Search Results (102)

Stricter drinking water regulations intensify the need to replace leaded brasses in fittings. This work reports preliminary results on internally coated fittings using the wrought zinc alloy ZnAl15Cu1Mg (ZEP1510). A straight-tube Model Geometry 1 was lined internally with HDPE by gas-assisted injection molding, achieving a continuous barrier of 1.55–1.70 mm without altering the external envelope. A press-type T-fitting (32–32–32) was defined as Model Geometry 2 to benchmark forgeability; process layout (FEM) and warm-forging trials are summarized. Recycling relevance was addressed via a partial-melt (drip-off) route, which removed a substantial polymer fraction but left measurable residues. A production-cycle PCF from material production to finished tee indicates 3.156 kg CO₂e for ZEP1510 vs. 5.385 kg CO₂e (CuZn40Pb2) and 6.301 kg CO₂e (CuZn21Si3), i.e., 41.85% and 50.06% savings. These findings establish manufacturability, indicate recycling feasibility, and quantify a CO₂ advantage, outlining the next steps toward lining complex geometries and drinking water compliance. Full article

It is crucial to investigate methods for improving the stiffness performance of machine tools according to their specific dynamic working conditions. This paper presents a complete computer-aided workflow for structural transient topology optimization (TO) design, which is applied to the structural design issue of the JH31-250 press machine (Zhejiang Weili Forging Machinery Co., Ltd., Shaoxing, China). The stiffness influenced by the shape of the press frame under long-term dynamic impact load is analyzed, and an optimal design for the frame structure of the press machine is explored. In order to reduce the iteration time of the dynamic analysis, we also proposed a way to simplify the physical structure of the machine tool into a thin-walled structure model with artificial pseudo-density and introduced the hybrid cellular automata (HCA) criterion to obtain the topological iteration direction. This simplified model can be transformed back into 3D solid design of the press. The maximum relative displacement of the worktable in this optimized press model is 0.4896 mm, which is reduced by 31.02% compared to the original press model, which shows that the transient dynamic stiffness of the press machine frame is improved. This work presents a topological optimization method and path, which can be used for the optimization of dynamic stiffness in forging machine tools, and proves the correctness and effectiveness of the design for the transient dynamic stiffness of the frame. Full article

To address the challenges of short allowable motion windows and complex motion planning inherent in dual forging manipulator systems, this study proposes a coordinated motion pattern tailored to dual-manipulator operations, focusing on forging deformation behavior and press control characteristics. First, six representative long-shaft forging materials were classified based on typical industrial applications. Using DEFORM-3D (V11.0) software, the deformation process during the elongation operation was analyzed, and the velocity and displacement characteristics at both ends of the forgings were extracted to clarify the compliant motion requirements of the grippers. Next, a segmented computation method for manipulator allowable motion time was developed based on the motion–time curve of the hydraulic press, significantly improving the time utilization efficiency for coordinated control. Furthermore, experimental tests were carried out to verify the dynamic response performance and motion accuracy of the dual-manipulator system. Finally, the dual-manipulator forging cycle was systematically divided into four stages—pre-forging adjustment, inter-pass compliance, execution phase, and forging completion—resulting in a structured and implementable coordination control framework. This research provides both a theoretical foundation and practical pathway for achieving efficient and precise coordinated motion control in dual forging manipulator systems, offering strong potential for engineering application and industrial deployment. Full article

The thermal deformation behaviour of a spray-formed 7055 as-forged aluminium alloy was studied using isothermal hot-press tests under different deformation conditions (strain rates of 0.01, 0.1, 1, and 10 s⁻¹, temperatures of 340, 370, 400, 430, and 460 °C). An Arrhenius constitutive model was developed using flow stress data corrected for friction and temperature, yielding a correlation coefficient (R) of 0.9877, an average absolute relative error (AARE) of 4.491%, and a deformation activation energy (Q) of 117.853 kJ/mol. Processing maps integrating instability criteria and power dissipation efficiency identified appropriate processing parameters at 400–460 °C/0.08–0.37 s⁻¹. Furthermore, this study investigated how strain rate and temperature influence microstructural evolution. Microstructural characterization revealed that both dynamic recovery (DRV) and dynamic recrystallization (DRX) occur simultaneously during thermal deformation. At low temperatures (≤400 °C), DRV and continuous dynamic recrystallization (CDRX) dominated; at 430 °C, deformation microstructures and recrystallized grains coexisted, whereas abnormal grain growth prevailed at 460 °C. The prevailing mechanism of dynamic softening was influenced by the applied strain rate. At lower strain rates (≤0.1 s⁻¹), discontinuous dynamic recrystallization (DDRX) was the primary mechanism, whereas CDRX became dominant at higher strain rates (≥1 s⁻¹), and dislocation density gradients developed within adiabatic shear bands at 10 s⁻¹. Full article

