The importance of the development of aluminum-lithium alloys

[China Aluminum Network] Li is a lighter metal element. Adding 1% of Li in an aluminum alloy can reduce the aluminum alloy density by 3% and increase the modulus by 6%. According to calculations, if the advanced aluminum-lithium alloy is used to replace the traditional aluminum alloy manufacturing Boeing aircraft, the structural quality can be reduced by 14.6%, the fuel saving by 5.4%, the aircraft cost by 2.1%, and the flying cost per aircraft per year will be reduced by 2.2%; Reducing 15% can shorten the aircraft's rolling distance by 15%, increase the voyage by 20%, and increase the payload by 30%. Each time the space vehicle reduces 1kg, its launch cost can save about 20,000 US dollars. Therefore, the development of aluminum-lithium alloys is of great significance in the aerospace field.

The research and development of aluminum-lithium alloys has been more than 80 years old. However, the early aluminum-lithium alloys have obvious disadvantages such as low ductility and fracture toughness, high notch sensitivity, difficulty in processing, and high prices. Get further promotion and application. By the 1980s, the situation has improved. Western countries have successfully developed a series of mature aluminum-lithium alloy products, such as low-density, medium-strength and damage-resistant, and high-strength, but there are still some obvious disadvantages, such as anisotropy. Severe; short transverse strength is low; plastic toughness is low; toughness is lost after heat exposure; most alloys are not weldable; overall strength levels are low, making it difficult to compete with high-performance aluminum alloys for overall performance and price. It was only in the last 20 years that a series of aluminum-lithium alloys with certain special advantages were developed. For example, the United States invented ultrahigh-strength aluminum-lithium alloys with good weldability and high-fatigue aluminum-lithium alloys; Russia developed high-strength weldable Aluminum lithium alloy. These newly developed aluminum-lithium alloys have the following characteristics: low density, high modulus; good strength-toughness balance; excellent damage resistance; small anisotropy; good thermal stability; corrosion resistance; good formability, especially Low-anisotropy aluminum-lithium alloys and high-strength weldable aluminum-lithium alloys are attracting attention. Due to the improvement of comprehensive performance, the performance of some new aluminum-lithium alloys has been significantly better than some of the traditional aluminum alloys currently used in the aerospace sector, and has been widely used in the aerospace and aerospace industries.

The new Al-Li alloy not only has the advantages of low density, high elastic modulus, high specific strength and high specific modulus, but also has the characteristics of low fatigue crack propagation rate, good high temperature and low temperature performance, and is considered to be aerospace. The ideal structural material. In view of the actual demand for weight loss in aerospace and the excellent comprehensive performance of the new aluminum-lithium alloy, Europe, the United States, Russia, and other countries all attach great importance to the development and development of new aluminum-lithium alloys for aerospace applications. Western aerospace giants have a large number of applications in the future aerospace industry. Alloy plan. For example, in the U.S. Next-Generation Aerospace Engineering Constellation Program, the upper stages of Ares series rockets, which are important elements of the new transport infrastructure for U.S. space exploration, will all be made of aluminum-lithium alloys.

In the past three decades, China South Central University, Southwest Aluminum Division, Institute of Aerospace Materials and Technology, and Beijing Aeronautical Materials Research Institute have made major breakthroughs in the research and development of aluminum-lithium alloys, which has enabled the development of aluminum-lithium alloys in China. Foreign countries basically maintain a fairly high level. At the same time, domestic aluminum-lithium alloys have also been applied to some of China's major aerospace vehicles. China, together with the United States, France, Russia and other countries, has become the world's few countries that can industrialize the production and application of advanced aluminum-lithium alloys. Further promoting the research and development of aluminum-lithium alloys in China is obviously of great strategic importance.

Eucalyptus Essential Oil is one of the best essential oils for sore throats, cough, seasonal allergies and headaches that is made from leaves of selected eucalyptus tree species.