US1832992A - Zinc alloy - Google Patents

Description

Patented Nov. 24, 1931 UNITED sTATEs PATENT oFFicE HENRY J'. LORANG, OF ST. LOUIS, MISSOURI, 'ASSIGOIR 0F ONE-'HALE T0 FRANK J'. KUNL OF ST. LOUIS, MISSOURI ZINC ALLOY No Drawing.

The general object of this invention is to provide a zinc alloy for use more particularly as bearing metal and which shall pos'ess properties which render it markedly superior,

both from an economical and functional stand-point, to commercial bearing metals now on the market.

Th'e characteristics which distinguish my improved alloy from other alloys used in forming bearing metals are, low co-eiiicient of friction; small bearing temperature rise; great transverse strength; absence of material shrinkage in cooling; and satisfactory machining properties.

In producing the alloy, I first `provide a fixed metal by mixing together equal parts by weight of copper and zinc. This, in reality, forms a brass. I then take one ounce of this fixed metal or brass and combine with it fourteen ounces of zinc and one-half ounce of aluminum. The combined metals are, of course, melted together and the resultant product is a metal alloy about five times harder than zinc and having a melting point but slightly greater than that of zinc. For purposes of comparison, it may be stated that the melting point of brass composed of equal parts by weight of copper and zinc is v1175 F.; that of aluminum is 1217o F.; and

that of zinc. 786 F. The melting point of my alloy is from 815 to 820 F.

Stated in terms of percentages by weight, my improved alloy is composed as follows:

Brass (equal parts of copper and zinc), 6-14/31% Aluminum, 3-7/31% Zinz (prime western), 9010/31%.

The proportions of the metals named, I have found to give the most satisfactory results. However, the invention is not limited to these exact proportionsas, particularly in the case of zinc, the proportions named may be varied within reasonable limits without departing from the spirit of the invention and still produce a satisfactory bearing metal. Referring particularly to the zinc ingredient,

I may vary the quantity used relative to the other lngredients within a range extending from thirteen ounces to sixteen ounces; as stated, however, I prefer to use approximately fourteen ounces. l

Application mea July 1s,

Friction tests were conducted with bearing blocks machined from my improved alloy which were used in conjunction with a Riehle friction testing machine. The zinc alloy friction test was parallel with a similar test using copper-tin-zinc bronze blocks, all test conditions being equal except the bearing blocks. Previous to the test run, my zinc alloy blocks were run-in under full lubrication for eight hours at full-load. The test run consisted of an eight-hour run beginning with the bearing at room temperature. Readings of the bearing friction and temperature rise were taken at frequent intervals throughout the run. The readings showed the stabilized conditions of operation for the t'wo alloys to be as follows:

Zinc alloy Bronze Coecent of f1'cton....v .00221 .00184 Temperature rise of bearing F 32. 2 28.8

It will thus be seen that the friction characteristics of the zinc alloy used in this test approach those of a high-grade bearing bronze.

The above test was conducted at the laboratories of the Massachusetts Institute of Technology, Cambridge, Massachusetts.

Tests for transverse strength were conducted at the testing laboratory of .Washing possessed by my improved zinc alloy, I utilize a relatively low grade of zinc in its composition. Commercial deliveries of prime Western slab zinc analyze, -as to constituents, about as follows:

lOLepi, .5U-1.50; iron, .O1-.08; cadmium,

The use of this grade of zinc thus enables me to produce a verly high-grade bearin metal at a relatively ow cost, as compa with other bearing metals now on the market. j I claim:

1. The method of making a zinc alloy, which consists in forming a fixed metal by combining equal parts by weight of copper and zinc, and then combining with a/given )o quantity of said xed metal aluminum and zinc theresultant allo having the metals combined in substantial y the following percentages by weight, namely: fixed metal, 614/31%; aluminum, 37/3l%; and zinc, 9am/31%. Y

` 2. rl`he method of making a zinc alloy which consists in forming a. fixed metal by combining equal parts by weight of copperi y and zinc, and then combining sa/id xed metal With aluminum and zinc in substantially the proportions of one ounce ofthe fixed metal to fourteen ounces of zinc and one-half ounce s of aluminum. F Q In testimony whereof, I have hereunto set 2.', my hand.

HENRY J. LORANG.