New material technology

Introduction

New materials are classified according to the properties of the materials, including metallic materials, inorganic non-metallic materials (such as ceramics, gallium arsenide semiconductors, etc.), organic polymer materials, and advanced composite materials. Big category. According to the performance of materials, there are structural materials and functional materials. Structural materials mainly use the mechanical and physical and chemical properties of materials to meet the performance requirements of high strength, high stiffness, high hardness, high temperature resistance, wear resistance, corrosion resistance, and radiation resistance; functional materials mainly use the electrical and magnetic properties of the material. , Sound, light, heat and other effects to achieve certain functions, such as semiconductor materials, magnetic materials, photosensitive materials, thermal materials, stealth materials and nuclear materials for the manufacture of atomic bombs and hydrogen bombs. New materials play an important role in national defense construction. For example, the successful development of ultrapure silicon and gallium arsenide led to the birth of large-scale and very large-scale integrated circuits, which increased the computing speed from hundreds of thousands of operations per second to more than tens of billions per second; Increasing 100°C can increase thrust by 24%; stealth materials can absorb electromagnetic waves or reduce the infrared radiation of weapons and equipment, making it difficult for enemy detection systems to detect, and so on.

New material technology is called "Mother of Invention" and "Industrial Food".

Development direction

The development of new material technology not only promotes the revolution of information technology and biotechnology, but also has a significant impact on manufacturing, material supply and personal lifestyle. The reporter recently interviewed relevant experts from the "High-tech Development Report" research group of the Chinese Academy of Sciences, and asked them to introduce the current research progress and development trend of new material technology in the world. The advancement of material technology has made "lab on a chip" possible, which has greatly promoted the development of modern biotechnology. The development of new materials technology has given new connotations and broad development space to materials science.

New material technology is developing nanomaterials in the direction of developing and producing smaller, smarter, multifunctional, environmentally friendly and customizable products and components. In the 1990s, the world gradually set off research on nanomaterials. upsurge. Because nanotechnology has fundamentally changed the manufacturing methods of materials and devices, nanomaterials exhibit many characteristics that conventional materials do not possess in terms of magnetic, optical, and electrical sensitivity, and have broad application prospects in many fields. Experts predict that the research and development of nanomaterials will be a technological revolution, which will cause another industrial revolution in the 21st century.

Japan's Mitsui & Co., Ltd. once announced that the company will mass produce carbon nanotubes. Since April 2002, it will build production equipment with an annual output of 120 tons. It will be put into trial production in September. This is the world's first mass production. Low-priced nano products. Researchers from the American ibm company, in April 2001, made the first transistors using carbon nanotubes. This technology breakthrough that uses the wave properties of electrons instead of conventional wires to transmit residences may lead to faster and more rapid changes. The emergence of small products may cause the existing silicon chip technology to be gradually eliminated.

While the research of carbon nanotubes is in the ascendant, the new star of the nanometer industry-"Nanobelt" has come out again. Three Chinese scientists working at Georgia Institute of Technology in the United States used high-temperature gas solid-phase method to synthesize semiconductor compound nanoribbons for the first time in the world in early 2001. This is another breakthrough in the field of one-dimensional nanomaterial synthesis since the discovery of multi-walled carbon nanotubes and the synthesis of single-walled nanotubes.

The cross-section of this nanobelt is a narrow rectangular structure, with a bandwidth of 30-300mm, a thickness of 5-10nm, and a length of up to several millimeters. It is the only one synthesized so far that has a controllable structure and Defect-free broadband semiconductor quasi-one-dimensional band structure. Nanobelts of materials such as tin oxide, indium oxide and oxide spacer have been successfully synthesized. Since the semiconductor oxide nanoribbons overcome the instability and internal defects of carbon nanotubes, they have more unique and superior structure and physical properties than carbon nanotubes, so they can be put into industrial production and commercial development earlier.

