At present, the world's magnesium resources are very rich, ranking 8th in the earth's crust, accounting for 2.35% of the crustal mass. Magnesium alloy has the characteristics of low density (about 1.78 g/cm3), high specific strength, excellent electromagnetic shielding and vibration and noise reduction, good heat dissipation, excellent biological characteristics and environmental friendliness. It is used in aerospace, transportation, high-end equipment and construction. 3C products, leisure products, energy storage equipment and other fields have a wide range of uses, known as the 21st century green materials and strategic new materials, has been highly concerned by the world, and is expected to become the third foundation after steel and aluminum. Metal structural material.China is a major magnesium alloy research country in the world. The academic papers on magnesium alloy furnaces published by Chinese scholars have been ranked first in the world for more than ten years. The total number of invention patents applied for and authorized is also far ahead in the world of intellectual property; the world's most plastic magnesium alloy material is developed, the widest Magnesium alloy sheet, the largest magnesium alloy hollow profile and the largest diameter magnesium alloy ring; the invention of a series of industrial lead technology such as self-purification, anti-gravity filtration, new asymmetric processing, high-precision rolling of sheet metal; Elsevier has founded the world's first magnesium alloy journal, the chairman and secretary of the International Organization for Standardization (ISO) "Magnesium and Magnesium Alloys Committee"; many of the world's top magnesium alloy scientists, often come to work with Chinese scientists on magnesium alloy research jobs. Since the first International Conference on Magnesium Alloys was held in Beijing in October 2003, six international conferences on magnesium alloys have been held. Each meeting brought together the top magnesium alloy scientists from dozens of countries including Germany, the United States, the United Kingdom, Canada, South Korea, Japan, Australia, and the scientific and technical personnel of representative magnesium and magnesium alloy enterprises. The latest research results of magnesium alloys and The effects of its large-scale industrial application have been fully demonstrated at each conference.China is a major producer of magnesium and magnesium alloy deep-processing products in the world. It has a large number of cast magnesium alloys and wrought magnesium alloys. The 2017 magnesium production and export volume account for 3/4 and 2/3 of the world respectively. Ranked first in the world. According to incomplete statistics, there are more than 100 magnesium and magnesium alloy deep processing enterprises in China, and more than 20 important magnesium alloy research and development platforms at the national and provincial levels. More than 50% of the international standards for magnesium and magnesium alloys are drafted and formulated by China. The world's largest magnesium alloy grade, more than two-thirds of the world's automotive magnesium alloy parts are produced in China. For the first time in the world, the production line of wrought magnesium alloy sheet with an annual output of more than 5,000 tons has been realized. For the first time in the world, large-scale production of wrought magnesium alloy and large-scale application in textile machinery, 3C products, rail transit and other fields have been realized. Magnesium alloy furnaces show an increasingly broad application prospect.China's magnesium mine resources are abundant, and proven reserves rank first in the world. Magnesium alloy has also become one of the few metal materials in China with international voice. With the gradual commissioning of magnesium smelting in Qinghai Salt Lake, China's advantages in the field of magnesium metal will be further strengthened. However, China and the global magnesium alloy industry also have many challenges: First, the market application scale is still very different from the bulk of basic metal materials; second, compared with steel and aluminum alloys, basic research is still quite lagging; third is suitable for High-performance alloy grades for large-scale market applications are still under-represented; Fourth, insufficient attention has been paid to the development of new magnesium smelting technologies. The low-cost advanced deep processing technology of magnesium alloys cannot fully meet the needs of larger-scale production and application; The level of scientificization needs to be further improved, and the construction of magnesium alloy database and product design platform needs to be strengthened. We expect more outstanding scientific and technological workers to join the research and development team of magnesium alloy furnaces to make new contributions to the realization of China's major countries from materials to materials.

