3,555 results on '"metal forming"'
Search Results
102. Application of enhanced coulomb models and virtual tribology in a practical study.
- Author
-
de Carvalho, Lucas A. and Lukács, Zsolt
- Subjects
TRIBOLOGY ,COULOMB friction ,FRICTION velocity ,METALWORK ,FRICTION - Abstract
For the final quality of the part, metal forming trends are depending on improvements of friction and tribology. As a consequence, there is a trend in which tribology and friction are becoming increasingly important for correctly replicating the forming simulation of those parts. The objective of this work was to improve the forming simulation of an automotive shell part on AutoForm. The part was provided by a vehicle industry supplier. Enhanced Coulomb models consider a change on friction coefficient due to different factors, better approximating the description of friction to reality. For the current study, pressure and velocity dependent friction models were chosen as long as the combination of both. The virtual tribology was simulated using the software TriboForm. Velocity dependent friction model and the virtual tribology have shown similar results with expected lower coefficients of friction. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
103. Tribological performance of iron- and nickel-base self-lubricating claddings containing metal sulfides at high temperature.
- Author
-
Torres, Hector, Caykara, Tugce, Hardell, Jens, Nurminen, Janne, Prakash, Braham, and Rodríguez Ripoll, Manel
- Subjects
HEAT resistant alloys ,HIGH temperature metallurgy ,NICKEL sulfide ,METAL cladding ,METALWORK ,TRANSITION metals ,IRON - Abstract
Iron-based coatings with the incorporation of solid lubricants have been prepared by means of laser cladding, in an effort to control friction and decrease tool wear at high temperatures during metal forming applications. The choice of a Fe-based powder has been considered advantageous, as it can lead to decreased costs compared to nickel-based claddings previously studied by the authors, in addition to having a lower environmental impact. In particular, the incorporation of transition metal dichalcogenides such as MoS
2 as precursors leads to the encapsulation of silver in Fe-based self-lubricating claddings, resulting in a uniform distribution of the soft metal across the thickness of the coating. Subsequent tribological evaluation of the claddings at high temperatures shows that the addition of lubricious compounds leads to lower friction at room temperature and significantly decreased wear up to 600 °C compared to the unmodified iron-based reference alloy, although higher than similar self-lubricating Ni-based claddings. In order to cast light into these observed differences, the corresponding microstructures, phase composition, and self-lubricating mechanisms have been studied and compared for Fe- and Ni-based claddings having both of them the addition of silver and MoS2 . The results suggest a key role of the formation of protective tribolayers on the counter body during high temperature sliding contact. Additional simulation of the phase evolution during solidification reveals that the formation of different chromium- and nickel-based metal sulfides in Fe- and Ni-claddings during laser cladding by the decomposition of MoS2 plays a key role in determining their tribological behaviour at high temperatures. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
104. Microstructure and Hardness of Cold Forged 42CrMo4 Steel Hollow Component with the Outer Flange.
- Author
-
Szala, Mirosław, Winiarski, Grzegorz, Bulzak, Tomasz, and Wójcik, Łukasz
- Subjects
LOW alloy steel ,METALWORK ,HARDNESS ,MICROSTRUCTURE ,STRAIN hardening - Abstract
For decades, steel has been a crucial structural material. Mainly low-alloy steel grade 42CrMo4 is utilized for manufacturing forgings. This paper investigates the microstructure and hardness development of the 42CrMo4 steel hollow component with an outer flange. The component has been formed via cold forging in combination with extrusion and upsetting technologies. Prior to forming, the workpiece was annealed to obtain hardness at the level of 181±9 HV0.3. The FEM analysis reveals the areas that undergo higher stress and strain. The flow lines macrostructure and microstructure of hollow parts were investigated using light optical microscopy (LOM) and scanning electron microscopy (SEM) equipped with EDS. Vickers hardness allows identifying the work hardening of the crucial element areas. The microstructure consists of ferrite matrix and semispherical carbides. Laboratory studies confirm appropriate flow lines arrangement, which corresponds well to those shown by FEM computer simulations. The highest hardness at the level of 293±7 HV0.3 was identified in the flange area, where the material shows a higher distribution of effective strain revealed by FEM. Cold metal forming results in work-hardening of the steel. The work hardening ranges up to 1.62 of the initial 42CrMo4 steel hardness. The metal forming process did not affect the microstructural uniformity of the flanged hollow part. The final outer flange component presents high quality and is free from plastic deformation nonuniformities. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
