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The need to reduce energy consumption means that it is necessary to reduce the weight of vehicles. However, a thick wall of massive elements promotes the formation of casting defects, which must be removed by either plastic processing (straightening) or welding methods (surface and internal discontinuities). Basic alloys contain Al and Zn as the main alloying elements. The studies involved an evaluation of the microstructure and properties of alloys at ambient and elevated temperatures. The microstructure observation revealed a dendritic structure with the presence of low-melting eutectic, and intermetallic and Laves phases in the interdendritic areas. The presence of these phases may pose significant limitations during welding work. Thermal conductivity coefficient measurements showed that it is constant at temperatures up to 200 °C and is 49 W/mK for 9% Al and 77 W/mK for 9% Zn. The tensile test reveal that the most favorable tensile strength (120 MPa) occurs at temperatures of 150 °C for the 9% Zn alloy and at 180 °C for the 9% Al alloy. [ABSTRACT FROM AUTHOR]

Reliable determination of the elastic moduli of metals can be quite demanding, especially as the apparent elastic modulus of metals is known to decrease with deformation. Traditionally, this dependence on plastic strain has been investigated through various tensile tests, but discrepancies persist across the different approaches. Here we compare several tensile test-based evaluation protocols based on loading-unloading experiments to measure the change in elastic moduli of the light metal alloys AZ31B, EN AW-6082, and Ti–6Al–4V during tensile deformation. Additionally, the initial Young's modulus determination via tensile testing, three-point-bending experiments, contact-free laser ultrasonic zero-group-velocity plate resonance, and piezoelectric contact ultrasonic time-of-flight measurements were compared. The results reveal non-negligible differences in the strain-dependency of elastic moduli between the determination techniques. Additionally, the laser ultrasound measurements demonstrate an improved accuracy and repeatability for the determination of the initial elastic moduli of light metal sheets. The benefit of considering the reduction of the elastic moduli in finite element springback simulation of three-point-bending tests is demonstrated and the use of the chord modulus is found to be generally most appropriate. [ABSTRACT FROM AUTHOR]

In single point incremental forming (SPIF), a technical challenge is to form multi feature parts, particularly those with unique structures. In response to this issue, a new process combining hydraulic bulging and SPIF is presented for the mouldless manufacture of multi-featured parts with sharp structures in a single clamping. In the first phase, hydraulic bulging is performed on the initial sheet to obtain a domed shell. In the second phase, local areas of the domed shell are subjected to SPIF with the assistance of hydraulic supports to achieve the concavo-convex features. In the third phase, the convex features are subjected to SPIF with the assistance of hydraulic bulging to achieve conical features. Simultaneously, the influence of hydraulic pressure on geometric accuracy, strain distribution, and forming mechanism is compared at different forming stages. The feasibility of the novel process can be verified through successful FEM and experiment of multi-feature parts. [ABSTRACT FROM AUTHOR]

Ultrasonic impact forming (UIF) is an essential cold working process for forming large thin-walled components. Stressing ultrasonic impact forming (SUIF) can produce more deformation than UIF in the prebending direction. In this paper, a four-step numerical model including prestress submodel, impact treatment submodel, data transfer submodel and prestress forming submodel is developed to simulate the SUIF process. The effect of nonuniform residual stress on plate deformation is investigated, the change regulation of residual stress is discussed, the effect of elastic prebending radius on the plate deformation is analyzed. The narrow plate can obtain a nearly single curvature deformation by SUIF. Compared to narrow plate, the square plate can produce smaller deformation in device offset direction. Compared to UIF, SUIF can produce smaller compressive stress in the top surface layer, larger tensile stresses in device moving direction, and smaller tensile stresses in device offset direction; SUIF can produce larger deformation in device offset direction. With the decrease in prebending radius, compressive residual stresses changes little, and the tensile stress increases in the device offset direction, the deformation increases in the device offset direction and decreases in the device moving direction. [ABSTRACT FROM AUTHOR]

It is one concern of the researchers how magnesium (Mg) alloys solidify under different conditions and how their microstructure evolves during solidification, and what are the relationship between the macroscopic properties and various microstructures. Such issues are difficult to be revealed through experiments only, especially for the newly developed Mg alloys, for which there is a lack of more systematic and mature system. However, multi-scale modeling and simulation can promote and deepen our understanding of the microstructure and its deformation mechanism. In this paper, we review and summarize the recent research progress of numerical simulation of Mg alloys in forming and microstructure, namely casting, extrusion, rolling, and welding, using crystal plasticity finite element (CPFEM) and molecular dynamics (DM) methods. Besides, the methods and innovations of modeling are also summarized. Lastly, the paper discusses the development prospects and challenges of the numerical simulation in the field of Mg alloys.

