High-strength high-modulus carbon fiber has a series of advantages such as high specific modulus, small thermal expansion coefficient, and stable dimensions. It is an irreplaceable key material for the main structure, functional structure and protective structure of satellites and spacecraft. The Special Fiber Division of Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences has long been committed to the research and development of domestic high-performance carbon fiber technology. In February 2016 and March 2018, it has achieved breakthroughs in domestic M55J and M60J high-strength and high-modulus carbon fiber preparation technology. Based on the serial preparation technology of domestic high-strength and high-modulus carbon fiber, the Specialty Fiber Division conducted in-depth research on basic scientific issues in the field of microstructure-macro performance correlation of domestic M55J high-strength and high-modulus carbon fiber. The cross-section of the domestic M55J high-modulus carbon fiber is regularly round, while the Toray M55J carbon fiber is waist-shaped (Figure 1). Further research on the evolution mechanism of the characteristic structure of the fiber graphite during high-temperature graphitization revealed that the tensile modulus and Raman spectrum of the high-mode carbon fiber The half-height width of D peak of medium disordered structure and G peak of graphite characteristic structure has a certain functional relationship. The smaller the half-width value of D peak and G peak, the higher the tensile modulus of the fiber. At the same time, the tensile strength of domestic M55J carbon fiber is up to 4.86GPa, significantly higher than 4.02GPa of Toray M55J carbon fiber, combined with this performance difference for its microstructure study found that graphite microcrystalline layer spacing and crystallite orientation are the key factors affecting the tensile strength of high modulus carbon fiber, domestic M55J high modulus The spacing between carbon fiber and Toray M55J carbon fiber graphite crystallite layer is the same, but the domestic M55J high modulus carbon fiber has a higher graphite crystallite orientation ( 2), highly oriented graphite crystallites described structure is advantageous to improve the tensile strength and high modulus of carbon fibers. The research results of this series were published in Composites Part A: Applied Science and Manufacturing. 2018, 112: 111-118; Journal of Raman Spectroscopy, 2019, doi.org/10.1002/jrs.5569 and other journals. In addition, for basic research on the impact of polyacrylonitrile preoxidized fiber body density and element content, low-high temperature two-stage graphitization on the performance of high-modulus carbon fiber, the Special Fiber Division recently applied for 5 national invention patents (application number 201810536653 .x; 201810431103.1; 201810431101.2; 201810339670.4; 201810311440.7), 2 authorized utility model patents (201820826573.3; 201820536161.6). This series of research work was funded by the key project of the field fund of the Ministry of Equipment Development (6140922010103) and the pilot project of the Chinese Academy of Sciences (XDA17020405). Free Energy Magnet Motor ,Simple Magnetic Motor ,Permanent Magnet For Servo Motor,Permanent Magnet For Servo Motors Ningbo Besten Magnet Co., Ltd. , https://www.bestenmagnets.com
Figure 1 Comparison of the cross-sectional morphology of domestic M55J high modulus carbon fiber and Toray M55J fiber 
Figure 2 Comparison of graphite crystallite orientation between domestic M55J high-modulus carbon fiber and Toray M55J fiber