More resistant metal coatings with sol-gel An EU-funded initiative has supported seven small manufacturing companies in redefining metal finishing processes. They combined, for the first time, nano-structured sol-gel coatings with ionic liquids to seal and protect aluminium, steel and zinc products. Industrial Technologies © Shutterstock Hot-dip galvanisation, electrogalvanisation and aluminium anodising are engineering solutions on which European manufacturers have in-depth expertise and know-how. Over the past years, these techniques have matured to a level that does not leave room for further improvements. To offer the market wear resistance, corrosion protection and aesthetic appearance exceeding the best standards available today, seven small manufacturing companies turned to new metal surface treatments. In this endeavour, they teamed up with three leading research and technology development providers. The aim of the EU-funded project AVCOP (Added-value for metallic coated products by new sol-gel process) was to derive significant benefits for their manufacturing processes. Specifically, they sought to reduce the energy input for the anodising process and eliminate toxic pre-treatments for the galvanising process. AVCOP partners applied technology that was previously considered not viable, combining nano-structured sol-gel coatings with ionic liquids to seal and protect. The sol-gel coatings developed are entirely solvent free and can replace commercial lacquers for anodised aluminium, hot-dip galvanised steel and electroplated zinc. In the past, sol-gel technology had been successfully exploited in the aerospace and automotive industries where chemical resistance and adhesion chemistry are critical. By incorporating ionic liquids into sol-gels, the AVCOP project has widened the spectrum of applications. The new processes will enable small European manufacturers to face the intense competition from a growing portion of cheaper and low-quality imports from low-cost economies. For example, galvanised finishes for guard rails in vivid colours could ensure a new position in a highly competitive market sector. Keywords Metal coatings, sol-gel, ionic liquids, aluminium anodising, wear resistance
