Metals

Severe plastic deformation is an effective process to modify materials’ structures. In this work, its new modification entitled channel angular extrusion was applied to a metastable metal-matrix composite consisting of a Ag matrix and spherical Cu particulates. During this process, the rod sample deforms in an inhomogeneous way and exhibits a gradient microstructure that is characterized by ellipsoidal Cu particulates at the edge of the sample but elongated and fragmented rectangular ones in the center. In addition to the different shapes, the edge and center of the sheet also differ in preferential orientations: the ⟨110⟩ direction predominates in the center of the sheet, while the ⟨111⟩ direction dominates at the sheet edge. The changed angle of the {111} shear plane relative to the extrusion direction explains these differences.

This study examined cast AZ31 magnesium alloy and its variant containing micro-alloying elements of Y and Ca (AZXW alloy), evaluating their potential as anode materials in magnesium–air batteries. The AZXW alloy was fabricated via two manufacturing techniques: casting and extrusion. The synergistic influence of Y and Ca, in conjunction with the production procedure, on the microstructure, electrochemical characteristics, and anodic discharge behavior of the examined alloys was investigated. The addition of Y and Ca results in the formation of secondary phases that affect grain size, particle size, and distribution, as well as the electrochemical performance and discharge properties of the Mg–air battery constructed for this study, over 24 h or until fully discharged. This work demonstrates the potential to enhance discharge performance and electrochemical behavior by adjusting the aqueous electrolyte solution in the battery through the incorporation of Citric Acid (C.A) at varying concentrations. The incorporation of citric acid into the aqueous electrolyte improves battery stability and specific energy as long as citric acid is present in the solution. Magnesium hydroxide (Mg(OH)₂) begins to form on the anode surface as its concentration progressively decreases due to complexation with dissolved magnesium ions. This diminishes the effective anode area over time, ultimately resulting in the distinctive “knee-type” collapse characteristic of electrolytes containing citric acid.

This study addresses the limited understanding of how build orientation and aggressive environments jointly affect the mechanical reliability of L-PBF 316L stainless steel. Specimens were fabricated in vertical, edge, and flat orientations and exposed for 360 h to 1 M H₂SO₄, 3.5 wt.% NaCl, and dry air oxidation at 800 °C. Tensile tests and microstructural analyses revealed strong anisotropy: edge and flat builds showed higher tensile and yield strength, while vertical builds exhibited greater ductility. Aqueous environments caused surface degradation and moderate strength loss, most severe in vertical samples. High-temperature oxidation induced σ-phase precipitation, increasing tensile strength (~20%) but reducing ductility and yield strength. These findings highlight the critical role of building orientation and service conditions in ensuring long-term performance of L-PBF 316L stainless steel.