The forming of aluminum sheets in automotive engineering is far more difficult to control than the forming of steel sheets. The thickness of the lubricant layer on the sheet is an important parameter for the quality of the forming process. The F-Scanner fluorescence measuring system is the only system that measures this thickness in production with spatial resolution. Four F-Scanners have now been delivered to a US car manufacturer to ensure the quality of car body parts.
Lower weight, corrosion resistance - an aluminum body has considerable advantages over a steel body. However, aluminum sheets cause significantly more problems than steel sheets during forming in the press shop: aluminum is comparatively brittle and the hard oxide layer leads to greater tool wear. If the forming of aluminum is to succeed perfectly, the dry lubricants used must be optimally distributed on the sheet surface. In future, a US car manufacturer will monitor this desired distribution directly in the press shop using the F-Scanner developed at Fraunhofer IPM. Four of these measuring systems will be integrated into the production line in the coming weeks.
Full-surface measurement of lubricant distribution in the production cycle
Two of the four identical F-Scanners each record the lubricant distribution on one bleaching side over a width of two meters. The measurements are carried out with millimeter resolution - in the production cycle at a feed speed of up to 2.5 m/s. At 400 lines per second, each of the four F-scanners scans the surface of the sheets, which are up to four meters wide, with a laser beam and detects the fluorescent signal, which varies in intensity depending on the lubricant coating. The entire measuring system generates and processes 160 million data points per second. The result of the full-surface fluorescence measurement is a high-resolution and complete map of the lubricant distribution for each individual component - perfectly documented for quality assurance.
