Papers by Keyword: Automotive

Abstract: A comparative study of state-of-the-art commercial 1200V trench-gate, planar-gate, and trench-assisted planar Silicon Carbide (SiC) MOSFETs is presented. The experimental study mainly focuses on disclosing the static and robustness characteristics of distinct SiC technologies targeting automotive applications under room and high temperatures. The benchmark study of static characteristics covers specific on-resistance (R_ON,SP), gate leakage (I_GSS​), drain leakage (I_DSS​), breakdown voltage (BV_DSS​), and drain-induced barrier lowering (DIBL) effects. The avalanche robustness is investigated by the unclamping inductive switching (UIS) setup under 25 °C and 175 °C while the single-pulse and repetitive short-circuit capability is evaluated under hard switching fault (HSF) under 25 °C.

Abstract: Uprights are one of the most critical structural elements in vehicles suspension systems. A standard upright serves as a physical mounting for the wheel hub and brake components as well as links the axle to the control arms. Uprights are relatively bulky by design to withstand the significant loads they observe during vehicle braking, maneuvering, and driving on rough terrain. In automotive design, specifically, race car design, utilizing lightweight components and reducing fuel consumption are imperative. This weight reduction-based paradigm is being adopted by the car industry at large, particularly due to the shift towards automotive electrification. Consequently, this work investigates the potential for using topological optimization to reduce the bulkiness and weight of uprights without compromising their structural integrity and reliability. An upright designed for a racing car is selected in this study. Topological optimization is performed on the upright using the finite element software ANSYS. Results show that a considerably enhanced upright is obtained after 48 topological optimization iterations while maintaining a factor of safety of 2.5. The optimized upright exhibited less stress concentrations and 39% lesser weight than the original upright.

Abstract: Recently, researchers have done a lot of efforts to develop new solid-state recycling processes, both experimentally and developing numerical models. This kind of process is energy-saving and environmentally friendly compared to the conventional aluminum recycling process because avoided the melting step. The purpose of this work is to evaluate the feasibility of an innovative solid-state recycling process through direct hot rolling in a non heat-treatable aluminum alloy for automotive applications. AA5754 chips have been produced by turning a bar without the usage of lubricants and compacted with a 150 kN load; the compacted billets were treated at 400 °C and directly hot rolled in several successive passes. Rolled samples are then analyzed in terms of Vickers microhardness and microstructure in both as-rolled and heat treatment conditions, this last was performed at 185°C simulating the process of paint-bake. The produced samples show an excellent bonding between chips.

Abstract: Additive Manufacturing (AM) [1] is playing every day a bigger role in the automotive industry because of its cost competitiveness, short delivery lead times and potential for design flexibility and optimization. Plastics and polymers are the most common materials used to produce AM parts in this sector, however metal AM is increasing its importance as there are specific applications that require mechanical characteristics that can only be achieved with metals such as stainless steel, titanium, hard steel, copper, aluminum, and others. There is an increasing number of metal AM technologies and Original Equipment Manufacturers (OEMs) competing in the industry with a very widespread list of advantages and disadvantages of each of them. We are at a point where automotive manufacturers need to make a complex decision on which metal AM equipment to purchase. This paper describes the main metal AM technologies and highlight the advantages and disadvantages of each of them. Additionally, three of the most competitive Metal AM technologies are compared: Powder Bed Fusion (PBF), Metal Filament Deposition Modeling (MFDM) and Bound Metal Deposition (BMD) on a specific experimental sample. For this study, a very common and representative automotive part has been chosen that is well suited to be printed in metal and can be manufactured in the three chosen technologies. A nozzle from the automotive body plant used to distribute accuratey a sealant bead onto a body panel before the final assembly operation was selected. These sample parts have been trialed for function and evaluated in general terms from a quality point of view. The conclusions included in this paper will help the automotive industry players understand which technology to use for this specific part and other parts with similar characteristics. Additional work will focus on specific quality characteristics such as material composition, mechanical properties, dimensional accuracy, and specific defects found to compare these technologies in detail. Furthermore, a selection of other automotive parts and technologies will be necessary to enlarge the knowledge on the application of metal AM on this field.