The aim of this work was to study the influence of temperature and strain rate on the formability and structure of C22 steel. This study was based on tensile and compression tests. In the case of the compression test, the study of the influence that the process parameters (temperature and strain rate) have on the nonuniformity of the deformation was taken into account. This work presents an experimental analysis of the effects of temperature and strain rate on the mechanical and structural properties of C22 mild steel. Uniaxial tension and compression testing at high temperatures (800 °C, 900 °C, 1000 °C, and 1100 °C) and strain rates 0.001 1/s, 0.012 1/s, and 0.089 1/s for tension and 6.35 1/s, 5.72 1/s, 4.67 1/s and, respectively, 0.106 1/s for the compression hammer and hydraulic press served as the foundation for the studies. Analysis was carried out on how temperature and strain rate affected yield stress, strain to fracture, hardness, and structural evolution. Additionally, the nonuniformity of the deformations obtained at various temperature and strain rate values was examined. The fracture behavior of C22 steel can be enhanced by raising the deformation temperature and lowering the strain rate. In the tensile tests, the study of stress and strain distribution and the variation in the normalized Latham–Cockroft failure criterion was performed by numerical simulation using FORGE^® NxT 4.1 software. Full article

In this paper, we propose the use of burnishing internal cylindrical surfaces with a hard tool in a mandrel shape. The burnishing force is exerted mainly by the press slide, which has pushing properties, moving the burnisher through the hollow tube. The burnishing of hollow surfaces is used as the finishing step for elements such as tubes. The purpose of using the burnishing method may be, for example, to increase the smoothness and accuracy of the object, for the improvement of its functional and operational properties, for economic reasons, or to increase its resistance to corrosion and fatigue. The depth of plastic deformation and the accuracy of processing are the main differences in the machining effects for individual burnishing methods. The selection of the burnishing conditions depends on the method of exerting pressure from the burnishing elements on the machined surface, which can be elastic or rigid. Computer simulations of the burnishing process were performed in FORGE^® NxT 2.1 software. A numerical analysis was performed using a three-dimensional triangular mesh. The theoretical and experimental research was determined to have very good compatibility, as determined by the numerically calculated results and by the mean deviation of residual stress method. This research analyzed the stress and strain state after the burnishing process, and a depth of deformation of approximately 20 μm to 30 μm in the material was determined. 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

In this study, the hot deformation behavior of novel 0.17C-3.92Mn-1.02Si-0.53Al-0.22Mo-0.032Ti-0.069V steel during continuous compression was predicted using numerical simulation, providing a reference for optimizing the process. Medium-Mn steels have not been applied for forgings yet. Therefore, their industrial application requires detailed investigations on their hot deformability. Results of finite element (FEM) simulations will be used for further optimization of the press forging process. The material model parameters used in the FEM method were identified based on stress–strain curves registered during hot compression tests carried out using a Gleeble thermomechanical simulator. The numerical simulation and physical investigations were performed at temperatures of 900, 1000 and 1100 °C to reflect a range of temperatures occurring during press forging. The influence of strain rates of 0.05, 0.5 and 5 s⁻¹ on the flow behavior of steel was also investigated. Colored maps of the plastic strain distribution in a sample volume were obtained as a result of the numerical research. The maps allowed for the identification of differently strengthened zones as a result of varied plastic strain. Results of FEM analysis were experimentally validated by hardness measurements. A good correlation between the hardness and plastic deformation zones was obtained. An increase in the material hardness was identified in the zones characterized by the highest plastic strain. Full article

