US2306899A - Alloy - Google Patents

Description

Patented Dec. 29, 1942 I ALLOY Albert J. Phillips, Plainficld, and Albert A. Smith,

Jr., Metuchen,

smelting and Refining Company,

N. J., assignors to American New York,

N. Y., a corporation of New Jersey No Drawing. Application February 28, 1942, Serial No. 432,794

2 Claims.

This invention relates to lead alloys and more particularly to alloys of lead, calcium and magposscss and exhibit are especially useful whereever a soft ductile material having high resistance to fatigue and creep is desired. The leadalloy products of this invention can be used in the manufacture of such lead products as cable sheathing, roofing and the like where the products must withstand considerable bending and shaping.

The invention in its broadest aspect may be said to provide ternary alloys of lead, calcium and magnesium possessing certain highly beneficial physical properties, and alloys comprising a base alloy of lead, calcium and magnesium with at least one additional alloying constituent imparting further desired properties to the alloy while at the same time retaining or enhancing the beneficial physical properties possessed by the base alloy. This invention is a result of further research and experimentation with related lead I alloys, which are the subject of prior patents to Betterton et al. 2,142,835 and 2,142,836 issued January 3, 1939, and wherein it has been discovered unexpectedly that lead containing very small percentage amounts of calcium and magnes'ium alloyed therewith produce a lead product possessing greatly improved physical properties.

Specifically the invention provides alloys of lead, calcium and magnesium in which the combined calcium and magnesium content amounts to less than 0.02% of the alloy. While 0.002% to 0.009% each of calcium'and magnesium is preferred, compositions containing magnesium and calcium within the limits of 0.001% to 0.009%, respectively, can be employed.

Other metals which may be present or added to the lead-magnesium calcium composition are copper, mercury, tin and cadmium, all of which modify the physical properties of the alloy somewhat without adversely affecting the principal physical characteristics of the ternary alloy. Small additions of copper, for instance, may be added to the Ca-Mg lead alloy, to stiiTen the alloy. Tin slightly improves its fluidity and casting properties. Bismuth on the order of 02%. as contained in certain commercial leads, may also be present. The amount of modifying or improvement metal which may be in'corporated'or contained thereinshould preferably be within the approximate limits of .02% to 3% or as a minimum about three or four times the masnesium content.

tive small percentage amounts of calcium and magnesium as compared with common lead and nesium which, by reason of the properties they antimony-lead alloy is shown in the following table:

Creep at 30 C. on rolled sheet Load in Material tested Tensile Percent lbs/sq. lIl.

(lbs/sq. elongation a g in.) in s" c 0.1% per year Common lead 1,800 Alloy containing 4 g r 0 12%"sn 2, 400 00 000 Balance Pb.

Alloy contalning- 0.257008 2, 700 45 800 Balance Pb...

The above data clearly show the improvement in creep resistance and tensile strength which is effected by the addition of very small percentage amounts of calcium and magnesium to lead. The calcium-magnesium-lead alloys containing less than 1%tin are decidedly superior in creep resisting properties than that of 6% antimony-lead metal. A lead alloy containing 0.005% magnesium, 0.004% calcium and 0.25% tin is equal to regular 6-8% antimony leads in general corrosion resistance. For cable purposes the use of the calcium-magnesium-lead base metal modified with approx. 0.06% copper or tin and containing about 0.02% bismuth is recommended. Various other metal additions may be made to produce the desired modified product.

The alloy compositions of the present invention may be readily compounded by conventional processes employed by those skilled in the art, as, for example, by simply incorporating the requisite amounts of th alloying constituents in a proper quantity of molten lead. After compounding the new lead alloy it can be used in the manufacture of various articles, for which it is suited, in the conventional manner.

What is claimed is:

1. An alloy consisting of 0.001% to 0.009% calcium, 0.001% to 0.009% magnesium, tin not exceeding 3%, and the balance substantially all lead.

2. An alloy consisting of 0.001% to 0.009% calcium, 0.001% to 0.009% magnesium, 0.01% to 3% tin, copper not exceeding 3% and the balance substantially all lead.

ALBERT J. PHILLIPS. ALBERT A. SMITH, JR.