Surface Enhancement

Aluminium Casting - Saint-Gobain Coating Solutions

Spinel spraying with the Master Jet.

Industry: Aluminium Casting Plant

Equipment: Spoons, chutes, funnels, moulds.

Principle of the Process: Aluminium metal casting requires tools to transfer the molten metal to the moulds or dies. Those tools (spoons, chutes, funnels) are made of steel.

Problem: Tools in contact with molten aluminum are subject to surface degradation and oxidation. Metal slag sticks on the tool surface.

Service Conditions: 

• High temperature ~660°C (1220°F), resulting from the contact with the molten aluminium.
• Metal slag sticks at the surface of the moulds, chutes, funnels.
• Severe thermal shocks resulting from the casting cycle.
• Corrosion and oxidation can occur with several aluminium alloy (Al-Si) compositions.

Metal slag sticks at the surface of the chute.

Coating Solution: Spinel Flexicord Coating.

Benefits of the Spinel Flexicord: 

• Spinel Flexicord coating provides reduced sticking (large wetting angle) versus liquid aluminum metal.
• Cleaning of the spinel coated tools is much easier and requires less time (low sticking of the metal slag).
• Spinel Flexicord coating is a thermal shocks resistant coating.
• The tools lifetime with a Spinel coating is at least twice versus tools without coating (minimum 200% benefit in lifetime).
• The spinel coating can be removed and it can be rebuilt indefinitely.
• Spinel Flexicord is easy to apply by hand on complex shapes and large components with a Top Jet or Master Jet gun.
• Spinel Flexicord coating is less stressed and less subject to spallation compared to plasma sprayed coatings.

Coating Features: 

• Product Ref: 9821 070 47 000.
• ~300 coating thickness on 100 to 150 µm of NiCrAlY bond coat.
• Roughness Ra 16 µm - Porosity 17 %.
• Expansion Coefficient (C.T.E) : 8.8.10^-6 at 0 – 980 °C.
• Micro Hardness: 1140 Hv_300g.
• Surface weight ~890 g/m²/0.3 mm.
• Surface coverage 2 m²/h/0.1 m.