Abstract: The overwhelming majority of automotive part manufacturing processes successfully process hot dip galvanized sheet metal. However, there were reported situations were abrasive wear (galling), visible as narrow and long scratches, was observed on the surface of the formed parts. Investigations using a Slider On Sheet Tester (SOST) were performed in order to determine the conditions that lead to scratch forming on the galvanized sheet metal surface and to identify parameters that would guarantee a scratch free situation. The tests identified the tool roughness and the contact pressure as important parameters governing the coating wear phenomena. The tests proved that the coating resists relative high contact conditions in case of smooth tool surface, explaining why in the large majority of the industrial applications coated materials can be used without issues.

Abstract: In this paper we report the progress of our SiC trench etch development using enhanced ICP-based etch technology. Computer modelling of the electric field strength in the gate oxide as a function of corner geometry was used to illustrate trench corner rounding as an effective method to avoid to high gate oxide field strengths. This is an effort to examine a major ongoing issue in device reliability, and to govern future device design.

Abstract: Additive Manufacturing has made significant progress for numerous applications, especially in the automotive industry. Various approaches have been developed to improve and expand its application throughout the manufacturing line and produce reliable and suitable components for automotive applications. A brief overview of different 3D printing methods and materials currently used in the automotive industry is covered in this review. The advantages and drawbacks it brings to the industry, and material developments for 3D printing application for automotive is presented. The future outlook is given, and challenges that are needed to be addressed are discussed.

Abstract: Hot stamping, also known as press hardening in the context of sheet steel, has steadily gained relevance in the automotive industry, starting off as a specialist application and turning into a staple technique in the production of safety cage products in little more than a decade. However, despite the weight reduction offered by martensitic steels, further improvement could be obtained by substituting these components by high-performance aluminium. In this regard, the very same process of hot stamping could be employed to attain the required combination of shape complexity and mechanical properties at a reasonable cost for mass-market application, if the limitations imposed by cycle time and process window could be overcome. In this work, the feasibility of hot stamping of 6000-series aluminium alloy sheet is studied, first in dilatometry experiments and later in semi-industrial conditions in a pilot facility. A cycle time shortening strategy is employed, and compared to the conventional thermal cycle in terms of implementation and obtained results. In addition to basic characterization, aluminium thus processed is studied in terms of fracture toughness, in order to obtain data relevant to crashworthiness that can be readily compared with alternative materials.

Abstract: Arc welding processes are widely used in the automotive industry among other welding processes. Consequently, laser welding technology is being used instead of arc welding due to the rapid heating and cooling characteristics of the laser. In this study, empirical investigations and comparative study are held out on the arc and laser beam welded joints of DP780 dual-phase steel. Accordingly, weld joint microstructures, hardness distribution, and fatigue properties cross the butt-welded joints were investigated. The results showed that laser beam welding produces narrow fusion and heat-affected zones while gas metal arc welding produced wide welds with incomplete penetration. It was observed that the microstructure of the laser joint weld metal has mainly lath martensite in the ferritic matrix, while microstructure of gas metal arc weld metal relies upon filler type. Heat-affected zone in DP780 steel exhibit hardness softening in both laser beam welding and gas metal arc welding due to martensite tempering, a wider softening region was clearly observed in heat-affected zone welded by gas metal arc welding than laser beam welding. Generally, fatigue ratio, fatigue limit and fatigue life of the welded joints were improved by using laser welding.

Abstract: SPC (Statistical Process Control) is one of the Lean Manufacturing techniques, but especially Six Sigma, being a method of improving the quality of the manufacturing process, which allows the identification of errors before their production, with the help of which a process can be supervised and when needed, it is possible to carry out an intervention of regulation, respectively of correction of the process, before being nonconformities. The paper presents a study regarding the use of SPC at a company in the automotive field in order to improve the quality of the manufacturing process for a knuckle. Thus, a number of 25 samples were taken, each sample containing a number of 5 pieces. After sampling, a series of techniques and statistical data were used, respectively diagrams and control sheets, which allowed the determination of the process capability by using MiniTab software.