Design And Mechanical Properties Characterization Of Epoxy Composite Material Used For Crygenic Field

Cryogenics is filled with all aspects of our society, and not only related to our lives, but also plays an important role in cutting-edge fields.Important projects of Many countries and the world are related to the research and application of cryogenic technology,such as aviation, aerospace, energy, transportation and medical, etc.Carbon fiber reinforced resin matrix composite material with its high specific strength and specific modulus characteristics gradually become the main research spacecraft materials research, and is that other materials can not hold a candle in reducing the weight of the structure, improving the structural efficiency, etc.But in hydrogen oxygen and other ultra-low temperature environment, the overall composite structure is subjected to a severe test environment.Because its structure and properties of the material are a far cry from traditional materials, the evaluation of the composite’s mechanical properties in ultra-low temperature is very important.Through the molecular structure design, this paper selects cyanate ester resin with low viscosity modified TDE-85 epoxy resin, and the epoxy resin matrix composite system is prepared for the ultra low temperature environment.After the investigation into the wettability of resin and micro debonding test of interface,the experiments show that the surface tension and the dynamic contact angles of the modified epoxy resin are better than pure epoxy, and it can form good infiltration with carbon fiber. The interfacial properties between the modified epoxy resin and carbon fiber of the composites are excellent.Secondly, the unidirectional plate of modified epoxy resin based composite was prepared by wet winding process, and the mechanical property test specimens suitable for cryogenic environment were prepared according to the relevant test standards.The mechanical properties under-196℃,-150℃,-90℃ and room temperature 25℃ were tested, and the mechanical properties of the composites were obtained.It provides the design basis for the application of the composite system in cryogenic environment.Finally, SEM method was used to characterize the microstructure of epoxy matrix composites after different temperature tests. Combined with the mechanical properties under cryogenic environment, the molecular structure of the resin, the difference of thermal expansion between the resin matrix and carbon fiber,this paper reveals the evolution law of the mechanical properties of the composite under cryogenic environment, and provides a basis for the structural design and performance prediction of the composite material and its reliable application.