US2000115A - Alloy - Google Patents

Description

ther characterized by increased tensile strength Patented May 7, 1935 UNITED STATES PATENT OFFICE ALLOY No Drawing? Application September 20, 1933, Serial No.'690,293

5 Claims.

The invention relates to magnesium-base alloys and is directed to the development of alloys oi. this class which, while possessing the desirable characteristics of the class as a whole, are furmany of the strong aluminum alloys. It is quite generally appreciated that any improvement in magnesium alloys which means increased yield point, strength and elongation will be very valuable, and for this reason eiiorts have been continuously expended in the search for improvement along these lines. It is to this general ob- -ject that the present invention is directed.

A particular object of the invention is the modification of magnesium-base alloys containing tin, manganese and aluminum by the addition of at least one of the metals of the class comprising zinc and cadmium to produce an alloy of increased tensile strength, yield point, elongation, and corrosion resistance.

I have discovered a very useful range of composition over which aluminum additions are particularly effective in producing the desired improvement in tensile properties without serious detriment to the other properties of this class of alloys. According to my invention the alloys may contain from 0.1 to 12.0 per cent tin, from 0.5 to 10 per cent of aluminum and from 0.1 to 1.0 per cent of manganese. Alloys of this general nature are disclosed and claimed in my copending application, Serial No. 643,033, filed November 17th, 1932, of which this present application is a continuation-in-part. The aluminum increases the tensile strength as much as 15 per cent, the yield point as much as 20 per cent and the elongation as much as 100 per cent. As a result of the tests which I have conducted I have found further that the magnesium alloy containing tin, aluminum, and manganese is superior to a magnesium-base alloy containing only aluminum because of improved hot Working characteristics, particularly, within the preferred range, hammer-forging characteristics, and, over the whole disclosed range, extrusion characteristics.

The improvement in physical properties is particularly marked throughout what I consider to be the preferred range of composition, which includes alloys containing from 4.0 to 6.0 per cent of tin, 3.5 to 4.5 per cent of aluminum, and 0.5 to 0.8 per cent of manganese.

When used for purposes suited to articles produced by extrusion processes, my improved alloys may contain at least one of the class of metals composed of zinc and cadmium. -In my alloy these elements are substantially equivalent with respect to their effect on the corrosion resistance of the alloy. Amounts of zinc or cadium between about 0.1 per cent and 5.0 per cent materially improve. the corrosion resistance of the alloy without any undesirable effect on the physical properties. Improved alloys according to the scope of the present invention contain from about 0.1 to 12.0 per cent of tin, from about 0.5 to 10.0 per cent of aluminum, from about 0.1 to 1.0 per cent of manganese and at least one of the class of metals composed of zinc and cadmium in total amount between about 0.1 per cent and 5.0 per cent, the balance being substantially magnesium. As a preferred magnesium-base alloy within this range I use an alloy containing from about 4.0 per cent to about 6.0 per cent of tin, from about 3.5 per cent to about 4.5 per cent of aluminum, from about 0.5 per cent to about 0.8 per cent of manganese and from about 1.0 per cent to about 3.0 per cent of at least one of the elements zinc or cadmium. If the alloys are to be forged orrolled, as distinguished from extruded, they should preferably not contain over about 1 per cent of zinc.

While the magnesium-base alloys containing tin, aluminum and manganese, and at least one of the class of elements cadmium and zinc, are entirely satisfactory in achieving the objects and advantages hereinabove enumerated, other elements may be added to produce a new property in the alloys or to aifect or modify an old property without substantially departing from the invention so long as the material properties of the alloy are not substantially impaired.

The alloys herein disclosed and claimed may be subjected to the usual thermal treatments for the purpose of improving or altering their properties.

I claim:

1. An alloy containing from about 0.1 to about 12.0 per cent. of tin, from about 0.5 to about 10.0 per cent of aluminum, from about 0.1 to about 1.0 per cent of manganese, and at least one of the class of elements composed of zinc and cadmium in total amount betwen about 0.1 per cent and 5.0 per cent, the balance being substantially magnesium.

2. An alloy containing from about 0.1 to 12.0

per cent of tin, from about 0.5 to 10.0 per cent of aluminum, from about 0.1 to- 1.0 per cent of manganese and from about 0.1 to 5.0 per cent of zinc, the balance being substantially magnesium.

3. An alloy containing from about 0.1 to 12.0 per cent of tin, from about 0.5 to 10.0 per cent of aluminum, from about 0.1 to 1.0 per cent of manganese and from about 0.1 to 5.0 per cent of about 0.5 per cent to about 0.8 per cent of manganese, and from about 1.0 per cent to about 3.0

per cent total of at least one of the class of elements composed of zinc and cadmium, the balance being substantially magnesium.

5. An alloy containing from about 0.1 per cent to about 12.0 per cent of tin, from about 0.5 per cent to about 10.0 per cent of aluminum, from about 0.1 per cent to about 1.0 per cent of manganese, and from about 0.1 per cent to about 1.0 per cent of zinc, the balance being substantially magnesium.

ROBERT T. WOOD.