High strength casting aluminum alloy material

Abstract

A high strength casting aluminum alloy material comprises (in weight %) Cu 2.0-6.0%, Mn 0.05-1.0%, Ti 0.01-0.5%, Cr 0.01-0.2%, Cd 0.01-0.4%, Zr 0.01-0.25%, B 0.005-0.04%, rare earth 0.05-0.3%, and balance aluminum and trace impurities. The alloy has reduced cost.

Description

TECHNICAL FIELD[0001]The invention relates to an aluminum alloy material, in particular to a high strength casting aluminum alloy material.BACKGROUND[0002]The aluminum alloy as a younger metal material was not put into industrial use until early in the twentieth century. During the World War II, the aluminum material was mainly used to manufacture military aircraft. In the post-war years, the sharp drop in the demand for the aluminum material in the military industry led the aluminum industry to turn to the development of the aluminum alloy for civil use, so as to extend the applicable range thereof from aviation industry to various fields of national economy such as construction industry, container packaging industry, transportation industry, power industry, electronic industry, mechanical manufacturing industry, petrochemical industry and so on and apply the aluminum alloy to daily life. Nowadays, owing to high consumption and wide range, the aluminum material ranks second next to...

AI Technical Summary

Benefits of technology

[0006]The invention intends to solve the technical problems that the existing high-strength casting aluminum alloy has the disadvantages of high formula cost, low strength, poor castability, short fatigue life and poor resistance to stress corrosion and to develop a high-strength, high-toughness and high-corrosion-resistance casting aluminum alloy material for both military and civil uses by optimizing the common formula and the processes of casting and purifying.

[0014](3) then, refining the alloy melt in the melting furnace, adding a refining agent (chlorine gas, hexachloroethane, manganese chloride and the like may be selected as the refining agent according to different working conditions) to the alloy melt and evenly stirring, wherein the melt should be refined in a closed environment as possible, in order to prevent the melt from water absorption and melting loss;

[0018]Compared with the prior art, the invention has the following advantages:

[0019](1) Advanced designs of alloying and micro-alloying. By determining the reasonable design of micro-alloying elements (Ti, Cr, B, Zr, Pr, Ce, La and mixed rare earth elements) and composition range thereof based on the main components of Al—Cu—Mn, the invention can achieve the effect of substituting for precious metals, such as Ag and V and reduce the formula cost by 5% to 10%.

[0020](2) Advanced techniques for melting and impurity removal. The invention can effectively break through the technical bottleneck in impurity removal and ensure that the tensile strength of the material is higher than 450 MPa and the coefficient of elongation is higher than 5% at the same time.

[0021](3) The invention can maintain the high strength of the material and obviously increase the plasticity thereof at the same time.

Problems solved by technology

Nowadays, owing to high consumption and wide range, the aluminum material ranks second next to steel in metal materials.

The plasticity of ZL205A (T5) is good, and the coefficient of elongation thereof reaches 7%, so ZL205A has been widely applied in the field of aerospace, however, ZL205A contains precious metal V as an element and is high in cost; meanwhile, ZL205A is based on refined aluminum or high-purity aluminum as a base metal, thus increasing the cost and limiting the material supply.

Additionally, ZL209, which is made by adding RE to ZL205A, is still subject to the limitation of high cost due to the addition of the element V. The aluminum alloy developed by LV Jie, BIAM (Beijing Institute of Aeronautical Materials) is similar to ZL205A in the aspect of main components, however, the aluminum alloy contains 0.1% to 0.25% of V in the trace elements, has a tensile strength of 385 MPa to 405 MPa and the coefficient of elongation reaching 19% to 23%, and it is disclosed only in document study, the tensile strength of the aluminum alloy is lower, and the raw materials include high-cost element V.

In conclusion, the existing research on the field of high-strength casting aluminum alloy at home and aboard has the following problems: the strength of the aluminum alloy is not high enough, more particularly, few of casting aluminum alloys has the tensile strength higher than 450 MPa; precious metals and rare elements (Ag, V and Be) are added in an amount higher than 1%, and high-impurity aluminum is used as the base metals, thus increasing the cost, limiting the material source and making the aluminum alloy difficult to be popularized and put into civil use; the problem of the ratio between strength and plasticity is yet to be solved, and the contradiction between the strength and castability of the alloy is serious; and the fatigue life is short, and the resistance to stress corrosion is poor.