US1360346A - Lead-base alloy - Google Patents

Description

UNITED STATES GEORGE H. WOBRALL, OF KIRKWOOD, MISSOURI, ASSIGNOR TO UNITED LEAD COM- PATENT OFFICE.

PANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

LEAD-BASE ALLOY.

No Drawing. Application filed August 11, 1919,

T 0 all whom it may concern:

Be it known that I, GEORGE H. WORRALL, United States citizen, residing at Kirkwood, Missouri, have invented the followin -described Improvements in Lead Base Al oys.

My invention consists in a hard lead alloy suitable for machine bearings and like purposes and containing lead, one of alkaline metals,-sodium or potassiumyand mercury, with or without other ingredients. I have discovered that mercury exercises a hardening effect upon lead alloyed with either of these lead-hardening metals and can be used for this purpose with economy and general improvement in the characteristics of the re sulting alloy.

1 My new alloy is made substantially as folows:

To a quantity of molten lead there is added in any suitable manner an amount of either sodium or potassium constituting less than 3% of the product. This alloy if allowed to cool will be found to possess a certain degree of hardness according to the known effect of sodium, or potassium, on lead. To this mixture I add either in. the same vessel or elsewhere a small percentage of mercury approximating 1} and generally not over 3%, and then cast the alloy into ingots ready for sale. The addition of mercury raises the hardness of the alloy and improves the fluidity when it is molten. By way of example an alloy containing potassium 2%, the balance being lead, has a hardness approximating 18 on the Brinell scale. The addition to such alloy of .5% mercury increases the hardness to above 20 on the same scale thereby enabling an in- Specification of Letters Patent. Patented Nov. 30, 1920.

Serial No. 316,607. Renewed May 28, 1920. Serial No. 385,083.

creased hardness to be attained with a minimum amount of potassium, and at less expense. Variation in the amount of mercury produces corresponding Variation in the resulting hardness. The outside limits of the ingredients may be stated as over 90% lead, less than 3% sodium or potassium, and less than mercury, these proportions being subject to variation according to the effects desired. I prefer to use less than 1% potassium and less than 1% mercury. Other metals, such as alulnlnum, tin or z nc may be added when desired to give certain additional effects to .the product, aluminum being useful for this purpose to prevent drossing of the product when molten, and when aluminum is introduced it is generally added in very small amounts less than 1% of the whole alloy, although still larger quantities of this or other metals can be added when it is desired to produce an alloy of less specific gravity or of different appearance, the essential feature of this in vention being 'the presence of a small GEORGE H. WORRALL.