This review considers the use of fractal concepts to improve the development, fabrication, and characterisation of catalytic materials and supports. First, the theory of fractals is discussed, as well as how it can be used to better describe often highly complex catalytic materials and enhance structural characterisation via a variety of different methods, including gas sorption, mercury porosimetry, NMR, and several imaging modalities. The review then surveys various synthesis and fabrication methods that can be used to create catalytic materials that are fractals or possess fractal character. It then goes on to consider how the fractal properties of catalysts affect their performance, especially their overall activity, selectivity for desired products, and resistance to deactivation. Finally, this review describes how the optimum fractal catalyst material for a given reaction system can be designed on a computer. [ABSTRACT FROM AUTHOR]

Duplex stainless steel (DSS) 2205 finds wide application in aircraft industries and for surgical implants. However, the formability of 2205 steel sheets is limited under normal conditions, requiring hot-working to enhance strain hardening at lower temperatures. Furthermore, there is a lack of research on the single point incremental forming process (SPIFP) applied to DSS 2205. Hence, the current study aims to explore the fracture characteristics of 2205 steel sheets using SPIFP, while varying several parameters such as tool type, tool diameter, speed, feed rate, and vertical step down. Optimal process parameter selection holds significant importance due to its potential for cost reduction and enhancement of quality. This choice involves determining suitable process parameters while considering multiple conflicting factors, necessitating the application of the multiple criteria decision-making (MCDM) approach. Hence, this work addresses the MCDM challenge using the additive ratio assessment (ARAS) and complex proportional assessment (COPRAS) techniques. The experiment carried out with two different forming tools such as hemispherical-ended forming tool and ball-ended forming tool, assessment carried out by varying the stated independent parameters. The dependent parameters include straight groove depth, wall angle depth, spring back, formability, and surface roughness. The SPIFP alternatives are assessed using the aforementioned two techniques, and the outcomes are subsequently analyzed. The best possible arrangement was determined using ARAS and COPRAS methods to achieve both maximum and minimum values for all the responses. This arrangement was identified with the hemispherical-ended forming tool and the specific set of process parameters: a tool diameter of 10 mm, a feed rate of 600 mm/min, a speed of 200 rpm, and a vertical step down of 0.6 mm. In 77.78% of instances, the rankings from ARAS are in agreement with the rankings from COPRAS. Notably, the lower and higher orders of rankings are the same, adding an intriguing dimension to the observation. However, the patterns of different dependent variables, influenced by the diversity of independent variables, were not consistent. These intricate mechanisms have been recognized and documented. [ABSTRACT FROM AUTHOR]

The wide application of composite materials is an important trend in the aerospace field, and its excellent material properties make its demand increasing. However, with the continuous emergence of new materials and the complexity of structural forms of components, manufacturing costs continue to increase, hindering the application and development of composite materials. At present, the use of manufacturing process simulation technology to improve the level of composite material manufacturing and reduce manufacturing costs is an effective and important way. The structural function design simulation technology of composite materials was reviewed, and the development dynamics of simulation design technology were analyzed from three aspects of mechanical properties, geometric structure and special functions. The mechanical and thermal characteristics of materials in the molding process and the simulation method of molding deformation prediction control were summarized. The mechanical and thermal state of the cutting interface, the damage process of the material and the difference of the damage caused by different processing techniques were analyzed. Finally, suggestions were given from the aspects of composite constitutive model and damage theory, influence factors of composite forming process, performance parameter database, molding simulation of ceramic matrix composite, evaluation criteria of composite surface quality, and computational efficiency of manufacturing process simulation. [ABSTRACT FROM AUTHOR]

• Multi-scale modeling and simulation enhance our insights into magnesium alloys' microstructures and deformation mechanisms. • This review highlights recent advancements in numerical simulations of magnesium alloys' forming processes and microstructural evolutions. • The paper outlines modeling innovations and discusses future challenges in magnesium alloys' numerical simulation. It is one concern of the researchers how magnesium (Mg) alloys solidify under different conditions and how their microstructure evolves during solidification, and what are the relationship between the macroscopic properties and various microstructures. Such issues are difficult to be revealed through experiments only, especially for the newly developed Mg alloys, for which there is a lack of more systematic and mature system. However, multi-scale modeling and simulation can promote and deepen our understanding of the microstructure and its deformation mechanism. In this paper, we review and summarize the recent research progress of numerical simulation of Mg alloys in forming and microstructure, namely casting, extrusion, rolling, and welding, using crystal plasticity finite element (CPFEM) and molecular dynamics (DM) methods. Besides, the methods and innovations of modeling are also summarized. Lastly, the paper discusses the development prospects and challenges of the numerical simulation in the field of Mg alloys. [ABSTRACT FROM AUTHOR]

Copyright of Nordic Journal of Art & Research is the property of InFormation - Nordic Journal of Art & Research 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 Bearing is the property of Bearing 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.)