This study investigates the effects of graphite particle reinforcement on the mechanical and tribological properties of aluminum alloy AA6061 composites produced via hot press forging (HPF), a direct recycling method for aluminum chips. Graphite content varied from 2.5% to 12.5%, with the Al6061-7.5%Gr composite achieving the highest tensile strength (102.36 MPa) and yield strength (87.07 MPa). Hardness peaked at 24.73 HV with 5% graphite. Tribological tests showed improved wear resistance at higher graphite levels, with the Al6061-12.5%Gr composite exhibiting the lowest wear rate (0.00033 mm³/N·m). These findings highlight HPF’s potential for sustainable fabrication of high-performance aluminum composites. Full article

A novel nickel-based powder metallurgy superalloy was processed using two different thermal–mechanical processes, including hot isostatic pressed (As-HIP) and hipped + hot extruded + isothermally-forged (IF) heat treatments following two processed alloys, designated as As-HIP-HT and IF-HT. The objective of this study is to investigate the microstructure and mechanical property evolution in a nickel-based powder disk alloy fabricated by two processes. The findings revealed that both As-HIP and IF alloys underwent substantial recrystallization, with grains in the IF alloy being finer. Notable Prior Particle Boundaries (PPBs) were identified in the As-HIP samples. The IF-HT alloy exhibited a larger grain size due to a greater amount of stored energy. Significant differences in the secondary γ′ precipitates were observed between the two processes. More uniform substructures in the IF-HT alloy led to a higher density of finer γ′ precipitates. At temperatures of 704 °C and 760 °C, the As-HIP-HT alloy displayed a higher yield strength, but its plasticity significantly declined as temperature increased, while the IF-HT alloy showed a relatively stable plasticity. The presence of PPBs in the As-HIP-HT alloy minimally affected the alloy’s strength but reduced its plasticity. The creep property of the two processes was compared at 800 °C/330 MPa; the IF-HT alloy demonstrated lower creep rates and a longer creep life, which was attributed to its finer γ′ precipitates. Dominant creep deformation mechanisms in the As-HIP-HT alloy included Orowan dislocation loops and deformation twinning, while the primary mechanisms in the IF-HT alloy involved dislocation cutting through γ′ precipitates, dislocation slip, and micro-twins. These findings support the use of isostatic pressing + hot extrusion+ isothermally-forging process for critical high-temperature components. Full article

Cooling Rate (CR) definitively influences the microstructure of metallic parts manufactured through various processes. Factors including cooling medium, surface area, thermal conductivity, and temperature control can influence both predicted and unforeseen impacts that then influence the results of mechanical properties. This comprehensive study explores the impact of CRs in diffusion, microstructural development, and the characterization of aluminum alloys and the influence of various manufacturing processes and post-process treatments, and it studies analytical models that can predict their effects. It examines a broad range of CRs encountered in diverse manufacturing methods, such as laser powder bed fusion (LPBF), directed energy deposition (DED), casting, forging, welding, and hot isostatic pressing (HIP). For example, varying CRs might result in different types of solidification and microstructural evolution in aluminum alloys, which thereby influence their mechanical properties during end use. The study further examines the effects of post-process heat treatments, including quenching, annealing, and precipitation hardening, on the microstructure and mechanical properties of aluminum alloys. It discusses numerical and analytical models, which are used to predict and optimize CRs for achieving targeted material characteristics of specific aluminum alloys. Although understanding CR and its effects is crucial, there is a lack of literature on how CR affects alloy properties. This comprehensive review aims to bridge the knowledge gap through a thorough literature review of the impact of CR on microstructure and mechanical properties. Full article

Valve-controlled hydraulic systems are widely used in various hydraulic equipment, but their asymmetric characteristics are the most critical factor restricting further improvements in system performance. This paper takes large asymmetric complex hydraulic equipment as the industrial background, and proposes a state feedback-based symmetric switching control method to address the complex control strategy and difficult control accuracy caused by input–output asymmetry and the inconsistent response of asymmetric valve-controlled hydraulic systems. A system state space model is established, and the parameterized expression that satisfies the state space switching-based symmetric control law is solved. Feedback and feedforward links based on state space symmetric switching are designed to transform the asymmetric system into a state space symmetric system. And the research results will be applied to the experimental setup of the 300 MN forging hydraulic press control system. Through simulation verification, under asymmetric PID control conditions, due to the influence of the asymmetric characteristics of the system structure, load, and their coupling relationship, the forward response time is shorter than the unloaded response time, and the overshoot is larger than the unloaded response time. The reverse response time is longer than the unloaded response time, and the overshoot is smaller than the unloaded response time. After symmetric control, the forward and reverse dynamic system characteristic curves completely overlap, proving that the system has achieved symmetric transformation; through experimental verification, under asymmetric PID control conditions, when the proportional valve opening remains constant, changes in the load pressure will cause changes in the load speed. For every 1 MPa increase in the load pressure, the load speed will slow down by about 0.0033 m/s. The load speed of the system after symmetrical control replacement will be much less affected by changes in the load pressure. The simulation and experimental results have shown that this method is expected to solve the key problem of inconsistent dynamic characteristics of complex equipment hydraulic systems in both the forward and reverse directions due to asymmetry, and the inability to ensure control accuracy in both directions using symmetric control strategies. This paper has developed a set of control theories and methods applicable to hydraulic systems with complex asymmetry. Full article

