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The objective of this work is to study the ability of friction surfacing to deposit metal alloys that are difficult to process with traditional methods. Creep and neutron irradiation-resistant oxide dispersion strengthened (ODS) materials cannot be produced via the conventional casting route due to the insolubility of the oxidic and metallic alloy constituents, causing unintended inhomogeneous oxide dispersion and material behavior. Increasing the silicon content of iron-silicon (Fe-Si) improves electromagnetic properties but embrittles the material significantly, and fusion-based manufacturing methods are unable to process this steel. The solid-state nature of the friction surfacing process offers a potential alternative processing route to enable wider usage of difficult-to-process alloy systems. Both ODS and Fe-Si materials are available in powder forms. While the existing literature in friction surfacing focuses on depositing composites by incorporating small quantities of powders through holes in consumable rods, this is the first study showing that a large charge of powder can be converted to a homogeneous fully consolidated deposit in friction surfacing. A novel methodology is used that incorporates the high portion of powder feedstock into hollow consumable friction surfacing rods (up to 35% volume fraction). It was found that fully consolidated deposits can be produced with powder feedstocks using the proposed methodology. A recrystallized, homogeneous, equiaxed microstructure was observed in Fe-Si 6.8 wt% and a new-generation FeAlOY ODS alloy deposits processed with hollow stainless steel friction surfacing rods. Both powder and rod material plasticize and deposit without bulk intermixing. [ABSTRACT FROM AUTHOR]

Obtaining the desired strip profile is of paramount importance in cold rolling. The final strip profile depends on several parameters of the plants including crown and taper profiles and segmented backup roll positions. This paper aims to present a newly developed combined finite element-analytical model of the rolling mill able to model not only the roll cluster but also the mill housing and backup bearings deformations. This makes the proposed model especially suitable to simulate cluster-type rolling mills. The model exploits a modified elastic foundation formulation for a precise computation of the contact forces between rolls, taking into account rolls' crown and taper. A reduced stiffness matrix approach is implemented for accurate mill housing modeling. A full 3D finite element model of the rolling mill and experimental data are used for the validation of the presented model. By exploiting the validated model, the paper shows that the deformation of supporting bearings and mill housing plays a crucial role in the strip profile calculation and should be included in any cluster-type roll mill model. [ABSTRACT FROM AUTHOR]

One-step (F100) and three-step (F30-60-40) hot forging of Al0.35CoCrFeNi alloy was investigated to achieve a uniform equiaxed grain structure. In the as-cast and forged state, only a single-phase face-centered cubic structure was observed. The formation of twins, recrystallized and partially recrystallized grains in the volume of the samples was observed depending on used forging process. To predict uniform grain-size formation numerical simulation of the hot-forging process was used. The numerical model was calibrated and validated by means of measured compression experimental data of as-cast Al0.35CoCrFeNi alloy before forging. Thermal analysis using finite element analysis was used to simulate cooling of sample during the relocation from the furnace on the lower die. Simulations were run under different thermo-mechanical conditions and the regions for the formation of dynamically recrystallized grains were predicted. Room temperature mechanical properties were evaluated after F100 and F30-60-40 hot-forging process. The F30-60-40 hot forging optimized the grain size, which was evident in the very small dispersion of the room temperature mechanical properties in tension. Elongation after F30-60-40 hot forging increased by 17%. The correlation between temperature, equivalent stress, equivalent plastic strain, microstructure, tensile properties, and strain-hardening behavior is discussed. [ABSTRACT FROM AUTHOR]

