Study on tensile properties of carbon fiber reinforced AA7075 composite at high temperatures

The short carbon fiber reinforced AA7075 composites were fabricated through powder metallurgy and extrusion. The effects on the tensile strength of composites were investigated by the volume fraction of short carbon fiber and temperature. The results showed that the carbon fiber was aligned to the extrusion direction in the composites. The yield strength of composites with 8 and 12 vol % short carbon fibers tested at 150 °C were approaching that of AA7075 tested at 100 °C produced by the same methods. The hardness of composites with 12 vol % short carbon fibers increased to over 200 HV0.1. The interface is mainly composed of Al4C3 and segregated by Mg, resulting in an efficient coupling between fiber and matrix. The enhancement in high-temperature strength is dependent on the load transfer mechanism and the contribution of residual thermal stress. The tensile strength of composites corresponded to the prediction model.