What are the mechanical parameters of carbon fiber wound tube?

Carbon fiber composite materials are typical difficult-to-machine materials. Parts with complex shapes are usually manufactured by material molding, but secondary processing is often required after molding to meet precision or assembly requirements. Due to the high strength and hardness of the material, poor thermal conductivity, anisotropy, and low interlayer bonding strength, traditional processing methods often lead to processing defects such as delamination, cracking, burrs, and fiber pullout, and it is difficult to achieve higher The machining accuracy of carbon fiber composites is high, the tool wear is serious, and the processing cost is high, which brings great trouble to the processing and application of carbon fiber composite materials. Non-traditional processing methods such as laser processing, water jet processing, and ultrasonic processing can be used to process carbon fiber composites, but they often produce processing defects such as large heat-affected zones, impact damage, stepped delamination, and cracks.

EDM is thermal processing. The local and instantaneous high temperature generated by the pulsed spark discharge between the two poles causes the processing material to be eroded due to melting, splashing or vaporization. It is a typical non-traditional processing method. There is no direct mechanical contact during processing. Not limited by the mechanical properties of materials, it is suitable for processing some conductive materials with high hardness, high strength and high brittleness, and can obtain high processing accuracy. It is widely used in aerospace, mold manufacturing and other industries.

Wire EDM uses the moving metal wire as the electrode to perform discharge erosion on the workpiece, cutting and forming. According to the wire speed of the electrode wire, it can be divided into fast wire and slow wire. The slow wire processing generally uses brass as the electrode. The wire and electrode wire move in one direction, and the wire speed is usually lower than 0.2m/s. It can be cut multiple times and can obtain high machining accuracy. For difficult-to-machine materials, plates, special-shaped holes, narrow slits, and complex shape workpiece The high-precision machining of etc. has obvious advantages. In order to promote the development of carbon fiber reinforced composite material processing and application field and solve the processing defects caused by traditional processing, it is of great significance to use wire EDM in the field of carbon fiber composite material processing.

Studies have shown that EDM CFRP, the thermal conductivity of carbon fiber and epoxy resin, and the huge difference in melting and boiling point lead to obvious directionality in the erosion of the material; studies have found that bare carbon fiber will lead to frequent short circuits during processing. The pulse accounts for about 10%~60% of the total number of pulses, but in the process of CFRP EDM, the short-circuit phenomenon can speed up the erosion speed of CFRP. When the fiber direction is parallel to the machined surface, the short-circuit phenomenon is more likely to occur, and the material removal rate is higher. , When the discharge gap is reduced, the frequency of short-circuit phenomenon decreases; CFRP has anisotropy, the discharge pits in different directions have different shapes, and the erosion speed of the material is different, resulting in uneven steps on the machined surface. The material removal rate is higher when the feed direction is parallel to the fiber direction than the vertical direction.

Using a thermal camera to observe the characteristics of EDM CFRP, the study found that the shape of the discharge trajectory depends on the arrangement direction of the carbon fibers, not the current flow, and the discharge energy is consumed on the carbon fibers on the surface of the workpiece. With the increase of pulse energy, defects such as delamination and heat-affected zone increase, and the surface roughness increases. High processing quality can be obtained by processing at low energy. Design a special fixture to introduce compressed air and deionized water into the upper and lower surfaces of the workpiece, cool the inlet and outlet surfaces of the hole in time, and blow out the arc to improve the processing quality. Compared with the non-spray processing, the spray processing effectively reduces the heat on the inlet and outlet surfaces. The affected area is improved, the machining accuracy and surface quality are improved, and the machining efficiency is increased by about 21.6%.

Founded in 2006, Jiaxing Longshine Carbon Fiber Products Co., Ltd. is China Custom Carbon Fiber Composite Manufacturers and OEM Carbon Fiber Material Suppliers, located in the center of Yangtze River Delta, the state-level Xiuzhou High-tech Industrial Development Zone of Jiaxing. In recent years, we committed to the r&d and production of carbon fiber and other composite materials in the military and civil fields, including participating in the R&D and production of C919 aircraft parts, high-speed rail accessories, and several logistics support projects.