JPS62214151A - Aluminum alloy having superior strength at high temperature - Google Patents

Abstract

PURPOSE:To improve the strength of an Al-Cu-Mg-Zr alloy at high temp. by adding a small amount of Mn or V to the alloy. CONSTITUTION:The composition of an Al alloy is composed of 4.0-7.0% C, 0.3-1.0% Mg, 0.05-0.2% Zr, 0.2-0.7% Mn and/or 0.05-0.2% V and the balance Al with inevitable impurities. The alloy has superior strength, e.g., tensile strength in the wide temp. range of room temp. - about 250 deg.C.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an aluminum alloy with excellent high-temperature strength.

[Prior art] For engines and compressors, from the viewpoint of lightweight,
Aluminum alloys are used in vacuum equipment because of their low gas adsorption. These parts are 100~
Since it is used in a temperature environment of 250°C, it is required to have high strength not only at room temperature but also at high temperatures.

2 as an alloy with high high temperature strength among aluminum alloys
618 and 2219 are listed.

[Problem that the invention attempts to solve] However, the above aluminum alloy has the following drawbacks.

The strength of 2618 is high in the temperature range from 150°C to 200°C, but low in the temperature range above and below 150°C.

On the other hand, the strength of 2219 is high in the temperature range above 250°C, but low in the temperature range below.

Therefore, there has been no aluminum alloy that has excellent strength over a wide temperature range from room temperature to 250°C.

In recent years, as demands for thinner parts have increased, aluminum alloys with higher high-temperature strength than conventional materials are desired.

[Means for Solving the Problems] The present invention is based on the conventional heat-resistant aluminum alloys 2618 and 221.
To provide an aluminum alloy having superior high-temperature strength than No. 9.

That is, the present invention provides an aluminum alloy that has higher strength than conventional aluminum alloys in a wide temperature range from room temperature to 250°C.

In other words, 1 the present invention has Cu: 4.0 to 7.0%, Mg: 0
．． Contains 3 to 1.0%, Zr: 0.05 to 0.2%,
And Mn: 0, 2-0, 7%, V: 0.0
It is an aluminum alloy with excellent high-temperature strength, characterized by containing 5 to 0.2% of one or more kinds, and the remainder being An and unavoidable impurities.

The reason for limiting the ingredients will be explained below.

Cu: Cu is an essential element for maintaining high-temperature strength. For that purpose, 4.0% or more is required. Cu contributes to maintaining strength from both solid solution strengthening and precipitation strengthening, but has a higher contribution rate to improving high temperature strength than Mg, which has a similar function. When it exceeds 7%, crystallized products of Cu A and Q4 are generated, resulting in deterioration of workability such as extrudability and forgeability, as well as deterioration of strength.

Therefore, the amount of Cu is set to 4.0 to 7.0%. In addition, the most desirable range from both strength and workability is 5 to 6%.

Mg is an additive element that improves strength, particularly in the temperature range from room temperature to 200°C. If it is less than 0.2%, there is no effect, and if it is more than 1.0%, the effect on improving strength is lost because the amount of solid solution of Cu is reduced. It also reduces workability.

Therefore, the appropriate range for Mg is 0.2 to 1.0%.

The most desirable range is 0.4 to 0.7%.

Zr improves strength by making the structure after processing such as extrusion or forging into a fibrous structure.

There is no effect at less than 0.05%, and the effect is saturated at 0.2%. Therefore, it is set in the range of 0.05 to 0.2%.

A part of Mn is solid-solved in the aluminum alloy, and the other part increases the strength by creating a fibrous structure similar to Zr. If it is less than 0.2%, it will not contribute to improving the strength, and if it exceeds 0.7%, it will generate giant crystallized substances.
It has an adverse effect on strength, especially fatigue strength, and the larger the Mn content, the lower the extrudability. Therefore, the amount of Mn is 0.
2 to 0.7%.

Similarly to Zr, (2) improves strength by making the structure after processing such as extrusion and forging into a fibrous structure. 0.0
There is no effect at less than 5%, and the effect is saturated at 0.2%. Therefore, it is set in the range of 0.05 to 0.2%.

M n and V contain one or more of them. In addition, Vo
, 08-0.11%, the Mn amount is 0.2-0.4%
is appropriate. In addition, if it does not contain ■, the amount of Mn is 0.
．． By setting it to 5 to 0.7%, V: 0.08 to o
, tt%, and Mn: almost the same strength as in the case of 0.2 to 0.4%.

In addition to the above components, 1 to 0.05% of TiO and OO may be contained in order to refine the ingot structure and stabilize mechanical properties.

[Example of the invention] The aluminum alloys shown in Table 1 were melted by the conventional method and 15
The ingot was made into a 5φ ingot.

These ingots were subjected to homogenization treatment (525°C x 8 hours) and hot extruded into a 20φ round bar. The extrusion temperature is 470°C. A tensile test piece was prepared from this extruded material and subjected to quenching and tempering treatments.

Next, this tensile test piece was tested at 150°C and 200°C.

After holding at each temperature of 250° C. for 100 hours, a tensile test was conducted at each temperature. The high temperature strength of each material was compared using 0.2% proof stress.

The results are shown in Table 1.

In Table 1, No.1, No.12. No. 13 is a comparative example, of which No. 11 is 2219 and No. 13 is 2618. No2~N.

11 is an example of the present invention.

As shown in Table 1, the examples show higher strength than the comparative example 2219.2618 at any temperature from 150 to 250°C.

[Effect of the invention]

Claims (1)

[Claims] Contains Cu: 4.0 to 7.0%, Mg: 0.3 to 1.0%, Zr: 0.05 to 0.2%, and
Mn: 0.2-0.7%, V: 0.05-0.2% 1
An aluminum alloy having excellent high-temperature strength, characterized in that it contains one or more species, and the remainder consists of Al and unavoidable impurities. (However, % is weight %. The same applies below)