Numerical simulations are crucial for predicting outcomes in forging processes but often neglect dynamic interactions within forming tools and presses. This study proposes an approach for achieving accurate real-time prediction of forging outcomes. Initially, a simulation-based surrogate model is developed to replicate key process characteristics related to the billet, enabling prediction of geometry, deformation field, and forging load after an upsetting operation. Subsequently, this model is integrated with a mass-spring-damper model representing the behavior of forging machine and tools. This integration enables the prediction of blow efficiency and energy distribution after each blow, including plastic, elastic, damping, and frictional energy of the upsetting operation. The approach is validated by comparing predictions with experimental results. The coupled model outperformed Finite Element Method (FEM) predictions, exhibiting mean absolute errors (MAE) below 0.1 mm and mean absolute percentage errors (MAPE) below 1% in geometry predictions. Deformation field predictions showed errors below 0.05 mm/mm, and load-displacement curves closely matched experimental data. Blow efficiency predictions aligned well with experimental results, demonstrating a mean absolute error below 1.1%. The observed energy distribution correlated with literature findings, underscoring the model’s fidelity. The proposed methodology presents a promising approach for accurate real-time prediction of forging outcomes. [ABSTRACT FROM AUTHOR]

The inhomogeneity present in the deformation and microstructure during the open die forging of large size ingot significantly influences the mechanical properties of the final part. This study aims to develop a microstructure-based finite element (FE) model and investigate the influence of deformation path on microstructure evolution during the upsetting process of large size ingot of a high strength steel. The difference in deformation path is achieved by modification in anvil shape such as flat, v shape, convex, and concave die. To achieve this goal, hot compression tests were carried out using the Gleeble 3800 thermomechanical simulator. Utilizing the acquired and corrected flow stress data, a material model and a microstructure model were established, and both formulated models were then integrated into the Forge NxT 3.2 finite element simulation software through the inclusion of a dedicated user subroutine. The predictions from the FE analysis were validated with experimental results on standard size hot compression specimens, which allowed for the accurate prediction of the dynamic recrystallized average grain size at the end of hot deformation. Afterwards, the validated FE model was scaled up to simulate the industrial upsetting process, making it possible to investigate the effect of deformation path on inhomogeneity of strain and microstructure evolution at the end of upsetting process for large sized forged ingots. An evaluative analysis of four die geometries, aimed at identifying the optimal die shape for minimizing inhomogeneity in strain and grain size across a large size forged ingot, was conducted. It was found that the convex die provokes the lowest deformation, while the concave die induces the highest deformation values at the center of the ingot. Utilizing the coefficient of variation as an indicator of heterogeneity, it was determined that the v-die and concave die resulted in a more consistent grain size distribution compared to the flat and convex dies. [ABSTRACT FROM AUTHOR]

The tribological phenomena concerning the lubrication regime change (LRC) during bulk metal forming are comprehensively studied. A multi-step cold forward extrusion process shows the evolution of LRC and reveals the shortcomings of the traditional Coulomb friction law. The previous works of the specific author's research group on friction are reviewed, focusing on the LRC during bulk metal forming. Various LRC phenomena from various examples are revealed. It has been found that the drawing and forward extrusion processes are vulnerable to LRC because of significant sliding motion at the material–die interface, and that when the strain hardening of the material is slight, the influence of friction increases, and as a result, the influence of LRC increases excessively. The new findings also include the impact of LRC on the macroscopic phenomena of the process and the reason for the sharp increase in friction coefficient via LRC, which is validated by the work of Wilson. This paper aims to make engineers and researchers think much of the tribology with lubricant in bulk metal forming with a focus on the dependence of tribological phenomena on the state of the lubricants and the irrationality of traditional friction law, especially in the forging of materials with a low strain hardening capability. [ABSTRACT FROM AUTHOR]

The liner is affixed to the inner side of the ball mill cylinder to protect the cylinder. Through isothermal compression experiments, Arrhenius constitutive models, peak strain models, critical strain models, dynamic recrystallization dynamic models, and grain size models suitable for the forging process of Mn–Cr–Ni–Mo steel used in ball mill liners were established. By utilizing Deform software, a 3D thermo‐force‐structure coupling model for the hot forging process of ball mill liners was constructed, and the volume fraction of dynamic recrystallization and average grain size during forging was predicted. The response surface model was employed to investigate how process parameters interacted with each other and affected microstructure uniformity in ball mill liners. After optimization, the optimal parameters were determined: initial forging temperature at 1200 °C, forging speed at 30 mm s−1, and friction coefficient at 0.3. Subsequently, a hot forging experiment on ball mill liners was conducted using these optimized parameters; samples were analyzed through backscattered electron diffraction device experiments and microscopic tissue observations. Results demonstrated that microstructural changes observed during actual forging processes aligned with numerical simulation results—thus verifying both the accuracy of the Mn–Cr–Ni–Mo steel material model and numerical simulation method. [ABSTRACT FROM AUTHOR]