You don't need traditional coal, gas, electricity to provide power, the train speed can reach 400~500 kilometers, do you believe it? Recently, the reporter saw such a "high-speed pneumatic suspension train" model at the School of Vehicle Engineering of Chongqing University of Technology. Do you know a bird named 鹈鹕? The inspiration for the high-speed pneumatic suspension train comes from it. Experts say the train is expected to change the world's transportation system.The bullet head looks like a high-speed rail, and the body has a ring-shaped wing like an airplane.The reporter saw that the model of this high-speed pneumatic suspension train is more than one meter long. The head of the bullet is like a high-speed train. The body has a ring wing and an air propeller, which is similar to the aircraft.“The first-generation and second-generation style trials and real-time tests of high-speed pneumatic suspension trains have been completed in Japan.” Lai Chenguang, a professor at Chongqing University of Technology who is involved in the development of high-speed aerodynamic suspension trains, said that such high-speed pneumatic suspension trains are completely natural. Energy-driven, low-cost, and very fast. “If the speed is 500 km/h, the energy consumption of the pneumatic suspension train is 1/3 of that of the high-speed train and 1/6 of the maglev train.”Lai Chenguang said that he was exposed to this project in 2004. “At that time, I participated in this project as a teacher at Jilin University.”In 2007, Lai Chenguang came to Japan and participated in the research of the project more deeply. "Mainly responsible for aerodynamics."I have not been out of the lab for two months and proposed a ring wing design.From 2007 to 2011, Lai Chenguang conducted four years of research in Japan. In the past four years, he stayed in the wind tunnel laboratory every day, used the smoke method to observe the flow of air, and even caused poisoning and hospitalization. "With two months, I couldn't leave the lab, and the rice was sent in." In a test, Lai Chenguang was poisoned and fell down and stayed for several days.In 2011, Lai Chenguang came to Chongqing University of Technology. He led 4 teachers and more than 20 graduate students to continue to tackle high-speed pneumatic suspension trains.After in-depth research and analysis, the automobile aerodynamics team of Chongqing University of Technology put forward the theory and method of driving stability control of high-speed aerodynamic suspension trains, which provided key theoretical guidance and basis for its in-depth research and development. At the same time, the team also proposed the design concept of the ring wing and verified it, which further improved the aerodynamic performance of the train. "In short, it is mainly to study the stability of train travel, and proposed the design of the ring wing." Lai Chenguang said.New design to improve transportation capacity, the commercial pace of the car is acceleratingLai Chenguang told reporters that in the previous design, the wing (wing) of the high-speed pneumatic suspension train was similar to the plane. It was a pair of horizontal wings with vertical winglets attached to the tail end, but such "wings" were on the train. When driving, unstable airflow is generated behind the wing, which affects the smoothness of the train during driving.“And we designed the ring wing to form a frame on a three-dimensional surface, and the top and bottom of the frame are not on a vertical line, but on the back. This design makes the airflow much more stable than before, which will greatly improve The stability of the train," Lai Chenguang explained.In addition, the design of the ring wing can also improve the transport capacity. “With the design of the ring wing, the lift-to-drag ratio (lift force divided by the resistance) is increased by 30%-40%, and the transportation efficiency is improved.” Lai Chenguang introduced that the high-speed aerodynamic suspension train should have high operating efficiency and strong carrying capacity. It must be designed long. "But the consequence is that the track area is large and the construction cost is much increased. We propose that this ring wing can increase the transportation by 30%-40% when the width of the track is constant. ability."The increase in stability and operational capability has accelerated the commercial pace of high-speed aerodynamic suspension trains.The first high-speed pneumatic suspension train line is expected to open in Japan in 2025According to the results of aerodynamic research, combined with industrial design and aesthetics, culture and other factors, the automotive aerodynamics team of Chongqing University of Technology designed the third generation train model "LOOP", making this "flying train" closer to people's lives. One step. Next, the Sino-Japanese team will be equipped with a flame retardant magnesium alloy body based on the newly designed “LOOP” model and conduct more in-depth experimental research and verification.According to the plan, Japan will open the first high-speed aerodynamic suspension train line in 2025. "We plan to go from Narita Airport in Japan to Haneda Yang, all underground tunnels, with a design speed of 400 kilometers per hour. It can realize the intercommunication between the two airports in more than 10 minutes. Now, it takes more than an hour to walk from the ground. The second from Tokyo to Osaka, with a speed of 500 kilometers per hour, can realize the intercommunication between the two places within an hour, and now it takes two hours."