A project of the INPLAS-AG "Tool Coatings"

ÖkoClean – Ecological and functionally optimized pretreatment chain for plasma coating of complex shaped cutting tools

Depending on the size of the plant, the production of coated tools generates several tons of environmentally harmful waste per year. The work in this project was aimed at creating a cleaning chain for the component coming out of the production line up to the coated tool, which can be

  • due to high cleaning effect,
  • significantly lower environmental impact,
  • marked conservation of resources and
  • high economic attractiveness

distinguishes. High-quality hard coatings, e.g. based on TiN, TiAlN, CrN or CrAlN, can only be applied to component surfaces that have been cleaned without leaving 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 involves the release of environmentally harmful waste materials (acidic or alkaline wastewater, 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. Various mechanically acting or fluidic cleaning processes as well as optimized plasma fine cleaning steps are used.

Specifically, these are cleaning with CO2 snow, use of novel ecological aqueous media with ultrasonic support, and plasma electrolytic polishing. Newly developed plasma sources were used for plasma fine cleaning, enabling effective sputtering processes with high-performance pulsed atomization and plasma chemical treatment of the surface before coating. All process combinations were applied to synthetically contaminated cutting tools and examined after plasma coating for their technological suitability in cutting tests with regard to tool life.

The developed methods and processes were finally evaluated ecologically and economically and their transfer to industrial application was prepared.