Forging of sintered Al–Fe–Sn samples was carried out in a closed die at different temperatures. The flow of the material under the influence of frictional forces was non-uniform, and the sample was fractured. It has been established that in order to maintain the integrity of the two-phase material, forging must be carried out with the application of back pressure. It is recommended to forge the composites at elevated temperatures. [ABSTRACT FROM AUTHOR]

In this paper, a forging tool of a new design is proposed, which allows to implement shear and alternating strain in the entire volume of the deformed billet with a smaller change in its initial dimensions. To confirm the effectiveness of the proposed new forging tool in obtaining billets and forgings of the plates and slabs type of the required quality, a laboratory experiment was conducted. During the laboratory experiment, the forging of billets made of the steel 45 was carried out in such forging tools as step-wedge dies of two different variants (proposed and previously known) and in step dies. Analysis of the shape change of billets and the evolution of the microstructure of steel after two deformation cycles showed that the use of the step-wedge dies with a wedge protrusion on the upper die and a wedge cavity on the lower die is more promising for forging billets and forgings of the plates and slabs type with a given level of mechanical properties, since it allows to obtain a fine-grained structure with a smaller change in the initial dimensions of the billet. [ABSTRACT FROM AUTHOR]

Structural automotive components are extensively made of aluminum alloy forgings, due to the elevate strength and low weight required. These products are frequently subjected to recrystallization. Recrystallization, often limited to surface or forging portions, is expected to reduce its tensile strength and corrosion resistance, but the literature is scarce on this subject. For a more comprehensive understanding, the present research studied the corrosion behavior of samples collected from EN AW 6082‐T6 forged components, designed to expose both recrystallized and not recrystallized surfaces to the corrosive environment. Several standardized corrosion tests (i.e., PV 1113, ISO 11846, and VW 96380) were applied to assess the most representative with respect to real field exposure. Tensile tests were performed in four different conditions, recrystallized and not recrystallized specimens in an as‐forged state or after corrosion. The recrystallization led to a reduction in tensile properties, but this gap was compensated by a higher corrosion resistance than the not recrystallized samples. Consequently, the mechanical properties became comparable after the corrosion test. [ABSTRACT FROM AUTHOR]

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Copyright of BHM Berg- und Hüttenmännische Monatshefte is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As a core component in the industrial sector， the efficient and high-precision forming of hollow shafts is crucial for ensuring product performance and improving production efficiency. However， traditional open die forging and closed die forging methods face significant challenges， such as low material utilization， insufficient forming precision， and limited production efficiency. These issues severely restrict the development and application of hollow shafts. This paper reviews the latest research advancements in hollow shaft manufacturing， analyzes the current technical challenges， and explores the prospects of emerging forming technologies as well as the application of digital and intelligent technologies in this field. The paper summarizes the applications and advantages of various technologies， including rotary forging， squeeze casting， wedge cross rolling， and three-roll skew rolling， in enhancing the manufacturing efficiency and forming precision of hollow shafts. Rotary forging， by rotating and forging the material， effectively improves material utilization and product performance. Squeeze casting achieves high precision and consistency by pressing liquid metal into molds under high pressure. Wedge cross rolling drives the billet through the mold for reverse rotation， causing radial compression and axial elongation deformation of the metal， ultimately forming the desired stepped shaft parts， thereby improving dimensional accuracy and production efficiency. Three-roll skew rolling technology optimizes the loading mechanism to achieve efficient and continuous axial plastic forming through localized loading. With the manufacturing industry moving towards digitalization and intelligence， hollow shaft manufacturing technology is expected to achieve significant advancements and breakthroughs in the future.

