Search Results (267)

This study investigates the influence of die design parameters on forging forces and thermomechanical responses during near-solidus forging (NSF) of complex steel components. Finite element simulations using Forge NxT analyzed six die configurations varying geometry orientation, gating system design (conical, cylindrical, curvilinear), and draft angles (20° and 30°), with 42CrMo4E steel modeled at 1360 °C. Key responses including punch and lateral forces, temperature distribution, strain localization, and die stress were evaluated to assess design effects. Results showed that the gating system geometry critically controls material flow and load requirements. The conical gating design with a 30° draft angle yielded the lowest punch (141.54 t) and lateral (149.44 t) forces, alongside uniform temperature and strain distributions, which improve product quality by minimizing defects and incomplete filling. Lower lateral forces also reduce die opening risk, enhancing die life. In contrast, the base case with a 20° draft angle exhibited higher forces and uneven strain, increasing die stress and compromising part quality. These findings highlight the importance of selecting appropriate gating systems and draft angles to reduce forming loads, increase die life, and improve uniform material flow, contributing to better understanding of die design in NSF of complex steel components. Full article

Innovative approaches in hot forging, such as the use of floating dies, which aim to minimise burr formation by controlling material flow, require precise management of die geometry distortions. These distortions, primarily caused by thermal gradients, must be tightly controlled to prevent malfunctions during production. This study introduces a comprehensive thermal analysis framework that captures the complete forging cycle—from billet transfer and die closure to forging, spray-cooling, and lubrication. Two advanced heat transfer models were developed: a pressure- and lubrication-dependent contact heat transfer model and a spray-cooling model that simulates fluid dispersion over die surfaces. These models were implemented within the finite element software FORGE-NxT to evaluate the thermal behaviour of dies under realistic operating conditions. These two new models, contact and spray-cooling, implemented within a full-cycle thermal simulation and validated with industrial thermal imaging data, represent a novel contribution. The simulation results showed an average temperature deviation of just 5.8%, demonstrating the predictive reliability of this approach. This validated framework enables accurate estimation of thermal fields in the dies, and offers a practical tool for optimising process parameters, reducing burr formation, and extending die life. Moreover, its structure and methodology can be adapted to various hot forging applications where thermal control is critical to ensuring part quality and process efficiency. Full article

Precision extrusion forging is an innovative manufacturing process for trouble-free production of high-quality components with an accurate shape. The process provides a reduced technological chain and high production efficiency, as only certain surfaces need additional processing. This study used QForm software as an environment for simulating precision extrusion forging. The main goal of this research was to present a brief overview of the latest research on the simulation of precision extrusion forging, with an emphasis on the production cycle rather than on mathematical description. This article examines the processes of simulation modeling of precision extrusion forging with newly designed tooling for the manufacture of a newly introduced asymmetric load-bearing facade element patented by Braykov. With the help of simulation modeling, appropriate modes for specific production were established, and were later implemented. The production process itself is briefly presented at the end of this article. Full article

We introduce a quantum integrated-information measure $\Phi$ for multipartite states within the Relational Quantum Dynamics (RQD) framework. $\Phi \left(\rho \right)$ is defined as the minimum quantum Jensen–Shannon distance between an n-partite density operator $\rho$ and any product state over a bipartition of its subsystems. We prove that its square root induces a genuine metric on state space and that $\Phi$ is monotonic under all completely positive trace-preserving maps. Restricting the search to bipartitions yields a unique optimal split and a unique closest product state. From this geometric picture, we derive a canonical entanglement witness directly tied to $\Phi$ and construct an integration dendrogram that reveals the full hierarchical correlation structure of $\rho$. We further show that there always exists an “optimal observer”—a channel or basis—that preserves $\Phi$ better than any alternative. Finally, we propose a quantum Markov blanket theorem: the boundary of the optimal bipartition isolates subsystems most effectively. Our framework unites categorical enrichment, convex-geometric methods, and operational tools, forging a concrete bridge between integrated information theory and quantum information science. Full article

