Fabrication and interface optimization of continuous CF/Al composites with different reinforcement volume fraction

Abstract

Interface is the key factor to determine the properties of composites. In this work, the Ni coated continuous CF/Al composites were fabricated via twin-roll casting method. After interface optimization, the interfacial bonding strength was enhanced and the dispersion of carbon fibers was improved. The effect of reinforcement volume fraction on microstructure, mechanical properties and strengthening mechanism of CF/Al composites was studied. The microstructural showed that the increase of reinforcement volume fraction was easy to cause more defects in composites. Transmission electron microscopy (TEM) and thermodynamic calculation were used to characterize the interfacial phase composition of composites after interface optimization. The results revealed that the exterior of carbon fibers bundle was mainly composed of Al3Ni intermetallic phase, and there was no obvious Al4C3 phases were found interior of the CFs bundle. In addition, the composites with 13.6 vol% CFs had the best UTS of 218.7 MPa and well dispersion. Furthermore, Vickers hardness test and Nano-indentation results showed that Al-Ni intermetallic compound can enhance the whole hardness of CF/Al composites. Dislocation strengthening in the Al-Ni intermetallic compound region was observed by TEM. The interface evolution mechanism of CF/Al composites were revealed for the first time.