CN101403060B - High damnification resistant aluminum alloy - Google Patents

Abstract

The invention belongs to the technical field of metal alloys. A high damage-resisting aluminum alloy provided by the invention is characterized in that 0.001-1.0 percent (weight percent) of bismuth is added to a substrate of the aluminum alloy and the optimal content range of the added bismuth is 0.001-0.3 percent. The preparation method of the high damage-resisting aluminum alloy is realized by adding metal bismuth in the melting process of the aluminum alloy. Owing to the addition of minim bismuth, the invention remarkably improves the toughness of the material and particularly promotes the fatigue and damage resisting performances of the material. The high damage-resisting aluminum alloy can be used in the structural members of aviation, automobile and other industries.

Description

A high damage-resistant aluminum alloy

technical field

The invention relates to the non-ferrous metal alloy technology in the field of metallurgy, and specifically belongs to an advanced aluminum alloy material through microalloying.

Background technique

Aluminum alloy has a series of advantages such as low density, high strength, corrosion resistance, easy processing, and rich resources, and is widely used in aviation, transportation, power electronics, construction packaging and other industries. It is not only a kind of basic material with large quantity and wide range, but also occupies a very important position in national defense construction and plays an irreplaceable role. How to continuously develop new varieties and further improve the performance of aluminum materials has become a common concern of the international aluminum industry today. At present, the research and development goal of aluminum alloy has changed from the simple pursuit of high strength in the past to the overall improvement of the comprehensive performance of materials, that is, to further improve the durability and damage tolerance of the alloy while improving the strong plasticity of the aluminum alloy. Aluminum alloys are developing towards high specific strength, high specific modulus, high damage tolerance, heat resistance, and corrosion resistance, and the existence of small or even trace amounts of certain elements will significantly affect the structure and properties of aluminum alloys. Microalloying is becoming It is an important means to tap the potential of alloys, improve the properties of alloys and further develop new aluminum alloys, which has attracted widespread attention at home and abroad.

Contents of the invention

The problem to be solved by the present invention is to seek a suitable aluminum alloy microalloying element, which can strengthen and toughen the aluminum alloy while improving the fatigue damage resistance of the alloy, so as to improve the comprehensive performance of the material as a whole.

The high damage-resistant aluminum alloy provided by the present invention is characterized in that bismuth with a weight percentage of 0.001%-1.0% is added to the matrix of the aluminum alloy.

The optimal content range of the metal bismuth mentioned above is: 0.001-0.3%.

Due to the addition of a small amount of bismuth, the present invention significantly changes the precipitation kinetics of the alloy, increases the precipitation density of the strengthening phase and makes it evenly distributed; at the same time, the bismuth atoms adsorbed on the recrystallized grain boundary reduce the interface energy of the interface, hinder The movement of grain boundaries makes the growth of recrystallized grains suppressed, that is, the presence of trace bismuth not only refines grains, but also strengthens grain boundaries.

Description of drawings

Accompanying drawing 1 is the test result of the fatigue crack growth rate of Al-4.2Cu-1.4Mg-0.08Zr-0.6Mn alloy before (a) and after (b) adding a small amount of Bi at R=0.1.

Detailed ways

EXAMPLE An alloy ingot was prepared by graphite crucible and iron mold casting, and the raw materials used were 99.99% high-purity aluminum, pure magnesium, pure bismuth, and an intermediate alloy of 10.12% Mn and 2.98% Zr. The cast ingot was homogenized and then hot-rolled and cold-rolled to form a 2mm plate. Both materials were subjected to T4 heat treatment (water quenching after solution treatment at 500°C, natural aging at room temperature for 96 hours), and then the tensile properties and fatigue properties at room temperature were tested. Table 1 lists the mechanical properties of the two alloys before and after the addition of trace bismuth. It can be seen from the table that the tensile strength σ _b and yield strength σ _0.2 And elongation δ have been significantly improved at the same time. Figure 1 shows the test results of the fatigue crack growth rate of the two alloys before and after T4 treatment at R = 0.1, before and after the addition of trace Bi. It can be seen from the figure that the fatigue crack growth rate da/dn of the alloy containing trace Bi is significantly less than Alloys that do not contain Bi.

Table 1 Tensile properties of alloy Al-4.2Cu-1.4Mg-0.08Zr-0.6Mn-(0.05Bi)T4 state after treatment

alloy σ_b(Mpa) σ_0.2(Mpa) δ(%) Al-4.2Cu-1.4Mg-0.08Zr-0.6Mn 448.4 288.0 22.8 Al-4.2Cu-1.4Mg-0.08Zr-0.6Mn-0.05Bi 469.6 307.5 26.0

Claims (1)

1. a high damnification resistant aluminum alloy is characterized in that: the bismuth that adds 0.05% weight percent in the Al-4.2Cu-1.4Mg-0.08Zr-0.6Mn alloy substrate.

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