Aurolia Success Stories
AC 46000: A masterpiece in surface technology.
The Aurolia team has earned a reputation for viewing their clients’ challenges as exciting opportunities, and this case was no exception. It wasn’t just about producing a desired component from AC 46000 in a decorative and appealing form. Rather, our goal was to achieve a very specific attribute associated with exceptionally high adhesion strength.
AC 46000, also known as AlSi9Cu3(Fe), is an aluminum alloy known for its excellent casting properties and commonly used in die casting applications. The microstructure of AC 46000 primarily consists of α-aluminum grains surrounded by eutectic silicon and also contains iron and copper phases.
Our customer had specifically requested to apply a nickel layer with a phosphorus content of less than 6% and a minimum layer thickness of 15 µm [ISO 4527 Al < AC 46000 > // NiP (6) 15 //].
Silicon, an essential component of this alloy for enhancing strength and wear resistance, forms a passivating layer of silicon dioxide on the surface. This renders it insoluble in water and most acids, with only chlorinated acids and hydrofluoric acid capable of dissolving the element.
Our company philosophy precludes the use of hydrofluoric acid or any other processes that may pose a health risk to our employees and the environment.
In this project, the actual coating itself posed no challenge, but selecting the right chemicals for pretreatment was crucial. Therefore, we turned to our proven and highly esteemed development team to jointly devise a technological process flow that not only delivers the desired properties but also minimizes risk to human health and the environment.
After numerous attempts, we succeeded…
to develop a process bath that completely removes the interfering alloying elements, presents a manageable risk within the realm of electroplating, and causes only minimal impairment to the exposed aluminum. With this process bath and the developed technology, we were able to conduct initial trials together with our customer. The results were not only promising but also exceeded our expectations. The adhesion strength test, according to DIN EN ISO 2819 Section 4.1, revealed that the surface exhibits excellent adhesion strength.
