Magnesium powder coating and surface treatments
We have over a decade of experience in processing magnesium, used extensively in the automotive, electric vehicle, aerospace and bio-medical industries. As light weighting becomes ever more crucial in markets with strict emission targets, die-cast magnesium alloys are being used for light-weight structures to reduce weight yet further without compromising overall strength.
Magnesium also has a vibration damping capacity which is beneficial in applications where the internal forces of high-speed components need to be reduced. For electronic devices magnesium alloys are often chosen as they can dissipate heat and shield against (EMI) electromagnetic interference.
Magnesium is a highly reactive metal and also only forms a weak natural oxide layer on exposure at room temperature. This makes it particularly susceptible to corrosion, meaning that careful cleaning, suitable pre-treatments and edge to edge final coating are imperative.
Powder coating and its benefits
The powder is paint in dry powder form, made of resins, binders and pigments. It picks up an electrostatic charge as it leaves the end of a spray gun and becomes attracted to the metal substrate. The coating is then cured by heat to form a smooth hard skin of uniform thickness on the surface of the metal. Powder coating is a one-coat system and after application the coat can be cured in 20 minutes.
The powder coated surface formed by the curing process is a bonded layer with excellent resistance to weather corrosion, scratches, abrasions, chipping and fading. Being dry, powder coatings have no solvents containing volatile compounds.
Powder coatings are a dry powder and emit zero or negligible volatile organic compounds (VOCs).
Powder coatings contain no halogens or heavy metals.
Powder coating does not mean ‘end-of life’ status for the metal. The coating can be removed and the metal recycled with no adverse effect.
Pre-treatment for magnesium
We use only chrome-free pre-treatments in our plant and were the first powder coater in the UK to do so, back in 2001.
We have extensive experience in these safe and effective systems.
Automotive: We operate all large automotive OEM approved magnesium chrome-free pre-treatment systems.
Aerospace: Gardobond X4729 eleven-stage chrome-free pre-treatment (also known as Ardrox 1769) is used for aerospace-approved magnesium alloys to class L (with top coat) or class S (no top coat) specification.
