Zirconia Nanopowder: A New Material for "Behind" 5G Mobile Phone

Source: Science and Technology Daily: The traditional production process of zirconia powder will produce a large amount of waste, especially the large amount of low-concentration alkaline wastewater which is difficult to treat, causing serious environmental pollution. High-energy ball milling is an energy-saving and efficient material preparation technology, which can improve the compactness and dispersibility of zirconia ceramics and has a good industrial application prospect.With the advent of 5G technology, smart phones are quietly changing their own "equipment". 5G communication uses the spectrum above 3 gigahertz (Ghz), and its millimeter wave wavelength is very short. If the 5G mobile phone uses a metal backplane, it will seriously interfere with or shield the signal. Therefore,Ceramic materials with the characteristics of no signal shielding, high hardness, strong perception and excellent thermal performance close to metal materials have gradually become an important choice for mobile phone companies to enter the 5G era. Bao Jinxiao, a professor at Inner Mongolia University of Science and Technology, told reporters that as an important inorganic nonmetallic material, new ceramic materials have become the best choice for smart phone backboard materials.In the 5G era, mobile phone backboard needs to be upgraded urgently. Wang Sikai, general manager of Inner Mongolia Jingtao Zirconium Industry Co., Ltd. (hereinafter referred to as Jingtao Zirconium Industry), told the reporter that according to the data released by Counterpoint, a world-renowned research institution, the global smartphone shipments will reach 1.331 billion units in 2020. With the increasing demand for zirconia ceramics used in mobile phone backboards, its R&D and preparation technology has also attracted much attention.As a new ceramic material with extremely high technical content, zirconia ceramic material can be competent for the harsh working environment that metal materials, polymer materials and most other ceramic materials are not competent for. As structural parts, zirconia ceramic products have been applied in many industries such as energy, aerospace, machinery, automobile, medical treatment, etc., and the global annual consumption is over 80,000 tons.With the advent of the 5G era, ceramic devices have shown greater technological advantages in making mobile phone backboards, and zirconia ceramics have a broader development prospect. "The performance of zirconia ceramics directly depends on the performance of powders, so developing controllable preparation technology of high-performance powders,It has become the most critical link in the preparation of zirconia ceramics and the development of high-performance zirconia ceramic devices. "Wang Sikai said frankly. Green high-energy ball milling method is highly sought after by experts. Domestic production of zirconia nano-powder mostly adopts wet chemical process, and rare earth oxide is used as stabilizer to produce zirconia nano-powder.This process has the characteristics of large production capacity and good uniformity of chemical components of products, but the disadvantage is that a large amount of waste will be produced in the production process, especially a large amount of low-concentration alkaline wastewater which is difficult to treat, and if not handled properly, it will cause serious pollution and damage to the ecological environment. "According to the survey,It takes about 50 tons of water to produce one ton of yttria-stabilized zirconia ceramic powder, which will produce a large amount of wastewater, and the recovery and treatment of wastewater will greatly increase the production cost. "Wang Sikai said. With the improvement of China's environmental protection law, the enterprises preparing zirconia nano-powder by wet chemical method are facing unprecedented difficulties.Therefore, there is an urgent need to develop a green and low-cost preparation technology of zirconia nano-powder. "Against this background,It has become a research hotspot to prepare zirconia nano-powder by cleaner and lower energy consumption production process, among which the high-energy ball milling method is the most sought after by the scientific and technological circles. "Bao Jin's novel. High-energy ball milling refers to the use of mechanical energy to induce chemical reactions or to induce changes in the structure and properties of materials, so as to prepare new materials. As a new technology,It can obviously reduce the reaction activation energy, refine the grain size, greatly improve the distribution uniformity of powder particles, enhance the interface combination between substrates, promote the diffusion of solid ions and induce low-temperature chemical reactions, thus improving the compactness and dispersibility of materials. It is an energy-saving and efficient material preparation technology with good industrial application prospects.Unique coloring mechanism creates colorful ceramics. In the international market, zirconia nano-powder materials have entered the stage of industrial development. Wang Sikai told reporters: "In developed countries and regions such as the United States, Western Europe and Japan, the production scale of zirconia nano-powder is large and the product specifications are relatively complete. Especially American and Japanese multinational companies,It has obvious competitive advantages in the patent of zirconia ceramics. According to Wang Sikai, at present, China's new ceramic manufacturing industry is in a stage of rapid development, and the demand for ceramic powder is increasing year by year, so it is more and more urgent to develop the production process of new nanometer zirconia. In the last two years,Some domestic research institutes and enterprises have also started to independently research and produce zirconia nano-powder, but most of the research and development is still in the stage of small-scale trial production in the laboratory, with small output and single variety. In the project of "Color Rare Earth Zirconia Nanopowder" implemented by Ceramic Zirconia Industry, zirconia nanopowder was prepared by high-energy ball milling solid-state reaction method."Water is used as grinding medium to grind and refine the particles, so that non-agglomerated grain powder with a size of 100 nanometers can be obtained, which has no pollution, low cost and good batch stability." Bao Xin said. The preparation technology can not only meet the powder requirements of 5G mobile phone ceramic backboard, thermal barrier coating materials for aviation turbine engines, ceramic balls, ceramic knives and other products,But also can be popularized and applied in the preparation of more ceramic powders such as cerium oxide composite powder preparation. According to the self-developed coloring mechanism, the technical team of Ceramic Zirconium Industry adopted solid-phase synthesis and composite method for coloring without introducing extra metal ions through process optimization.The zirconia ceramics prepared by this method not only have high color saturation and good wettability, but also do not affect the original mechanical properties of zirconia ceramics. "The original particle size of the color rare earth zirconia powder produced based on the new technology is nanometer, which has the characteristics of uniform particle size, high sintering activity, low sintering temperature and so on. Compared with the traditional production process, the comprehensive energy consumption is significantly reduced.Production efficiency and ceramic processing yield are greatly improved. The advanced ceramic devices prepared by this method have excellent properties such as high strength, high toughness and high hardness. "Wang Sikai said.