Rotary friction welding is a solid-state welding process that can manufacture high-integrity joints between similar and dissimilar materials with short weld times. However, access to expensive and complex industrial-grade friction welding machines is not always possible. This study explores the design process and functionality of a laboratory-scale friction welding setup following the fundamentals of large-scale machinery. The proposed setup is designed to be easily manufactured, employing the use of a calibrated drill press and load cell, thus ensuring welding parameters such as rotational speed and applied axial load are monitored. The decision to investigate rotary friction welding of aluminium bronze Ca104 to austenitic stainless steel AISI316 was taken to explore the limitations of this bespoke friction welding machine for prospective applications in the nuclear energy sector. The workpieces were friction welded at four sets of rotational speeds with constant friction and forging pressures. The microstructural evolution and mechanical properties of the dissimilar material welds were investigated via optical and scanning electron microscopy with energy dispersive spectroscopy, 4-point bend testing and microhardness measurements. Results show a change in the hardness along the weld interface and evidence of metallic diffusion between the dissimilar materials, demonstrating the successful application of the small-scale experimental setup. Full article

Due to carbon dioxide (CO₂) levels, driven by our reliance on fossil fuels and deforestation, the challenge of global warming looms ever larger. The need to keep the global temperature rise below 1.5 °C has never been more pressing, pushing us toward innovative solutions. Enter carbon capture, utilization, and storage (CCUS) technologies, our frontline defense in the fight against climate change. Imagine a world where CO₂, once a harbinger of environmental doom, is transformed into a tool for healing. This review takes you on a journey through the realm of CCUS, revealing how these technologies capture CO₂ from the very sources of our industrial and power activities, repurpose it, and lock it away in geological vaults. We explore the various methods of capture—post-combustion, oxy-fuel combustion, and membrane separation—each with their own strengths and challenges. But it is not just about science; economics play a crucial role. The costs of capturing, transporting, and storing CO₂ are substantial, but they come with the promise of a burgeoning market for CO₂-derived products. We delve into these financial aspects and look at how captured CO₂ can be repurposed for enhanced oil recovery, chemical manufacturing, and mineralization, turning waste into worth. We also examine the landscape of commercial-scale CCS projects, highlighting both global strides and regional nuances in their implementation. As we navigate through these advancements, we spotlight the potential of Artificial Intelligence (AI) to revolutionize CCUS processes, making them more efficient and cost-effective. In this sweeping review, we underscore the pivotal role of CCUS technologies in our global strategy to decarbonize and forge a path toward a sustainable future. Join us as we uncover how innovation, supportive policies, and public acceptance are paving the way for a cleaner, greener world. Full article

This paper introduces a multi-objective optimization problem (MPO) for the forming process parameters of disc forgings using grey relational analysis (GRA) and the response surface methodology (RSM). Firstly, an experimental design based on the Box–Behnken design (BBD) principle was established, and simulations were performed in Deform to obtain response data. Secondly, GRA was used to transform the MPO into a grey relational degree (GRD) problem, and the entropic weight method was integrated to ascertain the influence weights of each variable on GRD. Then, a quadratic polynomial prediction model based on the RSM was constructed, and its accuracy was ensured through model validation. Finally, the optimal process parameter combination was determined through the particle swarm optimization algorithm, which included a friction coefficient of 0.3, an initial temperature of 1250 °C, and a downward pressing speed of 7.5 mm/s. The results of the experimental investigation indicate that optimized process parameters significantly reduce the forming load, equivalent stress, and damage value, effectively enhancing the overall quality of forged parts. Full article