Mechanical Properties of Novel Aluminum Metal Matrix Metallic Composites: Application to Overhead Conductors

Rhee, H., Whittington, W. R., Oppedal, A. L., Sherif, A. R., King, R., Kim, H., & Lee, C. (2015). Mechanical Properties of Novel Aluminum Metal Matrix Metallic Composites: Application to Overhead Conductors. Materials & Design. Elsevier. 88(25), 16-21. DOI:10.1016/j.matdes.2015.08.109.

Abstract

The mechanical behavior and microstructural evolution of aluminum metal matrix metallic composites fabricated under various process conditions were investigated to understand their process-structure–property relations. The novel techniques for arranging the matrix and reinforcement materials and controlling the processing atmosphere were applied to the extrusion process. The composites were comprised of matrix 1050 and reinforcement 6061 aluminum alloys with varying percent weight compositions and were arranged in a tailorable concentric annular pattern. The composites were shown to substantially increase compressive strength when the atmosphere of composite arrangement was evacuated prior to extrusion. Mechanical response of the composites were compared to the pre-extruded 1050 and 6061 aluminum alloys. The yield strengths of each composite, with varying percent weight compositions, were found to lie between those of matrix and reinforcement alloys, and abided by a simple rule-of-mixtures when considering weight composition. Highly elongated grains were oriented in the as-extruded composites along the extrusion direction and grains near the interface between two constituent alloys showed higher aspect ratio than in the interior region. The present study could lead to the optimum composite design for various industrial applications including all aluminum alloy overhead conductors with high strength and improved electric conductivity.