The forging industry has increasingly emphasised quality and reproducibility, making computer simulations essential for predicting and improving the process. A major challenge in cold upset forging is billet buckling, which leads to defective products. Existing numerical models, such as the Euler and Rankine-Gordon formulas, mainly focus on elastic buckling. This study aimed to develop a numerical model that defined inelastic buckling during forging, particularly in cold upset forging, which could be used to determine the buckled billets and their stresses, identify the deflection point for different billet geometries, and specify the optimum billet geometry for aluminium. A numerical approach was used to model the forging operation and obtain simulation data for stress variation against die strokes. Seven billet geometries (10–40 mm in diameter, each with a length of 120 mm) and three frictional conditions (µ = 0.12, 0.16, and 0.35) were applied. The simulation results showed that the billet geometry and the strain hardening exponent had a crucial impact on the buckling behaviour, while friction seemed to alter the overall billet stresses. Rigorous non-linear regression and iterations showed that the numerical model successfully estimated the buckling stresses but failed to identify the buckling points through stress differences. Full article

Accurate preform design in forging processes is critical for improving part quality, conserving material, reducing manufacturing costs, and eliminating secondary operations. This paper presents a finite element (FE) simulation-based methodology for preform design aimed at achieving flashless and near-flashless forging. The approach leverages material point backtracking within FE models to generate physics-informed preform geometries that capture complex material flow, die geometry interactions, and thermal gradients. An iterative scheme combining backtracking, surface reconstruction, and point-cloud solid modeling was developed and applied to several three-dimensional forging case studies, including a cross-joint and a three-lobe drive hub. The methodology demonstrated significant reductions in flash formation, particularly in parts that traditionally exhibit severe flash under conventional forging. Beyond supporting the development of new flashless forging sequences, the method also offers a framework for modifying preforms during production to minimize waste and for diagnosing preform defects linked to variability in frictional conditions, die temperatures, or material properties. Future integration of the proposed method with design of experiments (DOE) and surrogate modeling techniques could further enhance its applicability by optimizing preform designs within a localized design space. The findings suggest that this approach provides a practical and powerful tool for advancing both new and existing forging production lines toward higher efficiency and sustainability. Full article

To achieve high-performance forgings of the C83600 tin bronze valve body with a uniform structure that is free from forging defects, rheological data were collected via hot compression experiments. Subsequently, an Arrhenius constitutive model incorporating strain compensation was established. The correlation coefficient, root mean square error, and mean relative error between the predicted values of the model and the experimental results were 0.99326, 5.1898, and 4.022%, respectively, which validated the model’s capability to accurately describe the rheological behavior of C83600. Using this model, the rheological data were incorporated into the Deform material library to enhance its database. A thermal processing map for C83600 under various deformation conditions was then developed. This map indicates that the material demonstrates excellent thermal working stability when the deformation temperature ranges from 850 to 900 K and the strain rate varies between 0.0067 and 0.0483 s⁻¹. Furthermore, numerical simulations were conducted to analyze the forging process, focusing on regions of stress concentration where the average strain rate aligns with the optimal parameters derived from the thermal processing map. This alignment not only verifies the reliability of the hot working map but also confirms the feasibility of the forging process through trial production. Full article

Titanium and its alloys have been widely used in high-end fields such as aerospace and biomedical engineering due to their excellent corrosion resistance and comprehensive mechanical properties. However, traditional titanium alloy processing technologies suffer from low material utilization and numerous defects. The emergence of near-net shape forming technology for powder titanium alloys via hot isostatic pressing (HIP) has broken through the limitations of traditional casting and forging, significantly improving the mechanical properties of titanium alloy materials, increasing material utilization, and shortening the production cycle of products. The application of numerical simulation technology has provided a scientific basis for the design of capsules and cores of complex high-performance components and has offered theoretical support for the densification of powders under thermomechanical coupling, becoming an essential foundation for achieving controllable shape and properties of components. This paper introduces the characteristics and process flow of HIP technology for powder titanium alloys, summarizes the current development status and research achievements of this technology both domestically and internationally, elaborates on the research progress of numerical simulation of HIP, and concludes with an analysis of the existing technological challenges and possible solutions, as well as an outlook on future development directions. Full article