The present study systematically investigated the influence of forging strategies on the microstructures and deformation behaviors of a Ti–5Al–5Mo–5V–1Cr–1Fe (Ti-55511) near β-titanium alloy. Microstructure analysis revealed that the as-cast alloy exhibited a basket-weave structure predominantly comprised of lamellar α phase. Three different forging methods were used to adjust the morphology of the primary α phase during the final two forging steps: 1) dual-phase (825 °C) + dual-phase forging (DD sample), 2) dual-phase + β single-phase (900 °C) forging (DS sample), and 3) β single-phase + dual-phase forging (SD sample). After standard heat treatment, the DD samples exhibited equiaxed αp due to sufficient deformation in dual-phase region, while DS samples transformed into lamellar shape due to αp reforming during the cooling process of the final β single-phase forging. In contrast, the SD samples displayed short-rod αp due to reforming in the single-phase region and insufficient deformation in the dual-phase region. All these αp and βt phases can hinder dislocation motion to enhance the strength. The DS sample exhibited the best combination of strength, ductility, and impact toughness. During tensile deformation, planar dislocation slip and {101‾1} twinning were dominant in the αp, while wave slip occurred in the βt phase. The fracture behavior transitioned from brittle to ductile after forging and heat treatment. Overall, this study offers a practical and effective method for optimizing the mechanical properties of the Ti-55511 alloy.

In this study, CuCr50 alloys were prepared by aluminum thermal reduction-high frequency refining process, and the properties were improved through hot forging and heat treatment. With increasing deformation, large Cr particles were spheroidized and refined, significantly improving the performance of the alloy. When the deformation exceeds 27%, the conductivity reaches 17.73 MS/m, the hardness reaches 116.5 HB, and the density reaches 7.91 g/cm3. After solution at 975 °C for 1h and aging at 550 °C for 4h, the conductivity of the CuCr50 alloy further increased to 19.63 MS/m, the hardness reaches 121.5 HB. Compared with the as-cast alloy, the conductivity, hardness and density are increased by 71.07%, 18.81% and 2.99%, respectively. In the 5% deformed CuCr50 alloy the precipitates of nanoscale Cr particles formed a co-lattice with the copper matrix. In the 14% deformed CuCr50 alloy, nanoscale Cr particles precipitated and dispersed in the Cu matrix, and the relationship between the precipitated Cr phase and the Cu matrix was incoherent. The amount of precipitated Cr phase in the 27% deformed CuCr50 alloy had a semi-coherent relationship with the Cu matrix, the orientations of Cu(2‾00)//Cr(110). The hardness enhancement is mainly attributed to grain refinement and density increase, and the conductivity enhancement is mainly attributed to Cr particle precipitation after aging treatment.

Aluminium finds wide application in mechanical engineering due to its low density and corrosion resistance. In this research, aluminium was subjected to two different metal forming technologies—cold forging (upsetting) and equal channel angular pressing (ECAP)—to obtain improvement in its exploitation properties. Parallel to changing mechanical properties by using these two processes, there was a change in the microstructure of the material. The resulting microstructures were examined using an optical microscope. A different treated aluminium was subjected to erosion wear in various time intervals. Wear testing was conducted for two different impingement angles causing abrasive wear and impact wear. The erosion mechanisms were examined by scanning electron microscopy. These results showed that there is no statistically significant difference in erosion wear for different states at the same impingement angle. However, the difference is noticeable at different wear angles. The significance of the difference in wear of the samples treated with the forging and ECAP techniques was validated by statistical analysis with tests of different sensitivities. The results of the t-test showed that ECAPed samples present a statistically significant difference in the loss of mass due to variations in erosion angle during the 30, 45, and 60 min wearing. A substantial difference in the change in sample mass is also visible for the forged state worn for 60 min. [ABSTRACT FROM AUTHOR]

