This study compares the tensile properties of commercial aluminum matrix composites (AMCs) with those of AMCs produced via a nitrogen-induced self-forming process. This process is a newly developed AMCs manufacturing process that takes advantage of the price competitiveness and productivity of large-scale products produced via the liquid process. Additionally, this process has the freedom of choice of the reinforcement phase and the homogeneous dispersibility of the powder process. Compared to commercial monolithic 6061 alloys, 6061 aluminum alloy matrix composites exhibit increased Young’s modulus, yield strength, and ultimate tensile strength by 59%, 66%, and 81%, respectively. This study also compares the tensile properties of AMCs with different matrix compositions, including 2009 and 7050 aluminum alloys. The study shows that AMCs produced using the nitride-induced self-forming aluminum composite (NISFAC) process exhibit comparable or superior tensile properties to those obtained using existing commercial powder metallurgy (P/M) processes.

The aluminum composite with dispersed high entropy alloy were developed by stir casting involving the powder-in-tube method. First, Al0.5CoCrCuFeNi high entropy alloy (HEA) powder was made by mechanical alloying, and the powder was extruded in a tube-type aluminum container to form HEA precursor. The extruded HEA precursor was then dispersed in the aluminum matrix via stir casting. As a result, Fe-Cr-Ni based high-entropy phases was uniformly formed in the aluminum matrix, revealing ~158, 166, 235% enhancement of tensile strength by incorporating 1, 3, and 5 wt% HEA particles, respectively.

This study suggests a new way to modify the size and morphology of Al-Fe phases in modified AA 7075 by using an Fe-Mn solid solution powder as the precursor. When Fe and Mn are added in the form of a solid solution, the diffusion of Fe and Mn toward the Al is delayed, thus altering the chemical composition and morphology of the precipitates. The fine, spherical precipitates are found to provide a good balance between strength and ductility compared to the case where Fe and Mn are separately added.