105. Perspectives on data-driven models and its potentials in metal forming and blanking technologies.
- Author
-
Liewald, Mathias, Bergs, Thomas, Groche, Peter, Behrens, Bernd-Arno, Briesenick, David, Müller, Martina, Niemietz, Philipp, Kubik, Christian, and Müller, Felix
- Abstract
Today, design and operation of manufacturing processes heavily rely on the use of models, some analytical, empirical or numerical i.e. finite element simulations. Models do reflect reality as best as their design and structure may appear, but in many cases, they are based on simplifying assumptions and abstractions. Reality in production, i.e. reflected by measures such as forces, deflections, travels, vibrations etc. during the process execution, is tremendously characterised by noise and fluctuations revealing a stochastic nature. In metal forming such kind of impact on produced product today in detail is neither explainable nor supported by the aforementioned models. In industrial manufacturing the game to deal with process data changed completely and engineers learned to value the high significance of information included in such digital signals. It should be acknowledged that process data gained from real process environments in many cases contain plenty of technological information, which may lead to increase efficiency of production, to reduce downtime or to avoid scrap. For this reason, authors started to focus on process data gained from numerous metal forming technologies and sheet metal blanking in order to use them for process design objectives. The supporting idea was found in a potential combination of conventional process design strategies with new models purely based on digital signals captured by sensors, actuators and production equipment in general. To utilise established models combined with process data, the following obstacles have to be addressed: (1) acquired process data is biased by sensor artifacts and often lacks data quality requirements; (2) mathematical models such as neural networks heavily rely on high quantities of training data with good quality and sufficient context, but such quantities often are not available or impossible to gain; (3) data-driven black-box models often lack interpretability of containing results, further opposing difficulties to assess their plausibility and extract new knowledge. In this paper, an insight on usage of available data science methods like feature-engineering and clustering on metal forming and blanking process data is presented. Therefore, the paper is complemented with recent approaches of data-driven models and methods for capturing, revealing and explaining previously invisible process interactions. In addition, authors follow with descriptions about recent findings and current challenges of four practical use cases taken from different domains in metal forming and blanking. Finally, authors present and discuss a structure for data-driven process modelling as an approach to extent existing data-driven models and derive process knowledge from process data objecting a robust metal forming system design. The paper also aims to figure out future demands in research in this challenging field of increasing robustness for such kind of manufacturing processes. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
106. Evaluation of in-line monitoring of micro-forming tribo-systems by consecutive U-bending
- Author
-
Arinbjarnar, Ú., Moske, J., Nielsen, C. V., Arinbjarnar, Ú., Moske, J., and Nielsen, C. V.
- Abstract
Robustness in micro-forming, a critical part of which is system monitoring, is important due to increasing demand for micro-components. In this work, a simulation of a micro-deep drawing tribo-system is applied to investigate the influence of die radius and production speed on process stability and tool wear. Monitoring of force and thermoelectric current are used as tools for wear detection, showing that both signals respond well to wear. The thermoelectric current is more sensitive to slight changes in process conditions and can be recommended as a wear monitoring method in micro-forming over using the force signal. The results of signal monitoring are compared to the surface roughness of formed parts as function of number of strokes, showing a good correlation.
