1. Introduction to electromagnetic manufacturing technology
Electromagnetic manufacturing technology is an important direction in the advanced manufacturing industry. Electromagnetic manufacturing technology is a collection of electromagnetic mechanics, high-speed forming technology, high-speed collision and other technologies. Manufacturing technology, which can be applied to basic manufacturing applications in many fields such as welding, forming, powder pressing, riveting, etc.
Electromagnetic manufacturing technology uses electromagnetic force, a reliable and clean energy, as the main driving force, which can realize high-speed forming, welding, curling and forming of thin-walled metal materials, non-metallic materials and other materials. process, solve the problem of difficulty in forming strain rate sensitive materials and difficulty in welding dissimilar metals, promote the application of my country's magnesium alloys, aluminum alloys, titanium alloys and other lightweight materials in industry, and promote the development of my country's manufacturing industry in the direction of high quality.
The application of magnesium alloys in automobiles is mainly concentrated in three parts: body, engine and interior parts, and the production demand is growing rapidly. In Europe, more than 60 auto parts have been made of magnesium alloys. The North American and Japanese auto industries are using magnesium alloys in more and more parts, including gear levers, seat frames, etc. There are more than 100 types of magnesium alloy parts currently in use and developed. In order to ensure the stiffness of the parts, some use electromagnetic pulse magnesium-steel hybrid connections. As a lightweight material in modern automobile manufacturing, aluminum alloy has been widely used in automobile skins, parts and other aspects. For example, the representative model developed by Audi, the Audi A8, was the first to use an all-aluminum body. The use of electromagnetic crimping connection technology can achieve high-strength connections of various materials such as carbon fiber, aluminum alloy, and steel. Therefore, connection technology will promote the rapid development of the manufacturing industry.
(1) Electromagnetic pulse welding technology
Electromagnetic pulse welding technology is one of the main application directions of electromagnetic manufacturing technology. It has developed rapidly in recent years because of the emergence of problems with heterogeneous products in many industries. Material welding needs. Lightweight materials mainly include titanium alloys, aluminum alloys, etc. The melting points of them are quite different from those of traditional metal materials, making melt welding difficult to achieve. At the same time, such metals and their alloys generally have oxide films, which also increases the difficulty of welding. In order to solve this kind of problem, one or two of the workpieces to be welded are instantly raised to a higher speed and collided with each other at high speed. A good welding joint can be formed between the workpieces. This welding method is high-speed impact welding. As a new welding method, electromagnetic pulse welding has fast welding speed and good controllability. It has been gradually applied to the welding of various dissimilar metal plates and has great application potential. Compared with other welding, electromagnetic pulse welding has the following advantages: (1) It is widely used in the welding of dissimilar metals, such as copper aluminum, aluminum magnesium, aluminum iron, aluminum steel, copper steel, etc.; (2) Solid phase welding process does not require cooling , one-time molding; (3) The process has fast molding speed, high production efficiency, stable and reliable quality; (4) No flux and solder are required in the welding process; (5) The weld structure is higher than the strength of the base metal; (6) Green and environmentally friendly Pollution-free, with the advantages of no smoke, no waste gas, etc.
(2) Electromagnetic pulse forming technology
High-speed forming is another major area of ??rapid development in the application of electromagnetic manufacturing technology. Aluminum alloy plates have low forming plasticity at room temperature, poor local drawability, are prone to cracks, and have large springback. The processing results using traditional processing techniques are not ideal. Therefore, the research on light alloy electromagnetic forming technology has important scientific and practical significance in solving the engineering needs of my country's aerospace, automobile and other fields.
Electromagnetic forming is a rapid forming technology. Studies have shown that when the deformation speed of the material reaches a certain level, the forming performance of many metal materials will be greatly improved. This characteristic of metal materials is called " Hyper-plasticity”. As a high-energy forming method, electromagnetic forming technology has the following advantages compared with traditional processing methods:
(1) Significantly improve the forming limit of metal;
(2) Improve processing strain distribution;
(3) Reduce wrinkles, etc. Compared with other high-energy rate forming explosive forming, electro-hydraulic forming, etc., electromagnetic forming has the advantages of high production efficiency and good process repeatability.