SU971914A1 - Liquor for pickling magnesium alloys - Google Patents

Description

The invention relates to the chemical treatment of metals and alloys, in particular, solutions for the etching of parts from magnesium ions produced by pressure.

A known solution for the etching of magnesium, o alloys, cast by injection molding, containing phosphoric acid 50-80% vol. one.

However, the use of this solution requires further processing in an alkali solution at 20-80 C.

: A known solution for etching alloys containing phosphoric acid 1290 g / l 2.

However, the use of a known solution does not provide high quality machined surfaces of parts made of magnesium alloyed, BOB, obtained by casting under pressure. The disadvantage of this solution is also strong peioobrazovanie.

Known use for etching

| M Magnesium alloys, obtained under pressure,

| ni | 1-solution solutions, for example, 70% NaOH

and 10% NaNoa NLI 20% HF; 50 to 70% NaOH 3 and 4.

However, processing in concentrated and hot (120-170 ° C) alkaline solutions is not technological.

A known solution for etching magnesium alloys containing phosphoric (27.5-75% by volume) and sulfuric (25-66% by volume) acids 51 ..

The disadvantages of this solution are the poor quality of the surface to be treated, the adhesion of the chromate coating, and, in addition, the high foaming of the solution.

The aim of the invention is to increase the purity of the surface of magnesium alloys produced by pressure and to reduce

15 foaming pickling solution.

This goal is achieved by the fact that in a solution for etching magnesium alloys containing phosphoric and sulfuric acids, JQ components are taken in the following ratio, g / l:

Phosphoric acid500-800

Sulfuric acid5.0-60,0

Solution temperature, ° C 18-30 When 5–60 g / l of sulfuric acid is added to a solution containing 500–800 g / l of phosphoric acid, the heating of the solution during etching decreases. Practically sulfuric acid in this solution plays the role of defoaming agent. The surface finish in this solution is v6 - v7. Example. Parts made of alloy ML-5 (systems MD - "- A1 - Zn4-Mn), ex: sie method 97 4; pour UNDER pressure, processed in the proposed solution and the solution of the prototype. The results of etching are shown in the table. The use of the proposed solution makes it possible to obtain uniform non-metallic inorganic coatings that provide high adhesion of paint coatings.

I

h 4

E "

g

 fi

| i

u

with

n

a

fo

I

l§

f2

p8

And RI

Claims (5)

Is isb 9 Formula of the Invention A solution for etching magnesium alloys containing phosphoric and sulfuric acids, characterized in that, in order to increase the surface purity of magnesium alloys obtained by injection molding, and to reduce foaming solution, acids are introduced in the following ratio, g / l Phosphoric acid 500-800 Sulfuric acid 5.0-60.0 Sources of information taken into account in the examination 7191410 1. Reference guide to electroplating. P.111, Metallurgi, 197 :, p. 18-20. 2. Spencer W. F. Metal. Finish. V. 68, N 9--10, 1970. 5 3. In zhir M. Ya. And tsp. The effect of anti-corrosion treatment on the dimensional accuracy of parts made from magnesium alloys. - Bulletin of Machine Building, 1973, No. 5, p. 60 4. Lieberman, MD, et al. Experienced work on the manufacture of magnesium parts for the automotive industry. M., YOU, 1971, .N 78, p. 181. 5. US patent N 2650156, cl. 156-21, .opub. 1953 (prototype).