Laser forming technology of titanium alloy structural parts for aviation
Titanium alloy has the advantages of low density, high specific strength, excellent corrosion resistance and high temperature mechanical properties. The amount used in military and civil aircraft structures has become one of the important indicators for measuring the advancement of aircraft. In terms of civil aircraft, Boeing and Airbus continue to increase the amount of titanium alloy used in the renewal of aircraft. The amount of titanium alloy used in Boeing 757 and A320 is 6% and 4.5%, respectively. The amount of titanium alloy used in Boeing 777 and A340 is 7% and respectively. 6%, while the titanium alloy consumption of the new generation of Boeing 787 and A380 has reached 15% and 10%. In terms of military aircraft, the Su-27, F-16 and F-18 aircraft used a large amount of titanium alloy, especially the fourth-generation fighter F-22 titanium alloy used reached 41% of the total weight of the structure.
However, due to the characteristics of the titanium alloy itself, the large-scale titanium alloy parts manufactured by the traditional 'forging + machining' technology have large machining allowances and low material utilization. (Generally less than 10%), resulting in high manufacturing cost and long production cycle of titanium alloy parts. In particular, some titanium alloy structural parts with complex shapes cannot be formed using traditional manufacturing techniques. The above reasons severely restrict the development and production of my country's aviation equipment.
Laser forming technology is a new type of manufacturing technology that combines high-power laser plating technology and prototype technology to melt and directly deposit metal powder, which can be used without any mold Under the conditions of tooling and tooling, the metal materials are melted and deposited layer by layer by laser, and the three-dimensional mathematical model of the part is directly used to complete the forming and manufacturing of high-performance 'near-end forming' complex parts in one step. It has high material utilization, small processing allowances and short trial production cycles. , The outstanding advantages of high process flexibility, have great potential in the field of aviation applications.
Laser forming technology and application progress of titanium alloy structural parts for aviation
The United States first applied laser forming technology to the aviation field In 1997, AeroMet, with the support of the US Air Force, Army and National Defense related research programs, conducted application research on laser forming titanium alloy aircraft structural parts. In 2000, it completed the ground verification test of laser forming titanium alloy full-size aircraft wing structure. As of 2005, the company's Ti6Al4V alloy parts manufactured by laser forming have been installed on F/A-18E/F carrier-based aircraft and F-22 fighters and other aircraft, and developed a special technical standard (AMS 4999).
The successful application of American laser forming technology in the aviation industry has greatly promoted my country's research boom in this field. Units such as Northwestern Polytechnical University, Beijing Aviation Manufacturing Engineering Research Institute of AVIC, Beijing University of Aeronautics and Astronautics, Beijing General Research Institute of Nonferrous Metals actively carry out research work on laser forming technology, parts manufacturing and processing, and have achieved rapid development.