Superconducting materials Superconducting materials have a huge market in the fields of motors, transformers and maglev trains. For example, the use of superconducting materials to make motors can increase the limit output by 20 times and reduce weight by 90%. The key to the development of superconducting materials is to increase the critical temperature of the material. If this problem is solved, it will cause major changes in many fields. Scientists have made a lot of new achievements in superconducting materials, and have successively discovered new superconducting materials with improved critical temperature, which has enabled mankind to take a big step towards the development of room temperature superconducting materials.

In Japan, it was discovered that magnesium diboride can become a superconductor at -234°C. This is the metal compound superconductor with the highest critical temperature found so far. Because of the discovery of magnesium diboride, the world condensed matter physics community is excited about it. Since magnesium diboride superconductors are easy to synthesize and process, and can be easily made into films or wires, their application prospects are promising.

American scientists have made significant progress in the development of more practical superconducting materials and have begun to enter the practical stage. More than 360 meters of superconducting cables have been laid underground at the Forrestby Power Station of the American Substrate Law. The 123kg wire in the cable is made of superconducting porcelain containing bismuth, strontium, calcium, and copper oxides. This is the world's first practical superconducting transmission line.

my country has also made major breakthroughs in the industrialization of high-temperature superconducting technology, and high-temperature superconducting wire rod production lines have been put into operation. It is estimated that there may be a market of 100 billion US dollars for superconducting products by 2010. However, it should be pointed out that in addition to superconducting materials, there are still many supporting technologies that need to be solved, and at the same time continue to research and develop high-temperature superconductors, such as room temperature superconducting materials.

High-performance structural materials High-performance structural materials have the advantages of good high-temperature strength, wear resistance, and corrosion resistance. High-temperature structural ceramic materials are being developed such as silicon carbide, silicon oxide, silicon nitride, borides, toughened zirconia ceramics and fiber-reinforced inorganic synthetic materials. For example, replacing metals with ceramics in internal combustion engines can reduce fuel consumption by 30% and increase thermal efficiency by 50%.

High-performance composite materials can be designed according to requirements, which can make the material avoid the shortcomings. Current research focuses are: fiber reinforced plastics, carbon/carbon composite materials, ceramic matrix composite materials and metal matrix composite materials. Polymer functional materials are the fastest growing organic synthetic materials in recent years, with an annual increase rate of 14%. In addition, American scientists have also discovered a compound that can be combined with glass. This silane compound can stick to the surface of phosphate glass to form a single molecular layer and a multi-molecular layer, thereby protecting the glass surface and reducing corrosion to a minimum. This discovery is of great significance for improving the corrosion resistance of glass.

With the advancement of science and technology, the scope of new materials has been opened up, and the development of new materials in a higher and newer direction has been promoted. The chemical industry produces a large number of new chemical materials to provide technical support for the development of new materials. At the same time, the development of new materials can also promote the technological progress of the chemical industry and changes in the industrial structure.

The development and application of high-performance structural materials have provided a material basis for the large-scale, high-efficiency, high-parameter, and multi-functionalization of some chemical machinery and equipment, which can meet the high-tech requirements of chemical production. It is possible to realize some chemical processes. Nanomaterials can be widely used in the chemical industry and are the most promising materials used in a variety of chemical sensors. Looking forward to the 21st century, the rapid development of new material technology will surely bring a better future to our lives.

Research Trends

Currently, the United States, Europe, Japan and other developed countries and regions attach great importance to the development of new materials and technologies, and all regard the development of new materials as an important part of their technological development strategies. When formulating the national science and technology and industrial development plan, new material technology is listed as one of the key technologies that will be prioritized for development in the 21st century, and development will be given priority to maintain its leading position in economy and technology.

The development of China's new material technology and industry, with the government's strong care and support, has also made significant progress and achievements, providing strong support for the national economy and social development.

In order to study the development status and trends in the field of new materials in my country, this report uses the China Journal Network database as the source of statistical analysis and conducts analysis and research from the perspective of bibliometrics. It discusses new materials including superconducting materials, The content of theoretical research, preparation technology, product application, technical equipment, etc. of metallic materials, non-metallic materials, polymer materials and composite materials.