Forming simulation is an indispensable analysis tool in industry, the most important objective of which being the reproduction of the material deformation behavior during the process as accurately as possible to predict forming defects and determine optimum forming conditions precisely. This paper reviews the material models suitable for metal forming simulations and the material test methods that can reproduce the various types of stress states occurring in real forming operations. These test methods are essential to verify the validity of material models. Examples of forming simulation results for aluminum alloys are presented, illustrating the significant influence of the material models on the accuracy of the process predictions. Finally, the emerging research trends in the field of material modeling and testing are discussed. [ABSTRACT FROM AUTHOR]

Metal screw extrusion (MSE) is a continuous, solid-state forming method utilizing an inherently high degree of deformation to consolidate fragmented input materials into a solid bulk by breaking their oxide skins. Severe plastic deformation with equivalent strain in the range of 10–20 can be achieved depending on set process parameters. Rigorous mixing can be employed to form sophisticated materials like bulk composites, nanocomposites, particle-reinforced metals, and fine-grained materials. Furthermore, the inherent solid-state processing is well suited for recovery of difficult-to-recycle materials. A range of non-ferrous materials has been manufactured by MSE and further characterized in terms of microstructural evolution and mechanical and functional properties. Furthermore, MSE has been studied in terms of flow, accumulated strain, and environmental impact. The following review aims to critically highlight the existing work performed on MSE, compare it to existing and emerging technologies as well as explore future development and possible applications. MSE has the potential to be utilized for numerous commercial applications. To realize industrial use of MSE, key aspects of the process and the influence of processing parameters on the resulting product must be understood. [ABSTRACT FROM AUTHOR]

Thermal management is crucial in composite part manufacturing, as it directly impacts final quality. Controlling tooling surface temperature is essential to minimize defects and achieve desired mechanical properties. This article explores the use of lattice structures with heat transfer fluid circulation to enhance heat exchange, ensuring composite part quality and improving manufacturing productivity and energy efficiency. These structures improve temperature uniformity, increase heating and cooling rates, and reduce thermal inertia without causing thermal marks, thus decreasing cycle time and energy consumption. A steady-state numerical study examines the impact of geometry and materials on the tooling thermal-hydraulic performance. Analysis of fluid flow and heat transfer highlights the impact of the lattice structure on fluid and heat transfer flows. The disturbance created by lattice structures is the main driving force behind improved heat transfer in the system studied. In the presented configuration, i.e., water and high fluid flow rate, the performances do not depend strongly on the lattice structure material. Even if the lattice structures increase the pressure drop, the system studied generates a higher performance than a conventional thermal management method. Following this numerical study, experimental work was carried out in the unsteady regime, providing a proof of concept. The results show an improvement in the uniformity of the temperature field at the tooling surface during transient phases compared with a conventional design using straight channels. The use of lattice structures improves temperature uniformity at the tooling surface by over 50% and heating and cooling rates by 77%. Finally, the possibility of locally controlling the temperature field by adjusting the porosity of the lattice structure is highlighted. [ABSTRACT FROM AUTHOR]

This paper presents a post-forming technique utilising both induction heating and rotary draw bending (RDB) for carbon fibre-reinforced polyetherentherketone (CF/PEEK) tubular structures. Existing post-forming techniques are unable to form CF/PEEK tubes due to the lack of a suitable mandrel material to provide internal support to the tube while withstanding high heat from melting the PEEK matrix during forming. This is addressed by using a steel spring mandrel in the tube induction heating process. In this study, four sets of [±60°]4 CF/PEEK tubes were formed using an induction heater-incorporated RDB setup into 45°, 90°, 135°, and 180° bends with a bending ratio of 2. Optical characterisation was performed to analyse tube fibre angle changes. A post-forming fibre angle prediction model previously derived for CF/polyamide 6 tubes was validated for its application in predicting fibre angle changes for CF/PEEK tubes by comparing the prediction with the characterised results. [ABSTRACT FROM AUTHOR]

