Surface Treatment & Coating

Surface treatment and coating protects an aluminium casting against corrosion and wear and gives it the required appearance. Kılıçaslan runs these processes through an approved supplier network; preparation, dispatch, incoming inspection and final responsibility stay with us, so you never deal with a separate coating shop.

Why aluminium is coated

Aluminium forms a thin oxide layer on contact with air, and that layer is protective up to a point. In casting alloys it is neither thick nor uniform enough. Parts working outdoors or exposed to salt air, moisture or chemicals need an additional surface treatment.

The second reason is appearance: colour, gloss and texture expectations on most finished products are met by coating. The third is function — some coatings increase surface hardness or provide electrical insulation.

The processes we apply

Chromating (conversion coating)

Chromating forms a thin conversion layer on the aluminium surface with two purposes: raising corrosion resistance and providing a key for paint. It is classified as yellow or green chromate and is the most widely used chemical preparation before painting.

Anodising

Anodising thickens and hardens the oxide layer electrochemically, improving wear and corrosion resistance; the layer can also be dyed. In casting alloys the resulting colour and uniformity depend on silicon content, so anodising expectations should be discussed together with alloy selection from the outset.

Electrostatic powder coating

Powder coating sprays electrostatically charged powder onto the part and cures it in an oven, giving a thick, impact-resistant film in a wide colour range. It is common in exterior and lighting applications and requires degreasing and chromating beforehand.

Preparation: degreasing and blasting

The life of any coating depends on what happened before it. Skip degreasing, pickling, rinsing or blasting and even the best coating blisters. We handle mechanical preparation in our own plant: Deburring & Surface Preparation.

Choosing the right process

• Colour and outdoor durability first: powder coating
• Hardness and wear resistance first: anodising
• Protection under paint or electrical continuity: chromating
• Short-term storage protection only: light passivation may be enough

The service environment decides. In luminaire bodies the relation between coating thickness and heat dissipation matters; in enclosures, earthing points must be left uncoated — see lighting luminaire bodies and electrical and electronic enclosures.

Incoming inspection

• Coating thickness measured against the specified range
• Adhesion checked by standard methods
• Colour and gloss compared against the approved sample
• Visual inspection for runs, blisters, uncoated areas and staining

A batch returning from coating passes our inspection before shipment. A batch that fails goes back to the supplier, not on to you.

Why Kılıçaslan

• One point of contact. You do not chase a coating shop.
• Approved supplier network. Coaters are audited; those whose performance drops leave the network.
• Preparation stays with us. The most critical step of coating is under our own control.
• Inspected before dispatch. A coated batch is not shipped unmeasured.

Frequently asked questions

Can die cast aluminium be anodised?

It can, but colour and uniformity depend on the silicon content of the alloy, so decorative anodising is rarely realistic on die casting alloys. Where appearance is critical, powder coating is the safer choice.

Can I specify a RAL code?

Yes. We work to RAL codes in powder coating, and for special colours or textures we coat a sample part for approval first.

Does coating change dimensions?

Powder coating adds measurable thickness, so tight mating faces and threads are masked or machined afterwards. This is defined in the machining plan up front.

Can you arrange salt spray testing?

On request we have corrosion testing carried out by accredited laboratories and deliver the report with the batch.

Tell us the service environment and we will select the right treatment with you.