DE1758489A1 - Fine zinc alloy - Google Patents

Description

Fine zinc alloy

The invention relates to a ductile fine zinc alloy which is long-lasting and ductile even in the cold-rolled state.

A not belonging to the prior art zinc alloy with contents of lead from 0 to 1%, cadmium from 0 to 0.05%, copper from O to 1.2% _t titanium from 0.05 to 0.25%, aluminum of more than 0.003 to less than 0.05 %, preferably from 0.01 to 0.03 % t, remainder fine zinc and / or metallurgical zinc, which is free of magnesium, lithium, beryllium and calcium, is characterized by a comparatively good creep strength.

This alloy can thus be characterized as a zinc-titanium-aluminum type because the titanium content increases the fatigue strength, the aluminum content determines the casting behavior and thus the profitability.

To increase the strength, it is known to add copper to most titanium-containing zinc wrought alloys in amounts of more than 0.15 to 2 % . In order to achieve sufficient ductility in addition to a fatigue strength that is useful in practice, additional heat treatment is required in such alloys.

It has now been found that you can already in the cold-rolled state a considerable long-term stability combined with a good one Ductility is obtained when a fine zinc with a purity of

009887/0588

99.9 Ms 99.995 % is alloyed with 0.05 to 0.25 % titanium, 0.02 to 0.20% copper, preferably 0.05 to 0.1 % and 0.005 to 0.05 % aluminum. The comparatively low copper content of 0.02 to 0.20 % is sufficient to increase the strength.

Should for special purposes, a heat treatment is required, these can advantageously at comparatively low temperatures of 120 to 180 ⁰ C. The alloy can be hot-rolled in this temperature range.

The invention is illustrated below by way of example.

In a lying mold, both of a known and on the inventive zinc rolling alloy per a 1000-kg block of 80 mm thickness was poured, which was rolled down at 250 ⁰ C at 8 mm and mm at room temperature of 8 cold-rolled mm to 0.8.

For the well-known alloy with

0.5 to 0.8 % copper 0.1 to 0.15. % Titanium remainder fine zinc

the following values are determined:

Condition Strength Folding Endurance strength kg / mm ² -x 180OC *% kg / mm ² for 1 % Il JL Il JL elongation per year

cold
rolls 21st 26th fracture Well 2, 5 kg / mm after 2 * ¹
200 ⁰ C 18th 24 Well Well 7, VJ. kg / mm

For the alloy according to the invention with

*) perpendicular or parallel to the rolling direction

- 3 009 887/0586

0.05 to 0.15 % copper 0.10 to 0.15 % titanium 0.01 to 0.02 % aluminum, the remainder fine zinc

In contrast, the following results could be achieved:

Condition Strength Folding Permanent stability kg / mm ² 180 ⁰ C kg / mm ² for 1 % yy / *) y / y *) elongation per year

cold
rolls 19th 26th ' Well - Well 5 ρ
kg / mm after 2 ^h _n
at 150 ^° C 17th 22nd Well Well 7th ρ
kg / mm

*) perpendicular or parallel to the rolling direction

The zinc-titanium-aluminum rolled alloy according to the invention, with its low copper content of less than 0.2 %, preferably 0.05 to 0.1%, has a considerable fatigue strength even in the cold-rolled state. This is a decisive step forward, because the alloys produced up to now with higher copper contents without aluminum lose their creep resistance to the greatest possible extent after permanent static annealing if the strip material treated in this way was cold-formed during processing. The ductility in the cold-rolled state is also so good that a break-free folding through 180 ° is easily possible.

- 4 claims

009887/0586

Claims (2)

PATENT CLAIMS 1) Fine zinc alloy, which is long-lasting and ductile even in the cold-rolled state, characterized by the composition 0.05 to 0.25 % titanium, 0.02 to 0.20% copper, preferably 0.05 to 0.1 % and 0.005 to 0 , 05% aluminum, balance refined zinc from 99.9 to 99ι995% · 2) A method for heat treatment of the fine zinc alloy according to claim 1, characterized in that the heat treatment P is carried out in the temperature range from 120 to 180 ^° C. New 009887/0586