Development of new methods for determination of trimming die wear

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This project addresses a current problem that impedes productivity and product quality at Ford plants where trimming operations are performed on automotive body panels made of advanced high strength steel (AHSS). Parts made of AHSS steels provide high strength-to-mass ratio and thus are important for automotive light weighting strategy but in order to increase their use the significant wear damage they cause to the trim dies should be reduced. The trim die wear has undesirable consequences including deterioration of trimmed parts' edges and an increased cost of operation as the worn dies need to be replaced frequently. In order to alleviate the die wear problem the first step should be to develop a measurement method that will determine the die life accurately and in a consistent way. The proposed work consists of development of a methodology for wear measurements on upper and lower trim dies as a function of the number of trimming cycles-- and by considering the die-workpiece clearance as well as the die angle. Wear measurement methods that have not been previously applied to trimming die measurement will be assessed at University of Windsor's Tribology of Materials Research Centre. These will consist of three dimensional non- contact interferometry methods supported by specialized digital optical microscopes with large depth of field focus. Both uncoated and coated DP980 type AHSS will be trimmed at Ford's facilities and the worn dies will be evaluated for the amount of damage as well as the type of surface damage that may consist of galling, material transfer abrasion, plasticity or micro-chipping controlled damage features. The research will correlate wear measurements to the particular type of wear that may occur at the cutting edge and the results will be transferred to Ford. The results are expected to contribute to the development of a Ford Standard for determining die wear. The project will help to increase the efficiency of trimming operation schedules and implementation of new tool wear reduction strategies.