Surface Treatment

Zinc-nickel plating

Zinc-nickel platings 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 surfaces typically have layer thicknesses of 5 µm to 10 µm. These layers easily achieve 720 h in the salt spray test against red rust, thereby complying with all current standards in the automotive industry. Zinc-nickel coatings are resistant to corrosion at temperatures up to 180 °C and are therefore also suitable for components in internal combustion engines where pure zinc coatings fail. The ZnNi surfaces offer 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 powdered metals. We offer electrodeposition both as rack plating and as barrel plating. We offer various Cr(VI)-free post finishing treatments for zinc-nickel surfaces such as black, blue or transparent, with additional possibility of top coats (sealings).

Zinc plating

Zinc protects more precious metals from corrosion and as such is indispensable in many industries. The gloss level of the surface can be adjusted from matt to glossy by adding organic substances. The layer thicknesses are usually between 8 and 15 µm. Steel components with a zinc plating are well protected against red rust. If no further protective measures in the form of subsequent treatments are taken, the zinc surface will soon show signs of corrosion (so-called "white rust"). As zinc has a negative potential in relation to iron, it is suitable as a sacrificial anode for cathodic corrosion protection of iron alloys (remote protective action). In comparison with other plating systems, zinc also has the advantage that, even if the coating should be damaged, the base material is not affected, i.e. no rust forms underneath the plating. 
We offer a large range of Cr(VI)-free finishing post treatments for zinc surfaces: Passivations are available in blue, black or transparent form, also as thick coatings. Top coats (sealing) are optional but not always necessary. Various systems are used, including those with lubricant additives. Heat treatments (tempering) can also be carried out after the coating process to remove hydrogen.

Nickel plating

Nickel is the all-rounder of surface technology. With its diverse properties, nickel is one of the most important and frequently used coatings because it is almost universally applicable. Nickel layers are characterised by high resistance to atmospheric corrosion, many acids, sea water and alkali solutions. Chemical resistance is increased by the formation of an oxide layer. Nickel is also valued for its tribological benefits, such as wear resistance and slipperiness.

Its silvery white look that has a slightly yellowish tone, which can be adjusted from matt to glossy, is ideal for decorative applications.

Tin plating

Tin deposits are used in the manufacture of food processing, pump parts and automotive pistons, copper and steel wire and in the plating of electrical components. Solderable tin plating is utilized for a range of purposes across diverse industries including: medical, aerospace and aviation.

Tin plating can be applied to several different materials like steel, stainless steel, copper, brass, aluminium and die cast zinc.

Galvanic tin coatings are proven to be very flexible and show good resistance to corrosion and oxidation. Tin coatings are also appreciated for their good contact resistance, excellent solderability and lubricity.

At Iskra ISD Galvanika, we offer:

• High lustre lead-free tin plating
• Nickel/tin system
• Lead/tin alloy plating

Phosphating

Phosphating is a chemical process for treating the surface of steel, where barely soluble metal-phosphate layers are formed on the base material. The layers created are porous, absorbent and suitable as a conversion layer for subsequent powder coating without further treatment. They are also ideal as temporary corrosion protection if subsequently treated with oil, water or passivation.

It is a temporary corrosion protection for steel, which is to be stored for a limited period before further treatment. Good promotion of adhesion for subsequent colour coating. It can be done with or without oiling in barrels, racks or trays.