Ribbed tube is a thin-walled and shaped cladding tube, multi-pass cold drawing (MPCD) is considered to be one of the preferred manufacturing techniques for ribbed tube forming. However, unreasonable process design results in poor forming quality and the number of deformation passes increased in vain. The purpose of this paper is redesigning a reasonable MPCD process to obtain the defect-free ribbed tube and to investigate the surface quality and microstructural evolution of the formed tube comprehensively. The problems of the original MPCD are analyzed, the MPCD process is redesigned by theoretical calculation and the reasonable distribution of deformation degree. Furthermore, the material produces grain refinement due to the cumulative deformation, and lathy α′-martensite at intersections of shear bands and few carbide precipitation are generated. The surface roughness of tube and rib are 2.73 μm and 4.89 μm respectively, which indicates that the forming quality of the tube is good. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department 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.)

Artikkelen er skrevet frem med utgangspunkt i en undervisningssituasjon sammen med en gruppe barnehagelærerstudenter og store mengder kassert ull fra norsk villsau. Med a-r-t-ografi som forskningsmetodologi og pedagogisk strategi undersøker vi hvordan vi kan (med)virke forskende, lærende og skapende i egen undervisning med ull, filting, studenter og steder, og på hvilke måter a-r-t-ografien bidrar til å utvide vår tenkning om undervisning når vi flytter verkstedet ut i friluft. Undersøkelsen er forankret i prosessfilosofi, posthumane perspektiver og kunstbasert forskning. Foto: Ann-Hege Lorvik Waterhouse, Kari Carlsen og Trude Iversen

This paper proposes a hybrid T-DEA-P (Taguchi-Data Envelopment Analysis-Pareto) method to optimise and rank parameters of the electrohydraulic forming process using the aluminium (AA1100) sheets for automotive panel application. A linear programming model was formulated based on the integrated Taguchi – DEA data and solved using DEA software. The design variables are the stand-off distance, electrode gap voltage and medium. The constraints are formulated according to the levels specified in the level-factor table. Using literature data, the validation of the method was made. An important result shows that case 1 has the optimal parametric setting is SOD3E2V2M2. This is interpreted as a stand-off distance of 3mm, an electrode gap of 30mm a voltage of 260 volts and the medium as Oil with a viscosity of 0.89cP. The delta values are 16.026, 16.0605, 17.1109 and 37.3587. Delta values measure the rate of change of the average signal-to-noise ratios relative to the changes in levels. Based on the Pareto intervention, the medium is ranked first while voltage, electrode gap and stand-off distance are ranked second, third and fourth, respectively. The method aids in the planning activity for the forming process.

The aim of the work is to study the effect of the acid comonomer content and forming conditions on the dyeability of gel fibers based on copolymers of acrylonitrile (AN), methyl acrylate (MA) and 2-acrylamide-2-methylpropanesulfonic acid (AMPS). For this purpose, model copolymers AN, MA and AMPS were synthesized with an acid comonomer content in the monomer mixture from 0 to 2 % (wt.) by changing the proportion of MA. It has been established that the actual content of the acidic monomer in the fiber-forming copolymer is higher than expected based on the composition of the initial monomer mixture. Analysis of the dyeability of model samples of polyacrylonitrile fibers formed from synthesized copolymers by the dimethylformamide method with varying technological regimes showed that the amount of dye selected from the dye bath by the gel structure of the fibers is proportional to the content of the acid comonomer in the fiber-forming copolymer. The most significant decrease in the whiteness index (lightness) of the finished fibers is observed with an increase in the AMPS content in the copolymer from 0 to 0.7 % (wt.). Microscopy of model fibers was carried out. Based on the experimental data obtained in the course of the work, it was suggested that in order to achieve an acceptable intensity of dyeing and ensure a soft handle of polyacrylonitrile fibers, the optimal content of acid comonomer during the synthesis of fiber-forming copolymers based on AN, MA and AMPS should be in the range of 0.9 up to 1.3 % (of the mass of monomers in the reaction mixture).

The work is devoted to the study of the formation of stress concentrators on the inner surfaces of "tube"-type parts, the main function of which is to ensure the minimum consumption of fracture energy under the influence of tensile loads. The work shows the effectiveness of the application of deforming broaching (stitching) and technological lubricant specially developed for forming stress concentrators under the action of high contact loads, which are accompanied by deformation. The patterns of deformation hardening of the material during the formation of longitudinal grooves on the inner surfaces of parts such as bushings by deforming broaching are studied. At the qualitative level, the influence of technological parameters of the process on the distribution of microhardness along the depth of the wall of the processed part and along the cross-section profile of the tool was established. The identified regularities can be used in the design of technological operations of forming grooves by methods of cold plastic deformation and correction of technological regimes based on the requirements for mechanical characteristics that ensure the efficiency of product use. The studied regularities are valid for forming grooves in tubular products made of structural steels with a hardness in the range of HB 110-200.

