US1903843A - Aluminum alloy - Google Patents

Description

I Patented Apr. 18, 1933 I sonar 0. mos, or

m ao'ax. n. 1.,

amnnmnr ALLOY Ho Drawing.

My invention relates to a series of aluminum alloys of novel composition and properties. The alloys of my invention are particularly characterized by the presence of boron and magnesium.

' Alloys consisting principally of aluminum and containing .substantial amounts of boron and magnesium are characterized by being both lighter and harder than aluminum. The amount of magnesium in the new alloys may T vary from about 0.25% to about 2.25%, the preferred amount bein from about 0.75% to 1.5%, and the boron mm 0.05% to 2%, although at least 0.25% is preferable and in many cases it is preferable not to add over 0.75% of boron due to the increased brittle ness caused by higheramounts. A particu lar composition havingvaluable properties is magnesium 1%, boron 0.5%, and the' remainder aluminum.

While the alloys consisting substantially solely of aluminum, magnesium and boron are valuable. for many uses, the alloys are Vanadium -a particularly valuable when they also contain other metals. Alloys of aluminum, mag- I 'nesium andboron, containing such metals as vanadium, tungsten, molybdenum, chromium, cobalt, copper and zinc, provide a series of alloys characterized by their light weight, together with 'a high hardness and tensile'strength. In neral, the new alloys also have surprisingly high electrical conductivity and resistance to corrosion.

The following specific formula; are illustrative of the wide range of compositions of the invention:

A particularly valuable alloy embodying 40 my invention has the following composition:

Magnesium 1.25% Boron y 0.75% Vanadium 0.75% Tungsten 0.75%"

Aluminum remainder Application am June so, ma. sci-m Io. mazes.

Another very valuable alloy having high tensile strength and electrical conductivity and characterized'byits. malleability, noncorrosiveness and good casting properties is:

Magnesium 1.50% Boron 0.50% Vanadium 0.50% I Coba v 0.75% Aluminum remainder copper containing alloy of high tensile strength is obtained from the following composition: u Magnesium 1.00% Boron r 0.7 5% Copper 3.75% Aluminum remainder A strong and readily orkable alloy is represented by the following composition:

Magnesium 1.00% Boron 0.50%

0.50% Copper 3.00% Aluminum remainder An alloy of valuable roperties, includmg a high degree of bar ness, has the following composition Magnesium 1.00% Boron 0.50% Vanadium, 0.50% Zinc. 1.25% Aluminum remainder In general it is advantageous to use metals other than aluminum, magnesium and boron, in amounts of from 0.25% to- 5%. The amounts added will, of course, vary with the nature of the added metals and with the number of alloying metals used.

In neral 1t may be said that a principal funct on of boron in the alloys of the invention is to increase the hardness, and a principal function of the magnesium is to decrease the specific gravity and increase the v resistance of the alloys against corrosion.

' As indicated above, other metals may be added for the purpose of increasing tensile strength, malleability, resistance to corrosion, electrical conductivity and other special roperties.

loys of the invention as described above have been obtained having a specific gravity of 2.66 to 2.70; a tensile strength when cast of 30,000 to 41,000 pounds per square inch, and when mechanically worked of from 51,000 to 56,000 pounds; and an electrical conductivity of 50-58 (Ag=100).

The metals may be utillzed either in the cast condition, or they may be rolled, drawn or otherwise worked. Mechanical working is preferably carried out at a temperature of 150450 C. and such working eflects a material increase in the tensile strength of the alloys. WVire drawn from the alloys of the invention is particularly valuable, since it combines a relatively hlgh tensile strength with a relatively high conductivity. A further valuable property of such Wires is that sleet and snow do not readily stick to them.

Anadvantageous method of producing the alloys of the invention is as follows: The aluminum is melted in a crucible and covered with a layer of powdered charcoal. The charcoal serves to protect the metal from oxidation and to reduce these metals which are added in the formof oxides. The magnesium is added as metal and the boron as oxide. Other metals may be ,added as such, or in the form of their oxides, according to the nature of the particular metal. The added metals or their oxides are advantageously added enclosed in aluminum capsules. The boron oxide is preferabl added first,although it may be added together with the magnesium. The other metal oxides may be added together. I

This application contains subject matter in common with my application Serial No. 612,651, filed May 20, 1932.

I claim: I

1. Alloys consisting principally of aluminum and -characterized by containing from 0.05 to 2% of boron and from 0.25 to 2.25% of magnesium.

2. Alloys consisting principally of aluminum and characterized by containing from 0.25 to 0.75% of boron and from 0.75 to 1.5% of magnesium.

' In testimony whereof, I affix my signature.

COURT C. TITUS;