Ematal ti e pdf

EUGEN SEITZ
Hard-Ematal surface treatment
for solenoid valves
Hard-Ematal coating
High resistance to wear
The surface of aluminium and its alloys is The Ematal coating exhibits high wear re- In its the final state the Ematal coating is isolating aluminium oxide coating, with in- (breakdown voltage approx. 35 . 50 Vper m).
Treatment takes place in a special elec-trolyte via anodic surface conversion ofthe base metal, to form a hard, wear-resi- Excellent anti-friction properties
stant oxide, with the simultaneous inclusi- Choice of alloy
Thanks to the glaze-like, poreless surfa- ce, the Ematal coating exhibits an extre- The selection of the right alloy is of ut- mely low coefficient of friction on suitably properties of the Ematal coating of parti- optimal characteristics of the Ematal coa- cular significance for technical applicati- Just as with all other methods for electro- by extremely high wear and abrasion resi- Increased surface hardness
stance, excellent anti-friction properties ting. The best coating characteristics are and offer a high level of protection against atmospheric and chemical influences.
by all alloys which are known to be suita- coating thicknesses and properties, with- (Al Mg Si 1) is most frequently used.
out essentially altering the dimensions oftreated parts.
The insoluble bond between the Ematalcoating and the base material completely High covering capability
excludes any possibility of the coatingpeeling or chipping off.
The Ematal coating also forms with thesame thickness and characteristics on Maintaining dimensional accuracy
Coating begins at the point with the least resistance to the flow of current, until the (thickness increase), usually unevenly dis- entire component is uniformly coated.
tributed, this is avoidable when the Ema-tal process is used. Hard-ematalising can Application
be controlled so that the dimensions ofprecision areas after coating are kept wit- For workpieces requiring highly abrasion- hin extremely close tolerances (approx.
resistant surfaces: rotors, disks, bearing Other characteristics
Depending on the alloy, the colour of the Ematal coating varies from light grey tobrownish grey. Where the silicon contentis high, the colour is black. In the case of TECHNICAL INFORMATION
EUGEN SEITZ
Chemical resistance of Ematal coating on Aluminium
resistant against.
conditionally resistant against.
resistant if the substance is waterfree. Practically all of them are unqualified since these salts absorbe water.
not resistant against.
Fixing salt (fixing bath, photographic) 1 EUGEN SEITZ
Lead arsenat (strongly diluted solution) 1 Lead tetraethyl (standard solution in fuel) 1 Salt of hartshorn (s. ammonium carbonate)1 EUGEN SEITZ
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Source: http://www.seitz.ch/pdf/ind/chemical/en.SurfaceTreatment.pdf