- Published
- 2024
107. Teaching Metal-Forming Processes Using a Laboratory Micro-extrusion Press
- Author
-
Ben-Artzy, Adi, Ben-Ze’ev, Snir, Frage, Nahum, Lee, Jonghyun, editor, Wagstaff, Samuel, editor, Lambotte, Guillaume, editor, Allanore, Antoine, editor, and Tesfaye, Fiseha, editor
- Published
- 2020
- Full Text
- View/download PDF
108. On the Friction Test for Metal Forming Applications
- Author
-
Alexandrov, Sergei, Vilotic, Marko, Vilotic, Dragisa, Correia, José A. F. O., Series Editor, De Jesus, Abílio M. P., Series Editor, Ayatollahi, Majid Reza, Advisory Editor, Berto, Filippo, Advisory Editor, Fernández-Canteli, Alfonso, Advisory Editor, Hebdon, Matthew, Advisory Editor, Kotousov, Andrei, Advisory Editor, Lesiuk, Grzegorz, Advisory Editor, Murakami, Yukitaka, Advisory Editor, Carvalho, Hermes, Advisory Editor, Zhu, Shun-Peng, Advisory Editor, Bordas, Stéphane, Advisory Editor, Fantuzzi, Nicholas, Advisory Editor, Gdoutos, Emmanuel, editor, and Konsta-Gdoutos, Maria, editor
- Published
- 2020
- Full Text
- View/download PDF
109. Emerging Trend in Forging Operation
- Author
-
Ikumapayi, Omolayo M., Akinlabi, Esther T., Onu, Peter, Cavas-Martínez, Francisco, Series Editor, Chaari, Fakher, Series Editor, Gherardini, Francesco, Series Editor, Haddar, Mohamed, Series Editor, Ivanov, Vitalii, Series Editor, Kwon, Young W., Series Editor, Trojanowska, Justyna, Series Editor, Emamian, Seyed Sattar, editor, Awang, Mokhtar, editor, and Yusof, Farazila, editor
- Published
- 2020
- Full Text
- View/download PDF
110. Model-Based Manufacturing System Supported by Virtual Technologies in an Industry 4.0 Context
- Author
-
Mandic, Vesna, Chaari, Fakher, Series Editor, Haddar, Mohamed, Series Editor, Kwon, Young W., Series Editor, Gherardini, Francesco, Series Editor, Ivanov, Vitalii, Series Editor, Wang, Lihui, editor, Majstorovic, Vidosav D., editor, Mourtzis, Dimitris, editor, Carpanzano, Emanuele, editor, Moroni, Govanni, editor, and Galantucci, Luigi Maria, editor
- Published
- 2020
- Full Text
- View/download PDF
111. Analyzing metal forming process
- Author
-
Berdiyev, D.M., Yusupov, A.A., and Abdulayev, B.K.
- Published
- 2021
- Full Text
- View/download PDF
112. Mathematical modelling of asymmetrical metal rolling processes
- Author
-
Minton, Jeremy John and Brambley, Ed
- Subjects
671.3 ,metal forming ,rolling ,analytical models ,asymptotic analysis - Abstract
This thesis explores opportunities in the mathematical modelling of metal rolling processes, specifically asymmetrical sheet rolling. With the application of control systems in mind, desired mathematical models must make adequate predictions with short computational times. This renders generic numerical approaches inappropriate. Previous analytical models of symmetrical sheet rolling have relied on ad hoc assumptions about the form of the solution. The work within this thesis begins by generalising symmetric asymptotic rolling models: models that make systematic assumptions about the rolling configuration. Using assumptions that apply to cold rolling, these models are generalised to include asymmetries in roll size, roll speed and roll-workpiece friction conditions. The systematic procedure of asymptotic analysis makes this approach flexible to incorporating alternative friction and material models. A further generalisation of a clad-sheet workpiece is presented to illustrate this. Whilst this model was formulated and solved successfully, deterioration of the results for any workpiece inhomogeneity demonstrates the limitations of some of the assumptions used in these two models. Attention is then turned to curvature prediction. A review of workpiece curvature studies shows that contradictions exist in the literature; and complex non-linear relationships are seen to exist between asymmetries, roll geometry and induced curvature. The collated data from the studies reviewed were insufficient to determine these relationships empirically; and neither analytical models, including those developed thus far, nor linear regressions are able to predict these data. Another asymmetric rolling model is developed with alternative asymptotic assumptions, which shows non-linear behaviour over ranges of asymmetries and geometric parameters. While quantitative curvature predictions are not achieved, metrics of mechanisms hypothesised to drive curvature indicate these non-linear curvature trends may be captured with further refinement. Finally, coupling a curved beam model with a curvature predicting rolling model is proposed to model the ring rolling process. Both of these parts are implemented but convergence between them is not yet achieved. By analogy this could be extended with shell theory and a three-dimensional rolling model to model the wheeling process.
- Published
- 2017
- Full Text
- View/download PDF
113. Investigation of material strength and oil compressibility on the hydrostatic pressure build-up in metal forming lubricants.
- Author
-
Zwicker, Maximilian, Spangenberg, Jon, Martins, Paulo, and Nielsen, Chris V.
- Abstract
Friction in sheet metal forming is largely governed by the flattening of surface asperities. Liquid lubricants can reduce flattening and friction by filling the surface valleys and carry a substantial amount of the pressure. Experimental and numerical work is presented for investigating the influence of the compressibility of the lubricant and the material strength on the deformation of a simple cylinder with an enlarged surface pocket filled with oil. Results show that deformation is not sensitive to differences in compressibility of typical lubrication oils under hydrostatic pressure conditions. This was observed independent of the material strength. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
114. 3D crack initiation and propagation applied to metal forming processes.
