Category: Zinc Aluminium

Different advantages of zinc aluminum flake coating are as follows :

1. No Hydrogen embrittlement – The treatment process of zinc aluminum flake coating do not involve treatment with acid for removal of corrosion products like mill scales, rust. Mechanical cleaning (shot blasting, grit blasting) followed by coating avoids the risk of hydrogen embrittlement.
2. Overall coverage – The coating process is non electrolytic. Articles are coated by dip mode of application or spray mode of application depending on size, weight of article. The articles are coated ensuring complete coverage.
3. Corrosion resistance – The corrosion resistance is higher due to overall coverage and also due to sacrificial protection of zinc /aluminum flakes. The film structure is like brisk wall minimizing penetration moisture. The film also has self healing property.
4. Thermal stability – Cured film of zinc aluminum flakes do not changes its properties even at higher temperatures. There is no degradation in corrosion resistance property.
5. Excellent adhesion and recoat ability – Zinc aluminum flakes coating film adheres firmly to metal surface. It has also excellent recoat ability. Top coat with different lubrication properties can be applied on zinc aluminum flake coating to further enhance different properties.
6. Free from pollution – The water-based zinc aluminum flake coating process do not involve generation of waste water. The coating is free from water and air pollution.

Generally zinc aluminum flake coating process involves cleaning to remove oil, shot blasting to remove rust/mill scales, coating and curing. Desired properties are achieved essentially with two coats. The properties are further enhanced by application of suitable top coat.

Use of ferrous and non- ferrous material is unavoidable in the industry due to its availability, strength, durability, work-ability and ability to recycle. Automobiles, bridges, house- hold appliances, power generation equipment’s, railways, engines etc. are manufactured using ferrous and non -ferrous materials by adjusting metal properties in terms of hardness, flexibility, resistance to corrosion, weight to strength ratio etc.

Loss of metal due to various types of corrosion processes is a perennial problem in the industry. Thousands of dollars are wasted due to loss of metal (corrosion) and also thousands of dollars are invested in protecting the metal from corrosion. This in turn increases the life span of manufactured items, avoids the probable risk of accident.

Use of different types of fasteners, nuts, bolts, clips are necessary to manufacture different articles. The adequate strength required for the articles is provided by different sizes of fasteners, nuts and bolts.  Fasteners are subjected to failure due to atmospheric corrosion, hydrogen embrittlement, temperature variations and bi- metallic corrosion.

Different types of phosphating systems and also painting systems with different types of resins, film thickness varying from few microns to few millimeters are used to protect the main structure. However higher film thickness of any coating is a limiting factor for fasteners.

 Different types phosphating, blackodizing, zinc plating followed by passivation layers are used to improve the corrosion protection of fasteners. However, zinc plating has limitations in terms of corrosion protection and possibility of hydrogen embrittlement. Adverse effect on environment due to use of hazardous chemicals also needs to be considered while using such coatings.

Zinc aluminum flake coating is developed with the extensive research to provide protection against all types of corrosion for fasteners, brake disc etc with a very thin film of 6~10 microns. Zinc aluminum flakes with water or solvent based, binders free from hexavalent chromium (environmentally friendly) and adequate additives to improve different properties are widely used in the industry. Even at low film thickness zinc aluminum flake coating provides excellent protection against corrosion considering different environmental cycles. Zinc aluminum flake coating also helps in preventing bi metallic corrosion.