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UF340 is a new type of cold-rolled fine grain high-strength steel with excellent formability developed by Shougang Co., Ltd Company. In this paper, the formation mechanism of recrystallisation texture of UF340 during annealing at 720 °C were systematically investigated. The as-received cold rolled sheet displayed a pronounced α-fiber texture together with a weak γ-fiber texture. With increasing annealing time, recrystallization occurred in the elongated grains, γ-fiber texture grains generated and grew up gradually. The texture component of the original α-fiber grains shift toward 112 , 023 , 223 and finally 111 . High r-values of UF340 in all directions were achieved by the development of the remarkable γ-fiber texture. In addition, the r ¯ value of the annealed UF340 was as high as 1.96, and the Δr value was only 0.2. As a result, excellent deep drawability and relatively high strength of UF340 were realized simultaneously, making it one of the ideal materials for automobile outer panels.

This study presents design, construction, and demonstration of a patented die system (UltraDRAW) used for deep drawing applications with utilization of ultrasonic vibrations. The developed system enables application of high-frequency vibrations onto the blank holder of die system in axial direction. Such design is considered to be effective in improving drawability of blank material, resulting in drawing of blanks with greater limiting drawing ratio (LDR) and lower forming load. For this purpose, an innovative ultrasonic horn with specific geometry, used directly as blank holder, was designed with steady-state harmonic response analyses using finite element method. To evaluate the performance of developed system, a series of cup drawing experiments using conventional and ultrasonically assisted die system were performed on cold-rolled low carbon steel sheets of DC01 and DC04 under dry and lubricated surface conditions. Compared to conventional drawing, UltraDRAW improved LDR and cup depth by 9.4% and 26.5% (for DC01) and 15.1% and 43.6% (for DC04) with reduction in forming load by 22.2% (for DC01) and 18.2% (for DC04).

The early design phase of deep-drawn structural components involves time-consuming iterative development. Traditional drawability assessments rely on finite element simulations, which are computationally expensive and slow the design process. Alternative machine learning (ML) approaches show promise in accelerating this process but face challenges with existing methods. Existing low-dimensional ML models only provide global predictions without identifying specific geometric regions prone to failure. High-dimensional models provide local predictions but require significant amounts of training data. We propose a data-driven approach leveraging graph neural networks (GNNs) for face-wise drawability prediction of sheet metal components in their computer-aided design (CAD) representation. Our method aims to bridge the gap between the computational efficiency of ML and the spatial resolution of simulation by providing face-wise insight into potential failure regions. This study utilises a dataset of parametric U-channel geometries with variability in both geometry and topology. Ground-truth labels are generated using inverse analysis simulations. Geometric entities are represented through the use of UV parameterisations, whereby 3D surfaces are mapped into 2D space to facilitate geometric encoding. Concurrently, the topological relationships are captured using a face adjacency graph. To address data scarcity, we evaluate how different amounts of training data affect model performance and perform ablation studies to analyse the impact of different CAD representation features. Our results show that the proposed approach achieves high accuracy even with limited training data. In addition, the ablation studies provide insights into the most critical CAD features, guiding future research. These results highlight the potential of our GNN to predict face-wise drawability in the early design phase.

The Brass commonly used in pipe industry, radiator, screw, and firearm’s cartridge case because their mechanical properties combination such as strength, ductility, corrosion resistance and good drawability. Deep drawing process are used to make cartridge case. In deep drawing process, the materials with high drawability are needed. In some case, drawability of metal can increased with adding alloying element, cold working, and heat treatment. In this research, the influence of addition 0.5 wt. % Al and 0.15 wt. % Mn on microstructure and hardness of Cu-32Zn alloy are investigated. The sample of Cu-32Zn-0.5Al-0.15Mn will be cold rolled with variation deformation levels of 20, 40 and 70%. Further, sample are annealed at temperature of 300, 400, 500 and 600 °C for 30 minutes. The result showed that the as-cast samples of Cu-32Zn-0.5Al-0.15Mn have the hardness of 72.4 VHN. Further, the as-homogenized showed the hardness of 70.66 VHN. Sample with 70 % deformation level showed the structure of shear band and have the highest hardness number of 236.6 VHN. On the other hand, sample with 20% deformation level and follow up by annealing process at 600 °C showed the lowest hardness of 135.94 VHN. The optimum hardness are reached on sample with 70 % deformation level and annealing temperature at 300 °C. This research conclude that the increase of deformation level follow up by the increase of sample hardness. Further, annealing process tend to decrease the sample hardness due to the grain growth.

This study presents a comprehensive experimental investigation for utilization of ultrasonic vibrations on the formability of materials in deep drawing process. For this purpose, a novel die system was designed, constructed, and mounted on an in-house developed servo press. The developed system enables application of high-frequency vibrations at various amplitude levels onto the blank holder in axial direction. Conventional and ultrasonically assisted cup drawing experiments were carried out on cold-rolled low carbon steel sheets of DC01 and DC04 using crank and soft motion scenarios with application of three levels of preloading under dry and lubricated surface conditions. The effects of process parameters on limiting drawing ratio (LDR), cup depth, and forming load were analyzed and compared for conventional and ultrasonically assisted drawing operations. The results revealed that application of ultrasonic vibrations in deep drawing significantly improved LDR and cup depth with considerable reduction in forming load, regardless of amplitude level of vibrations, amount of blank holder force, motion scenario, material type or surface condition. Under certain processing conditions, increase in LDR by up to 17% and cup depth by up to 50% with reduction in forming load by up to 32% was achieved with implementation of ultrasonic vibrations by means of the developed die system. Graphical abstract