- Author
-
Eldahshan, Hazem, Munoz, Daniel Pino, Alves, José, Perchat, Etienne, and Bouchard, Pierre-Olivier
- Abstract
Numerical simulation of ductile fracture in the field of metal forming represents one of the most challenging tasks. Throughout the chain of manufacturing processes, the accurate prediction of the crack surfaces is essential for the quality of the final products. The application of a crack initiation and propagation algorithm known as CIPFAR is presented in order to model the complex ductile fracture processes. In addition, a phase field approach is coupled with a ductile damage criterion to simulate the transition from damage to fracture. The self-contact between crack faces is also modeled through the penalization method in order to prevent the penetration of crack faces. The presented algorithm serves as an efficient computational tool for the industrial purposes in terms of the robustness and quality of the obtained results. Comparisons are carried out with the classical element deletion method in order to show the ability of the new algorithm to tackle the issues of mesh dependency and volume loss. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
115. Evidence-based redesign of engineering education lectures: theoretical framework and preliminary empirical evidence.
- Author
-
Ralph, Benjamin James, Woschank, Manuel, Pacher, Corina, and Murphy, Mariaelena
- Subjects
- *
ENGINEERING education , *LECTURES & lecturing , *INDUSTRY 4.0 , *UNIVERSITIES & colleges , *DIGITAL technology , *ENGINEERING students , *METALWORK - Abstract
While the fourth industrial revolution continues to change manufacturing enterprises all over the world, not all enabling key technologies are taught sufficiently at universities. For this purpose, a new lecture at the Montanuniversität Leoben was designed, teaching students of miscellaneous engineering disciplines, the fundamentals of digitalization and digital transformation, tailored to the requirements of the industry. To elevate the necessary data from these segments, a representative part of the Austrian metal forming companies was analyzed by conducting a large-scale survey. For the sake of teaching efficiency, a survey revealing students' knowledge regarding digitalization and digital transformation and preferred learning methods were also carried out. As a result, a stakeholder-oriented lecture was developed. Furthermore, a general framework on how innovative transdisciplinary academic lectures in engineering can be developed in an efficient, effective, and practical way was derived, which aims to close the gap between modern engineering education and required practical skills. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
116. Optimized shape calibration process using flexible dies for annular and rectangular corners with small radius of thin-walled shell components.
- Author
-
Shu, Yi-quan, Xiang, Nan, Wang, Hao-ran, Wang, Peng-yi, Huang, Tao, Wang, Zhi-fei, Lin, Yong-jian, and Guo, Jun-qing
- Subjects
- *
THIN-walled structures , *CALIBRATION , *RADIUS (Geometry) , *METALWORK , *ELASTOMERS , *HARDNESS - Abstract
Since the structure of thin-walled shell component is sensitive to the thinning of shell thickness, it is essential to prevent material in critical deformation region, such as sharp corners, from exceeding the forming range. As a result, a shape calibration process (SCP) using flexible die was developed in this work, aiming at reducing the excessively accumulative strain in the corners with small radius in the multi-pass stamping. Elastomers with specific geometry were employed as the pressure-carrying medium in the SCP of annular and rectangular corners of a target shell component. Optimal process parameters in the proposed SCP were determined numerically, on the basis of which, forming experiments were conducted. The results showed that the forming accuracy and resultant uniformity of shell thickness were improved by selecting flexible die with appropriate Shore hardness, thickness, and geometry. Compared with SCP using rigid dies, thinning ratio of the shell thickness showed a sharp decrease of 72.9% in the SCP of rectangular corner and springback exhibited a dramatic decrease of 57.4% in the SCP of annular corner using flexible dies. Distribution of in-plane pressure, vector of metal flow, and load paths of deformed sheet were employed to clarify the forming mechanism of the SCP using flexible dies. More industrial applications of the proposed method will be expectable. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
117. INFLUENCE OF ENHANCED COULOMB'S MODEL ON THE DRAWIN OF THE HOOD INNER PANEL.
- Author
-
de Carvalho, Lucas Alexandre and Lukács, Zsolt
- Subjects
METALWORK ,FORMING limit diagrams (Metalwork) ,COMPUTER software ,PHYSICAL measurements ,COMPUTER simulation - Abstract
A constant coefficient of friction (Coulomb) is commonly used as the current industry standard to describe friction on the sheet metal forming simulation software. The use of constant Coulomb's friction may reduce precision and so the effectiveness of the simulation to represent real-world processes. This paper presents an approach using a physical measurement of friction combined with pressure dependent friction model as an input for the metal forming simulation of a hood inner part on AutoForm. The input variable parameters are the constant Coulomb and the enhanced pressure-dependent model. For the output this study analyses the Forming Limit Diagram (FLD) and blank's draw-in in a real problem provided by a car manufacturer. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
118. Theoretical and Experimental Study on the Effect of Selected Parameters in a New Method of Extrusion with a Movable Sleeve.
