SU1255660A1 - Composition for pickling aluminium alloys - Google Patents

Description

at

The invention relates to the chemical treatment of parts from sintered aluminum alloys with a high percentage of silicon, such as CACj in particular etching, and can be used in engineering and instrument making in the manufacture of parts with high thermal properties.

The circuit of the invention is an increase in the class of surface cleanliness.

Example. All the acids and isopropyl alcohol are introduced into the required amount of water, and before the treatment, hydrogen peroxide,

In order to obtain the optimal conception of the proposed solution, 5 mixtures are prepared, the composition of which is pre-set is given in the table.

The test results of the resistors at various concentrations are given in Table 2, with the use of parts made of CAC-1 alloy after mechanical working with 15 μm Aeusen size And | with a surface roughness of 1.25, Solution temperature B-20 ° C, processing time -5 min,

Analysis of the results shown in Table 2 shows that the selected concentration of the components of the solution is optimal. The etching process is stable, the burrs are removed completely, and the surface roughness does not deteriorate,

For comparison, known solutions based on nitric, sulfuric, hydrofluoric, orthophosphoric acids, surfactants and WATER are prepared; a solution based on phosphoric and acetic acids, iodine, ammonium fluoride and nitric acid, as well as a solution of the proposed composition containing nitric acid.

4.0 5.0 6.0 7.0 8.0

1.0 2.0 3.5 5.0 6.0 4.0 5.0 5.5 6.0 7.0

20

3

 ABOUT

3

556602

orthophosphoric, tartaric, silica-hydrofluoric acid, isopropyl alcohol, hydrogen peroxide and water.

Before processing, the surface roughness of the samples and the amount of burrs are checked. Then the samples are degreased, washed in water and processed in various compositions.

Experienced parts of aluminum alloy type SAS-1 and SAS-2. Samples are parts with a burr size of 0.030 nm and a surface roughness of 1.25.

Chemical etching is carried out in industrial-made ultrasonic baths, the operating frequency of ultrasonic vibrations is 22 kHz. Solution temperature is 18-20 s.

The treatment is carried out in solution for 5 minutes. After processing, the samples are dried and examined. The test data are summarized in table 3.

6

From Table 3 it follows that the proposed solution ensures complete removal of burrs with high quality and will process the surfaces. In the well-known solutions, the surface is poorly processed and the depressed section is not completely removed. The use of the proposed solution with the effect of ultrasonic vibrations makes it possible to effectively process not only the external surfaces, but also the surfaces in the holes, grooves and crevices. At the same time, a small metal removal makes it possible to ensure the dimensions of parts according to I and II accuracy classes. :

The solution can be used repeatedly by adding the required amount of decomposed hydrogen peroxide.

Table 1

Components of the solution

Cream-hydrofluoric acid

Isopropyl alcohol

Hydrogen Peroxide Water

but

4.0

1.0 4.0

6.0

0.4 7.0

Remaining 5.0

2.0 5.0

7.0

Continued table.

Component content, wt.X,

in composition

1 23 5

7.0 8.0 9.0 10.0

0, .5 0.7 1.0 1.1 8.0 9.0 10.0 11.0

OS-OS-OS-OSTALTAL-TALTAL ICE

Table 2

The process of etching proceeds very medg leno, burrs are not removed

0.00

1.25 0.015

Process

Gravlein

is leaking

stable

burrs

sleep you

in terms of

0,005

1 .5 0,000

Composition t acT8opei

Alcohol yoprop - Lovy

Hydrogen peroxide

Water

Nitric acid

Phosphoric acid

Tartaric acid

Fluorosilicic acid

Isopropy alcohol left

Hydrogen peroxide

Water

Nitric acid

Phosphoric acid

Tartaric acid

Hydrofluorocarbon

acid

Isopropyl alcohol

Peak Sea

Water

Nitric acid

Phosphoric acid

Tartaric acid

Continuation of table 2

Also

0,004, 25 0,000

0,004

1.25 0,000

The process of etching proceeds rapidly, the process is removed, the surface is etched.

Iewebty Azotna

Acid25

thirty

0, 5

25

1.5

20

76

15

2

T blitz

1.25 0.028

1.25

0.027

1.25 0.030

.five

J, 030

6

five

Compiled by V.Oleynichenko Editor I.Derbak Tehred I.Verescorrector M.Samborska

Order 4788/30 Circulation 878 Subscription

VNIIPI USSR State Committee

Inventions and discoveries 113635, Moscow, Raushsk nab. 4/5

Production and printing company, Uzhgorod, yh. Project, 4

1255660

10 Continuation of table

Claims (1)

. SOLUTION FOR ETCHING ALUMINUM ALLOYS containing nitric, phosphoric acid, organic acid and water, characterized in that, in order to increase the surface cleanliness class, it contains tartaric acid and additional hydrofluoric acid, isopropyl alcohol and hydrogen peroxide in the following ratio components, wt.%: Nitric acid 5-7 Phosphoric acid 2-5 Wine acid 5-6 Fluorosilicic acid 7-9 Isopropyl alcohol _; 9.5-1.0 ABOUT Hydrogen peroxide 8-10 Water Rest cl | s Λ shk ··