The traditional method of manufacturing propellant tanks for rockets and spaceships involves significant amounts of forging, and machining, making it expensive and environmentally unfriendly. A novel approach for manufacturing propellant tanks that reduces the need for machining and friction stir welding processes has been presented in this paper. This approach involves manufacturing a tank half starting from a single metal plate, using innovative and advanced metal forming processes such as hot stretch forming, magnetic pulse forming, hub forming, and integrated stiffened cylinder (ISC) flow forming followed by orbital welding of two tank halves. A life cycle assessment (LCA) study was conducted in accordance with ISO 14044:2006 standard using the ReCiPe 2016 Midpoint (H) method to compare the environmental impacts of the traditional and newly developed approaches for manufacturing propellant tanks. The results of the LCA study showed that the new approach based on advanced forming technologies reduced carbon footprint by 40%, cumulative energy demand by 35%, water footprint by 17%, and materials waste by 4% compared to traditional manufacturing. The lower environmental impact of the new approach was attributed to a decrease in friction stir welding requirements due to the implementation of advanced forming techniques that enable integrated tank production. This lowered the overall energy consumption in the novel approach by a factor of 1.5 and in turn resulted in lower environmental impact compared to traditional forging and machining-based method. Furthermore, a futuristic scenario that involves in-house tank production using the novel approach with minimal transportation of inventories was also simulated. Based on the LCA results, it was seen that the newly developed approach for manufacturing propellant tanks was more environmentally friendly than the traditional approach and its environmental footprint could be further reduced by implementing the futuristic scenario with minimal transportation. This novel approach is also expected to reduce the lead time and production cost of manufacturing a propellant tank. Hence, future efforts in cost assessment and further optimization of raw material and energy usage are recommended. [ABSTRACT FROM AUTHOR]

In the era of Industry 4.0, deploying highly specialised machine learning models trained on unique and often scarce datasets is an attractive solution for advancing automated quality control and minimising production costs. Therefore, the main aim of this research is to evaluate the capabilities of three deep learning models (ResNet-18, ResNet-50 and SE-ResNeXt-101 (32 X 4d)) in the identification of surface defects in forged products. Leveraging advanced photography techniques, including studio lighting and a shadowless box, high-quality images of complex product surfaces were acquired for the training data set. Given the relatively small size of the image dataset, aggressive data augmentation techniques were introduced during the training and evaluation process to ensure robust model generalisation ability. The results obtained demonstrate the significant impact of data augmentation on model performance, highlighting its importance in training and evaluating deep learning models with limited data. This research also emphasises the need for innovative data pre-processing strategies in an efficient and robust machine learning model delivery to the industrial environment. [ABSTRACT FROM AUTHOR]

Bangladesh is increasing agricultural mechanization to reduce labor-intensive drudgery and to address labor shortages in farming. Agricultural equipment, such as power tillers and threshers, are used to achieve this goal and require regular replacement of the spare parts that experience significant wear in use. Spare parts are currently imported at twice the cost of domestic ones. This paper supports the development of domestic manufacturing by analyzing the manufacturing processes for two fast-moving spare agricultural parts, tiller blades and threshing teeth, and providing a method to develop more efficient processes. The manufacturing processes, which focused on the design of forging and bending dies, reflect the constraints of the manufacturing equipment and stock materials available in Bangladesh. The die designs and manufacturing processes were verified by FEA simulations and by experimental testing. The experiments and simulations suggest that the spare parts should be made at elevated temperatures and high rates of forming. Recommended die designs and processing conditions and forces required to achieve the final part and that can be implemented in manufacturing facilities in Bangladesh are presented. [ABSTRACT FROM AUTHOR]

