Zinc-nickel

Brief technical description:

• Zinc/nickel coatings were developed as a result of increasing requirements with regard to corrosion protection, in particular from the automotive industry, against exposure to temperature, road salt and climatic conditions. Zinc/nickel coatings are normally used if the traditional zinc-plating process is insufficient, due to high temperatures or aggressive environmental conditions.  The Ni incorporation rates amount to approximately 10-15%. The ZnNi surfaces offers optimal cathodic corrosion protection and are highly resistant to thermal loads (up to 120 °C). This type of surface finish is usually used on steel, ferrous cast components and sintered metals.
• The Holzapfel Group coats zinc nickel according to the following standards: VW TL 244, DBL 8451, Opel GME 00252, GMW 0047, BMW GS 90010 and DIN 50962. Zinc-iron standardization concerning spay constancy (CrVi-free systems) in hours  DIN EN ISO 9227

Advantages:

• High degree of corrosion resistance of the Zn/Ni coats: no voluminous corrosion products in comparison with zinc coatings.
• Protection against base metal corrosion: extremely long-term cathodic corrosion protection with practically no risk of hydrogen brittleness when used with all common hydraulic media.

Please note:

• Zn/Ni coatings for steel substrates are the chosen medium to prevent contact corrosion with aluminium.

We offer various Cr(VI)-free post finishing treatments for zinc/nickel surfaces:

• Passivations are available in black or transparent form. 
• Top coats (sealing) are optional, but not always necessary. Various systems are used, including those with lubricant additives.
• In the event of special requirements for corrosion protection, we recommend transcor (link), a transparent Zn/Ni surface that offers the best results without sealing.
• Preservation of uncoated internal surfaces, for example the inside of pipes, as well as heat treatments (tempering) to remove hydrogen after the coating process, are offered to complement our range.

Area of utilisation:

• Automotive and supplier industry (e. g. brackets and pipes in the engine compartment that are subject to high thermal load, rotating parts (for brake and magnetic systems))
• Building machinery
• Precision engineering