Surface finishing is an integral part of a components design. From automobiles and airplanes to washing machines and jewelry, protecting the surface has been Coventya’s main objective. One of the keys to protecting certain finishes, such as zinc or zinc alloys or some substrates, like aluminum, is the use of conversion coatings. Yesterday, this was accomplished with solutions based on hexavalent chrome, often referred to as a “chromate”. Today, environmentally safe and sustainable processes based on trivalent chrome are called “passivates” and they’ve come a long way from when they were first introduced.
The conversion process is simply a reaction between the metallic base layer or metallic deposit (e.g. zinc or zinc-nickel) and an acidic solution usually containing trivalent chromium ions. The complexity of this reaction requires creativity, intuition and hard work to constantly maintain the balance between the demands of the challenging application and the requirements of a very eco-conscious world.
Coventya pioneered the introduction of trivalent chromium conversion coatings into the European market, gaining one of the first automotive approvals for such a process at OPEL in 1997. Shortly thereafter, COVENTYA and our international partners led the industry by introducing Nanopassivates and dedicated Top-Coats for high performance applications that pushed the toxic chromates further into oblivion.
In 2007, Coventya did it again by introducing a thick layer passivate (LANTHANE 316) which, in contrast to earlier processes, did not require the process solution to be heated. This groundbreaking product was another big win for our planet which eliminated roughly seven tons of CO2 emissions per year for every 1000 Liters of operating solution.
In the last ten years Coventya continued these efforts by introducing a broad portfolio of cobalt-free passivates marked by a “CF” appendix in the brand name. The elimination of cobalt is desired because of the hazardous (SVHC) nature of several cobalt salts and also due to Cobalt scarcity driven by the increasing demand of cobalt in electric vehicle batteries. Coventya was among the first, if not THE first supplier offering a full range of Cobalt-free passivates for all applications. These efforts are already delivering results for our customers with approvals from Ford (S450B) and GM (GMW4700).
COVENTYA’s focus goes well beyond ecology and includes the economic benefits and quality side of passivation technology. By addressing metallic contaminations, which typically limit the lifetime of a passivate, COVENTYA offers both formulation options, designed for reduced attack of Zn and Fe, as well as purification technologies to remove these impurities. Both of these approaches work together, keep the cost in control and deliver reliable quality.
It is clear to the surface finishing industry that innovative and eco friendly conversion coatings are in Coventya’s DNA. For our customers and valued OEM partners, this brings comfort knowing that future challenges will be met all while doing what’s right for the planet.