Chromium-Free Pretreatments for Improved Paint Adhesion

LumiShield Technologies has created a revolutionary metal treatment platform based on non-toxic, sustainable, aluminum oxide. The initial product, Lumidize^®, is a pre-treatment for steel and aluminum surfaces to improve paint adhesion and corrosion resistance. Lumidize^® will replace the current use of phosphate, chromate, and grit-blasting. Lumidize^® is a HAP-free, VOC-free technology based on electroplating. Lumidize^® uses the exact same infrastructure as common zinc or nickel plating processes but with a far less toxic waste stream.

The Lumidize® coating can be applied to mild steel, stainless steel or aluminum, making it a versatile surface treatment for multi-metallic applications. Furthermore, the matching of steel and aluminum surfaces will lead to the mitigation of galvanic corrosion in aircraft. Lumidize^® can also be adapted to bind specifically with many top-coats such as polyurethane, epoxy and fluoropolymers leading to strong chemical bonding from the top-coat to the base metal.

So far, Lumidize® offers far improved adhesion of paint to mild steel test panels under scribed salt spray exposure, with no scribe creep detected after 1500 hours, far surpassing the performance of phosphates. For aluminum alloys, Lumidize^® is being benchmarked against leading chromium-based pretreatments, with no paint delamination of Lumidize^® samples detected in scribed salt spray testing to date.

Being composed of thin aluminum oxide, Lumidize^® will also help facilitate the lightweighting of aircraft, allowing thinner paint layers and aluminum or magnesium alloy components compatibility with steel fasteners.