Composition, characteristics and application of th

  • Detail

Composition and characteristics of epoxy resin composite material, application

composition and characteristics of epoxy resin composite material, application

December 03, 2003

-- composition of epoxy resin composite material

I. epoxy resin matrix. It is the solidified product of epoxy resin glue. Epoxy resin glue is composed of epoxy resin, curing agent, accelerator, modifier, diluent, coupling agent and other additives. Select according to different use and process requirements

II. Reinforcing materials. Fibers and their fabrics are mostly used, as well as particulate (powdery) materials. The reinforcement effect generally increases with the increase of the length diameter ratio of the reinforced

material. The reinforcing effect of particulate materials is low, and they are mostly used for functional composites, such as si02

powder for insulating materials, colloidal graphite for plastic bearings, etc. However, with the rapid development and application of nanoscale materials, it is expected that their reinforcement effect and functional composite effect will be greatly improved. A large number of fiber materials are

glass fibers and their fabrics. Cotton fabrics were used in the early stage. Due to the limitation of sources, they are rarely used except for special needs. Chemical fibers such as polyester can also be used. Short glass fibers are often used in epoxy engineering plastics, and asbestos fibers and cotton fibers can also be used in

. Carbon fiber and its hybrid fiber with aramid fiber and high-strength glass fiber are mainly used in high-performance epoxy composites. In addition to E-glass fiber and d-glass fiber, quartz fiber with better dielectric properties can also be used in the radome

Third, the interface layer between epoxy resin matrix and reinforcing materials. In the process of compounding epoxy resin and reinforcing materials, an interface layer is formed between them. The structure and properties of the interface layer are different from those of epoxy resin matrix and reinforcing materials. The performance of the interface layer with high

quality ensures the high play of the potential ability of the matrix and fiber and the full realization of the composite effect

-- characteristics of epoxy resin composites

first, low density, high specific strength and specific modulus. The specific strength of several engineering materials is listed in table 9-2 and figure 9-1 according to the calculated displacement (ratio of strength to density) and specific modulus

(ratio of modulus to density). It can be seen from the table and figure that the specific strength of high modulus carbon fiber epoxy composite is 5 times that of steel, 4 times that of aluminum alloy and 3.2 times that of drill alloy. Its specific modulus is 5.5-6 times that of steel and aluminum alloy

gold and Qin alloy. Therefore, with the same strength and stiffness, the weight of carbon fiber epoxy composite components can be greatly reduced. This can not be compared with any existing metal

materials in saving energy and improving the service performance of components

II. High fatigue strength and good damage safety characteristics. Under static load or fatigue load, epoxy composites first

appear damage at the weakest place, such as transverse crack, interface debonding, delamination, fiber fracture, etc. However, many fibers

and interfaces will prevent or delay the propagation of cracks, and the matrix will quickly redistribute the load and transfer it to the last broken

fibers through the interface, so that the whole component can continue to bear the load without immediate overall fracture. In the fatigue process, the crack propagation is very slow,

it does not break rapidly until about 90% of the fatigue life. There is an obvious omen before the overall fracture, so the damage safety characteristics are

good. However, metal materials are often destroyed suddenly without obvious warning under fatigue load

III. good shock absorption performance. The white vibration frequency of the structure is not only related to the shape of the structure itself, but also proportional to the square root of the specific modulus of the material. Epoxy composites have high specific modulus, so they also have high natural frequency. High natural vibration

frequency is not easy to cause resonance during operation, which can avoid early damage caused by resonance. At the same time, the interface between the fiber and the matrix in the composite material

has vibration absorption capacity, so its vibration damping is very high. Vibration tests were carried out on light metal alloy beams and carbon fiber composite beams with the same shape and size

, which showed that it took 9s for the light alloy beam to stop vibration,

while the composite beam only took 2.5s to rest

IV. good corrosion resistance, dielectric performance, electromagnetic wave transmission performance and comprehensive performance. Heat resistance is also good

v. the whole component can be formed with a mold at one time, thus reducing the number of parts, fasteners and joints, improving the stress state, saving raw materials and reducing the weight of the component. The tooling is simple, the production cycle is short, and the cost can be greatly reduced

VI. anisotropy and designability of material properties. This is the outstanding feature of composites, especially high-performance composites. According to the load distribution and service conditions of the engineering structure, the formulation design and ply design of composite materials can be carried out. Give full play to the role and potential performance of each constituent material reasonably and effectively, meet the predetermined requirements of material performance,

realize the optimal design of components, and achieve safety, reliability, economy and rationality

of course, epoxy composites also have shortcomings. According to the

solution of China's epoxy resin industry (), the main reasons are: the dispersion of material properties will be greatly improved compared with the working efficiency, the aging resistance is poor, the moisture and heat resistance is not very high, and the transverse performance and the shear strength between layers are not good enough

-- Application of epoxy resin composites

I. epoxy resin engineering plastics are mainly used for engineering plastic parts that require high strength, good impact toughness and certain heat resistance. Such as rocket tail fins, armor piercing sabots, sonar fins, etc. It is also used as functional

plastics, such as plastic packaging materials for electronic components, water lubricated plastic bearings, etc

II. Epoxy laminated plastics are mainly used as insulation structural parts of motors and electrical appliances. Among them, epoxy copper clad laminates are used

III. epoxy FRP is mainly used as corrosion-resistant containers, such as storage tanks, tank cars, electrolytic cells, pickling towers, etc., and also used

as radomes

IV. high performance epoxy composites are mainly used as structural parts of aircraft, satellites, spacecraft, solid rocket motor

shells, as well as high-end sporting goods such as rackets and balls. The number of imports of extruders this year, except in March, has increased year-on-year, such as fishing poles, racing boats, etc

Copyright © 2011 JIN SHI