US2256788A - Copper-zinc alloy - Google Patents

Description

. rolled hot.

Patented Sept. 23, 1941 COPPER-ZINC ALLOY Wolf Johannes Miiller and Moritz Niessner,

Vienna, Germany, assignors, by mesne assignments, to Aktiengesellschalt Dynamit Nobel, Pressburg, Czechoslovakia, a company No Drawing. Application No. 215,856. In Austria 2 Claims.

It is known that gamma-brass, that is to say copper zinc alloys with a copper content of about 31-40%, 1. e. alloys which are characterized by a low copper .content, are more resistant to cor-' rosion than the brass alloys of the alpha. and alpha and beta region with for instance 68-72 percent and more of copper, i. e., a higher copper content. The technical employment of gammaalloys poor in copper is however impossible, since these alloys are extremely hard and brittle and are consequently not machinable.

From such alloys, as is described in our prior Patents No. 2,006,598 and 2,006,599 it has been disclosed that it is possible, by the addition of a few percent of a metal soluble in gamma-brass or alloyable therewith, such as nickel or, with more advantage cobalt, preferably by a simultaneous additionof nickel and cobalt, to obtain allow, which possess the good resistance to corrosion of gamma-alloys poor in copper, but are also capable of being worked up, that is to say can be treated with machine tools and can also be Such alloys with an addition of approximately 3-12% of cobalt, nickel or the like individually or in mixture, that is to say for. instance pure copper-zinc alloys with a minimum content of nickel of approximately 7-8% or of cobalt of approximately 6% have extremely good technical properties, and when cobalt and nickel are used simultaneously it is possible with a much smaller cobalt content to obtain the same effects as with the use of cobalt alone. Consequently alloys that are deficient in copper, even those most deficient, can be made utilisable for industrial purposes or as constructional material for the production of articles, if the copper-zinc alloys are alloyed with copper, nickel or the like individually or in mixture. The present invention is based on the ascertained fact that such copper zinc alloys, containing between 30 and 45% of copper and between 3 and 12% of cobalt and/or nickel, can have their properties substantially improved when containing also between 4 and 15% 01' manganese and at least a small but effective amount of one of the metals of the following group:

Percent Ir n up to 1.8 Aluminium up to 1.5 Silver upto 2.0 Chr mi m up to 3.0 Tin up to 2.0 Lead up to 0.3 Selenium up to 0.6

June 25, 1938, Serial June 21, 1934 but in no greater amounts than are soluble in the solid solution and the zinc constituting substantiallythe remainder.

It has been ascertained'that such alloys are suitable for cold working, including cold rolling, pressing and drawing and atthe same time have a high resistance to corrosion.

In carrying out the invention, the manganese content should be smaller in the case of alloys of higher copper content than in the case of alloys of lower copper content. The higher themanganese content the more suitable is the alloy for cold working a rising addition of manganese up to about 10% leading to an approximately proportional improvement in the cold working properties.

By the addition of the metals of the group: iron, aluminium, silver, chromium, tin, lead, selenium and tellurium the workability in the cold, the color and other properties of the alloys are favourably influenced as compared with such alloys containing only copper, zinc, nickel and/or cobalt and manganese as are subject of our c0- pending application Ser. No. 148,506 filed June 16, 1937, from which the present application is divided out. 7

Thus an, enhanced workability in the cold can be imparted to the alloys of the invention, by

so of the elements iron,

the addition of suitable amounts of one or more lead, tin, selenium and tellurium within the limits hereinbefore set forth while their corrosion resistance can be enhanced .by the addition of one or more of the metals aluminium, chromium and tin without the limits hereinbefore set forth.

\ It is easy to ascertain empirically, the amount of each element that will produce the most favourable eflect.

A suitable alloy in accordance with the inven- 40 tion is one containing between 30 and of copper, between 3 and 12% of cobalt and/or nickel, between 4 and 15% of manganese and between 0.5 and 1.5% of iron.

The addition of up to 0.3% of phosphorus to 45 the hereindescribed alloys is advantageous since it very considerably improves the fineness of structure of the alloys.

By means of the additions according to the in up to 0.6 be converted into a state corresponding to gamma brass and rendered suitable for applications, such as cold rolling-or drawing, from which they are otherwise excluded on account of their copper content. I v

The i'ollowing is a typical example of an alloy according to the invention:

Percent Cu 36 Ni j 6 I 2 Mn 10 F 1.2 Zn Remainder What weclaim is: l. A corrosion-resistant copper-zinc alloy which is workable in the cold state, comprising copper in an amount of 30% to 45%, at least one metal of the group cobalt and nickel in an amount 01' 3% to 12%, manganese in an amount or 4% to of 3% to 12%, manganese in an amount or 4% 15%, iron 0.5% to 1.5%, and aluminum which 20 to 15%, iron 0.5% to 1.5% and aluminum in a small but effective amount which is capable of increasing the corrosion of resistance of the al- 10y, said aluminum being present up to 1.5%,

the zinc constituting substantially all the remainder.

WOLF JOHANNES MORITZ NIESSNER.

Patent No. 2,256,788-

It is hereby certified of the above numbered line 57, for column, line 514., for

Patent should be rea form to the record 0 and iealed column,

Signed (Seal) CERTIFICATE OF CORRECTION.

September 25, 19141.

WOLF JOHANNES M L ILLER, ET AL.

that error appears in the printed specification Page 1, first patent requiring correction as follows;

second the word "copper" read -cobalt; same page,

"without" read -within-; and that the said Letters d with this correction therein that the same may conf the case in the Patent Office. this Ltth day of November, A. D. 191d.

Henry Van Arsdale, Acting Commissioner of Patents.