- Author
-
Winiarski, Grzegorz
- Subjects
- *
EXTRUSION process , *ALUMINUM alloys , *HYDRAULIC presses , *NUMERICAL calculations , *TUBES - Abstract
This paper presents a new method for forming hollow flanged products. The method involves extrusion with the use of a sleeve moving in the opposite direction to that of the punch. A tube with a constant hole diameter and two different outside diameters, made of aluminum alloy EN AW 6060 was used as a material. Numerical calculations were performed using Deform 2D/3D. Experiments were conducted on the PYE 160SS hydraulic press equipped with a specially designed device in which the punch is driven by the press slide while the moveable sleeve is driven by two hydraulic servomotors. Both numerical simulations and experiments were conducted under cold forming conditions. The aim of this study was to determine the effect of selected parameters (flange diameter, height of the cavity in the moveable sleeve, and the chamfer angle between the regions with different outside diameters on the workpiece and in the moveable sleeve cavity) on the stability of the extrusion process. Results were then used to undertake detailed comparative analyses of underfill, flange heights, and flange flank inclination angles. Findings of the analyses served as a basis for drawing conclusions regarding the effect of the analyzed parameters on the investigated extrusion process. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
119. Simulation of metal forming – Visualization of invisible phenomena in the digital era.
- Author
-
Yanagimoto, J., Banabic, D., Banu, M., and Madej, L.
- Subjects
METALWORK ,MANUFACTURING processes ,PLASTIC analysis (Engineering) ,VISUALIZATION ,MATERIAL plasticity - Abstract
The simulation of manufacturing processes has significant importance. The research and development of metal forming simulation started in the 1960s from the elastoplastic analysis of a simple plastic deformation, and it now covers a wide range of forming processes. The accuracy and applicability of metal forming simulation have significantly progressed, driven by the development of plasticity theory and numerical methods such as the remeshing technique and contact analysis algorithm. Now the targets of metal forming simulations are undergoing a transition from the macroscale analysis of deforming bodies to coupled analyses of deformations of deforming bodies and tools, and multiscale analyses of microstructure and texture. Past achievements of metal forming simulation show that it has reached the level of 'visualizing forming phenomena', but it will continue to evolve in the digital era, impacting the digital society and factories of the future, where machines work autonomously without human intervention. Emergent technologies require advanced materials, augmented reality, and, of course, metal forming simulation. In this paper, we reinforce the role of simulation as a means of performing computational (virtual) experiments and as a tool for the high-fidelity numerical visualization and quantification of unknown, unmeasurable, and invisible phenomena in formed components and their assembly. We will also discuss simulation–machine interactions, such as online simulation with process operation, to realize the triad of 'process operation – data – simulation' in the near future. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
120. Numerical and experimental analysis of single-acting stroke deep drawing of symmetric low-depth products without blank holder
- Author
-
Amr Shaaban and Ahmed Samy Elakkad
- Subjects
Deep drawing ,Metal Forming ,Die design ,Finite Element Analysis ,Forming limit diagram ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
This study conducts numerical and experimental analyses to study the parameters affecting deep drawing of symmetric low-depth products, such as die geometry, punch movement, and cushioning. The methodology proposed in this paper is applied on the deep drawing of a frying pan manufactured out of AL99.9%. The finite element model (FE-model) is developed using LS-Dyna© and an experiment is carried out to validate the FE-model. The numerical and experimental results have shown minor deviation of 3.5% and 0.92% for maximum pressing load and maximum thickness, respectively. The validated FE-model is then employed to study the parameters affecting the maximum pressing load and maximum thinning. It is proved that the cushion stiffness and the initial blank thickness have the major influence, while the punch speed shows an insignificant impact. The results are justified and hence the FE-model proves to be reliable for further analyses.
