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
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
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
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
Lead arsenat (strongly diluted solution) 1
Lead tetraethyl (standard solution in fuel) 1
Salt of hartshorn (s. ammonium carbonate)1
EUGEN SEITZ AG 1999 10.0024/E Printed in Switzerland 9911/1.0
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Communicating with citizens? Representations of public opinion in Polish public discourse Robert Szwed ABSTRACT: While political scientists and communication scholars have long been interested in the relationship between democracy, media and public opinion, still too little attention has been focused on how these concepts and institutions are perceived by diff erent actors functioning
Procédure N° 009 Rédacteurs Date Validation Dr A. BARONDEAU-LEURET, SAU Chalon/Saône Approbation Conférences d’actualisation SFAR 1998, pp 635-47Elsevier, Paris Sources Révision de la 3ème Conférence de consensus : Prise en charge des crises d’asthme aiguës graves de l’adulte et de OBJET : Préciser les éléments de gravité et la prise