ÖkoClean - Ecological and function-optimized pretreatment chain for plasma coating of complexly shaped cutting tools
Depending on the size of the company, the production of coated tools generates several tons of environmentally harmful waste every year. The work in this project was aimed at creating a cleaning chain for the component coming from the production line up to the coated tool, which
•through high cleaning efficiency,
•significantly lower environmental impact,
•striking resource conservation and
•high economic attractiveness
is excellent. High-quality hard material coatings, e.g. on the basis of TiN, TiAlN, CrN or CrAlN, can only be applied firmly on component surfaces that have been cleaned without leaving any residues. The effective removal of particles, machining residues, corrosion products and lubricants is essential. Currently, a number of different processes are used for this purpose, e.g. wet chemical treatment, which often results in the release of environmentally harmful waste materials (acidic or alkaline waste water, sometimes contaminated with heavy metals or poorly degradable organic substances).
In this project, novel environmentally friendly and at the same time cost-efficient combinations of coordinated pretreatment processes were developed, which are particularly suitable for geometrically complex cutting tools. Different mechanically acting or fluidic cleaning processes as well as optimized plasma fine cleaning steps are used.
In particular, these include cleaning with CO2 snow, the use of novel ecological aqueous media with ultrasonic support and plasma electrolytic polishing. For plasma fine cleaning, newly developed plasma sources were used, which enable effective sputtering processes with high-power pulsed atomization and plasma-chemical treatment of the surface prior to coating. All process combinations were applied to synthetically contaminated cutting tools and, after plasma coating, their technological suitability was examined in cutting tests with regard to tool life.
Finally, the developed methods and processes were evaluated ecologically and economically and their transfer to industrial application was prepared.