- Published
- 2021
- Full Text
- View/download PDF
121. Numerical analysis of ductile fracture in stretch bending of AA6061-T6 aluminum alloy sheet using GTN damage model.
- Author
-
Khademi, Maziar, Javad Mirnia, Mohammad, and Moslemi Naeini, Hassan
- Subjects
- *
ALUMINUM sheets , *DAMAGE models , *ALUMINUM alloys , *DUCTILE fractures , *NUMERICAL analysis , *MODEL airplanes - Abstract
[Display omitted] • The original and shear-modified GTN ductile fracture criteria are utilized during the stretch bending process. • The original GTN model can be used only in processes where the stress state is the same as the calibration test stress state. • The evolution of damage, principal strains, and displacement of fractures under different forming conditions are investigated. In this paper, the original and shear-modified GTN ductile fracture criteria are utilized to investigate the fracture behavior of the AA6061-T6 aluminum alloy sheet during the stretch bending process. An appropriate calibration strategy is presented to find the unknown coefficients of the fracture models. In this way, different tension tests such as uniaxial tension, plane strain, notched tension, and shear tension specimens are utilized. Results show that the shear-modified GTN model calibrated by the mentioned tension tests is able to predict the onset of fracture of the stretch bending process with a 5% error, while the original GTN model, calibrated by the uniaxial tension is unable to predict the fracture properly. Since the accuracy of fracture prediction depends on the stress state, the effects of the calibration test on onset of fracture were investigated. It is shown that using the original GTN model with a proper calibration test (plane strain tension) can achieve a good accuracy with 3.5% error in the stretch bending process. In addition, results show that any change in the friction coefficient and bending radius in the stretch bending process can lead to different fracture behavior. Several investigations are carried out to examine the evolution of damage and displacement of fractures in the stretch bending process under different forming conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
122. Detection of Phase Transformation during Plastic Deformation of Metastable Austenitic Steel AISI 304L by Means of X-ray Diffraction Pattern Analysis
- Author
-
Julian Rozo Vasquez, Bahman Arian, Lukas Kersting, Werner Homberg, Ansgar Trächtler, and Frank Walther
- Subjects
X-ray diffraction ,metastable austenite ,phase transformation ,plastic deformation ,metal forming ,Mining engineering. Metallurgy ,TN1-997 - Abstract
This paper evaluates the suitability of the X-ray diffraction (XRD) technique to characterize the phase transformation during the metal forming of the metastable austenitic steel AISI 304L. Due to plastic deformation, phase transformation from γ-austenite into α′-martensite occurs. The XRD peaks at specific 2θ diffraction angles give information about the phase amount. Analyses of the results with different characterization techniques such as microscopic analysis, including electron backscatter diffraction (EBSD), macro- and microhardness tests and magneto-inductive measurements of α′-martensite, were carried out. A qualitative and quantitative correlation to compute the amount of α′-martensite from the XRD measurements was deduced. XRD was validated as a suitable technique to characterize the phase transformation of metastable austenites. Additional data could provide necessary information to develop a more reliable model to perform a quantitative analysis of the phases from XRD measurements.
- Published
- 2023
- Full Text
- View/download PDF
123. Pressure-Assisted Lubrication of DC01 Steel Sheets to Reduce Friction in Sheet-Metal-Forming Processes
- Author
-
Tomasz Trzepieciński, Krzysztof Szwajka, and Marek Szewczyk
- Subjects
deep drawing ,lubrication ,metal forming ,coefficient of friction ,Science - Abstract
Friction in sheet-metal-forming processes not only affects the values of the force parameters of the process but also determines the quality of the surface of the drawpieces. This paper presents an approach to reducing the coefficient of friction by directly applying pressurized oil to the contact zone. For this purpose, a special test stand was built to carry out the strip draw test, commonly used to model the phenomenon of friction in the deep-drawing process. This test consisted of pulling a strip between flat countersamples made of 145Cr6 cold-work tool steel covered with an abrasion-resistant Mtec (AlTiN) coating. During the pilot tests, various contact pressures, lubricants with different viscosities, and different lubricant pressures were used. The influence of friction conditions on the surface roughness of the samples and the relationship between the friction conditions and the value of the coefficient of friction were determined. The supply of the lubricant under pressure into the contact zone has a beneficial effect on reducing friction. The coefficient of friction decreases with increasing lubricant pressure for contact pressures of 2–6 MPa. For a contact pressure of 8 MPa, the lubricant pressure is the least favorable for reducing the coefficient of friction. At higher lubricant pressures (12 and 18 bar), the lubrication efficiency depends on the viscosity of the lubricant and decreases with increasing contact pressure.