This research aims to study the wear behavior that occurs with hot forging dies caused by the influence of the work piece's temperature, the die's temperature, and the coefficient of friction. The material of the die used in this study was steel with JIS standards and SKD61 Grade. The material of the workpiece was 5CM435 Grade. The default size of the workpiece and production factors were calculated and analyzed by using the Finite Element Method. The study was started by simulating workpiece forging at 850 degrees Celsius, 950 degrees Celsius, 1000 degrees Celsius, 1150 degrees Celsius, and 1250 degrees Celsius for analyzing the workpiece's flow and wear behavior of the die's surface under forging pressure of 400 tons with a die temperature from 120 degrees Celsius to 180 degrees Celsius. The results of the analysis revealed that the die's temperature at 692.41 degrees Celsius and the workpiece's temperature at 1,250 degrees Celsius yielded the most absolute workpiece flow. The absolute default size of a cylindrical workpiece had a diameter of 13 millimeters with a length of 155 millimeters and the workpiece's temperature was set at 850 degrees Celsius. Abrasive wear occurred with the die's lower surface at the highest level. At 1,000 degrees Celsius, plastic deformation occurred at the die's lower surface. Stress occurred when the workpiece was in the scope of the graph on fracture criteria. From computer simulation forging, It indicated that appropriate adjustment of variables helped to reduce plastic deformation and mechanical fatigue. [ABSTRACT FROM AUTHOR]

Forging is a traditional and important manufacturing technology to produce various high strength products and is widely used in engineering fields such as automotive, aerospace and heavy industry. To produce highly accurate product, underfill that the material is not filled into the cavity should strongly avoided. For material saving and near-net product, flash should be minimized. To make the tool life long, it is preferable to produce product with low forging load. It is also preferable to uniformly deform the billet as much as possible for high strength product. Crack is a crucial defect and should strongly be avoided. Therefore, many requirements are taken into account in order to produce the forged product. To meet the requirements, design optimization in forging coupled with computer aided engineering (CAE) is an effective approach. This paper systematically reviews the related papers from the design optimization point of view. For the billet or die shape optimization, the papers are classified into four approaches. The process parameters optimization such as the billet temperature, the die temperature, the stroke length and the friction coefficient is conducted, and the related papers are also classified into four categories. The design variables and the objective function(s) used in the papers are clarified with the design optimization technique. The multi-stage forging including the hammer forging for producing complex product shape is also briefly reviewed. Finally, major performance indexes and the future outlook are summarized for the further development of design optimization in forging. [ABSTRACT FROM AUTHOR]

Copyright of Steel Pipe is the property of Steel Pipe Magazine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Central South University is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Industrial Metrology Business Unit of Nikon Corporation, on behalf of ScottishPower Renewables and Maritime Archaeology (MA), Southampton, UK, has employed X-ray CT (computed tomography) to visualise the internal structure of an anchor found in the North Sea. The non-destructive method of internal inspection and measurement has helped to determine approximately when it was made. The results indicate that the artefact, initially thought to be potentially Roman, is probably more recent, likely dating to between the late 16th and early 17th centuries CE. This paper presents the discovery, recovery, analysis and interpretation of a significant find from a UK offshore wind farm and underscores the valuable role that non-destructive X-ray CT played in the investigation.

High-strength metastable β-titanium alloys like Ti-5553 (Ti–5Al–5Mo–5V–3Cr) are frequently used in highly loaded aerospace components. Such aerospace parts tend to be expensive to traditionally manufacture due to current industry process limitations such as inflexibility for complex geometries, costs related to tooling for large forgings, extended lead times, poor machinability and high material waste. These challenges are leading to increased interest in exploring alternative manufacturing routes. This work investigates the use of additive manufacturing to deposit cost-effective and machinable Ti-64 (Ti–6Al–4V) alloy onto a forged Ti-5553 alloy substrate. The microstructure evolution, microhardness and tensile properties have been investigated for both the as-deposited as well as for stress relief heat-treated conditions. The results confirmed the formation of coarse columnar β grains with a fine basketweave α structure. The heat affected zones (HAZs) developed in the Ti-5553 substrate material from the cyclic thermal fluxes introduced from the melt-pool were characterized by a gradient microstructure of dissolving constituent phases with nearing proximity to the fusion zone. Tensile testing in the as-deposited condition was characterised with a UTS of 884 MPa and a ductility of 15%. Tensile samples extracted across the substrate-deposit interface all failed in the WAAM Ti-64 material and demonstrated comparatively greater strength but poorer ductility. A band of tensile residual stresses was imparted along the substrate, but was adequately stress relieved after heat-treatment at 600 °C. The heat-treatment led to the formation of more homogeneous α-phase laths throughout the HAZ of the Ti-5553 material and provided overall improvements to the strength and ductility.

