SU1578594A1 - Method of checking porosity of nonmetallic inorganic coatings based on aluminium and alloys thereof - Google Patents

Abstract

The invention relates to instrumentation and can be used to control the quality of non-metallic inorganic coatings on aluminum and its alloys. The aim of the invention is to increase the accuracy of determining the size and number of pores of non-metallic coatings. The paper is impregnated with a solution containing aluminon, ammonium chloride, ethyl alcohol and water, while complying with the following ratio of components, g / l: aluminon 0.5-1.5

ammonium chloride 25-50

ethyl alcohol (ml) 600-800

water 200-400.

Description

The invention relates to instrumentation and can be used to control the quality of non-metallic inorganic coatings on aluminum and its alloys.

The aim of the invention is to increase the accuracy of determining the size and number of pores of non-metallic inorganic coatings.

When applying to the coating paper impregnated with this solution, the aluminon in the pores interacts with aluminum ions, forming a red dye.

The dye is printed on paper. The number of red dots printed on paper and their magnitude are quantitative characteristics of the porosity of the coating. The distribution of red dots on paper shows the localization of pores on the product.

Average number of pores per surface unit

Ncp. N / S,

(one)

where N - pore prints on paper;

S is the area of the test surface, see

Pore diameter is determined by the diameter of prints D

GRT

DnoP К ° 6t

(2)

SP “-4

00

ate

SO

where K is a coefficient taking the value of 0.1-0.2, depending on the amount of alcohol in the solution.

Porosity II is determined by the ratio of the pore area to the measured area S :.

AND

snop -loo / s,%

formula (2). The coefficient K for a given solution at a relative humidity of 45% (21 ° C) of the air was 0.15.

Example 1. A disk made of aluminum alloy 154) was coated with a chromate phosphate film (0.15 μm). Determine the average number of pores per surface unit Ncp and porosity II. The test surface was degreased and indicator strips () were placed on it in five different places. They were pressed to the surface of the film with a glass plate (0.5 N / cm) and held for 10 min. The strips are made of a dense, de-ashen filter (blue ribbon, TU 6-09-1678-77).

To compare the known and proposed methods, solutions were prepared containing, g / 100 ml: a known solution, Hematoxylin 1 Water 1000.

the proposed solution Aluminon1

Ammonium chloride 50 Ethyl alcohol, ml 700 Water300

The proposed solution was prepared as follows. Aluminone and ammonium chloride were dissolved in water and then alcohol was added, the pH of the solution was 4.8.

In these solutions, filter paper pads were impregnated, they were applied to the surface of the coating. Strips removed from the disk surface were dried. On the strips impregnated with a hematoxylin solution, violet spots were observed, merging with each other. A change in the color of the indicator paper indicates that chromate phosphate films are defective. It was not possible to quantify the porosity with this solution, since the boundaries of individual points are fuzzy.

In the aluminon solution on a strip of 10 cm, the following number of discrete prints of 16.21, 10, 23, 15, Ncp disk 8550 1., 7 2 pores / sm was established.

The pore diameters were determined by the diameter of the Dorn footprint and calculated by

On the total area of five strips, 50 cm wide, pores were distributed according to the size as follows: 10 µm (40), 47%

20 microns (25), 29.4% 30 microns (10), I 1.8% 50 microns (5), 5.9% 100 microns (5), 5.9%

The total area of all pores of Sn is 0.0007 cm. P is calculated by the formula (3) and is equal to: P 0.0007-100 / 50 - 0.001%.

The method is an improvement of the indicator methods for controlling the open porosity of chromate phosphate films and makes it possible to characterize it quantitatively, which was not possible using the known indicator methods. The use of the proposed control method makes it possible to obtain a higher-quality surface, which makes it possible to use it in the thin technology of producing hard disks of magnetic recording, in microelectronics, and other branches of the national economy.

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Formula 1 inventions

The method of controlling the porosity of non-metallic inorganic coatings on aluminum and its alloys by applying the test coating to a paper impregnated with a solution that gives a colored imprint on paper when interacting with non-base metal and recording defects by the number of prints, characterized in that determining the number of pores and paper is impregnated with a solution containing aluminon, ammonium chloride, ethyl alcohol and water in the following ratio of components, g / l:

Aluminone 0.5 - 1.5

Ammonium chloride 25 - 50 Ethyl alcohol (ml) 600 - 800 Water 200 - 400

Claims (1)

Claim The method of controlling the porosity of non-metallic inorganic coatings on aluminum and its alloys by applying a solution impregnated with a solution to the test coating, giving a painted imprint to the paper when interacting with the base metal ions and registering defects by the number of prints, characterized in that the number of pores, the paper is impregnated with a solution containing aluminon, ammonium [chloride, ethyl alcohol and water at (the following ratio of components, g / l: Aluminon 0.5 - 1.5 Ammonium chloride 25 - 50 Ethyl alcohol (ml) 600 - 800 Water 200 - 400