Interfacial enhancement and mechanical properties of CF/Al composites with improved interfacial structure induced by Al-Ni-Mg ternary reaction

In the present study, an Al-Ni-Mg ternary reaction was used to provide an improved interfacial structure of carbon fiber reinforced Al-matrix (CF/Al) composites fabricated by a rapid process in open space. Driven by ternary reaction, better infiltration behavior of Al matrix can be obtained. With increasing Mg element addition, the ternary reaction was enhanced with the formation of Al-Ni-Mg IMCs with gradually larger size. When the value is 2.5 wt%, the relative density increases from 96.3% to 97.1%, and the crack density is reduced by 88.5% compared with those of Al-matrix composites due to the elimination of micro-defects. At the same time, the formation of IMCs with optimal size and distribution was obtained, which indicates the suitably Al/Ni interfacial state and provides effective load transfer and significant enhancement of the mechanical properties. The ultimate tensile strength (UTS) of the composites with Al-2.5 Mg matrix is 108 MPa, which is 18.7% higher than that of the corresponding matrix, and the improvement of UTS is the largest compared with that of the composites with 1.25 wt%, 3.75 wt%, and 5 wt% Mg element addition.