Closed-die forging preforms are usually made by open die forging operations, which are subject to significant variabilities. A sensitivity study covering a wide range of influencing parameters has highlighted the predominant influence of the initial billet geometry. The forging die strokes were also highly influential, while their fidelity is sufficient to use them as control parameters in order to compensate the geometrical dispersions of the billet. Consequently, their optimization was performed by taking a nominal preform geometry as the target. Polynomial surrogate models have been constructed to enable real-time optimization. A specific preform was used as a demonstrator in this study, while the approach was generic. The surrogate models were built using data from finite element simulations, which were first validated with an experimental campaign. On the one hand, this approach introduced agility by allowing changes in the billet geometry, and on the other hand, it allowed individual customization of the specific route to each billet. [ABSTRACT FROM AUTHOR]

The Industrial Metrology Business Unit of Nikon Corporation, on behalf of ScottishPower Renewables and Maritime Archaeology (MA), Southampton, UK, has employed X-ray CT (computed tomography) to visualise the internal structure of an anchor found in the North Sea. The non-destructive method of internal inspection and measurement has helped to determine approximately when it was made. The results indicate that the artefact, initially thought to be potentially Roman, is probably more recent, likely dating to between the late 16th and early 17th centuries CE. This paper presents the discovery, recovery, analysis and interpretation of a significant find from a UK offshore wind farm and underscores the valuable role that non-destructive X-ray CT played in the investigation. [ABSTRACT FROM AUTHOR]

The quests and advocacies for co-operations, alliances, integration and unity amongst African countries are quite historical, and are ever resonating in discourses on international relations. It is such advocacies that birthed the idea for the formation of the Organization of African Unity (OAU), Economic Community of West African States (ECOWAS), Southern African Development Community (SADC), etc. Unfortunately, not even the rationale for the metamorphosis from OAU to the African Union (AU) has been able to entrench the much desired unity of purpose amongst African states. This paper posits that the conversations on strategies for a closer and sustainable integration in Africa should not only be centred on socio-economic and political paradigms, but should deeply reflect cultural cum educational matrixes. The paper hypothesizes that cultural transmission, which is a fundamental goal of any educational system, has to be emphatically explored in the drive for integration and unity in Africa. It therefore conceptually highlighted the link between culture and education in regional integration, with reminiscences of such linkages in Africa. The paper however observes that, beyond the affirmations and declarations arising from Treaties and Charters by some regional fora in Africa, the varied uses of education for the purposes of cultural transmission, promotion of African history and languages, in addition to the merits of intellectual exchanges, are to be further surveyed as the plausible templates that would encourage integration in Africa. Consequently, the paper suggests that socio-political institutions, governments, sub-regional blocs and other agents of diplomacy and development in Africa should carefully reconsider the multi-dimensional values of education in the realization of the dreams of African nationalists for a well-integrated and united Africa. [ABSTRACT FROM AUTHOR]

Tube hydroforging with non-circular shaping has been conducted to show the deformation mechanics of an AHSS tube. In this paper, the tube was hydroforged in a multistage FEA simulation to show the effects of axial forging distance on noncircular cross-sections during hydroforging. The tube will be allowed to expand with a ramped internal pressure, then be shaped to a certain expansion ratio by the axial compression in the forging step and finally be shaped into either a square or an equilateral triangle shaped cross-section. It was observed that triangular shaped models have a greater resistance to thickness loss than the square shaped models. The forging die distance for both square and triangular shaping models each influence the maximum amount of shaping die distance for the process. The simulations show that as the forging die distance increases, the lateral radius increases for both the square and triangular shaped models. For the square shaped models, there is an uncorrelated relationship between the vertical and horizontal longitudinal radii but is correlated in the equilateral triangle configurations. The thickness distributions for the triangular shaped configurations show greater stability in the deformed wall portion than the square shaped configurations. All the model setups failed due to wrinkling, except the triangular shaped model with 20 mm of axial displacement, which failed due to bursting. [ABSTRACT FROM AUTHOR]