“Tokyo to Osaka is full of natural energy. We have tested the climate and wind along the track. Solar panels are installed according to the sun exposure time in this area, and the windmills are installed according to the natural conditions of the wind.” Lai Chenguang said, “ The solar energy and wind energy collected and converted along the way of the prior art can drive the system to make a round trip every 12 minutes. According to the calculation of three cars and 120 cars per car, 360 people can be transported at a time."Lai Chenguang said that this project, which only uses natural energy and is driven by zero pollution, seems unlikely to be completed, but is actually very close to the lives of ordinary people.Developed body materials and accidentally discovered magnesium air batteriesIn the study of high-speed pneumatic suspension train materials, the R&D team also "accidentally" discovered a highly efficient magnesium air battery.At the time of material research and development, Professor Takahama Tatsuo of Tohoku University in Japan proposed the use of magnesium alloys as body materials because magnesium alloys are light and strong. In the process of researching the processing of magnesium alloys, Xiaobin Taizhao discovered that “the reaction between magnesium alloy and air will discharge, so Xiaobin Taizhao began research on magnesium air battery and made great progress.”"The emergence of high-efficiency and controllable magnesium air batteries will greatly promote the development of new energy vehicles. Several companies have invested billions of dollars to promote the industrialization of the magnesium air battery." Introduction, the emergence of high-efficiency and controllable magnesium air batteries has great benefits for China. "China's magnesium reserves are very large and the quality is very good. According to Xiaobin Taizhao's estimate, magnesium is enough for humans to use for hundreds of millions of years. The magnesia produced can also be reduced by the sun. It can be said to be inexhaustible. It uses magnesium to generate electricity. The energy generated by magnesium oxidation is higher than the energy efficiency. It is much higher than the current battery. ”At present, Xiaobin Taizhao has entrusted Lai Chenguang as a Chinese agent to find a partner.Inspired by research and development, a bird called cockroachSurprisingly, the research on high-speed pneumatic suspension trains is related to a bird. Professor Takahama Tatsuo of Tohoku University in Japan discovered that a bird called 鹈鹕 (Albatross) can fly more than 900 kilometers per meal when it migrates, with an amazing “fuel efficiency ratio”. Why is its "fuel efficiency ratio" so high, after in-depth research, "discover that they are taking advantage of the natural phenomenon of WIG."Lai Chenguang explained that the so-called WIG phenomenon is that when the wing shape (bird's wings) is close to the ground, the lift will increase sharply and the resistance will decrease. "If the bird is flying in the sky, it often flaps its wings to generate lift, but close to the ground, as long as the wings are opened, the resulting lift is much larger than the high altitude. This lift is related to the height of the wings from the ground, when the bird's flight is controlled At a certain height, you can support the weight of the body without flapping your wings. We have found that the closer to the ground, the greater the lift."In fact, before the development of high-speed aerodynamic suspension trains, former Soviet scientists used this principle to develop the "Caspian Monster" - a plane that floats in the air, its fuselage is similar in size to the Boeing 747, and the speed of the sea cruise is about It is 500 kilometers per hour.

Key words: magnesium alloy; NaCl solution; corrosionMagnesium alloys are widely used in automotive, aerospace, transportation and other fields due to their low density, high specific strength, large specific modulus, good heat dissipation, good shock absorption and high impact load capacity compared with aluminum alloys. Especially with the light weight and environmental protection needs of the automotive industry in recent years, as well as the continuous advancement of magnesium alloy research and development technology and recycling technology, magnesium alloys are increasingly used in the automotive industry. As we all know, the core technology of automobile competition is to develop high-performance engines, the so-called "the engine is the best in the world."Magnesium alloys are widely used in automobile engines because they require the engine to be lightweight and high-speed. The working environment of the automobile engine system is relatively complicated, and the temperature variation range is large (-40~150 °C). The requirements for the material properties of the engine are generally high, and it is required to withstand the heat resistance, the flame resistance and the corrosion resistance in different corrosive media.However, there is still a big gap between the domestic application of magnesium alloy materials as automotive engine materials and the theoretical reasons. The main reason is that the corrosion problem of magnesium alloys has not been overcome. It is of great practical significance to study the corrosion behavior and mechanism of magnesium alloys used in automobile engines for guiding the application of magnesium alloy materials to automobile engines.

