Equipment and technology for microarc oxidation metals and alloys

Power facilities - specialised power sources;
Boshes in which one to be held surface treatment, treating and washover;
The positioning device for movement of a hanger with details (in case of the serial Productions);
Metallic structures for disposing of boshes and the positioning device;
Auxiliary equipment - the finestiller, the pump-filter for water treatment and Pumping-overs of solutes, idle capacities, quality control instruments Coatings and electrolyte states.

From power sources on terminals of boshes pulses of a current of the determined move Moulding boxes, thus the detail executes an anode role, in the capacity of the cathode the bosh is or Additional electrodes, as a rule, from stainless steel.

Operations.

The Amount of indispensable operations at MDO is essential less, Than at traditional processes of an anodic oxidation. It follows from lack Numerous preparatory operations and ecological compatibility of applied solutes. After wiring of details on a hanger degreasing, then details is held Arrive on treating. At big scales of production after a bosh Conversion coatings put a bosh of trapping for more rational Usages of chemicals and rinsing water.

Serving staff - the process man (the higher technical education) and workers (srednetehnicheskoe formation). For a lease the floor space 150-200 м2, as a rule, There is enough 2 workers for one shift. Also periodic monitoring is indispensable Lines from outside the sanitary technician and the electrician.

Makeup:

MDO-COATINGS represent ceramics of the complicated makeup. Coating at The microarc oksidirovanii it is derivated at the expense of oxidising of a surface of metal, Are thus reshaped oxide and gidroksidnye moulding boxes of this metal. With another The sides coating grows at the expense of actuation in its makeup of members from electrolyte. Electrolyte members go into coating in the form of salts, magnesias and hydroxides The complicated makeup. If necessary technics MDO allows to inject in Coating any necessary chemical element. Than it is more time to manufacture Detail treating, the there are more than members from electrolyte it is accumulated in Surface layer. The underlayer of coating which is fitting to to metal-basis, Consists predominantly of its oxide joints.

the Diagram of variation of a contents of aluminium and phosphorus on a surface of the MDO-COVERING from processing time in the phosphatic Electrolyte.

Width:

Width of coatings is instituted by several major factors. It is the nature Electrolyte, a material of an alloy of metal, a treatment schedule and a process time. MDO Allows to gain coatings by width from fractions to hundreds microgauges. Indispensable width of coating depends on assigning and service conditions. For underlayer plotting under colouring, 5-10 microns there are enough for giving Dielectric properties or high passive hardness it is necessary 50-100 Micron. Ornamental properties and anticorrosive properties in the atmospheric Requirements ensure 20-40 microns of coating.

Porosity:

Porosity of coatings varies in the interval 5-50 %, sizes from 0,01 to 10 microns. Constitution of holes at width of coating more than 5-10 micrometre complicated, furcated with Assemblage of derivations and selfcontained rooms. Coatings free of holes It is impossible to gain that is stipulated by the process nature. If necessary Porosity can be depressed by means of imbibition by various materials Or by means of plotting of a stratum of a polymetric compound (colouring agent). Most often Imbibition by fluoroplastics and plotting of the polymeric powdered is applied Colours. In some cases porosity is the positive factor. By operation Coatings on deterioration in the conditions of lubrication, last goes into holes of coating and Ensures gradual invading in friction allowed band. In medicine the bioactive MDO-COVERINGS can contain medical products in holes.

Passive hardness:

Coatings are used as abrasive resistant in various knots and aggregates of ambulances and Dodges. At the expense of it in many cases it is possible to apply articles from Aluminium - metal enough soft and complicated for traditional methods Superficial treating (for example, galvanizers). The comparative were held Trials of samples with the MDO-COVERING on aluminium and a steel sample with The plotted abrasive resistant stratum of chrome. Unit load at trials Compounded 0.64 Н/мм2. MDO - coverings have demonstrated smaller deterioration, specially at Elevated temperatures.

the Temperature stability:

MDO-COATINGS have heightened stability to thermal and thermal-cycle To offloadings. Coatings can work without limitations at temperatures from-40 to +60В°С. At gradual heat of a detail the MDO-COVERING temperature stability It is confined to melting point of metal of the detail, as these Values for metal certainly more low, than for ceramics. Trials have demonstrated that Coatings can stand to 280 thermocycles 310-15ВЭС and to 25 thermocycles 500-15ВеС. At such trials, the sample with coating is heated to the set Temperatures in the oven and then it is launched in cold water.

Unevenness:

In the course of treating the surface roughness raises with fluxion Time. It is possible to gain coatings with unevenness to 8 class-rooms. Unevenness Depends on a material of an alloy, a state of its surface and a treatment schedule.

the Corrosion stability:

Method MDO allows to gain coatings, resistant in atmospheric conditions and in Various corrosive medium - chemically aggressive solutes, pairs, To brine and so forth As MDO coating represents ceramics of the complicated Makeup the corrosion stability of a material of coating is great enough. It is possible to ensure metal-basis corrosion prevention with width of coating and Regulating of amount and constitution of holes. Additional security attaches Imbibition of holes by an inert material (more often a fluoroplastic). Trials (GOST In 20.57.304-76, 20.57.304-88) have demonstrated GOST RV that the gained coatings Can be operated as non-corrodible within 15 years.

the Dielectric properties:

Stress at which one there is a puncture of coating, as well as corrosive Stability, depends on width of coating, type and pore sizes. Also this magnitude Can be essentially augmented application of the material which is filling the grains. Mean breakdown voltage of coating - 600 n of coating with Filling up of holes - to 2500 V

Adhesion:

MDO-COVERINGS have excellent adhesion with metal-ground, which one Metal coating is ensured with transition layer presence on boundary. The transition layer is reshaped as in metal, and outside, and also has Profile with assemblage of flexures.

As a result, adhesion of coating with metal appears more hardnesses The coating and at a loading does not originate coating breakoff on boundary Has undressed metal-coating. Counted by results of Scrach-testirovenija Values of adhesion attain 350 MPa.

The INSTANCE: the Production plant has substituted a material of a spraying apparatus from hard metal on aluminium with the MDO-COVERING and as a result has gained major passive hardness of a surface and saving from hard metal substitution on easier and low-cost aluminium. The monthly program compounded to 5000 details, all has been boarded more than 800000 details. Implementation of technics of the microarc oksidirovanija was restrained till now by small notoriety of a method and lack of implementations of industrial lines MDO. Now this situation varies. The amount of the architectures was augmented, starting to be occupied by study of process MDO.

Any alternative of delivery of the equipment - from the selective complete equipment before delivery "on a turn-key basis"