Elucidating the Effect of Additive Friction Stir Deposition on the Resulting Microstructure and Mechanical Properties of Magnesium Alloy WE43

In this work, the effect of processing parameters on the resulting microstructure and mechanical properties of magnesium alloy WE43 processed via Additive Friction Stir Deposition (AFSD), a nascent solid-state additive manufacturing (AM) process, is investigated. In particular, a parameterization study was carried out, using multiple four-layer deposits, to identify a suitable process window for a structural 68-layers bulk WE43 deposition. The parametric study identified an acceptable set of parameters with minimal surface defects and excellent consolidation for the fabrication of a bulk WE43 deposition. Microstructural, tensile, and fatigue life characterization was conducted on the bulk WE43 deposition and compared to commercially available wrought material to elucidate the process-structure-property-performance (PSPP) relationship of the AFSD process. This study shows that the bulk WE43 deposit exhibited a refined homogenous microstructure and a texture shift relative to the wrought material. However, a reduction in hardness and tensile behavior was observed in the as-deposited WE43 compared to the wrought control. Additionally, fatigue specimens extracted from the bulk deposition exhibited a decrease in life in the low-cycle regime but performed comparably to the wrought plate in the high-cycle regime. The outcomes of this study illustrate the potential of the AFSD process in additively manufactured structural load-bearing components made with magnesium alloy WE43 in the as-built condition.

Automated summary

The effect of processing parameters on WE43 magnesium alloy processed via Additive Friction Stir Deposition (AFSD) was investigated. A parameterization study identified suitable parameters for bulk WE43 deposition, resulting in a refined homogenous microstructure and specific changes in mechanical properties compared to wrought material. Fatigue life in the low-cycle regime was decreased in as-deposited WE43, but comparable to wrought material in the high-cycle regime, demonstrating the potential of AFSD process for additively manufactured load-bearing components with WE43 magnesium alloy.