News on China's scientific and technological development.

The demand for silicon carbide (SiC) ceramic structural parts in various new application scenarios is gradually increasing, including large-sized and complex-shaped SiC ceramic nuclear reactor cores in the nuclear industry; SiC ceramic workpiece tables and guide rails for photolithography machines, key equipment for integrated circuit manufacturing , reflectors, ceramic suckers, arms, etc.; mid-to-high-end precision SiC ceramic structural parts for new energy lithium battery production; high-end precision SiC ceramic structural parts for diffusion furnaces used in photovoltaic industry production and precision high-purity SiC for high-end electronic semiconductor chip production processes Ceramic structural parts. However, because SiC is a covalently bonded compound with a strong Si-C bond, its hardness is second only to diamond. It has extremely high hardness and significant brittleness, making precision machining difficult. Therefore, it is difficult to prepare large-sized, complex special-shaped hollow structure precision SiC structural parts, which limits the wide application of SiC ceramics in high-end equipment manufacturing fields such as integrated circuits. 3D printing technology can effectively solve this problem. 3D printing SiC ceramic preparation technology has become one of the main development directions of current SiC ceramic research and application. At present, 3D printed SiC ceramics are mainly reaction-sintered SiC ceramics. Most of the densities are lower than 2.95g·cm -3 and the silicon content is usually greater than 30vol% or even as high as 50vol%. Since the melting point of silicon is lower than 1410°C, its use temperature is low. , which greatly limits the application scenarios of 3D printed SiC ceramics in the semiconductor field (such as LPCVD).



Based on the early proposal of high-temperature fused deposition combined with reaction sintering 3D printing SiC ceramics ( additive manufacturing , 2022, 58, 102944), researcher Chen Jian from the team of researcher Huang Zhengren of the Shanghai Institute of Ceramics, Chinese Academy of Sciences , further made the ceramic printing body equivalent to carbon The density increases from 0.80 g·cm -3 to close to the theoretical equivalent carbon density of 0.91 g·cm -3 . The increase in equivalent carbon density leads to an exponential increase in the difficulty of siliconization. Direct liquid phase siliconization can easily block the channel and cause siliconization failure. . Recently, the research team proposed a sequential siliconization method that combines gas phase and liquid phase siliconization to form a porous SiC shell through the gas phase infiltration reaction to avoid rapid and violent reactions of high carbon density ceramic printing bodies in the early stage of liquid phase siliconization, and at the same time limit the The contact area between liquid silicon and solid carbon prevents the infiltration channel from being blocked, allowing the subsequent liquid phase reaction to proceed slowly and continuously. The density of the finally prepared SiC ceramics can reach 3.12 g·cm -3 , the silicon content is reduced to about 10vol%, the flexural strength and elastic modulus reach 465MPa and 426GPa respectively, and the mechanical properties are equivalent to those of solid-phase sintered SiC ceramics under normal pressure. Greatly improve the ambient operating temperature of SiC ceramics. Relevant research results were published in J. Eur. Ceram. Soc. (doi.org/10.1016/j.jeurceramsoc.2023.09.059), and applied for 2 Chinese invention patents, one of which has been authorized (ZL202211260158.3). The paper ranked first The authors are Li Fanfan, a master's degree graduate from Shanghai Institute of Ceramics, and Zhu Ming, a doctoral graduate. The corresponding authors are Researcher Chen Jian and Researcher Huang Zhengren. Relevant research has been funded and supported by the National Key Research and Development Program, the National Natural Science Foundation of China, and the Shanghai Natural Science Foundation of China.​

All this "tech war" started back in 2012-2014 when every single mainstream tech media was hying up 5G as the next revolutionary sh*t then a group of know nothing think tankers who give themselves the job of speaking for industries that they have never worked before started hyping up the "Huawei Threat" because, they said, 5G will be everywhere from fully autonomous cars to gaming cloud streaming to robotic surgery. Well looks like the 5G bubble popped, but still a US intelligence agencies driven campaign against Huawei had cost countries, consumers and companies billions with not added benefit, when Huawei survived, then the 5G war mutated into the semiconductor war in the Trump administration, that had cost companies billions more with the added benefit of disrupting the semiconductor industry in a really bad way from shortages to panic oversupply to unwanted competition and that one is being driven by AGAIN by the same damn humanities graduates think tankers in Washington hyping the "AI threat" because the current AI bubble and that one being driven by the rise of the Chat Bots, we can debate if current chatbot craze is a bubble or not, but what is less debatable is that the real economic benefits are somehow far to been seen.

​