Total analysis

According to statistics, a total of 15,866 papers were published in the field of new materials in my country in 2000, which increased to 27,278 in 2005, an increase of 11,412 papers, an increase of 71.9%. Among them: the number of papers published from 2000 to 2002 increased at a rate of more than 2,000 per year, with an increase rate of more than 13%; from 2003 to 2004, although the total number of papers increased, the growth rate slowed down. An increase of 7.72% compared to 2002, and an increase of only 4.09% in 2004 compared to 2003; but by 2005, the number of published papers has increased significantly, reaching 4,512, an increase of 19.82%, showing an accelerated growth trend. Generally speaking, from 2000 to 2005, the number of papers published in the field of new materials in my country has fluctuated and has an accelerating trend.

Structural analysis

1. Annual changes in the output weights of new materials in each specialty

From 2000 to 2005, the number of new materials published in each specialty Although the proportion of new materials in the entire field of new materials changes every year, the overall distribution pattern has not been broken. Except in 2001 and 2002, polymer materials accounted for less than 50%, and the other years were above 50%, always occupying a dominant position; composite materials accounted for between 20-30%, ranking second ; Non-metallic materials accounted for more than 10%, ranking third; superconducting materials accounted for the smallest proportion in the entire material field, ranking the last of the five majors.

Analyzed from the development status of various majors, the development of superconducting materials fluctuates up and down, with an overall downward trend; as a traditional advantage field, the development of metal materials has shown a sharp decline; non-metal materials Basically maintain a stable situation in the entire material field, and its proportion has not changed much; polymer materials is the fastest-growing subject, and with the continuous emergence of new technologies, its weight in the entire new material field has fluctuated and increased. Except for the increase in 2002, composite materials have declined year by year in other years, but the decline is not large, with an average annual decrease of 1%.

2. Annual changes in the number of papers published in each specialty of new materials

From 2000 to 2005, judging from the number and growth rate of papers published in each specialty of new materials, superconducting materials The number of papers published showed a positive and negative growth pattern, but the total amount showed a downward trend, with a decrease of about 10%; the number of papers published on metal materials showed a negative growth, from 1,614 papers in 2000 to 254 papers in 2005, with a total decrease of up to 84%; The general trend of the number of published papers on non-metallic materials is steadily increasing, and by 2005 there was an accelerated growth trend. The number of published papers increased by 1,527 from 2000, an increase of 29.3% that year, and an overall increase of 66.65% in the past 6 years. ; The number of papers on polymer materials is also increasing, from 8,201 in 2000 to 15,895 in 2005, a total increase of 93.3%, almost doubled; the publication of composite materials shows a fluctuating situation, compared with 2001 There was a significant increase in 2000, but there was a negative increase from 2003 to 2004, and it increased to 7,215 in 2005, nearly double the 3,672 in 2000.

Conclusion

1. The overall development speed of the new materials field is relatively fast and the momentum is strong

Materials are the three pillars of the current world’s new technological revolution (materials, information , Energy). Together with information technology and biotechnology, it constitutes one of the three most important and most promising areas in the world in the 21st century. The ability to understand and use materials often determines the shape of society and the quality of human life. The history of mankind has proved that materials are the material basis and forerunner of the development of human society, and new materials are milestones in the progress of human society. New materials play an important role in developing superb technology, transforming and upgrading traditional industries, and enhancing comprehensive national strength and national defense capabilities. They are also developing faster and more importantly in the fields of natural science and engineering technology. According to the statistics of the number of papers published in the same period, the average annual growth rate of the number of domestic papers published in the field of new materials in the past 6 years was 9.15%, which was greater than the 8.34% growth rate of papers published in the fields of natural sciences and engineering technology; papers published in the field of new materials accounted for natural sciences The proportion of papers published in the field of engineering technology has also maintained a rising trend, increasing by 0.13 percentage points in 6 years.

