This study presents a comparative evaluation of two widely used chemical analysis techniques: scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX) and spectrophotometry. SEM-EDX is renowned for its ability to provide qualitative and quantitative elemental analysis at microscopic levels, making it a powerful tool for material characterization. On the other hand, optical emission spectroscopy, which analyses the light emitted by excited atoms, is highly effective for the rapid and precise quantification of elements in various sample types, especially metals and alloys. The research aims to assess the effectiveness, accuracy, and applicability of these techniques, by analysing identical samples (welding wire) using both SEM-EDX and spectroscopy, this study highlights the strengths and limitations of each method. Key parameters such as sensitivity, detection and data interpretation are compared to provide a comprehensive understanding of their performance in chemical analysis.
Ultrasonic welding is a process that has been in continuous development since it was first introduced in the 1940s. The process is widely used to join or reform plastic or metal materials using mechanical vibrations propagated at frequencies ranging from 20.000 Hz to gigahertz levels. These vibrations produce heat that melts the materials to be welded at their contact surface. In addition to the heat produced by the vibrations, a preset pressure is applied from the control panel of the welding machine to ensure perfect contact between the welded parts.[1] The ultrasonic welding process is time-efficient, taking less than 0.2 seconds in some cases, and does not damage the outer surface of the parts. The whole paper is structured in two parts, one theoretical and one practical, these parts are divided into six chapters. The first chapter of the paper explains the propagation process of ultrasound and what it actually is, as well as a brief history of ultrasound. In the second chapter there are generalities about ultrasonic welding and how this process is carried out and a history of ultrasonic welding. The third chapter introduces us to the subject of the paper, namely ultrasonic welding of plastics. Chapter four deals with the materials used to produce seat belts and their evolution over time. In chapter five we present all the equipment used for the case study. Chapter six is the case study and the explanation of all the steps performed to find out some results about ultrasonic welding of seat belt samples. Finally, I presented the conclusions drawn from the whole research process and the results obtained for the ultrasonic welding process of seat belts.
Lightweight steel structural systems like trusses or built-up beams, made of thin gage steel elements, are highly efficient, with ease of handling and construction. Self-drilling screws are commonly used for connecting thin-walled elements, but the time and manpower required for numerous connections necessitate an improved solution. One possible solution is to use welding technology, but the conventional methods are not suitable for joining thin sheets. Manufacturing defect-free, mechanically sound welding joints remains challenging due to defects like porosity and undesired microstructural phases in the heat-affected (HAZ) and fusion zones (FZ). Conventional welding processes increase heat input, causing difficult challenges. Brazing, a relatively new joining process, offers the advantages of lower heat input for thin and zinc-coated steel sheets. Therefore, the paper aims to present the effect of MIG brazing parameters on the macro-and microstructural properties of Cu-Al-based weld seams manufactured for joining thin sheets with thickens in the range of 0.8-2 mm. The weld seams were manually fabricated using a MEGAPULS FOCUS 330 compact equipped with TBI XP 363S/4m welding torch, focusing on optimal welding regimes. The macro-and microstructures of the joints were evaluated along with the mechanical properties in terms of hardness, confirming that MIG brazing is a promising method for manufacturing lightweight steel structural systems.
Magnesium alloys are used more and more in automotive industry due to specific strength (ratio between tensile strength and density) of 158kNm/kg versus 46kNm/kg in case of structural steel [1]. Another advantage of magnesium alloys is machinability, aspect and automated caste/extrusion. With this last procedure is possible to achieve high rate of productivity for complicate pieces, needed in automotive sector. Technologically, a big issue of magnesium alloy is its reactivity in contact with carbon steel, accentuated by high temperature and pressure from extrusion chambers.
Advances in additive manufacturing have facilitated the production of intricate geometries and customized components with high precision. This research focuses on the optimization of 3D printing parameters for H13 tool steel and Inconel powder using the InssTek MX-Mini metal 3D printer. Key parameters, including scanning speed and powder granulation, are systematically varied to assess their influence on print quality, while the laser power remains constant. The objective is to identify the optimal parameter combinations that enhance dimensional accuracy, reduce porosity, and achieve the desired hardness and tolerance levels in the printed specimens. An extended experimental analysis, using Design of Experiments (DOE), is conducted to evaluate the mechanical properties and microstructural characteristics of the printed parts. The findings provide essential insights into the correlation between the printing parameters and the overall performance and reliability of H13 and Inconel components produced via additive manufacturing. This study offers a valuable framework for manufacturers seeking to optimize 3D printing processes for high-quality H13 and Inconel applications.
