A Novel Approach for Enhanced Mechanical Properties in Solid-State Additive Manufacturing by Additive Friction Stir Deposition Using Thermally Stable Al-Ce-Mg Alloy

Abstract

An innovative approach to build a high-performance, thermally stable Al-8Ce-10Mg (wt.%) alloy via friction-stir based solid-state additive manufacturing, called additive friction stir deposition, has been demonstrated in this study. The deposited material displayed 22% higher yield strength and 181% improvement in ductility as compared to the base material. The deposit also exhibited excellent tensile properties at elevated temperatures. The improved performance has been attributed to multiple strengthening mechanisms active in the built component. Al-Ce particle fragmentation, grain refinement, and retention of Mg in solid solution during the process synergistically resulted in the improved mechanical performance. The fragmentation of Al₁₁Ce₃ particles occurred due to intense frictional heating and shearing during the process. Scanning electron microscopy, nanoindentation, tensile testing, differential scanning calorimetry, and X-ray diffraction analysis were used to establish process-structure-property correlations at multiple length scales.