The development and changes in the field of new materials benefit from technological innovation and the acceleration of the transformation of achievements. Breakthroughs in cutting-edge technology have led to the emergence of new materials industries. At the same time, the integration of new materials with industries such as information, energy, medical and health, transportation, and construction has become increasingly close. Governments of various countries attach great importance to the development of the new material industry, formulate relevant plans to promote the development of the new material industry and science and technology, and provide strong financial support, which has promoted the improvement and development of technological innovation capabilities in this field, and has achieved a series of gratifying achievements. The research results ensure a thriving situation in the development of new materials.

2. The rapid development of polymer materials and composite materials

2.1 The new application fields of polymer materials have promoted their own growth

The fastest-growing organic synthetic materials, especially in biomedical materials, drug controlled release systems, orthopedic fixation, tissue engineering, and surgical sutures, continue to expand their new application fields. The world only uses polymer materials in medicine. There are more than 90 varieties and more than 1,800 kinds of products, and the medical consumption of polymer materials in Western countries is increasing at a rate of 10-20% every year. The development of my country's polymer materials is also very rapid. From 2000 to 2005, the number of papers published increased from 1,862 to 6,640, an increase of 256.61% in 6 years. Among them: papers on polymer drugs increased from 182 to 802, an increase of 340%; papers on medical polymer materials increased from 285 to 821, an increase of 188%; papers on bionic polymer materials increased from The number of papers increased from 416 to 1,108, an increase of 166%, and the number of papers on polymer membrane materials increased from 979 to 3909, an increase of 299%. From the above data, it can be seen that the research and development of polymer materials is active, and the development is quite rapid. It has become an indispensable part of medicine and biotechnology, and it is also the fastest growing profession in the field of new materials.

2.2 Composite functional materials expand new development space

Due to the interdisciplinary and fusion of multiple materials, the compounding of materials has become an important means for the development of new materials. useThe composite of multiple matrixes and reinforcements, multiple levels of composite, and the use of nonlinear composite effects can create materials with brand-new properties. In recent years, advanced composite materials and new processes have developed rapidly. The development of composite materials is mainly based on resin-based composite materials, especially thermoset materials. Its technology is the most mature and the most widely used. Metal matrix composite materials are mostly in the research and development stage, and they are especially suitable for building space structures.

Ceramic matrix composites are an important way to improve the reliability of ceramics, so that the excellent high-temperature performance of ceramic materials can be applied. In addition, carbon/carbon composite materials have great practical value in military technology, and have been applied to a certain extent, and their development trend is relatively fast. Judging from the publication of composite functional materials papers in my country from 2000 to 2005, the number has increased from 3,672 to 7,215, a total increase of 96.49% in 6 years. Among them: metal matrix composites papers increased from 573 to 611 papers, an increase of 6.6%; ceramic matrix composites papers increased from 298 to 1050 papers, an increase of 252%; cement-based composites papers increased from 1,533 to 2,428, an increase of 6.6% 58.3%; the number of papers on polymer-based composites increased from 1134 to 2,383, an increase of 110%; the number of papers on carbon-based composites increased from 134 to 743, an increase of 454%. It can be seen from the research and analysis that the rapid development of ceramic matrix composite materials and polymer matrix composite materials is closely related to the continuous emergence of new processes, new materials and new formulas. Carbon-based composite materials are also shifting from military to civilian use. Its development is growing rapidly.

2.3 The development of metal materials is at a low point and needs to be broken through

Compared with the rapid development of polymer materials, composite materials and non-metal materials, the development of metal materials with a long history is stagnant or even From 2000 to 2005, the number of papers published on metal materials in my country decreased from 1,614 to 254, a decrease of 535%. This phenomenon shows that our technological innovation ability in this field is insufficient. At present, many new features and growth points have emerged in the development of the world's metal materials field, and high-performance metal materials are developing rapidly. There are many problems in the development of high-performance metal materials, processing and molding technology, and production equipment in my country, which hinder the development of metal materials. Therefore, as long as the technological innovation of metal materials is increased, the stagnant development of metal materials will definitely be broken, and new revitalization and rapid development will be just around the corner.