In recent years, with the year-on-year growth of automobile production and sales, the income and profit scale of China's automobile and parts manufacturing industry have further increased. However, due to factors such as fierce competition in the industry, the overall profit rate of the industry has declined. The competition situation has been divided, and some of the more competitive vehicle and component manufacturers still maintain a good profit margin.Faced with increasingly fierce competition, what are the favorable factors in the development of the auto parts market to help the healthy development of the industry?Favorable factor(1) Support for national policies and industrial policiesIn recent years, the state has successively promulgated the "Automotive Industry Development Policy", "Several Opinions of the State Council on Accelerating the Revitalization of Equipment Manufacturing Industry", "Automotive Industry Adjustment and Revitalization Plan", "Opinions on Promoting the Sustainable and Healthy Development of China's Automobile Products Export", etc. Industrial policy, the above policy proposes: we must vigorously promote the structural adjustment and industrial upgrading of the auto parts industry; improve international competitiveness, promote the sustained and healthy development of China's auto and parts exports; support the auto parts and components to expand the scale through mergers and acquisitions, Improve the market share of domestic and foreign auto accessories; promote automobile consumption, and encourage cars to enter the family. The introduction of the above-mentioned support policies has provided a good macro-policy environment for China's auto parts industry, which will effectively promote the sustainable and healthy development of the industry.(2) The demand for automobiles and passenger vehicles is growing steadilyThe continuous growth of China's auto market demand has effectively promoted the stable development of the auto parts industry. In 2009-2016, China's auto sales volume grew at a compound annual growth rate of 12.75%, and the proportion of auto sales to global auto sales was also 20.86% in 2009. It has rapidly increased to 27.43% in 2015. The growth rate of the passenger vehicle market, which is the main body of China's automobile market, is higher than that of the automobile market. The annual sales growth rate is 15.38%. It is expected that by 2020, China will still be in the stage of simultaneous acceleration of industrialization and urbanization, and the national economy will continue to develop steadily, and automobile consumption will be further upgraded.China's economic growth provides a solid foundation for the sustainable development of the passenger vehicle market.The development of the passenger car market has maintained a strong correlation with the development of the national economy, the income level of residents, the national industry and consumption policy, and the degree of urbanization. As the income of urban and rural residents and the level of disposable income in China continue to increase, the pace of upgrading the consumption structure will accelerate. Passenger cars have increasingly become ordinary consumer goods, and the rigid demand for passenger cars in the domestic consumer market will continue to increase. From the press release of the Traffic Management Bureau of the Ministry of Public Security, as of the end of 2016, the number of motorists in China was 360 million, including more than 310 million motorists, the number of drivers ranked first in the world, the huge number of drivers and the rigid consumer demand. It laid the foundation for the development of China's passenger car market.China's car ownership is still low, and its development momentum is strong.In recent years, China's automobile industry has developed rapidly. In the past ten years, the annual automobile production has increased to about 28 million vehicles. It has rapidly expanded to the world's first scale in terms of scale, but the difference in automobile consumption areas is still large. It is still low, and the Chinese auto market is expected to maintain steady growth in the next 5-10 years. At the end of 2014, the total number of civilian vehicles in the country was 144.75 million (excluding three-wheeled vehicles and low-speed trucks), and the number of 1,000-person vehicles was 105.83 vehicles per thousand, which is a gap compared with the level of more than 500 vehicles/1000 people in developed countries. Larger, so the future development of China's auto market is huge.According to the “Statistical Communiqué on National Economic and Social Development 2015” issued by the National Bureau of Statistics on February 29, 2015, the number of civilian vehicles in the country reached 162.73 million (excluding three-wheeled vehicles and low-speed trucks) at the end of 2015, and the number of thousand people was It reached 118.38 vehicles / thousand people.International experience shows that there is a significant positive correlation between