Aluminum’s amount in cars rising
The amount of aluminum used in automotive production is steadily increasing, as automakers and auto suppliers are reducing the weight of cars in order to meet the latest legislations on fuel consumption. Besides parts such as engine blocks and gearboxes, many other parts are now made from aluminum replacing complex and heavy steel components.
On top of this, upcoming electric vehicles contain a lot of additional aluminum components such as battery packs. Furthermore, the trend towards structural castings is getting even stronger, as more lightweighting is needed to compensate for the additional weight of the battery.
Preparing aluminum parts for welding and bonding
Bare aluminum is literally non-existent – due to its high chemical reactivity the metal surface is covered within seconds by an oxide layer. This passive oxide layer protects the metal from corrosion, but has a negative impact on welding and bonding processes.
To overcome this challenge, Henkel has developed the BONDERITE® 2040-process. This process, also known as “etch-passivation-process”, cleans and prepares the surface for future bonding processes.
The process starts with an alkaline degreaser to remove dirt, grease, and oil from the surface. Then, in the etch-passivation stage, the surface is slightly etched and simultaneously a thin titanium-conversion coating is applied on the aluminum, offering excellent corrosion resistance.
Stable surface properties for higher flexibility in production
The 2040-treatment stabilizes the surface resistance of the parts, as the Ti-conversion layer prevents the re-oxidation and re-passivation of aluminum surfaces for several weeks, up to several months. Due to this surface stabilization, it is possible to process parts like structural castings or battery boxes in welding and adhesive bonding processes long after they have been treated. Giving customers higher flexibility in their production processes and sourcing of parts, as they become more independent from locations, storage, and transport times.
Henkel’s BONDERITE® M- NT 2040 etch-passivation-process is approved by many OEMs and has an extensive track record of successful use cases in the automotive and general industry.
Please contact us for more information on the etch passivation process or questions concerning light metal or general metal pretreatment.