This article deals with the possibility of using 3D-printed models as an input for the production of a mould for cast iron castings. This new progressive process is significantly faster (with sufficient accuracy) compared to the current way of making models for moulds. The need to create a wooden model is removed by this process. The quality of this wooden model was highly dependent on the experience and qualifications of the worker. This article describes the manufacturing process of the model and mould in detail. The key dimensions of the final parts are compared with the model and, thus, the accuracy of the chosen procedure is verified. A 3D-printing technology known as Multi Jet Fusion (MJF) was used to produce the model. The material used for the production of the model is polyamide PA12 with 40% glass fibre filling. This material has sufficient structural and strength properties to be used for the given application. Taking into account the dimensions of the part and the printing space of the printer, it was necessary to structurally modify and divide the part. The inlet cone of a turbine is used as an example This cone is produced from grey cast iron as standard. [ABSTRACT FROM AUTHOR]

Wrinkles are detrimental to the performance of composite components. The prediction of wrinkling during forming is challenging because of complex material interactions. Current computational modeling methods are capable of wrinkle prediction but only for one given set of parameters per simulation cycle. To improve the prediction of wrinkles, this article presents a theory that correlates wrinkle formation with factors such as composite layup and part dimension. This theory allows one to perform design of experiments for physical or virtual forming tests and obtain binomial probability distributions capable of wrinkle prediction. The theory is validated with forming experiment data and demonstrates its potential in wrinkle prediction. [ABSTRACT FROM AUTHOR]

Carbon fibre reinforced thermoplastic tubular structures can be post-formed into desired curvatures via rotary draw bending (RDB) at elevated temperatures. During this process, a rigid internal mandrel is required to support the walls of the tubes to maintain their ovality and minimise unwanted geometrical distortions. This paper investigates four internal mandrel designs for post-forming carbon fiber reinforced polyamide 6 (CF/PA6) thermoplastic tubes. Mandrel designs include silicone rod, bullet, wire, and coil spring, were evaluated through RDB-forming experiments with [± 60°]4 CF/PA6 tubes formed to 90° bends. The designs were evaluated for their effectiveness on minimising distortions resulted from induced stresses during post-forming by measuring the post-formed tube diameter and extrados strains. The mandrel designs were also evaluated for their usability when integrated into the RDB process. Results from optical measurements and micro-computed tomography showed the spring mandrel outperformed others, producing tubes with the least geometrical distortions and no defects during the forming process. As compared to other designs, the spring mandrel is a reusable unibody design that is easy to assemble and remove from the tubes. [ABSTRACT FROM AUTHOR]

This paper proposes a hybrid T-DEA-P (Taguchi-Data Envelopment Analysis-Pareto) method to optimise and rank parameters of the electrohydraulic forming process using the aluminium (AA1100) sheets for automotive panel application. A linear programming model was formulated based on the integrated Taguchi – DEA data and solved using DEA software. The design variables are the stand-off distance, electrode gap voltage and medium. The constraints are formulated according to the levels specified in the level-factor table. Using literature data, the validation of the method was made. An important result shows that case 1 has the optimal parametric setting is SOD3E2V2M2. This is interpreted as a stand-off distance of 3mm, an electrode gap of 30mm a voltage of 260 volts and the medium as Oil with a viscosity of 0.89cP. The delta values are 16.026, 16.0605, 17.1109 and 37.3587. Delta values measure the rate of change of the average signal-to-noise ratios relative to the changes in levels. Based on the Pareto intervention, the medium is ranked first while voltage, electrode gap and stand-off distance are ranked second, third and fourth, respectively. The method aids in the planning activity for the forming process. [ABSTRACT FROM AUTHOR]

