Shaanxi Yunzhong Industry Development Co.,Ltd
Address: NO.128 Gaoxin Road, Baoji City, Shaanxi Province of China
Ti-Al intermetallic compound
Due to component containing large amounts of aluminum and covalent bond exists, the density of Ti Al intermetallic compound is low, with the use of high temperature and has excellent high temperature performance, in the field of Aeronautics and Astronautics has important application value. At present, the research focus of Ti-Al intermetallic compound is TiAl alloy and Ti2AlNb alloy.
The density of Ti2AlNb alloy is slightly higher than that of titanium alloy due to the addition of Nb, but the temperature can reach 650 C -700 C, which can be partly replaced by high temperature alloy. The Institute of metal, iron and Steel Research Institute and other units were on Ti2AlNb alloy and its thermal processing technology made important progress, and Ti2AlNb alloy have been developed, currently focused on optimizing composition and improve the processing technology research, and actively carry out Ti2AlNb alloy sheet metal forming in the field of aviation and aerospace engineering applied research.
But the Ti2AlNb alloy still has the disadvantage that the temperature is lower than that of the material, and it can not replace the high temperature alloy in the higher temperature. The proportion of TiAl alloy not to 50% of the nickel base alloy, using the temperature can reach 700-900 deg.c, has the advantages of light weight, high strength, corrosion resistance, wear resistance, high temperature performance advantages, is becoming a field of aviation, aerospace and other important alternative materials.
After more than a decade of research and hinder some defects in TiAl alloy application gradually improved, such as TiAl alloy at room temperature plastic low, more than 800 DEG C high temperature antioxidant insufficiency, tensile strength / plastic and fracture and creep resistance with anomalous relations were improved to some extent.
In recent years, domestic and foreign key research questions about TiAl alloy have been changed from material to material forming and application. GE company in 2007 has announced that the casting Ti-48-2-2 low-pressure compressor blade will be a large number of applications in the Boeing 787 aircraft engine GEnx-1B, has passed the test and qualification certification.
This will be the first major application of TiAl alloys in aero engines. Using TiAl alloy casting blades, engine direct weight loss of 800 pounds. The U. S. Department of defense in the "high performance turbine engine technology (IHPTET) project proposed development of 15-20 thrust weight ratio, reduce the quality of the 50% of high performance engine, materials and manufacturing process of the contribution will reach 50% to 70%. The United States NASA predicts that by 2020 the application of TiAl alloy in the aircraft engine may reach 20%. At the same time, the TiAl alloy has special attraction for the structural materials used as advanced propulsion system, thermal structure and thermal protection system (TPS).
TiAl alloy sheet has been listed as the candidate material for major US airlines plans to include reusable launch vehicle, NASA's future aircraft x, joint strike fighter, X-38Crew rescue vehicles, military space plane and supersonic transport and other.
In addition, in the automotive industry, TiAl Alloy Casting valve has been successfully applied to the formula 1 racing engine, the Mitsubishi Heavy Industries have a large number of the cast TiAl turbocharger is used Lancer Evolution series of car engine. The application of TiAl alloy in automobile engine has great significance in weight loss, noise reduction, less waste gas pollution, lower fuel consumption, increased start-up speed, longer service life and reliability.
The research institutes of our country are in the development of TiAl alloy material, precision casting, near isothermal forging, rolling, hot extrusion, powder metallurgy and so on. Beijing University of science and technology of the high Nb TiAl alloy, Central Iron and Steel Research Institute, Chinese Academy of Sciences Institute of metal precision casting, Central South University of powder metallurgy, Beijing Aviation Materials Research Institute of thermal extrusion has its own material and process characteristics. Harbin Industrial University in TiAl alloy casting, precision casting, heat treatment, thermo mechanical processing, sheet metal rolling theory and technology were thoroughly and systematically, has taken the lead in developing the maximum size ingots, forging blank and plate and pouring out of the complex thin wall castings. However, there is still a great gap between China and foreign countries in the application of TiAl alloy, both in the field of Aeronautics and Astronautics, TiAl alloy component has not been applied.
In general, the research on the application of Ti Al intermetallic compound component is main goal in our country at the present stage, it also requires strengthen exchanges and communication with application department, change the idea and method of design, in order to achieve from design to manufacturing a component of original innovation.