Aluminium Treatment — Sodium & Calcium-Free Fluxes

Sodium & Calcium- Free Fluxes

Sodium and calcium-free flux for aluminium is a specialist covering and drossing flux formulated without sodium compounds or calcium compounds, required where alloy specifications prohibit both elements — preventing sodium-related modification effects and calcium-induced intermetallic compound formation or sludge in the melt.

Standard flux formulations frequently contain both sodium salts (for fluxing effectiveness) and calcium chloride (to adjust melting point and viscosity). Both elements can transfer into the aluminium melt during treatment. Sodium causes modification of the Al-Si eutectic and corrosion issues in Al-Mg alloys; calcium forms calcium aluminides as hard inclusions and promotes sludge formation in high-iron alloys. For alloys where both are problematic, CFC Egypt's EGYFLUX 206 provides the covering and drossing function without contributing either element to the bath — the strictest exclusion available in the flux product range.

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Where Both Exclusions Are Required

Combined sodium-and-calcium exclusion is the most restrictive flux specification, required for alloys where either element causes property degradation.

High-Purity & Electrical Conductor Aluminium

Electrical conductor grade aluminium (1xxx series) and high-purity aluminium for electronics applications require extremely low contamination from all impurity elements. Flux used in these operations must not introduce any element above trace level. Sodium-and-calcium-free flux is the standard in high-purity aluminium remelting, where any flux-introduced impurity directly degrades electrical conductivity or purity specifications.

Al-Mg-Si Structural Die Casting Alloys

Structural die castings in Al-Mg-Si alloys — used in automotive body structures, EV battery housings, and structural nodes — are produced to tight mechanical property specifications that allow very little variation in alloy chemistry. Customer alloy specifications for these grades often list both sodium and calcium as controlled trace elements. Sodium-and-calcium-free flux eliminates both potential sources of unintended elemental pickup from the flux treatment step.

Tight-Specification Secondary Remelting

Secondary aluminium producers casting to customer-supplied alloy specifications — particularly for automotive Tier 1 and aerospace supply chains — frequently operate with customer-mandated chemistry windows that exclude sodium and calcium above specified ppm limits. Adopting sodium-and-calcium-free flux as the plant standard ensures compliance across all heats without requiring heat-by-heat flux selection based on alloy destination.

Wrought Billet & Slab Casting for Rolling/Extrusion

Wrought aluminium producers casting billet for extrusion or slab for rolling use a full melt treatment chain in which every step must be controlled to avoid unintended element introduction. Sodium-and-calcium-free flux in the covering and drossing step is part of the element-exclusion discipline that, combined with degassing and filtration, delivers the chemistry control required for tightly specified wrought products.

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CFC Sodium & Calcium-Free Aluminium Flux

EGYFLUX 206 — a covering and drossing flux free of both sodium and calcium compounds, for the most demanding aluminium alloy chemistry requirements.

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Frequently Asked Questions

Technical questions on why both sodium and calcium exclusion matter and when EGYFLUX 206 is required.

Sodium causes modification effects in Al-Si alloys and corrosion susceptibility in Al-Mg alloys. Calcium, when present in an aluminium melt, can form calcium aluminides — intermetallic compounds that remain as hard inclusions in the solidified casting and cause machining tool wear and mechanical property scatter. Calcium also promotes sludge formation in high-iron alloys by stabilising iron-containing intermetallics. For alloys where both effects are problematic, flux must be free of both sodium and calcium compounds.

The most common applications are Al-Mg alloys where sodium pick-up must be minimised and calcium would promote intermetallic formation; high-purity aluminium for electrical conductor applications where contaminant elements are strictly limited; and Al-Si-Mg alloys used in structural die casting where alloy chemistry is tightly controlled by the customer specification. Some casting alloy specifications explicitly prohibit both sodium and calcium above trace levels.

Standard aluminium flux formulations may contain calcium chloride as a component of the salt mixture, used because it modifies the melting point and viscosity of the flux to suit aluminium processing temperatures. When this flux is applied to the molten bath, calcium from the calcium chloride can transfer into the aluminium, particularly at higher melt temperatures or with prolonged flux contact. Using a calcium-free flux eliminates this transfer pathway entirely.

CFC Egypt supplies EGYFLUX 206 as the sodium-and-calcium-free covering and drossing flux for aluminium. It is formulated without sodium chloride, sodium fluoride, calcium chloride, or other calcium or sodium compounds, making it suitable for the most sodium-sensitive and calcium-sensitive alloy grades. Contact CFC for dosing guidance, furnace compatibility, and application recommendations for your specific alloy specification.

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Related Flux Categories

Other element-exclusion and specialist aluminium flux types from CFC Egypt.

Aluminium Treatment

Sodium-Free Flux

Covering and drossing flux formulated without sodium compounds for sodium-sensitive alloys.

Aluminium Treatment

Fluoride-Free Flux

Lower-emission flux alternatives eliminating fluoride salts for regulatory compliance.

Aluminium Treatment

Fluxes for Alkali Removal

Reactive fluxes that strip alkali metals (Na, Ca, Li) from the aluminium melt.

All Types

Aluminium Treatment Overview

Browse all twelve aluminium treatment product categories from CFC Egypt.

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Processing alloys with strict sodium and calcium limits?

Tell us your alloy specification, current flux product, and the chemistry limits you need to meet. Our technical team will confirm whether EGYFLUX 206 is the right choice and advise on dosing rate and application procedure for your furnace type.

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