This study proposes to study the sliding and slippage mesoscopic defects that appear during the preforming phase of dry reinforcements to produce complex composite shapes. For this purpose, experimental preforming tests were conducted on a plain weave fabric with low cohesion using a specific punch developed specifically for this purpose, and which combines the geometric facets of a square and a tetrahedron. The tests were conducted under several configurations varying the blank holder pressure intensity as well as its distribution, through the number and springs position that generate normal forces on the blank holders. The results showed that the corners of the geometry formed by orthogonal faces favor the appearance of mesoscopic defects and specifically slippage because of its severity. Sliding has shown itself to be very sensitive both to the singularities of the geometry where it appears, and to the heterogeneity of the pressure distribution of the blank holders. On the other hand, the sliding, which appears in the vicinity of the slippage on flat faces, is rather sensitive to the distribution of the pressure. The increase in the blank holder pressure, regardless of the conditions of its application, leads to an almost linear increase in the extent and number of these mesoscopic defects. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher 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 Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department 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 constantly increasing challenges of production technology for the economic and resource-saving production of metallic workpieces require, among other things, the optimisation of existing processes. Forming technology, which is confronted with new challenges regarding the quality of the workpieces, must also organise the individual processes more efficiently and at the same time more reliably in order to be able to guarantee good workpiece quality and at the same time to be able to produce economically. One way to meet these challenges is to carry out the forming processes in closed-loop control systems using softsensors. Despite the many potential applications of softsensors in the field of forming technology, there is still no definition of the term softsensor. This publication therefore proposes a definition of the softsensor based on the definition of a sensor and the distinction from the observer, which on the one hand is intended to stimulate scientific discourse and on the other hand is also intended to form the basis for further scientific work. Based on this definition, a wide variety of highly topical application examples of various softsensors in the field of forming technology are given. [ABSTRACT FROM AUTHOR]

The ply-ply friction behavior of unidirectional carbon fiber reinforced polyphenylene sulfide (UD CF/PPS) prepreg in thermoforming was investigated through an improved pull-through testing system. The effects of temperature, normal force and slipping velocity were considered in testing. The results indicated the existence of three key mechanisms underlying slipping: namely the resin shear, fiber–fiber contact and fiber-resin interaction. A three-stage division of the experimental curve was proposed, and several factors were defined to establish a quantitative definition of the ply-ply friction behavior. The results showed that the influence of slipping velocity is particularly evident. Its post-yield stress (12.8 kPa), steady-state CoF (0.118) and residual stress (0.705 kPa) were the highest, exhibiting the largest changes of 957.9 %, 736.9 % and 47.2 %, respectively. This indicated the strong contribution of resin in ply-ply friction. In addition, the Stribeck analysis also suggested the dominance of hydrodynamic lubrication condition in slipping. Based on the experimental results, a simple phenomenological model was proposed based on experimental curves to accurately describe the effects of processing parameters. This work presents a comprehensive characterization of the ply-ply friction behavior of UD CF/PPS prepreg in thermoforming, providing a substantial experimental foundation for the subsequent simulation research.

Artikkelen bygger på et utdanningsfaglig animasjonsprosjekt med studenter i barnehagelærerutdanninga. Gjennom en kunstbasert forskningsmetodologi undersøkes en utforskende og skapende digital praksis som involverer materialbasert stop-motion animasjon. Både Rammeplan for barnehagen fra 2017 og Kunnskapsløftet fra 2020 legger klare føringer for at barn og elever skal arbeide utforskende, kreativt og skapende med og gjennom digitale teknologier. Det er derfor behov for å utvikle og drøfte hvordan slike praksiser kan utformes og være. I artikkelen diskuteres koblinger mellom materialer og digitale teknologier i skapende arbeid med animasjon, og en utforskende praksis som er i tråd med barns og elevers kroppslige måter å lære på. Det teoretiske rammeverket knytter seg til embodiement-teorier som understreker hvordan vår kognisjon er dypt sammenvevd i omgivelsens materialiteter. Vi formes gjennom interaksjon med omgivelsene og gjennom å gripe og forme i et materiale med hendene.

For the first time, the underwater wet wire and arc directed energy deposition (UW-WADED) multi-tracks deposition layers with favorable morphology were obtained. The forming characteristics of single-track UW-WADED were determined through response surface methodology. It was found that the power function curve provided the best fit for the profile of single-track UW-WADED owing to its changing plumpness value. Subsequently, the formation characteristics of multi-track UW-WADED with varying intervals were investigated. The deposition layer exhibited the flattest surface and the least root-mean-square deviation, measuring 321.79 μm when the interval was 8 mm. The dynamic process of UW-WADED was unveiled through X-ray high-speed images, leading to the formulation of UW-WADED droplet force model. As the arc bubble expanded, the horizontal component of the air drag force pointed to the opposite side of the molten pool and was the principal factor for the droplets to become spatters in UW-WADED. The mechanism of the defect formation was also revealed. The accumulation of the molten pool on the previous deposition layer coupled with the downflow of the molten slag were the inducers of slag inclusion defect while the exorbitant molten pool increased the likelihood of molten pool explosion and subsequent spatter formation.