Aluminum alloys are widely used as first-choice materials for lightweight automotive applications. It is important that an alloy have a balance between strength and formability. In this study, the alloys were melted, cast, hot rolled, and cold rolled into 1 mm-thick sheets. The microstructure, mechanical properties, and precipitation behavior of Al–Mg–Si–1.0 wt %-Zn alloys with Mg/Si ratios of 0.5, 1, and 2 after solution treatment were studied using optical and electron microscopy, a tensile test, the Vickers hardness test, and differential scanning calorimetry. The results showed that a high density and number of Al–Fe–Si particles were observed in the matrix, thus causing the formation of more homogeneous and smaller recrystallized grains after treatment with the solution. In addition, a higher volume fraction of cubeND and P-types texture components formed during solution treatment. Also, a high r value and excellent deep drawability were achieved in the medium-Mg/Si-ratio alloy. The formation of denser strengthening precipitates led to a better paint-bake hardening effect in comparison with the other two alloys. Furthermore, the precipitation kinetics were enhanced by the addition of Si, and the addition of Zn did not alter the precipitation sequence of the Al–Mg–Si alloy. The dual-phase strengthening effect was not achieved in the studied alloys during paint-bake treatment at 175 °C.

The effects of microstructure and deformation mode on the formability have been investigated to understand and improve formability in twinning-induced plasticity (TWIP) steel. The tensile and wire drawing behaviors were compared using the ferritic, pearlitic, and TWIP steels. The drawability of ferritic and pearlitic steels was quite good in spite of the low tensile elongation of hot-rolled state, whereas TWIP steel showed a low drawability despite the extraordinary tensile elongation. In TWIP steel, the gradual increase in twin volume fraction with increasing strain with the aid of grain rotation increased the ductility by delaying the growth of a local necking to fracture, which is the main reason why TWIP steel had a higher elongation during tensile test. The local saturation of deformation twins due to the inhomogeneous plastic deformation during forming process led to the earlier fracture in TWIP steel. For example, the earlier saturation of deformation twin at surface area led to earlier fracture of drawn wire, resulting in low drawability. This proposed fracture mechanism well explained the lower formability and higher strain hardening rate in TWIP steels under the complex stress states such as wire drawing, cup forming, caliber rolling, hole expansion, and dome stretch. To improve the formability in TWIP steels, twinning rate needs to be delicately controlled with area during plastic deformation, especially complex forming process. Four strategies were proposed to improve the formability of TWIP steels, which can help in producing high strength products using TWIP steels.

The applicability of plastic tools additively manufactured by fused deposition modelling for sheet metal forming processes was evaluated. Aluminium and steel sheets were V-bent and deeply drawn with the plastic tools. The dimensional accuracy of bent sheets with the plastic tools was lower than that with steel tools due to low stiffness, and deteriorated with increasing flow stress of a sheet. The stiffness was increased by reinforcing the plastic tools with steel bars, and thus, the dimensional accuracy of the bent sheets was improved. Not only springback of the sheet but also elastic deformation of the plastic tools was successfully corrected by modifying the shapes of the tools. In addition, the deep drawability of a cylindrical cup with a plastic die was examined.

Highly oriented UHMWPE films were reinforced with functionalized graphene nanoplates (GNP). GNP was functionalized by deposition of polyaniline (PANI) on the GNP surface. The structure of GNP/PANI was studied by Raman spectroscopy, and the structure of xerogels and films based on UHMWPE was studied by DSC and SEM. PANI promotes the reduction of the GNP aggregation in the UHMWPE matrix and increases the degree of crystallinity due to heterogeneous crystallization. The new lamellar crystal structure has a high drawability. The highest value of the tensile strength 1330 MPa (an increase of 45%) was obtained with a filler content of 2 wt % GNP/PANI, and the highest value of Young’s modulus 41 GPa (an increase of 32%) was obtained with a filler content of 1 wt % GNP/PANI. The effect of GNP with PANI fillers on the dynamic mechanical properties of the UHMWPE films was discussed.

The flow behavior and drawability of commercial press hardening steel Usibor®2000 were investigated at different forming temperatures using tensile test and Swift test in this study. The drawing performance of the alloy in room temperature forming, warm forming and hot forming processes was compared, and a comprehensive analysis of the microstructure and crystallographic texture characteristics was conducted. The results show that the press hardening process at 860 ℃ achieves uniform grain refinement and excellent formability in a short time due to the significant softening effect of dynamic recrystallization, with a recrystallized grain fraction reaching 58.7%. The tensile strength decreases significantly at 860 ℃, while the total elongation and limiting drawing ratio increased by 17 and 16.5%, respectively. The alloy exhibits excellent drawability due to the deep drawing in the hot stamping process of strong < 110 >  α //RD textures in the transformed and < 111 >  γ //RD textures in the untransformed grains. A mixture of martensite (70.22%), ferrite (16.21%) and bainite (13.57%) was obtained during PH process, realizing the ideal mechanical properties. The ultrafine grain structure was obtained by thermoforming process while maintaining the good formability of ultrahigh strength parts. These findings can serve as a useful reference for improving the forming process of 2 GPa press hardening steel.