Additive manufacturing is an innovative solution to produce components characterized by complex geometries. The use of such parts requires a deep knowledge of their behavior under different service conditions, especially from mechanical and corrosion resistance points of view. One of the most well-known and employed materials produced by selective laser melting is nickel alloy 625. It is already commonly used in its conventional form, but the additive manufacturing technology, despite its higher production costs and lower productivity, is becoming competitive because of its excellent mechanical strength. It is in fact significantly higher compared to the conventionally manufactured alloy whose properties are often limited by the difficulty in retaining a fine grain size during plastic deformation and heat treatment. Even though the as-built performance is already quite good, further strength improvement can be attained upon tailored single- and double-aging treatments that are optimized starting from the experimental results obtained in the conventional alloy and also considering the influence on corrosion resistance. In addition, considering that the stress-relieving treatment recommended for the conventional forged alloy at 870 °C is not suitable for the selective laser-melted material because of the more rapid precipitation response, this temperature is optimized to improve both the tensile deformability and the corrosion behavior. Full article

The stereoselective total synthesis of an allylic epoxide-containing polyunsaturated fatty acid, in its triethylsilyl (TES) ether and methyl ester form, is described. Key features include a Sharpless enantioselective epoxidation to install the oxirane unit and Wittig coupling reactions to forge critical alkenyl configuration and secure the core carbon skeleton. The deprotected epoxy acid was recently demonstrated to play a central role as the precursor to biologically active resolvins D1, D2, and the cysteinyl conjugate in tissue regeneration (RCTR1) by human leukocytes. These natural products belong to a family of cell signaling molecules termed specialized pro-resolving mediators (SPMs). Full article

The hot deformation behavior of 4Cr16MoCu martensitic stainless steel alloyed with 1% Cu was investigated through hot compression tests at temperatures ranging from 900 to 1150 °C and strain rates of 0.001 to 1 s⁻¹. The addition of Cu is strategically employed to synergistically enhance precipitation hardening and corrosion resistance, yet its complex interplay with hot deformation mechanisms remains poorly understood, demanding systematic investigation. The results revealed a narrow forging temperature range and significant strain rate sensitivity, with deformation resistance increasing markedly at higher strain rates. An Arrhenius constitutive model incorporating a seventh-degree polynomial for strain compensation was developed to describe the flow stress dependence on deformation temperature and strain rate. The model demonstrated high accuracy, with a correlation coefficient (R²) of 0.9917 and an average absolute relative error (AARE) of 3.8%, providing a reliable theoretical foundation for practical production applications. Furthermore, a hot processing map was constructed based on the dynamic material model (DMM), and the optimal hot working parameters were determined through microstructural analysis: an initial forging temperature of 1125 °C, a final forging temperature of 980 °C, and a strain rate of 0.1 s⁻¹. These conditions resulted in a fine and uniform grain structure, while strain rates above 0.18 s⁻¹ were identified as unfavorable due to the risk of uneven deformation. Full article

This pioneering study examines metallographic characteristics of 19th-century steel semi-finished products, kept by the National Museum of Slovenia. These artefacts, manufactured in pre-industrial ironworks in present-day Slovenia, reflect the craftsmanship and technological practices of their time. Metallographic analyses revealed significant microstructural variations within individual samples, attributed to differences in carbon content, cooling rates, and forging techniques. All samples contain non-metallic inclusions composed of Si, Mn, and other oxide-forming elements. The results indicate that the semi-finished products were often manufactured by combining steels with varying carbon contents and were sometimes hardened. Additionally, this study highlights correlations between the metallurgical properties of the analysed materials and their historical classification as “iron” or “steel”. Full article

