With growing needs for industrial products, the focus is on demands for extensive production in each and every sector. Rapid engineering advancements are giving supporting wings to these production targets. But on the other side, there are a few factors acting as barriers on the critical path of massive production. Corrosion is one of the most critical factors among these.

Various research works done in field of surface engineering with the objective of getting long time protection against corrosion have resulted in emergence of processes like cathodic protection, galvanizing, electroplating, etc. But Thermal Spray Technology has evolved as the most phenomenal solution against corrosion. With most ease of applications, zinc (Zn), Aluminium (Al) and their alloys in semi molten forms are usually sprayed on surface of base material with a high velocity.

Thermally Sprayed Coatings

Aluminium Coating: Aluminium coating with structure of aluminium splat, which is surrounded on the outside by aluminium oxide. The thin oxide layer functions as a barrier coating, which is liable to pitting and damage by erosion. Such coating can be sealed to prevent further corrosion.

Zinc Coating: Zinc coating offers cathodic protection to the substrate. The high sacrificial action of zinc provides cathodic protection to the component's surface. Moreover the sacrificial action of zinc produces insoluble corrosion products, which blocks the porosity of thermal sprayed coatings, thus further restricting corrosion of the substrate by preventing the corrosive media to penetrate the coating and come into contact with metallic substrate.

Zn-Al Alloys: The Zn-Al pseudo alloy coating contains two phases - one is zinc rich and the other is aluminium rich. The zinc rich phase offers cathodic protection by its sacrificial action while the aluminium rich phase provides protection by barrier action. The porosity of the coating is partially closed by the products of zinc corrosion. Due to these reasons the aluminium-zinc coating offers considerable advantages with respect to corrosion protection vis-?-vis the conventional zinc and aluminium sprayed coatings

Benefits of Thermal Spray Coating

No curing time, easy application, no geometrical deformation, no thermal stress, more sustaining, and economical - these are few of the characteristics which provide competitive edge to the thermal spray coatings in comparison to other similar processes. Initial low-priced systems and methods often relied on by many users increase the overall cost by several times later on. So TS coating for long term protection is a viable option in each aspect. 

Thermal Spray Coating with Paint/Sealer Synergizes the Protection

In earlier times, paint was used to protect any metallic substrate against corrosion. But later on it was found that once applied the paint coat could not last longer for a longer period in drastic corrosive condition of saline water and high temperature.

Today thermal spray coating with sealer/paint as top coat is most economic and sustainable protection. Metallizing Equipment Company Pvt Ltd, Jodhpur (MEC) helps its customers by enabling them to choose proper material suiting best to their application.

Their Arcjet and Sprayjet models are most suitable for applying anti-corrosive coating of metals like Zn, Al, etc.

(Metallizing Equipment Company Pvt Ltd, Jodhpur. Tel: 0291-2747601. Email: sales@mecpl.com)