Study On Properties And Microstructure Of Unidirectional Carbon Fiber Reinforced Aluminum Alloy Matrix Composites Prepared By Hot Pressing Method

Carbon fiber reinforced aluminum matrix composites material is a kind of typical composites material which have the characteristics of light weight, high specific strength,high specific modulus, good electric conductivity and thermal conductivity, small thermal expansion coefficient and good dimensional stability. In many fields, especially in the aerospace field, it is most widely used. For the preparation of carbon fiber reinforced aluminum matrix composites prepared by liquid forming method, the problem of the wetting of carbon fiber and aluminum matrix is poor and the interface reaction is serious, and in the preliminary study of this subject,the problem of the carbon fiber volume fraction is low and the mechanical properties of the composites is low by hot pressing method and so on. This paper optimized the design of carbon cloth reinforced aluminum-aluminum alloy matrix composites, the thickness of 0.2mm pure aluminum sheet, the thickness of 0.02 mm pure aluminum foil and 4043 aluminum alloy powder are used as the matrix, M40 unidirectional carbon fiber cloth is used as the enhancosome, carbon fiber reinforced aluminum-aluminum alloy matrix composites is prepared by hot pressing method, the effects of hot pressing temperature, hot pressing time and hot pressing pressure on the microstructure, density, mechanical properties and fracture morphology of the composites material are studied. The main conclusions are as follows:Carbon fiber cloth reinforced aluminum-aluminum alloy matrix composites material were successfully prepared by hot pressing method. When the hot pressing temperature is 610?, the hot pressing time is 70 min, the hot pressing pressure is20 Mpa, carbon fiber cloth reinforced aluminum-aluminum alloy matrix composites material prepared by hot pressing method has good effect on the forming of aluminum-aluminum alloy matrix composites, the microstructure of the composites material is compact and have no defects, such as cracks, holes and so on. The interface reaction between carbon fiber and aluminum alloy matrix was formed, and generated brittle phase Al4C3.The density of the composites material increases with the increase of the hot pressing temperature, the hot pressing time and the hot pressing pressure. The effect of the hot pressing temperature on the tensile strength of the composites material is the greatest, followed the by hot pressing time, and finally the hot pressing pressure.When the hot pressing temperature is 610?, the hot pressing time is 70 min, the hot pressing pressure is 20 Mpa, the volume fraction of carbon fiber cloth is 36.67%,The density of carbon fiber cloth reinforced aluminum-aluminum alloy matrix composites material is 93.91%, the tensile strength is 169.89 MPa, the elastic modulus is141.76 GPa, the bending strength is 225 Mpa. Tensile fracture of carbon fiber cloth reinforced aluminum-aluminum alloy matrix composites is parallel and level, only a small amount of fibers are pulled out and fractures under low stress, which belongs to brittle fracture.By comprehensive analysis of process parameters on the effect of composites material, microstructure and density and the tensile strength of composites material,the best process parameter of carbon fiber cloth reinforced aluminum-aluminum alloy matrix composites material by hot pressing method is that the hot pressing temperature is 610?, the hot pressing time is 70 min, the hot pressing pressure is20 Mpa.