Application of the hottest magnesium alloy in auto

The application of magnesium alloys in automobiles

China is a big country in magnesium production and magnesium resources, as well as in automobile production. It enjoys unique conditions to develop magnesium for automobiles

characteristics of magnesium and magnesium alloys and starting point for automotive applications

the application of magnesium alloys in automobiles began in the 1920s when they were used in racing cars. In 1936, more than 18kg magnesium alloy was used in the engine and transmission system of Volkswagen Beetle cars. By the early 1980s, Volkswagen had produced 19million beetle cars, using about 380000 tons of magnesium alloy

in 1982, by strictly limiting the content of impurities such as Fe, Cu and Ni, the corrosion resistance of magnesium alloys was solved, which greatly promoted the application of magnesium alloys in the automotive industry

nowadays, steel, aluminum alloy and plastic are the three most used materials in automobiles. Calculated by weight, the three types of materials account for about 80% of the total vehicle, of which steel and iron account for about 62%, and aluminum alloy and plastic are roughly the same, accounting for 8% to 10%. The application proportion of magnesium alloy in automobile is about 0.3%, and the average weight is about 5kg, but the growth rate in recent years is large

the specific gravity of magnesium is 1.74g/cm3, aluminum is 2.7g/cm3, steel and iron are 7.8g/cm3, and plastics are usually 0.83~2.2g/cm3. Magnesium is about one third lighter than aluminum. The use of magnesium alloy is conducive to vehicle lightweight, energy conservation and emission reduction. According to the information, the fuel consumption can be reduced by 5% for every 100kg reduction in the mass of the car. If 70kg magnesium alloy is used for each vehicle, the annual CO2 emission can be reduced by more than 30%. Vehicle weight reduction can improve its acceleration performance; The weight reduction of the top and door can reduce the center of gravity of the car and enhance stability; The front weight reduction can make the center of gravity of the car move backward and improve the handling performance. Magnesium alloy has higher specific strength and specific stiffness. The specific strength of magnesium alloy is higher than that of aluminum alloy and steel, which is equivalent to engineering plastics. Its specific stiffness is close to that of aluminum alloy and steel, and much higher than that of engineering plastics

in addition, the damping coefficient of magnesium is much higher than that of aluminum and steel, which has excellent impact resistance and is conducive to vibration and noise reduction. Therefore, magnesium is widely used in automotive parts such as steering wheel framework, steering column support, valve cover and so on. Magnesium alloy has good castability and dimensional stability. It can be cast into thin-walled, shaped and complex parts. It can be cast as a whole, reducing the number of parts and improving the service life of the mold. At the same time, magnesium alloy has good machinability and reduces the production cost. Therefore, it has been widely used in automotive parts such as integral instrument panel framework. Magnesium also has strong anti electromagnetic interference ability, which can realize 100% recycling and reuse

however, magnesium alloys also have poor high temperature resistance and corrosion resistance

according to the statistics of the magnesium industry branch of China Nonferrous Metals Industry Association, in 2006, China produced 526000 tons of original magnesium and 211000 tons of magnesium alloys. China has become the largest producer and exporter of magnesium and magnesium alloys in the world. Due to the competition in China's magnesium industry, the former largest foreign magnesium manufacturer announced in 2006 that it would close its largest Canadian factory and was willing to sell two other factories. At present, Japan's domestic demand for magnesium is entirely dependent on imports, of which the proportion of imports from China is more than 90%

as for the price of magnesium alloy, the price of magnesium alloy has been higher than that of aluminum alloy for a long time, but since 2006, the price of magnesium alloy and aluminum alloy has been roughly the same

application of magnesium alloy in automobile

1 Steering wheel framework

at present, in North America, about 80% of new cars use magnesium alloy steering wheel framework

tmgi (Tonsberg magnesium group international) is a listed company in the Swedish stock market. It operates in Norway, Sweden, Poland, the United States and Mexico. Its main product is magnesium alloy steering wheel framework. Its research report points out that in 2004, about 26million of the world's 62million automobile production used Magnesium Alloy Steering wheel framework. Tmgi's main customers are first-class suppliers of safety and automotive interior parts with stable and reliable performance, such as Trinasolar, Autoliv, Kay safety system, etc., and the products of first-class suppliers are supplied to complete vehicle enterprises such as Ford and BMW. The output of tmgi supporting BMW reaches 200000 pieces/year; Its Mexican factory supplies Autoliv. An agreement was signed in 2007 to supply 1.5 million pieces in five years, and the final products are supplied to Ford