- Published
- 2023
- Full Text
- View/download PDF
124. Kinetostatic analysis, manufacturing, and experimental application of a press machine based on Stephenson II mechanism.
- Author
-
Jomartov, Assylbek, Halicioglu, Recep, and Kuatova, Moldir
- Abstract
Press machine tools are often used in important industrial establishments, such as automobiles, aerospace, and aviation; these machine tools must be produced with high precision. Therefore, studies related to improving press tools and enhancing their precision are being conducted. In this study, a press machine tool based on the Stephenson II mechanism is proposed. Compared to that of conventional crank presses, this mechanism increases the slider balance using a ternary link and unique connecting rods. Thus, the slider precision can be improved with a small addition to the mechanism, and load transmission can be ensured in a balanced manner. To test the contribution of the mechanism, dynamic analysis is performed using the kinetostatic method, and the dynamic data of the mechanism are obtained. Subsequently, a press machine prototype is designed and manufactured. The experimental results are verified against the theoretical results, confirming that the proposed press machine tool based on the Stephenson II mechanism has better characteristics than those of the conventional press machine owing to the favorable distribution of forces on the slide and lower reaction to the slide guides. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
125. Multiscale Analogue Modelling of Clinching Process to Investigate Thickness Tolerance and Tool Misalignment.
- Author
-
Nourani, Sia A., Pons, Dirk J., Symons, Digby, and Zhang, Senlin
- Subjects
- *
MULTISCALE modeling , *MOUTH protectors , *METALLOGRAPHY , *FINITE element method - Abstract
NEED—The effect of dimensional variability of sheet thickness (tolerance) and tool misalignment is poorly understood for the clinching process. Finite element analysis (FEA) is valuable but requires a lot of and is difficult to verify in this situation due to the asymmetrical geometry and nonlinear plasticity. OBJECTIVE—The objective of this work was to determine the effect of thickness tolerance, tool misalignment and sheet placement (top vs. bottom) in the clinching process, by use of analogue modelling with plasticine. METHOD—Experiments used a scaled-up punch and die, with plasticine as the analogue. Thickness tolerances were represented by sheet thicknesses of 11 and 7 mm, 12 and 8 mm, 8 and 12 mm and 13 and 9 mm for upper and lower sheets, respectively. Two types of lubricant were tested between sheets: glycerine and silicone oil. Angular variability was also introduced. Measured parameters were interlock (also called undercut) and neck thickness. Analogue results for deformation were compared with microscopy of metal clinching. FINDINGS—The results reveal that the multiscale analogue model is an efficient tool for studying the effect of dimensional deviation on a clinch joint. Thickness tolerance showed a critical relationship with interlock, namely a reduction to about half that of the nominal, for both maximum and least material conditions. Increased angular misalignment also reduced the interlock. Compared with glycerine, silicone oil tests showed reduced interlock, possibly the result of a lower coefficient of friction. ORIGINALITY—This work demonstrates the usefulness of analogue modelling for exploring process variability in clinching. The results also show that significant effects for sheet placement are ductility, lubricant (friction), thickness of samples and tool misalignment. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
126. Towards a wickless smooth–Wall aluminium food packaging tray mould tool digital twin - Advanced computational modelling supported by experimental validation.
- Author
-
Mahmoodi, P., Elrefaey, A., Hassan, O.I., Morgan, H.D., Sienz, J., and Belblidia, F.
- Subjects
- *
FOOD packaging , *DIGITAL technology , *ALUMINUM , *TRAYS , *METALWORK - Published
- 2022
- Full Text
- View/download PDF
127. Design for 3D Printed Tools: Mechanical Material Properties for Direct Polymer Additive Tooling.
- Author
-
Frohn-Sörensen, Peter, Geueke, Michael, Engel, Bernd, Löffler, Bernd, Bickendorf, Philipp, Asimi, Arian, Bergweiler, Georg, and Schuh, Günther
- Subjects
- *
MECHANICAL behavior of materials , *RAPID tooling , *INDUSTRY 4.0 , *METALWORK , *MASS customization , *POLYMERS - Abstract
In relation to the fourth industrial revolution, traditional manufacturing methods cannot serve the flexibility demands related to mass customization and small series production. Rapid tooling provided by generative manufacturing has been suggested recently in the context of metal forming. Due to the high loads applied during processes to such tooling, a purposeful mechanical description of the additively manufactured (AM) materials is crucial. Until now, a comprehensive characterization approach for AM polymers is required to allow a sophisticated layout of rapid tooling. In detail, information on compressive and flexural mechanical properties of solid infilled materials made by additive manufacturing are sparsely available. These elementary mechanical properties are evaluated in the present study. They result from material specimens additively manufactured in the fused filament fabrication (FFF) process. The design of the experiments reveals significant influences of the polymer and the layer height on the resulting flexural and compressive strength and modulus as well as density, hardness, and surface roughness. As a case study, these findings are applied to a cup drawing operation based on the strongest and weakest material and parameter combination. The obtained data and results are intended to guide future applications of direct polymer additive tooling. The presented case study illustrates such an application and shows the range of manufacturing quality achievable within the materials and user settings for 3D printing. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
