Break through the trillion-level Market of magnesium-based Materials with Innovation-- an interview with Pan Fusheng, Deputy to the National people's Congress and Academician of the Chinese Academy of Engineering

The importance of magnesium and magnesium alloys has attracted more and more attention all over the world. In recent years, China Baowu Group, Chinalco Group, Qinghai Salt Lake and other national super-large leading enterprises actively participate in and help the development of China's magnesium industry, which has become an important force in the development of China's magnesium industry. The National magnesium Alloy Materials Engineering and Technology Research Center of Chongqing University actively cooperates with these large enterprises to participate in the research and development of major national projects and become an important research and development base for the development of magnesium alloys. The international journal "Journal of magnesium and alloys" sponsored by Chongqing University has an impact factor of 7.115 in 2019, ranking second among similar journals in the world, showing China's important international influence in the field of materials.

At the same time, countries all over the world attach great importance to the revision and publication of magnesium and magnesium alloy standards, and the magnesium industry is very active in the preparation and revision of ISO international standards and national standards. The number of magnesium and magnesium alloy researchers in the world has increased greatly, and a number of high-level papers have appeared in top journals such as Nature and Science. Many research directions in the field of magnesium-based materials in China have been at the forefront of the world.

In order to know more about the development direction and research results of China's magnesium industry, in mid-May, the reporter interviewed the deputy of the National people's Congress, academician of the Chinese Academy of Engineering, chairman of Chongqing Association of Science and Technology, professor of Chongqing University and consultant of China Nonferrous Metals newspaper. He introduced to the reporter the current development status, application potential and market prospect of magnesium and magnesium alloy materials. It makes people look forward to the development potential of mg-based materials.

Great achievements have been made in the research and development of magnesium alloy technology.

The National magnesium Alloy Research Engineering and Technology Center of Chongqing University is the earliest magnesium alloy research institute in China, which initially carries the development and promotion of major research and development projects of magnesium alloy materials in China. At present, it has become an important base for magnesium alloy research and development. Pan Fusheng said that in the development of magnesium alloy structural materials, Chongqing University has developed the alloy design theory of "solid solution strengthening plasticization of magnesium alloy", which has become a new way to solve the optimization of strength and plasticity balance of magnesium alloy. Based on the development and application of the theory of "solution strengthening and plasticization of magnesium alloys", Chongqing University has developed a number of high-performance magnesium alloys, more than 10 grades of which have entered international or national standards, in which the tensile strength of high-strength cast magnesium alloys exceeds 350 MPA, the elongation exceeds 10%, and the tensile strength of low-cost, low-rare earth-free and high plastic magnesium alloys reaches 425 MPA, and the elongation reaches 11%. The plasticity of low-cost magnesium alloys containing Mn is 52 per cent and that of magnesium alloys containing Li is 56 per cent.

In addition, using conventional equipment and technology, a batch of ultra-high strength magnesium alloys jointly developed by Chongqing University and Beijing University of Technology have a plasticity of about 10% and a strength higher than that of 550MPa. In addition, using special processing technology, high strength wrought magnesium alloy has been jointly developed with Central South University, with a tensile strength of more than 710MPa and a yield strength of more than 650MPa.

Based on the metal strengthening characteristics of Ti reinforced magnesium matrix composites, Chongqing University put forward a new principle of "particle strengthening and plasticizing" composite strengthening and toughening. The tensile strength, yield strength and elongation after break of the newly developed AZ91-5Ti composites are significantly higher than those of AZ91.

The research and development of materials has promoted the improvement of magnesium alloy preparation and processing technology. Pan Fusheng said: taking missile shells, large automobile wheels, tank load wheels and other accessories as objects, the cumulative large ratio forging technology and semi-open forging technology of high strength and toughness magnesium alloy have been developed to realize the unity of forming and performance of large magnesium alloy forgings. break through the technical bottleneck of coordinated control of strength and toughening performance and dimensional accuracy of large forgings. At present, a number of new preparation and processing technologies in China reflect important application prospects, for example, melt self-purification technology, electromagnetically assisted solidification technology, low temperature extrusion technology, on-line torsional extrusion technology, liner rolling technology, composite rolling technology, rotary forging technology and so on.