per capita income and car penetration, with per capita GDP reaching 1,000-2,000 US dollars, and entering the era of Volkswagen consumption, while 3,000-6,000 US dollars and 6,000-10,000 US dollars are the fastest rising car ownership rate. In the two periods, China’s per capita GDP has exceeded US$7,500 in 2015, so in the future, China will still be in a period of rapid increase in car ownership.The demand for automobile consumption in second and third-tier cities began to break outSince 2009, driven by a series of encouraging automobile consumption policies, such as the automobile industry revitalization plan, the demand growth rate of passenger car market in second- and third-tier cities in China is higher than that in first-tier cities. This indicates that the automobile market in first-tier cities is gradually saturated in China's automobile market. The speed of transfer to second- and third-tier cities and rural markets will accelerate. The National 13th Five-Year Plan Outline clearly proposes to increase consumption power, improve public consumption expectations, tap rural consumption potential, and focus on expanding household consumption. Steadily promote large-scale consumption of housing, automobiles and health care. At the same time, it is proposed to speed up the pace of new urbanization, accelerate the development of small and medium-sized cities and characteristic towns, improve the level of socialist new rural construction, and strive to narrow the gap between urban and rural development and promote the integration of urban and rural development. With the promotion of the urbanization process in the country, the traffic environment in the second and third tier cities has improved, the population is concentrated, and the income of residents has increased. At the same time, the first-tier cities have gradually entered the stage of upgrading, which will generate huge demand for the automobile market and lead the Chinese automobile industry. A round of growth.At present, China's auto market has entered a second stage of growth, and the market focus extends from first-tier cities to second- and third-tier cities with greater development potential. China's current 1,000-person car ownership has just exceeded 100 vehicles, which is a huge difference from the US's nearly 800 vehicles. This means that China's auto market potential is still huge. With the continuous development of the economy and society and the acceleration of urbanization, China's automobile consumption will Growing.Continuous improvement of highway transportation infrastructureIn recent years, China's highway transportation infrastructure has been continuously improved. From 1998 to 2015, China's highway mileage increased from 1,278,500 kilometers to 4,457,300 kilometers, with an average annual compound growth of about 7.79%; among which the expressway increased from 0.87 million to 12,350 kilometers, which is a large-scale automobile in urban and rural areas. The application laid the foundation. The continuous expansion of the road network, especially the expressway network, has promoted the increase in demand for automobiles and provided a favorable development environment for auto parts manufacturers.(3) The global procurement strategy of vehicle manufacturers also provides new opportunities for domestic auto parts suppliers.Affected by the international financial crisis in 2008, cost control has become the mainstream strategy of vehicle manufacturing enterprises, and global parts procurement has become one of its important measures. The global procurement and centralized procurement strategies implemented by vehicle manufacturers have brought new market opportunities to domestic excellent auto parts manufacturers. At present, China has become a global auto parts production base. With the upgrading of products and the improvement of synchronous development capabilities, the share of China's component manufacturing enterprises in the global auto parts market will further increase.(4) Opportunities brought by the state's policy on maintaining normal competition order in the marketDue to the continuous “high zero ratio” of imported cars, in September 2014, the Ministry of Communications and other 10 ministries and commissions issued the “Guiding Opinions on Promoting the Transformation and Upgrade of the Automobile Maintenance Industry and Improving the Service Quality”, and proposed to break the monopoly of auto repair parts. Specific methods: “Breaking the monopoly of repair parts channels, encouraging original parts manufacturers to provide original parts and independent after-sales parts with independent trademarks to the aftermarket.” “Protect all maintenance companies and owners to enjoy the right to use the same parts to repair cars. ". The impact of the above guidance on international parts companies will promote the international vehicle joint venture to strengthen the localization strategy of auto parts production, bringing opportunities for domestic auto parts enterprises. (Article from reprint!)