Applications of new aluminum alloys: Al-Li alloys, Al-Ba alloys, Al-Ba alloys and Al-matrix composites

With the development of high-strength aluminum alloy materials such as high-strength, high-toughness and other high-performance aluminum alloy materials in the world, and meeting the needs of aerospace and other military industries and some special industrial sectors, a series of properties and functions have been developed to meet different needs. Conditions and uses of civilian aluminum alloy new materials.

The research and development direction of new aluminum alloy materials is mainly applying the theory of micro-alloying, adopting electronic metallurgy technology, adjusting the content and proportion of alloying elements, adding high-efficiency trace elements, and renovating the existing series of 1×××～9×××. Thousands of traditional aluminum alloys make full use of their potential. On the other hand, they design and develop a number of new types of high strength, high toughness, high modulus, wear resistance, corrosion resistance, fatigue resistance, high temperature resistance, low temperature resistance, radiation resistance, and fire resistance. Explosion-proof, easy-to-cut, easy-to-polish, surface-treatable, weldable and ultra-light aluminum alloy materials and extrusion products to meet the ever-evolving requirements of the defense industry, cutting-edge technology and high-speed development of the national economy.

1. Al-Li alloy (Al-Li).

The characteristics of aluminum-lithium alloys are low density, high elastic modulus and high strength. Currently developed aluminum-lithium alloys are mainly Al-Li-Sc-Zr-based and Al-Li-Mg-Zr-based alloys, and Al-Li-Cu-Mg-substitutions capable of replacing 7x×super-high-strength alloys Zr-based alloys. The most typical alloys are 2090 and 8091. The goal of the development is to achieve 7075-T6 strength and 7075-T73 corrosion resistance. In 1996, the aluminum-lithium alloy used in helicopters in the United States reached about 20% of the weight of the aircraft. After 2010, more than 20% of the structures on large passenger aircraft are expected to use aluminum-lithium alloys. Currently, mainstream domestic agents are Shanghai. Ai Ai Metal Materials Co., Ltd. and so on.

2. Aluminum-antimony alloy (Al-Sc).

Tantalum is a rare earth metal element that has a low density and a high melting point, because it can significantly increase the recrystallization temperature and mechanical properties of aluminum alloys, thus attracting great attention. In recent years, Russia and Germany have made great progress in the research of Al-Sc alloys, and Al-Zn-Mg-Sc-Zr and Al-Mg-Sc alloys have been developed. The former is characterized by high strength, good plasticity, fatigue properties and good welding performance. It is a new high-strength, high-toughness weldable aluminum alloy. Its application areas are also mainly aviation and aerospace, and can also be applied to high-speed ships and high-speed trains.

III. Al-Be alloy.

Niobium also belongs to the high-melting rare metals. Al-(7.0-30%)Be-(3-8)% Mg alloys are in the two-phase region of the Al-Be-Mg ternary phase diagram, and their microstructures are The solid solution Mg Al phase composition makes the alloy have a very good overall performance. For example, Al-7.0%Be-3%Mg alloy has tensile strength of 650 Mpa and elongation of more than 10%, which can be applied in the aviation industry. However, due to the complexity of the manufacturing process, its application is limited.

Four aluminum composite materials.

The current development of aluminum-based composite materials mainly B / Al, BC / Al, SiC / Al, Al2O3 / Al and so on. The added fibers can be divided into particles, whiskers, short fibers, and long fibers, of which the SiC/Al composite material is the most promising because it does not require the use of a diffusion layer to treat the coated fibers and is low in cost. Aluminum matrix composites are characterized by low density, high specific strength and specific rigidity, high specific elastic modulus, good electrical and thermal conductivity, corrosion resistance, high temperature resistance, creep resistance and fatigue resistance. The more than 10 meters long profiles and tubes made in the United States have been used on various spacecraft and have become important competitors for aluminum alloys and even aluminum-lithium alloys. In addition, aluminum-steel, aluminum-titanium and other laminated aluminum-based super high-strength composite materials have also been developed in recent years.