Pan Fusheng introduced to the reporter the recent major research achievements of domestic scientific research institutes, as well as major magnesium alloy promotion projects. He listed a number of new technologies and new processes: important progress has been made in the theory and technology of new magnesium alloy asymmetric processing technology (asymmetric extrusion and forging-extrusion integration, etc.) developed by Chongqing University; new breakthroughs have been made in magnesium alloy composite forging technology developed by Shanghai Jiaotong University, and magnesium alloy strip extrusion and rolling developed by Northeastern University and Chongqing University have begun to advance to industrialization. The directional residual stress relief technology developed by Beijing University of Science and Technology and Metal Research Institute of Chinese Academy of Sciences has a remarkable effect on the reduction of residual stress in thick plate products, and Xi'an Jiaotong University has formed a number of technical achievements in the preparation of high purity magnesium. Based on the modification of Ce elements, Shanghai Jiaotong University widened the corresponding processing parameters in the safe peak zone of the forging hot working map of magnesium-aluminum alloys, and put forward the instability criterion under different forging temperature and strain rate, which provided a basis for realizing high-strength magnesium-aluminum alloy forging with large deformation.

Expand the application space of magnesium-based structural materials

Pan Fusheng said that in terms of magnesium alloy structural materials, the increase in the original application fields and the expansion of new application fields are expected to double the output of magnesium alloy structural materials, and it may become a reality to break through the million tons within a few years. He said that the cooperation between Chongqing University and Baowu Group and Chinalco is being actively promoted. The demand for lightweight of automobiles, especially new energy vehicles, is becoming more and more urgent, and the application of magnesium alloy parts such as dashboard, central control bracket, battery box and so on is expected to increase greatly. Applications in the field of architecture, especially building formwork and movable buildings, are likely to become a new growth point of magnesium alloy structural materials. Pan Fusheng said that as far as building formwork is concerned, once a complete technological breakthrough is made, the annual application of magnesium alloy formwork may exceed one million tons, which is of great concern to the China Nonferrous Metals Industry Association and is actively promoting it. The functional characteristics of magnesium alloy structural materials are expected to promote the large-scale application of magnesium alloy structural materials in the information industry, military industry, aerospace, petrochemical and other fields, especially soluble magnesium alloys have a large application market in the field of oil and gas. As a new field of metal matrix composites, the development and application of magnesium matrix composites may have an important impact on the global metal matrix composite industry.

Break through the technological innovation of mg-based functional materials

Pan Fusheng said that in the field of magnesium-based functional materials, magnesium-based biomaterials and magnesium-based energy storage materials have broad prospects. Magnesium alloy biomaterials are advancing to the application field, and the characteristics of good biocompatibility and biodegradability provide a new way for the development and application of new generation biomaterials, and the application market is expected to reach more than 100 billion yuan. Chongqing University, in cooperation with Sichuan University and related companies and application units, is actively promoting industrial application. As a new generation of energy storage materials, magnesium-based hydrogen storage materials and magnesium batteries have begun to attract widespread attention at home and abroad. Once successful, it is possible to achieve a subversive revolution in the field of energy storage. Mg-based hydrogen storage materials have the advantages of high volume hydrogen storage density, low working pressure and good safety in metal hydrogen storage materials, which is expected to provide a new way to solve the storage and transportation bottleneck of hydrogen energy industry, especially hydrogen vehicles. Magnesium battery has the characteristics of rich resources, high energy density and good safety, which plays an important role in improving the safety of secondary battery, reducing the cost of secondary battery and alleviating the pollution of secondary battery. Once the technological breakthrough, the market capacity of magnesium-based energy storage materials can reach more than one trillion yuan. In the field of magnesium-based hydrogen storage materials and magnesium batteries, Chongqing University has built a research team of more than 30 people and formed a number of original technologies.