RU2432421C2 - Procedure for manufacture of thin films - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: procedure for manufacture of thin films on steel parts consists in treatment in water solution of molybdenum anhydride, Also, treatment is carried out in electric field at difference of potentials 2-20 V. An item corresponds to cathode, while a coal electrode - to anode. Duration of treatment is determined from ratio:

, where τ - is duration of treatment, sec; K - is empirical coefficient amounting to (10-12)·10⁴(c*g/l); C - is initial concentration of ions of molybdenum in solution, g/l.

EFFECT: raised processability and efficiency, manufacture of thin films on steel parts for increase of their wear resistance.

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Description

The invention relates to the field of producing thin films, and in particular to methods of processing steel parts to increase their wear resistance.

A known electrolytic method for applying anode coatings in an electrolyte stream containing fine particles of powder of insoluble metal or metalloid compounds in an electrolyte with the addition of material with an exothermic oxidation effect (RF patent 2224055, publ. 2004.02.20. BI No. 5).

The disadvantage of this method is the impossibility of obtaining wear-resistant coatings.

Closest to the proposed invention is a method of processing metal parts by boiling in an aqueous solution of molybdenum compounds (AS USSR No. 277501, publ., 1970. BI No. 24).

The disadvantages of this method are the low productivity and manufacturability of the processing process, due to the need for boiling parts in solution, and the boiling process itself is carried out for a very long time (within one hour), which significantly reduces productivity.

The technical result of the invention is to obtain thin films on steel parts to increase their wear resistance and increase manufacturability and productivity of the process.

The essence of the proposed method for producing thin films on steel parts is that the treatment is carried out in an aqueous solution containing molybdenum anhydride in an electric field with a potential difference of 2-20 V, the part being the cathode and the carbon electrode as the anode, and the processing time is determined from the ratio:

,

,

where τ is the processing time, s;

K is an empirical coefficient of (10-12) · 10 ⁴ (s · g / l);

C is the initial concentration of molybdenum ions in solution, g / l.

The proposed method is as follows.

The part is placed in an aqueous solution of molybdenum anhydride and a negative charge is supplied to it. A positive charge is brought to the carbon electrode. Depending on the conditions of the experiment, the voltage was varied (from 1 to 50 V, the current density was maintained at 15-20 A / dm ² ), the initial concentration of molybdenum ions (from 50 to 200 g / l) and the duration of the process (from 5 to 40 min), and the temperature is 40-50 ° C.

The results of the experiments are shown in the table.

Table Experience number The value of indicators Tension-
U, B Concentra-
c, g / l Duration, τ, min Conditional quality of the obtained film Wear resistance one one 200 5 Not satisfactory Low 2 2 200 10 Satisfactory Average 3 5 150 fifteen Good High four 10 150 twenty Good High 5 10 one hundred 25 Good High 6 twenty one hundred thirty Satisfactory Average 7 fifty fifty 40 Not satisfactory Low

And with the product value of these values from 10 · 10 ⁴ to 12 · 10 ⁴ (s g / l), the quality of the obtained film was good and it increased the wear resistance of the surface of the part.

Based on the experiments, an empirical dependence was obtained that allows one to relate the quality of the obtained film to the processing time and the concentration of molybdenum ions in the solution and it has the form;

,

,

where τ is the processing time, s;

K is an empirical coefficient of (10-12) · 10 ⁴ , (s · g / l);

C is the initial concentration of molybdenum ions in solution, g / l.

Since molybdenum oxide molecules are weakly paramagnetic, when electric current is passed, they settle on the surface of steel parts, forming thin films, and because of their layered structure and due to the property of a pair of MoVI / MoV ions, we believe that the obtained thin films contribute to the increase of wear resistance of steel details.

Using the proposed method for producing thin films on steel parts in an aqueous solution containing molybdenum anhydride will increase the productivity of the process by reducing the processing time by 3-4 times, and will also increase manufacturability by eliminating the need for long boiling of parts in a molybdenum solution.

Claims (1)

A method of producing thin films on steel parts in an aqueous solution containing molybdenum anhydride, characterized in that the treatment is carried out in an electric field with a potential difference of 2-20 V, the part being a cathode and a carbon electrode anode, the processing time being determined from the ratio

where τ is the processing time, s,
K is an empirical coefficient of (10-12) · 10 ⁴ ,
C is the initial concentration of molybdenum ions in solution, g / l.