Nowadays, cold forging is one of the most commonly utilised methods in industrial manufacturing, and most metal-forming lubricants are not ecologically friendly; in some cases, these chemicals may produce large chemical emissions and pose a risk to the community. Bio-oil lubricants have garnered increasing attention as potential alternatives for mineral oil-based lubricants, since they are critical in resolving existing obstacles. This article intends as a case study and demonstrating the usage of different derivatives of palm oil as a bio-lubricant in the closed forging test (CFT). As an outcome of the friction, wear behaviour and deformation, the closed forging test is important in the knowledge of materials and engineering studies. In this test, aluminium (A1100) was utilised to compare the formation of the workpiece using palm oil based and commercial metal-forming oil as a benchmark lubricant. During the forging process, these components' material flow patterns are analysed at intermediate phases of the die stroke level. Using the experimental data, the finite element approach will be used to predict the workpiece friction, effective stress and metal flow. By developing a Coulomb–Tresca friction model, a cold forging test also was used to do studies on the interaction between the Coulomb friction coefficient (CFC) and Tresca shear friction (TSF). From the results, certain types of palm oil-based lubricants perform better than mineral oil-based lubricants in terms of friction coefficient, with palm stearin having the lowest friction coefficient (m = 0.33/µ = 0.139), followed by palm kernel oil and palm mid olein (m = 0.39/µ = 0.159). The palm oil-based lubricant, on the other hand, has generated poor performance in terms of surface texture and surface roughness (Ra) with a high rate of wear compared to the no sample lubricant and commercial metal-forming oil (m = 0.42/µ = 0.1675). [ABSTRACT FROM AUTHOR]

A technique for simplified simulation of the forging of large ingots using modern machine-learning methods for constructing models that describe stages of thermomechanical processing is described. [ABSTRACT FROM AUTHOR]

The results of the analysis of the influence of temperature–speed deformation parameters and the shape of the billet on the structure and properties of stamped forgings with a complex configuration from titanium alloy OT4-1 are discussed. The influence of deformation on phase transformation processes and the rate of fatigue crack growth (FCGR) in the material of forgings and finished parts is thoroughly investigated. [ABSTRACT FROM AUTHOR]

As a field of forensic science, graphoscopy studies the legalities of writing and develops methods for examining and identifying the person who forged a document or signature. The identification is made on the basis of an expertise carried out by an expert in the field, ordered by the competent bodies.

The article presents methods for improving the quality of forgings and workpieces obtained by forging by intensifying shear or alternating strain in the bulk of the deformed metal. To increase the metal processing due to shear or alternating strain during forging, forging strikers are most often used, the feature of which is the geometric configuration that creates additional metal flows. Quite a lot of works from research teams from all over the world have been devoted to the problem of intensive metal processing during forging. In these publications, a number of new unique designs of strikers have been proposed and various route technologies have been considered, which can significantly increase the level of shear or alternating strain compared with the use of traditional forging tool designs.

The tribological phenomena concerning the lubrication regime change (LRC) during bulk metal forming are comprehensively studied. A multi-step cold forward extrusion process shows the evolution of LRC and reveals the shortcomings of the traditional Coulomb friction law. The previous works of the specific author’s research group on friction are reviewed, focusing on the LRC during bulk metal forming. Various LRC phenomena from various examples are revealed. It has been found that the drawing and forward extrusion processes are vulnerable to LRC because of significant sliding motion at the material–die interface, and that when the strain hardening of the material is slight, the influence of friction increases, and as a result, the influence of LRC increases excessively. The new findings also include the impact of LRC on the macroscopic phenomena of the process and the reason for the sharp increase in friction coefficient via LRC, which is validated by the work of Wilson. This paper aims to make engineers and researchers think much of the tribology with lubricant in bulk metal forming with a focus on the dependence of tribological phenomena on the state of the lubricants and the irrationality of traditional friction law, especially in the forging of materials with a low strain hardening capability.