Preparation And Properties Of Carbon Fiber Reinforced Aluminum Matrix Composite

Carbon fiber reinforced aluminum matrix composites based on carbon fibers as reinforcement, aluminum or aluminum alloy as the matrix materials. Aluminum matrix is used to transfer the loads, bear part of loads and consolidated carbon fibers,as the same time, carbon fibers are used as reinforcement to improve the inadequate performance of the metal matrix. carbon fiber reinforced aluminum matrix composites compared with metal materials, which has a series of advantages, such as low density, high specific strength and modulus, good dimensional stability and low expansion coefficient, wear-resisting corrosion resistance; Compared with ceramic materials, which has the advantages of high toughness and impact resistance. In recent years, with its superior properties such as low density, high strength, carbon fiber reinforced aluminum matrix composites is widely used in aerospace, automotive, electronic instruments and civil tools, etc. Therefore, the study of the composites has a certain guiding significance for practice.In this paper, carbon fiber reinforced aluminum matrix composites were fabricated by vacuum hot pressing sintering. The pretreatment methods of surface of carbon fiber impact on electroplating copper were studied. The layers were characterized and analyzed by SEM and XPS. Further more, the modification methods and the content of carbon fibers impact on composites mechanics performance and compactness were discussed.The pretreatment of carbon fiber show that: treated with nitric acid soaking, the surface of carbon fiber became rough, stripes obviously increased along axial direction; There were a lot of functional groups contained oxygen on the surface of carbon fiber, such as C-OH, C=O, COOH, etc. which can effectively improve the wettability between carbon fiber and the plating solution, makes carbon fiber dispersed evenly in the plating solution, ensure the smooth progress of the copper plating. Layers formed in three stages: nucleation stage, rapid growth stage, and saturation stage. Layers were composed of continuous accumulation of copper particles, which were compact and uniform and no obvious flaws. It was profile generated between carbon fibers and copper layer, forming a tight inlay system, makes more firmly combination between layers and carbon fiber. The most of copper of layers in the form of copper itself, and some of copper on the surface of layers was oxidized into Cu O. Layers gradually thickening with the increasing of plating voltage 、plating time and plating temperature.Composites microstructure observation showed that:when the content of carbon fiber was less, its distribution is relatively uniform, With the increase of carbon fiber content, carbon fiber began to appear together; Compared with no pretreatment carbon fiber, coated carbon fiber and alloy bonded excellently. The composites mechanics performance test showed that : Coatde carbon fiber reinforced composites microhardness increased with the increase of content of the carbon fiber; On the contrary, without coated carbon fiber reinforced composites microhardness decreased with the increase of content of the carbon fiber. With the increase of content of the carbon fiber, the tensile strength and bending strength of the composite s was increasing, when the content of carbon fiber was 6%, the comprehensive mechanics performance of the composites to achieve the best. Compared with short carbon fiber reinforced composites, the mechanics performance of the composite s reinforced by continuous carbon fiber better than short carbon fiber.The studies of compactness showed that: with the increase of content of the carbon fiber, the compactness of composites was decreased.