DE928673C - Use of aluminum alloys with added boron - Google Patents

Description

Use of .aluminum alloys with added boron For chemical and electrolytic surface treatment of workpieces made of aluminum and its Alloys, in particular made of pure aluminum and its alloys, for the purpose pickling, lustering or oxidizing very easily becomes undesirable the structure of the material visible. It can often be demonstrated that the different Cast structure of the bars, even if they are manufactured using the continuous casting process "and the uneven distribution of the alloy components streaky and flawed Surfaces leads.

This phenomenon can be avoided to a certain extent; that the cast ingots are homogenized by special annealing treatments and also several times be recrystallized. However, these measures are for economic reasons naturally limited as much as possible. In these experiments it has now been found that even very small additions of boron to the molten metal break the structure can be influenced in such a way that the finished semifinished product does not have any structural marks whatsoever has more.

It is known that certain additives to the molten metal, such. B. of titanium :, vanadium, zircon, carbon, boron and cerium, a fine-grain cast structure cause, experience shows, however, that in general the grain refinement of the Cast structure germ effective means to prevent structural markings in the finished product Semi-finished product forms. The essence of the present invention is based on the statement, that only the addition of boron prevents the structure from showing in the semi-finished product.

Of the other grain-refining agents, much larger ones would also have to be used Quantities, applied to achieve the desired effect on grain refinement of To achieve casting blocks. Such large additives would, however, be found in the chemical and electrolytic surface treatment are extremely disruptive.

The addition to the receipt has an effect, particularly in the case of extruded products favorably by eliminating the differences that have mostly occurred up to now between the beginning and the The end of the profiles are no longer visible during the surface treatment.

To increase the effect, of course, homogenization and Soft annealing treatments can be retained, but these heat treatment processes can be used be carried out at a lower temperature and / or with shorter times.

The additional receipt should be between o; oooi and 0.3 '/ 0, preferably between o, oor and 0.030 / 0. The higher additives can be used in such aluminum alloys, which in themselves have a higher content of other metals, especially in Hardenable alloys are used where the otherwise possibly required longer homogenization of the ingot at high temperatures easily to not again to: eliminating damage: leads. With pure aluminum and preferably its homogeneous alloys, especially those with magnesium up to 2.50 [o, the additional receipt is expediently kept below 0.0 oz%, preferably below 0.0030/0.

Claims (1)

PATENT CLAIMS: r. Use of aluminum and its alloys with a supplement of o, ooot to 0.3, preferably between o, oo r and 0.03%, for the production of kneaded semi-finished products, the surface of which is chemical and / or electrolytic treatment, in particular a gloss and / or a anodic oxidation. a. Use of stainless steel and its homogeneous alloys, especially those with up to a.5% magnesium, with additions of o, ooor to o, oa, preferably up to o; oo6%, for the claim i mentioned purpose.