 3D depth measurement offers a surface classification software that automatically distinguishes between OK and not OK surfaces.

Detection of smallest differences in roughness of the laser treated die casting surface

Even minimal process fluctuations in laser processing lead to the smallest changes in the micro surface quality of the processed die-cast surface. These can already have a critical influence on the durability of the bonding. In the evaluation of various measuring devices, great importance was therefore attached to the ability to detect even very small differences in roughness. In this way, it can be verified whether specified tolerances are maintained even if process changes are made. Conventional profile-based methods could not sufficiently quantify the specific roughness of the die cast surface, so Vitesco Technologies switched to optical metrology for this application and today uses Bruker Alicona's technology in series production. The InfiniteFocusSL measuring system detects even the smallest differences in roughness of the laser treated die casting surface. Therefore, deviations in the laser cleaning process can be detected quickly and it is possible to react promptly, e.g. by adjusting system parameters.

Automatic recognition whether OK or not OK component

The measuring system offers a further benefit which contributes significantly to the efficiency of the entire process chain. It is an automation option based on AI, which automatically distinguishes an OK surface from a not OK. surface. The corresponding evaluation is based on a combination of 2D texture data and 3D topography data, which are analyzed during the inspection process. Using a so-called classifier, both positive and negative examples ("golden samples") are trained to the measuring system or classification software, which enables the automatic detection of OK and non-OK die cast parts in near-series monitoring. 

Automatic measuring sequence for each operator in the production

A "production-suitable" measuring system has many facets. On the one hand, there is the need to provide a corresponding robustness, measuring speed and repeatability for use in production. On the other hand, there is the need for a measuring sequence that enables every operator in production to carry out a measurement without having specific knowledge of the measuring system. Automation is a future-oriented keyword at Vitesco Technologies. Currently, they are working with a semi-automatic measurement, but further steps towards full automation are already under discussion. Vitesco has already evaluated other Bruker Alicona measuring equipment and has come to the conclusion that the Cobots can be used here without restrictions.