2. Steering column bracket

meridian Technologies Inc. is the world's largest supplier of magnesium alloy automotive castings. Headquartered in Canada, it has six factories in five countries around the world, including one in Canada, the United States, Italy and the United Kingdom, and two in China (Shanghai Magnesium Alloy Die Casting Co., Ltd. and Chongqing maridin Boao Magnesium Industry Co., Ltd.), with a total of 1350 employees worldwide. Original shareholders: Teksid (Chinese Name: teksi, member of Fiat Group in Italy) 51%, hydro49%; After that, hydro transferred its shares to a consortium led by estatia, Switzerland. Now the consortium also plans to acquire Teksid's shares in the company to achieve sole ownership

at present, the company produces 4million steering column supports every year. In addition, it also produces 4million instrument panel frames, 2million four-wheel drive transmission shells and covers, 800000 front-end brackets, and 400000 seat frames

3. Instrument panel framework

the instrument panel framework made by lunt Manufacturing Co., Inc. for BMW X5, material AM60, equipment 4000t cold chamber die-casting. The project won the casting Excellence Award of more than 0.5 pounds from the North American Die Casting Association (NADCA) in 2007

4. Seat frame

produced by maridin technology company, supporting Jaguar models, material AM50A

5. Valve cover

material is basically AZ91D

6. Transmission housing and transmission cover

the transmission housing of Shanghai Volkswagen Santana car is made of magnesium alloy

Honda Accord 2006 acura tsx North America transmission housing is made of magnesium alloy

7. Other

(1) front end bracket

manufacturer maridin Technology Co., Ltd. in 2003, Ford f 150 began to use die-casting magnesium alloy front-end bracket, which supports radiators, headlamps, horns, etc., replacing the original components composed of 12 stamped steel parts

(2) intake manifold

plastic granulator is also a major energy consumer in China

manufacturer Pierburg GmbH, material AZ91D, applied to BMW V12 engine

(3) engine carrier

manufacturer maridine Technology Company material ae44, which applies the model general Chevrolet Z06 to replace the original aluminum alloy components

(4) door inner panel

manufacturer lunt manufacturing company, material AZ91D, application model general Cadillac XLR

(5) composite engine block

BMW is in the forefront of the application of magnesium alloy in engine block. In 2004, the cylinder block of 6-cylinder in-line magnesium aluminum composite gasoline engine was put on the market. The calculation fault of the cylinder part may cause the connecting rod connecting the two supports to be broken into aluminum alloy alsi17cu4mg, and the external base is magnesium alloy mgal6sr2, which has been mass produced

other applications include magnesium wheel, automatic transmission clutch piston, clutch housing, rearview mirror support, headlamp bracket, oil filter housing, valve cover and camshaft cover, etc

important factors restricting the application of magnesium alloys in automobiles

magnesium alloys have important application value for automobiles, but at present, the average magnesium consumption per vehicle in Europe and the United States is only 5kg~6kg, which is mainly constrained by the following factors:

1 Price. Economic comparison refers to the comparison with the total cost of the whole process of using existing materials, including materials, manufacturing, corrosion prevention, connection and assembly, maintenance, etc. In addition, price stability is also very important

2. Corrosion protection

3. Connection problems

4. In the process of mutual substitution of lightweight automotive materials, the basic work of magnesium alloy industry obviously lags behind the steel, aluminum alloy and plastic industries. Among the primary suppliers of automotive parts today, only a few companies supply magnesium alloy products

China is a big country in magnesium production and magnesium resources, and also a big country in automobile production. It enjoys unique conditions to develop magnesium for automobiles. China's automobile manufacturers, auto parts manufacturers, raw materials factories, equipment factories, scientific research institutes, financial institutions, associations, governments, etc. should actively work together to promote the rapid and healthy development of the automotive magnesium industry. (end)