Medical containers that sterilize surgical instruments are constantly needed in the healthcare industry. In line with this need, improvements in the fabrication of medical containers are important. Determining the design factors of medical containers fabricated by deep drawing saves time and cost. This study determined, the design factors of square medical containers and experimentally verified the deep drawing process modeled in Abaqus/Explicit finite element (FE) software. Taguchi statistical method was used to reduce the number of experiments. Blank holder force (BHF), punch radius (RP), die radius (RD), coefficient of friction between die and blank (µDB), coefficient of friction between punch and blank (µPB), coefficient of friction between holder and blank (µHB) as variable factors while selecting thickness reduction (TR) and maximum punch force (PF) were selected as output parameters. The effect of variable factors on the output parameters was determined by ANOVA analysis. As a result of the examinations, it was deter-mined that TR and PF increased as BHF, µDB and µHB values increased, whereas they decreased as RP and RD increased. On the other hand, it was determined that TR decreased and PF increased as µPB increased. In addition, the corners of the sheets were chamfered in different sizes to prevent the formation of ears in the containers. Finally, the appropriate chamfer size was determined by examining the sheet thicknesses. [ABSTRACT FROM AUTHOR]

A metallic foam specimen was plastically joined with a resin (polymethyl methacrylate, PMMA) sheet by applying friction stir incremental forming (FSIF) process. In FSIF process, a rotating flat-ended (no probe) rod tool was pushed vertically and fed horizontally against the resin sheet which was placed on the foam. The tool operation heated frictionally the resin and deformed incrementally to the resin, while the tool operation did not deform plastically to the cellular matrix of the foam. Due to the plastic flow of the heated resin, the bottom of the resin was interlocked mechanically to the pores near the top surface of the foam. In this study, the relationship between the pore morphology (form and size) and the joining characteristics (joinability, flow thickness of the resin, and joining strength) was investigated using commercial open-cell nickel and closed-cell aluminum foams. According to the experimental investigations, the foam with small size and low depression angle of the surface pore showed better results in relation with the joining strength and the (flow thickness of the resin)/(depth of the surface pore). [ABSTRACT FROM AUTHOR]

Demand for bent pipe profiles in various industrial sectors is increasing due to considerations necessitating lightweight construction, safety, as well as space and cost savings. Lightweight construction is becoming increasingly important for economic and ecological reasons. This can be seen in the automotive and aerospace industries, as well as in civil engineering, where curved structures are often required. In order to reduce the weight of the aircraft, the aviation industry often uses spatial truss structures with bent elements. The challenge is to meet all of the stringent requirements regarding design, safety, structure, size, cost, etc., without compromising a structure's stiffness. Profiles with complicated cross-sections and so-called tailored tubes are increasingly used in the production of automotive and aircraft structures (General Aviation). Pipe and profile bending technologies are constantly being improved upon to meet the growing expectations of customers and ensure greater process efficiency. Currently, efforts are being made to increase the level of automation in this area by combining the functionality of modern bending machines with the capabilities of industrial robots. CNC bending machines currently dominate the industrial pipe bending process. A technologically advanced bending machine allows for the production of increasingly complex shapes and profiles. [ABSTRACT FROM AUTHOR]

Tailor-welded blanks (TWB) facilitate strategic material placement, ensuring desired materials are positioned appropriately, while single-point incremental forming (SPIF) enables versatile shape manufacturing with minimal tooling. Despite both methods offering customization benefits, their combined potential remains largely unexplored. This study utilized friction stir welding to create one-millimeter-thick similar and tailor-welded blanks from AA6061 and AA6003. The weld quality was ensured through metallurgical analysis and mechanical testing. SPIF of welded blanks exhibited formability comparable to parent materials, free from weld-line movement or fractures in the weld zone during forming. However, TWBs demonstrated formability between their constituting parent materials. Fractures occurred in almost all blanks due to bi-axial stretching in the corner of the D-shape. Investigation into the effect of tool size and geometry revealed that too small tool diameters induced localized deformation, contributing to failure. While flat-bottomed tools exhibited higher material thinning than hemispherical tools. [ABSTRACT FROM AUTHOR]

