US1941039A - Magnesium alloy - Google Patents

Description

Patented Dec. 26, 1933 UITED STATES PATENT QFFICE No Drawing. Application December 14, 1931, Serial No. 581,050, and in Germany December 1 Claim.

Magnesium alloys with zinc or zinc and manganese are already in use for several technical purposes. However, their application is limited onaccount of their tensile strength, especially 5 with castings, being not very satisfactory. These known magnesium alloys also have no great resistance against chemical and corrosive attacks.

Besides they are inflammable, which renders their casting diflicult and forms a great source of danger. Finally these alloys do not flow and especiallycan not be used for castings, which have thin walls.

The invention obviates these drawbacks by the addition of iron and. silver or beryllium to alloys of the aforesaid type; it therefore refers to magnesium alloys with at least 80% Mg and Zn or Zn and Mn and Fe, Ag or beryllium.

The Mg, Zn, Fe, Ag alloys may contain up to 15% Zn, 2% Fe and 2% Ag, the rest being Mg.

to 15% Zn, up to 3% Mn, up to 1% Fe and up to The simultaneous presence of Fe and Ag or Be produces a very satisfactory crystal-formation and the structure of these alloys shows a fine,

homogeneous and uniform grain.

The addition of Ag prevents an incomplete equilibrium of the mixed crystals or with other words it prevents the so-called? inter-crystalline liquation.

The uniform structure protects the alloys against corrosive attacks of the surface; the re- The Mg, Zn, Mn, Fe, Ag alloys may contain upv loys have far .better mechanical capacities espe cially higher tensile strength, ductility, elongation and hardness. They are less inflammable, they flow well and can be easily cast; they can be mechanically worked with no difiiculty, have a very low spec. weightof about 1,7 and a silvery, wonderful colour. I

The silver can be replaced, wholly or partly, by beryllium; this addition increases particularly the hardness of these alloys.

The selection of the components used and their quantities depends mainly on the special application of the alloy, the maximum of spec. weight, which is allowable in the special case, and the varying working conditions.

In order to manufacture the present alloys the following manner was found to give best results.

A preliminary alloy which contains the necessary amount of Zn, Fe, Ag or Zn, Fe, Be or Zn, Fe, Ag, Be is added to the molten Mg or MgMn alloy. In case manganese is used, it has been found advisable to divide the quantity of this metal and to add one part to the same to the magnesium and the other part to the preliminary alloy of Zn, Fe, Ag or Zn, Fe, Be or zn, Fe, Ag, Be; in such way a better distribution of the manganese is obtained.

Aluminium may be present up to 5%, silicon only as an impurity.

What I claim is:

Magnesium-alloy containing not more than 15% and not less than 0,5% Zn, not more than 3% and not less than 0,01% Mn, not more than 1,5% and not less than 0,01% Fe, not less than 0,005% and not more than 1,23% Ag, the balance being Mg;

ALEXANDER LUSCHENOWSKY.