| Carbon fiber reinforced aluminum matrix composites have superior performance of high specific strength, high modulus, favorable thermal and electric conduction. It is still stable under elevated temperature. Pure Aluminum foil and 2024 Aluminum were chosen as base metal. The surface uncoated T300 carbon fiber cloth was selected as reinforcement. Carbon fiber cloth reinforced aluminum matrix composites were prepared by vacuum hot pressing diffusion method. Effect of temperature field distribution in furnace, the interface of composite material on tensile strength properties, the density and fracture appearance during the fabrication process was studied systematically. Main conclusions are as follows.When the furnace thermal insulation is in the range of 540°C- 700°C, hot pressing mold temperature increase with the furnace thermal insulation in 0-80 min.When the furnace thermal insulation time is in the range of 80-120 min, the mold temperature field tend to be stable. The mold temperature increase slowly, closing to the furnace temperature. The temperature difference between the center of the furnace and the distance from the center of the mold 50 mm is lower than 3°C, and the central temperature of the hot pressing furnace is 17°C lower than that of the furnace temperature. In this paper, counting hot holding time as the furnace thermal insulation time reaches 80 min, stable hot pressing temperature can be obtained.The fitting equation of the relationship between the central temperature of the mold and the heat preservation temperature and holding time was obtained and shown as below:4632T10388.500174.021.005.11149.250 tttt Tfurnacecenter-′-+-+-=The fitting equation of the relationship between distances from the center of the mold 50 mm and furnace insulation temperature and holding time was obtained and shown as below:463250T1035.500167.0189.048.971.202 tttt Tfurnacemm-′-+-+-=The increasement of hot pressing temperature enhances the mobility of the aluminum and the aluminum alloy matrix. Too high hot pressing temperature makescarbon fiber bundle burning damage. Extension of hot pressing time prolongs the diffusion time of the aluminum alloy and aluminum foil matrix to the carbon fiber bundle reinforcement. Too long hot pressing time results in a long period of preparation time, but also leads to massive generation of Al4C3. The increasement of hot pressing time overcomes the friction between the aluminum alloy powder and mutual wedged force, spillovers the air in the middle of the composite material. Too much hot pressing pressure make the carbon fiber bundle damage by shear force. It is concluded that composite material fabricated under the craft parameter 600°C, 70 min,15 MPa, and 16.39% volume fraction of carbon fiber exhibited highly integrated structure, and a high density reaching 98.96%, aluminum alloy base metal being wrapped by carbon fiber reinforcement by close integration with rare or almost no porosity.Composite fabricated under the craft parameter 600°C, 70 min, 15 MPa, a weak chemical reaction has occurred between the carbon fiber reinforcement and the aluminum alloy matrix, a small amount of Al4C3 are formed. The interface of the composite prepared by the craft parameters is hybrid interface, rely mainly on dissolution and wetting combination while mechanical combination and exchange reaction subsidiary.With the increaseing of hot pressing temperature, the extension of hot pressing time and the increaseing of the hot pressing pressure, the tensile property of carbon fiber cloth reinforced aluminum matrix composite increases first and then decreases.Under the craft parameter of 600°C, 70 min, 15 MPa, and 16.39% volume fraction of carbon fiber, the composite exhibits best overall properties, with the tensile strength of the fabricated specimen being 123.92 MPa. |
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