Cold spraying has great potential for additive manufacturing, especially of oxidation-sensitive metals, because the material is not melted and significantly higher deposition rates can be achieved than with conventional additive manufacturing processes such as selective laser melting or direct metal deposition. Titanium is regarded as a high-performance engineering material due to its unique combination of properties, including good corrosion resistance, biocompatibility and high strength at comparatively low density. However, due to its high price, it appears reasonable for many applications to use material compounds in which titanium is only used on the surface of the workpiece, while less expensive materials such as aluminum are used for the remaining volume. In the present work, cold sprayed pure titanium coatings were deposited on Al substrates and then formed to defined 3-dimensional final contours by die forging and rotary swaging. Different porosities were selectively set in order to evaluate their influence on the coating adhesion and cohesion in the forming process. Pre-consolidation of the coatings and the use of Al/Ti interlayers proved to be promising strategies. [ABSTRACT FROM AUTHOR]

TRIP (Transformation Induced Plasticity) steels belong to the group of advanced high-strength steels. Their main advantage is their excellent strength combined with high ductility, which makes them ideal for deep drawing processes. The forming of TRIP steels in the deep drawing process enables the production of a thin-walled final product with superior mechanical properties. For this reason, this study presents comprehensive research into the deep drawing of cylindrical cups made from TRIP steel. The research focuses on three main aspects of the deep drawing process, namely the sheet metal thinning, the maximum force value and the ear height as a result of the anisotropic material behaviour. Artificial neural networks (ANNs) were built to predict all the mentioned output parameters of the part or the process itself. The ANNs were trained using data obtained from a sufficient number of simulations based on the finite element method (FEM). The ANN models were developed based on variable material properties, including anisotropic parameters, blank holding force, blank diameter, and friction coefficient. A good agreement between simulation, ANN and experimental results is evident. [ABSTRACT FROM AUTHOR]

Hollow embossing rolling is a promising forming technology for metallic bipolar plates because of the high achievable production rates. However, the simulation-based process optimization is impeded by the incremental forming character and modeling of fine channel structures, which leads to large model sizes and long computation times. This paper presents a shell-based finite element approach validated by experimental forming tests using a miniaturized test geometry with typical discontinuities and varying channel orientations. The rolling experiments demonstrated that implementing restraining tension effectively decreases wrinkling, allowing successful forming of the selected test geometry by hollow embossing rolling. It was found that representing the manufacturing-related decreased rolling gap combined with the rolling gap changes due to roll system elasticity in the numerical model is essential for model accuracy. An optimized model approach with spring-controlled rollers was developed, which considers the effect of load-dependent rolling gap changes. With this approach the applied model achieves sufficient model accuracy for technological process simulation and optimization. [ABSTRACT FROM AUTHOR]

A low-density wood fiber insulation panel (WIP) composite was developed with 100 % petrochemical-free, bio-based binder with high mechanical strength, water resistance and thermal insulation properties. This study investigated the manufacturing process of composite WIPs made with mechanical pulp fibers with cellulose nanofibrils (CNFs), lignin-containing CNFs (LCNFs), hybridized CNFs-LCNFs, and CNFs-starch as a binder on different scales and evaluated the effects of binder type and content on the panels’ physical, mechanical, and thermal properties. All panels had excellent thermal resistivity values, which increased with the decrease in density. The WIPs made with LCNFs as binder had lower mechanical properties, but it was possible to replace 20 % CNFs with LCNFs to obtain the same performance as neat CNFs as the binder. Untreated panels had poor water resistance but the water absorption properties were significantly improved with the addition wax. The WIPs made with 5 % and 7.5 % binder content and 2 % wax addition could fulfill the criteria of regular and structural wall sheathing applications, respectively. Overall, the results confirm the potential of CNFs and LCNFs to be used as 100 % bio-based adhesives to produce eco-friendly composite WIPs with excellent thermo-mechanical properties to be used for regular and structural wall sheathing applications.

Metal screw extrusion (MSE) is a continuous, solid-state forming method utilizing an inherently high degree of deformation to consolidate fragmented input materials into a solid bulk by breaking their oxide skins. Severe plastic deformation with equivalent strain in the range of 10–20 can be achieved depending on set process parameters. Rigorous mixing can be employed to form sophisticated materials like bulk composites, nanocomposites, particle-reinforced metals, and fine-grained materials. Furthermore, the inherent solid-state processing is well suited for recovery of difficult-to-recycle materials. A range of non-ferrous materials has been manufactured by MSE and further characterized in terms of microstructural evolution and mechanical and functional properties. Furthermore, MSE has been studied in terms of flow, accumulated strain, and environmental impact. The following review aims to critically highlight the existing work performed on MSE, compare it to existing and emerging technologies as well as explore future development and possible applications. MSE has the potential to be utilized for numerous commercial applications. To realize industrial use of MSE, key aspects of the process and the influence of processing parameters on the resulting product must be understood.