The transfer mechanism of a toner pattern printed on a soft film using a laser printer to a metal surface in compression was investigated by experiment and computer simulations. The toner pattern can ...be transferred successfully to the workpiece surface under the conditions that the entire soft film continues to be squeezed out smoothly from the workpiece edge until the transfer process is completed. The results indicate that the average tool pressure needed for the complete transfer of the toner pattern to the workpiece surface can be predicted by the average compression pressure calculated with slab method
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Non-isothermal hot forming processes are of great scientific and industrial interest to produce e.g. high-strength aluminum components for lightweight applications. The interfacial heat transfer ...coefficient (IHTC) is a key factor in the design of these forming processes. However, the IHTC values reported in the literature vary significantly, even for the same material combinations and load conditions. The present work reveals the causes of these variations by a combined experimental and model-based approach. It is shown that the measurement of dynamically changing blank temperatures and the determination of the die surface temperature are two core aspects of non-isothermal experimental IHTC analysis.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The medium-Mn steel with M3 characteristics (multi-phase, multi-scale, meta-stable) is a promising third-generation automotive steel. Its chemical composition, microstructure, thermal and mechanical ...properties are introduced and a warm stamping process for the medium-Mn steel is proposed. The optimal process parameters are identified through mechanical testing and microscopic analysis to achieve balanced properties of hardenability, hardness, strength, elongation and fracture behavior. The optimal forming process consists of an austenitization temperature of 790–840°C, a soaking time of 4–7min, an initial stamping temperature of 450–500°C, and a cooling rate of 10–60°C/s. A typical automotive structural part B-pillar was stamped using the proposed process and the final part exhibits ultrafine martensite-lath microstructure and desired mechanical properties for intrusion prevention and energy absorption.
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•Introduced a multi-phase, multi-scale, meta-stable medium-Mn steel•Austenite reversion transformation (ART) annealing is a required•The optimal initial temperature of warm stamping is 450–500°C•The medium-Mn steel is not sensitive to strain rate and cooling rate•Warm stamped part has of 1220MPa YS, 1420MPa UTS and 12% TE
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
In this paper, the springback behavior of high strength aluminum alloy 7075 is studied by experiments and finite element (FE) simulation. Firstly, an analytical model is established to predict the ...springback angles and analyze the springback trend. The springback experimental tests are conducted by using the V-shaped stamping dies. The influence of deformation temperature, punch radius, and blank holder force on the springback angles is studied. Finally, an FE simulation model is performed to investigate the deformation characteristics and springback process of the aluminum alloy sheet. The results show that the change of springback angles is direct proportional to the punch radius. The springback angles increase with the decreasing deformation temperature and the increasing blank holder force. The stress relaxation that occurs during the die holding stage is the primary reason of reducing the springback compared with cold stamping. Low blank holder force will cause side wall curl, which results in the deviation of forming size. The FE simulation model considering stress relaxation is capable of precisely predicting the change of springback angles, and the simulation results exhibit good consistency with the experimental results.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The application of high strength steels (HSS) for automotive structural parts is an effective way to realize lightweight and enhance safety. Therefore, improvements in mechanical properties of HSS ...are needed. In the present study, the warm stamping process of the third generation automotive medium-Mn steel was discussed, the characteristics of martensitic transformation were investigated, as well as the microstructure and mechanical properties were analyzed, compared to the popular hot-stamped 22MnB5 steel in the automotive industry. The results are indicated as follows. Firstly, the quenching rate of the medium-Mn steel can be selected in a wide range based on its CCT curves, which is beneficial to the control of forming process. Secondly, the influence of stamping temperature and pressure on the Ms temperature of the medium-Mn steel is not obvious and can be neglected, which is favorable to the even distribution of martensitic microstructure and mechanical properties. Thirdly, the phenomenon of decarbonization is hardly found on the surface of the warm-stamped medium-Mn steel, and the ultra-fine-grained microstructure is found inside the medium-Mn steel after warm stamping. Besides, the warm-stamped medium-Mn steel holds the better comprehensive properties, such as a lower yield ratio, higher total elongation and higher tear toughness than the hot-stamped 22MnB5 steel. Furthermore, an actual warm-stamped B-pillar of medium-Mn steel is stamped and ultra-fine-grained martensitic microstructure is obtained. The mechanical properties are evenly distributed. As a result, this paper proves that the warm-stamped medium-Mn steel part can meet the requirements of lightweight and crash safety, and is promising for the industrial production of automotive structural parts.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The fast growth of portable smart electronics and internet of things have greatly stimulated the demand for miniaturized energy storage devices. Micro‐supercapacitors (MSCs), which can provide high ...power density and a long lifetime, are ideal stand‐alone power sources for smart microelectronics. However, relatively few MSCs exhibit both high areal and volumetric capacitance. Here rapid production of flexible MSCs is demonstrated through a scalable, low‐cost stamping strategy. Combining 3D‐printed stamps with arbitrary shapes and 2D titanium carbide or carbonitride inks (Ti3C2Tx and Ti3CNTx, respectively, known as MXenes), flexible all‐MXene MSCs with controlled architectures are produced. The interdigitated Ti3C2Tx MSC exhibits high areal capacitance: 61 mF cm−2 at 25 µA cm−2 and 50 mF cm−2 as the current density increases by 32 fold. The Ti3C2Tx MSCs also showcase capacitive charge storage properties, good cycling lifetime, high energy and power densities, etc. The production of such high‐performance Ti3C2Tx MSCs can be easily scaled up by designing pad or cylindrical stamps, followed by a cold rolling process. Collectively, the rapid, efficient production of flexible all‐MXene MSCs with state‐of‐the‐art performance opens new exciting opportunities for future applications in wearable and portable electronics.
Manufacturing of micro‐supercapacitors (MSCs) by stamping MXene inks is demonstrated. The interdigitated Ti3C2Tx MSCs exhibit high areal capacitance (61 mF cm−2), good cycling lifetime, and high energy and power densities. Scaled‐up production of high‐performance Ti3C2Tx MSCs is also demonstrated.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Abstract
Nowadays, the level of stamping dies in the world has been greatly improved, and stamping technology has also developed greatly. Based on the analysis of the pallet parts, it is determined ...that the required processes are punching and blanking. The compound dying for punching and blanking was chosen for processing after the processing method was examined. Specific design process: analyze the material used for the part, calculate the required punching force, and select the required press according to the punching force, the closing height of the die, and the size of the die handle hole. The parts required by the die, such as convex and concave die, stripper plate, fixed plate, and other components, should also be designed so that the processing of the parts can be completed after the assembly is completed. In the design process, CAD drawing software, three-dimensional drawing software, etc., can be used to complete the drawing of two-dimensional and three-dimensional drawings of parts, improve the efficiency of our drawing, and can also quickly solve problems existing in the drawing, which makes the design process simpler.
The demand for new processes to produce high strength parts, under appropriate cost and productivity, has grown with weight reduction and crash safety improvements in automobile design. The hot ...stamping processes of quenchable steel sheets potentially offer not only small forming load and high formability, but also high strength and no springback by die quenching. This paper aims to provide an overview of the state-of-the-art in such hot stamping processes, including quenchability, formability, heating and cooling approaches and lubrication. The paper also includes a description of the mechanism of formability and quenching, tailoring, analysis of hot stamping processes and applicability.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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