EXPERIMENTAL PREPARATION OF SHORT-CARBON-FIBER-REINFORCED Al-5Cu MATRIX COMPOSITES USING VACUUM SUCTION CASTING

Carbon-fiber-reinforced aluminum matrix composites have been widely used in many industrial fields. The carbon-fiber content and elements content of Mg and Si has a significant influence on the performance of composites. It is vital to study the effects of the carbon-fiber content and elements content of Mg and Si on mechanical and electrical properties of composites. Short-carbon-fiber-reinforced Al-5Cu alloy composites (Cf/Al-5Cu) were prepared by vacuum suction casting (VSC) in this work. The mechanical and electrical properties of Cf/Al-5Cu were measured by testing machines, and the microstructures were observed and analyzed using a scanning electron microscope (SEM). Experimental results show that the mechanical and electrical properties of the Cf/ Al-5Cu composites increase with the increase of the carbon-fiber content. The tensile strength of Cf/Al-5Cu-composites with 2 w/% carbon-fiber content reached 258.7 MPa. Its microhardness reached 112.6 HV, and the resistivity was 26.5 mu Omega/mm. The mechanical properties of the Cf/Al-5Cu composites can be improved by adding the elements Mg and Si. When the Mg content is 0.3%, the tensile strength of Cf/Al-5Cu composites reached 294.7 MPa, the microhardness reached 128.3 HV, and the resistivity was 18.4 mu Omega/mm. Adding Mg was more effective for the electrical properties than Si.