Superhard materials: leading the development of high-end manufacturing


Super hard materials and products represented by diamond are known as "the most rigid and sharp industrial teeth". In the fields of aerospace, defense industry, photovoltaic and electronic information, all kinds of difficult material processing problems are solved.

In the eyes of scientists, single crystal diamond is not only "industrial teeth" or "ultimate semiconductor". At the Symposium on the development of China's superhard materials industry held on July 17, some experts even said that "without diamond, there would be no information industry".

As a new material, superhard materials are leading the development of high-end manufacturing industry in China.

It is expected to trigger a new generation of semiconductor technology revolution.

According to Gan Yong, director of the National Consultative Committee of Experts on the Development of New Material Industry and former Vice-President of the Chinese Academy of Engineering, superhard materials are an important and unique sector in the field of new materials and have been widely used in the national economic construction.

"Industrial teeth" is well deserved. Taking the diamond turning tool as an example, the radius of its edge arc can be grinded to such a degree that it can not be detected by scanning electron microscopy (SEM).

"With the mechanical properties of diamond superhard, all known materials in the world can be machined." Li Zhihong, senior consultant of the Superhard Materials Branch of China Machine Tool Industry Association, told the China Science Journal, "Using its unparalleled thermo-opto-acoustic and electrical properties, it can be used for cosmic ray protection of astronauts, stealth and anticorrosion of sophisticated weapons and equipment, improving missile flying speed and striking accuracy, and high-power laser detection. As a leading area of large-scale integrated circuits and LED new light source heat sink. "

Some cell phones get hot as soon as they hit, and they don't work when the temperature is high because their semiconductor components don't withstand high temperatures. Single crystal diamond, which combines electrical, optical, mechanical, acoustic and thermal characteristics, will solve this problem.

Compared with other semiconductor devices, diamond electronic devices have the advantages of small size, high integration and no refrigeration. Zhang Tao, a professor of materials science and engineering at Beijing University of Aeronautics and Astronautics, believes that diamond will revolutionize a new generation of semiconductor technology.

The cutting-edge material of "obscurity"

"Superhard materials are indispensable high-functional materials in strategic emerging industries such as oil exploration and mining, machine tool machinery and automobile manufacturing, rail transit, nuclear power, defense, military and aerospace major projects, and photovoltaic and electronic information." Gan Yong said.

However, apart from the industry, these are not known to people. Zhang Tao quipped: "the most advanced material is also" obscurity "material.

By the end of 2017, China's synthetic diamond production has accounted for more than 90% of the world's total output, cubic boron nitride production has accounted for more than 70% of the world's total, China has become a real superhard material production and manufacturing power.

Although the quality and technology of superhard materials in China have reached the advanced level in the world on the whole, Gan Yong admits frankly that "there are still short boards in some high-end industries".

For example, in the field of cemented carbide bar grooved grinding wheel, the high-end market is basically monopolized by the United States, Japan, Germany and other developed countries. Although domestic superhard grinding wheel preparation technology has been developing, the contradiction between sharpness and shape preservation of grinding wheel is still a big problem.

"Small quantity, variety of products, enterprises do not want to do, but short boards are often in these places." Tian Yongjun, academician of the Chinese Academy of Sciences, bluntly said.

This challenges the innovative vitality and sustainable development of the superhard material industry. To this end, Tian Yongjun said that while the state attaches importance to scientific research, it should also tilt to related industries. Importing high-end frontier is not feasible.

Mentougou pyrophyllite

The development of any material is inseparable from the support of raw materials. Pyrophyllite is an irreplaceable medium for insulation, insulation, sealing and pressure transmission in the production of superhard materials.

Beijing Mentougou pyrophyllite belongs to high-alumina type. Its greatest characteristic is that its adiabatic and compressive properties are superior to domestic similar ores at high temperature, and its physical and chemical properties are more stable. Therefore, it is widely used in synthetic diamond manufacturing, accounting for more than 98% of the industry.

"Mentougou pyrophyllite has made an indelible contribution to the start, development and expansion of China's superhard materials industry," said Wang Mingzhi, a researcher at the School of Materials Science and Engineering of Yanshan University. "We hope to continue to uphold the concept of green, environmental protection and sustainable development and make greater contributions to the development of China's superhard materials industry in the new era. Contribution, for the development of national strategic emerging industries to make greater contributions to achieve the "Made in China 2025" national strategic ives to make greater contributions.