Key Engineering Materials Vol. 992

Abstract: Friction stir welding is a solid-state joining process of metallic materials using a rotating welding tool that can have different geometric configurations. The paper presents aspects regarding the influence of the welding tool pin geometry on the dimensions of friction stir welded joints in air and in liquid working environment for EN AW 1200 aluminium alloy. Welding tools with smooth and threaded cylindrical pin were used for experimental research, the joints dimensions being comparative analysed by macrostructural investigations. The results are useful in the case of experimental research on FSP processing in air and SFSP in liquid environment of aluminium alloys within the Nucleu PN 23 27 01 02 project underway at ISIM Timisoara.

Abstract: Additive manufacturing (AM), notably Laser Powder Bed Fusion (PBF-LB), has transformed metal component production, including the widely used AlSi10Mg alloy. However, optimizing surface properties for longevity remains challenging. Shot peening enhances mechanical properties, while silver shell-copper core (SSCC) coatings provide corrosion resistance and conductivity. This study investigates their combined effects on AlSi10Mg specimens, analyzing various shot media types' impact on surface roughness, coating thickness, and fatigue strength. Insights gleaned contribute to advancing surface treatment methodologies for AM components.

Abstract: Binder jetting is a rapidly evolving additive manufacturing technique, challenging the dominance of laser powder bed fusion in metal fabrication. This study focuses on the material properties of austenitic stainless steel 316L produced via binder jet technology. Porosity remains a significant challenge across additive manufacturing methods, adversely affecting material properties and fatigue life. To address this issue, we propose a novel approach employing severe shot peening as a post-processing treatment to enhance the material's characteristics. Microstructural analysis, including electron backscatter diffraction (EBSD), coupled with tensile testing, was conducted to evaluate the mechanical properties. Additionally, fatigue behavior was investigated under both axial and flexural bending loading conditions. The results revealed a substantial increase in material strength achievable through the post-treatment. Notably, the fatigue limit of the material in bending fatigue was elevated from 120 MPa to 190 MPa, indicating a significant enhancement in fatigue performance. This study contributes new insights into the enhancement of fatigue resistance in binder jet-manufactured 316L stainless steel through surface modification techniques. The findings underscore the potential of severe shot peening as an effective strategy to improve material properties and expand the applicability of binder jet printing in demanding industrial applications.