Aluminum-Scandium Alloy

Abstract

An aluminum-scandium alloy contains essentially of Si; Fe; Mn; Cr; Ti; from 1.9 wt % to 2.5 wt % Cu, from 2.0 wt % to 2.7 wt % Mg, from 5.9 wt % to 6.9 wt % Zn, from 0.08 wt % to 0.15 wt % Zr, from 0.01 wt % to 0.06 wt % Sc, balance aluminum and inevitable impurities.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

The application claims the benefit of U.S. provisional application No. 61/511597, filed on Jul. 26, 2011, the subject matter of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to an aluminum-scandium alloy and, more particularly, to an aluminum-scandium alloy for making metal tubes of a fitness equipment or sport equipment.

2. Description of the Related Art

Conventional aluminum-scandium alloy usually includes compositions such as Silicon (Si), Iron (Fe), Scandium (Sc), etc. The compositions are mixed with aluminum (Al) to produce a solution of aluminum-scandium alloy. The solution of aluminum-scandium alloy is poured into a mold. The aluminum-scandium alloy in the mold will naturally cool down as an aluminum-scandium alloy. However, although the aluminum-scandium alloy has a higher strength due to addition of Scandium (about 0.06 wt %), the formability of the aluminum-scandium alloy becomes poor. As a result, the aluminum-scandium alloy has only about 20 to 30 percent reduction of area.

In light of this problem, it is necessary to solve the disadvantages of the conventional aluminum-scandium alloy.

SUMMARY OF THE INVENTION

It is therefore the primary objective of this invention to provide an aluminum-scandium alloy with higher percent reduction of area as well as higher strength.

The invention discloses an aluminum-scandium alloy containing essentially of Si; Fe; Mn; Cr; Ti; from 1.9 wt % to 2.5 wt % Cu; from 2.0 wt % to 2.7wt % Mg; from 5.9 wt % to 6.9 wt % Zn; from 0.08 wt % to 0.15 wt % Zr; from 0.01wt % to 0.06 wt % Sc; balance aluminum and inevitable impurities.

In a preferred form shown, Si is less than 0.12 wt % but larger than 0 wt %.

In the preferred form shown, Fe is less than 0.15 wt % but larger than 0 wt %.

In the preferred form shown, Mn is less than 0.1 wt % but larger than 0 wt %.

In the preferred form shown, Cr is less than 0.04 wt % but larger than 0 wt %.

In the preferred form shown, Ti is less than 0.06 wt % but larger than 0 wt %.

DETAILED DESCRIPTION OF THE INVENTION

The invention discloses an aluminum-scandium alloy which comprises compositions such as Silicon (Si), Iron (Fe), Copper (Cu), Manganese (Mn), Magnesium (Mg), Chromium (Cr), Zinc (Zn), Zirconium (Zr), Titanium (Ti), Scandium (Sc), etc. The compositions are mixed with aluminum to produce a solution of aluminum-scandium alloy. The solution of aluminum-scandium alloy is quenched with cold water to manufacture metal tubes via continuous casting process. The compositions used are listed in the Table 1 below (in weight percentage):

TABLE 1
Compositions Used In The Aluminum-scandium Alloy
(In Weight Percentage wt %)
Si	Fe	Cu	Mn	Mg	Cr
below	below 0.15	1.9-2.5	below 0.1	2.0-2.7	below
0.12					0.04
Zn	Zr	Ti	Sc	Others	Al
5.9-6.9	0.08-0.15	below	0.01-0.06	below	Balance
		0.06		0.05

After the metal tubes are formed, the metal tubes have as high as 30 to 40 percent reduction of area while having a high strength. Advantageously, convenient manufacturing is achieved.

In the stage of mass production, the actual values of the compositions used are listed in the Table 2 below (in weight percentage):

TABLE 2
Compositions Used In The Aluminum-scandium Alloy In Mass
Production (In Weight Percentage wt %)
Si	Fe	Cu	Mn	Mg	Cr
0.04	0.07	2.23-2.33	0.01	2.3-2.4	below 0.01
Zn	Zr	Ti	Sc	Al
6.67-6.77	0.08-0.15	0.01	0.02-0.03	Balance

Table 3 shows experimental data between the conventional aluminum-scandium alloy and the proposed aluminum-scandium alloy:

	Mechanical Properties
	Tensile	Yield	Elong-	Reduction	Hard-
	Strength	Strength	ation	of Area	ness
Material	(ksi)	(ksi)	(%)	(%)	(HRB)
Conventional	98.3	90.6	10.2	22.5	92.5
Aluminum-scandium
Alloy (Tested Under
Test Board 1)
Conventional	98.8	91.2	9.8	21.6	91.8
Aluminum-scandium
Alloy (Tested Under
Test Board 2)
Conventional	99.1	91.6	10.3	23.1	92.8
Aluminum-scandium
Alloy (Tested Under
Test Board 3)
Conventional	98.1	92.1	9.9	21.4	92.3
Aluminum-scandium
Alloy (Tested Under
Test Board 4)
Conventional	98.4	92.3	10.2	20.9	92.8
Aluminum-scandium
Alloy (Tested Under
Test Board 5)
Conventional	99.2	92.7	10.5	21.2	92.7
Aluminum-scandium
Alloy (Tested Under
Test Board 6)
Proposed	97.8	91.6	13.4	36.8	92.1
Aluminum-scandium
Alloy (Tested Under
Test Board 1)
Proposed	98.1	91.8	14.2	37.4	91.9
Aluminum-scandium
Alloy (Tested Under
Test Board 2)
Proposed	99.1	92.3	14.1	36.4	92.3
Aluminum-scandium
Alloy (Tested Under
Test Board 3)
Proposed	98.7	92.4	13.9	35.9	92.1
Aluminum-scandium
Alloy (Tested Under
Test Board 4)
Proposed	98.6	91.8	13.8	36.1	92.2
Aluminum-scandium
Alloy (Tested Under
Test Board 5)
Proposed	98.3	92.1	14.3	37.9	92.1
Aluminum-scandium
Alloy (Tested Under
Test Board 6)

From the Table 3, it can be seen that the aluminum-scandium alloy of the invention has higher elongation as well as higher reduction of area over the conventional one. Thus, the invention does provide satisfactory properties of aluminum-scandium alloy.

Although the invention has been described in detail with reference to its presently preferable embodiments, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the invention, as set forth in the appended claims.

Claims

1. An aluminum-scandium alloy containing essentially of:

Si, Fe, Mn, Cr, Ti,

from 1.9 wt % to 2.5 wt % Cu;

from 2.0 wt % to 2.7wt % Mg;

from 5.9 wt % to 6.9 wt % Zn;

from 0.08 wt % to 0.15 wt % Zr;

from 0.01wt % to 0.06 wt % Sc; and

balance aluminum and inevitable impurities.

2. The aluminum alloy as claimed in claim 1, wherein Si is less than 12 wt % but larger than 0 wt %.

3. The aluminum-scandium alloy as claimed in claim 1, wherein Fe is less than 0.15 wt % but larger than 0 wt %.

4. The aluminum-scandium alloy as claimed in claim 1, wherein Mn is less than 0.1 wt % but larger than 0 wt %.

5. The aluminum-scandium alloy as claimed in claim 1, wherein Cr is less than 0.04 wt % but larger than 0 wt %.

6. The aluminum-scandium alloy as claimed in claim 1, wherein Ti is less than 0.06 wt % but larger than 0 wt %.