Optimize Metals Pretreatment with Chromium-free Conversion Coatings

Chrome-free conversion coatings can eliminate the need for plasma treatment surface modifications.

Achieving the best surface for multi-metal bonding is a challenge for automakers and suppliers. Body structures, as well as engine and drivetrain system components, contain a combination of materials, including aluminum, steel, magnesium or compacted graphite iron, to name a few.

The unique properties of each metal come into play when preparing the substrates for improved bonding performance. Use of conversion coatings is key to stabilizing substrate surfaces and achieving the highest level of adhesion. 

While plasma treatment is used as a surface modification technique to prepare metal surfaces for improved bonding it does have limits. For example, in some cases consistency of the substrate conditions may show variability in performance. Plasma’s operational window requires sequential application of treatment to allow adhesion to be successful. 

In contrast, Henkel’s BONDERITE® line of thin-film, conversion coatings chemically treat metal substrates by forming a uniform oxide layer for improved adhesive bonding. These coatings dramatically enhance the adhesion of formed-in-place liquid gaskets and are highly effective in providing improved sealing characteristics when applied to the mix of lightweight metals used in today’s vehicles. Additionally, these coating can be used for multiple applications including, engine covers, oil pans, seal retainers, transmission cases, covers, and axle covers.

BONDERITE thin-film conversion coatings:

• Increase liquid gasket adhesion by up to 4x’s times
• Decreases leak rates on sealing applications
• Cost effective alternative to plasma applications 
• Bonding performance can remain present for weeks after application
• ROHS compliant technology

Both BONDERITE M-NT 5700™ and BONDERITE M-NT 1455™ technologies can either be manually or robotically applied, and the surface ready for bonding in seconds following the application. 

To learn more register here to listen to the recording of the webinar Improving Adhesion Capabilities through the Use of Conversion Coatings.