Machine Tools And Devices For Special Technologies

Electrochemical depositions of coats

Slovak University of TechnologyFaculty of Material Science and Technology in Trnava

Electrochemical depositions of coatsGalvanic metallization is based on the cathodic

outgoing of metal from electrolyte. Metallized component is cathode, anode is electrode

of metal that is deposited. Anode is melted into electrolyte and on the cathode is from electrolyte outgoing metal.

On the rims the sharp burrs are originated, on the surface more closely to anode is more thicker put out layer.

Putting out of metal has character of crystallisation.

Electrochemical depositions of coats Protection of surface – protected the surface

against influence of background (Zn),

Decoration purposes – in addition to protection of surface has decorative function too. (Cr),

Functional purpose – coat on the surface is created for the change of functional properties (wear resistant, hardness, low index of friction),

Electrochemical depositions of coatsSpeed of the putting out is depend on valency

of metal putting out. It means between from 0,03 mm/hour in Cr layers to 0,5 mm/hour in Fe and Ni layers.

Negative effect is putting out of H2 that can

cause brittleness of deposited coat. It is removed by anealling.

Electrochemical depositions of coatsIs needed for preparation of surface:

cleaning – the surface is cleaning mechanically, Grease removing – removing from the surface the

impurities and grease, eventually surface film, bating – increase adhesion of deposition layer of

the surface, Deposition of technological intermediate layer –

increase the adhesion of deposition layer to surface.

Electrochemical depositions of coats – disperzing layersIn the coating are of record dispersion elements

(Al2O

3, SiC, TiO

2, TiC, teflon, grafit, diamant).

Disperzion layers have to increased several mechanical properties (strength ness, friction...)

They are originated by present putting out of metal and sedimentary of dispersoid (powder with granuality 0,1 – 6 m).

Is needed to intensively mixing of electrolyte. Supporting metal is usually Ni, Fe, Cu, Co, Ti.

Device for electrochemical machining Rigid frame for accuracy directing of tool

electrode, Numerical directed system with high accuracy, High straight power, maximum rate of stock material around 50

cm3/min, High usage of electric energy (1kW/4 till 6 cm3 of

material removing), High price.

Device for electrochemical machining

Device for electrochemical depositioning of coatings

Device for electrochemical depositioning of coatings

Device for electrochemical depositioning of coatings

Device for electrochemical depositioning of coatings

Device for electrochemical depositioning of coatings

Device for electrochemical depositioning of coatings