Co-Cr-Mo alloys are in high demand as materials for medical implants. However, hot processing of these alloys is quite difficult due to the need to maintain narrow temperature range of deformation to achieve the required mechanical properties and structure of the products. The features of formation of structure, phase composition and mechanical properties of Co-Cr-Mo alloy at the main stages of thermomechanical treatment were considered in this study. The results demonstrated a significant enhancement in the strength characteristics of the alloy during processing in both forging and radial shear rolling (RSR). At the same time, radial shear rolling processing simultaneously increased the strength and ductility of the alloy. According to the XRD analysis data, the phase composition changes from single-phase structure (FCC-phase) after forging to a mixture of FCC-phase and HCP-phase after RSR during processing. The structure gradient characteristic of RSR decreased as the total elongation ratio increased, maintaining a tendency towards a finer-grained structure near the surface of the bars and a coarser one in the center. This tendency was reflected in the average grain size and the level of mechanical properties. Combined thermomechanical treatment, including the RSR process, made it possible to achieve a unique formation of microstructure and phase composition in the Co-Cr-Mo alloy, ensuring high strength while maintaining ductility. Full article

This article focuses on the genealogy of the Mackintosh archive, showing how subjects are interpellated through archival networks that span imperial and metropolitan sites, linking people, ideas, knowledge and material resources. By tracing the Mackintosh archive across generations of family members embedded in British imperial society, it shows how archives call forth an individual—Sir James Mackintosh—as a symbol and a site of the interconnections between the patriarchal family, the male-dominated state and the production of cultural imaginaries of belonging. Tracing this archive, it argues that the ‘society’ to which James Mackintosh belonged is both reflected in, and constituted through, the letters and journals that comprise his archive. In form and content, they provide the material evidence for the interconnectedness of social, familial, intellectual and political lives. They function both as fantasies and representations of belonging to a social network—a community—and a constitutive part of the consolidation of that network. The letters and diaries that comprise the Mackintosh Archive bear witness to the formation of a literary elite at the turn of the nineteenth century and the mobility of that elite around European-imperial space. Thus, the Mackintosh Archive illustrates the point, made by an increasing number of imperial and global historians, that ideas and identities were forged through inter-connections across space. Full article

Eccentric camshaft components serve as critical elements in emergency pump systems for commercial vehicle steering mechanisms. To optimize material utilization efficiency, reduce production costs, and enhance manufacturing throughput, this investigation implemented a vertical upsetting extrusion forming methodology for camshaft forging production. Initial trials revealed defect formation in forged components. By analyzing the causes of the defects, an improved process method was developed to eliminate them. The chemical composition, macroscopic and microscopic morphologies of defects, forging process, and metal streamlines were analyzed and studied by means of a direct reading spectrometer, high-resolution camera, metallographic microscope, DEFORM finite element analysis software, and chemical etching. Findings indicate that the observed defects constitute forging-induced cracks, with subsequent normalizing heat treatment exacerbating decarburization phenomena in defect-adjacent microstructures. During the forging process of the forgings, the metal continuously extruded into the die cavity, and the inflowing metal pulled the dead zone metal downward, causing the flow lines aligned with the contour to bend into S-shaped metal streamlines. Cracks formed when the tensile stress in the dead zone metal exceeded the material’s critical tensile stress. An improved process was proposed: adopting a vertical upsetting extrusion forming method with a 40° diversion angle at the junction between the first step and the thin rod in the die cavity. Numerical simulations confirmed complete elimination of deformation dead zones in the optimized process. Experimental verification demonstrated crack-free forgings. Therefore, the eccentric camshafts formed by the initial process exhibited forging cracks, and the proposed improved method of vertical upsetting extrusion forming with a diversion angle effectively eliminated the forging cracks. Full article