128. Optimization and inverse analysis in metal forming: scientific state-of-the-art and recent trends.
- Author
-
Andrade-Campos, Antonio, Coppieters, Sam, and Strano, Matteo
- Abstract
Nowadays, the accuracy and fast result-delivery of numerical simulations allow to perform not simply feasibility and validation tasks but to actually accomplish optimized process designs and solutions for the metal forming industry. This paper present a wide overview of the role of optimization and inverse analysis in the scientific and industrial community of metal forming, including the contribution of the ESAFORM association to this thematic, which is still growing after about three decades of intense research. The number of efficient and effective solutions comprising metal forming and optimization seems to increase year after year. Representative process optimization problems in sheet, bulk, and tube metal forming are presented through significant examples, and the treatment of uncertainty is also shown in stochastic approaches combined with optimization methods. Inverse problems in metal forming, which are solved with the aid of optimization methodologies, are also discussed particularly with emphasis on parameter identification problems and inverse material characterization in mechanical plasticity. The paper also identifies the most recent research trends and formulates some predictions for the future needs of industrial users. This paper shows not only that the relevance of the field of study is still increasing, but also that optimization and inverse analysis in metal forming is playing and will continue to play an important role in the digital transition of the metal forming industry, where simulation still represents the most advanced frontier. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
129. Rancang Bangun dan Uji Kinerja Mesin Bead Roller untuk Perbaikan Bodi Kendaraan
- Author
-
Andika Wisnujati and Mirza Yusuf
- Subjects
metal forming ,bead roller ,electric motor ,body repair ,Technology - Abstract
In developing the 4.0 industrial revolution era, vehicle body repair manufacturing companies are required to carry out technological innovations to support effective and efficient performance. One way is in the metal forming process, namely by changing the metal's shape into a variety of products by the company to increase the selling value of the material. The method of forming metal or these materials uses a bead roller machine with a compressive force to carry out the forming process on sheet metal plates according to the size of the tools' geometry and shape. The design of this bead roller machine is operated by using an electric motor with a power of 0.5 HP, using an Alternating Current (AC) voltage, the thickness of the iron frame dimensions of 1.2 cm, and using a reducer with a ratio of 1: 100. Selection of engine parts such as shafts, bearings, tools, and sprockets using materials that are economical and easy to obtain. The design uses Autocad 2014 Software, starting with designing a bead roller machine design paying attention to the strength of the materials used, then assembling the components and the machine's electrical system. The result of this design will be displayed by performing the bead roller machine performance. This bead roller can increase work productivity efficiently and effectively concerning sheet metal media for vehicle body repair compared to manual roll bending tools.
- Published
- 2021
- Full Text
- View/download PDF
130. Using the Upper Bound Technique for Calculating the Strain Rate Intensity Factor
- Author
-
Alexandrov, Sergei, Vilotic, Dragisa, Grabco, Daria, Correia, José A.F.O., Series Editor, De Jesus, Abílio M.P., Series Editor, Ayatollahi, Majid Reza, Advisory Editor, Berto, Filippo, Advisory Editor, Fernández-Canteli, Alfonso, Advisory Editor, Hebdon, Matthew, Advisory Editor, Kotousov, Andrei, Advisory Editor, Lesiuk, Grzegorz, Advisory Editor, Murakami, Yukitaka, Advisory Editor, Carvalho, Hermes, Advisory Editor, Zhu, Shun-Peng, Advisory Editor, and Gdoutos, Emmanuel E., editor
- Published
- 2019
- Full Text
- View/download PDF
131. Selection of Blank Size for Deep Drawing of Rectangular Parts
- Author
-
Bodhe, Arvind B., Mandavgade, Nitin K., Tajne, Amit, Davim, J. Paulo, Series Editor, Kolhe, Mohan Lal, editor, Labhasetwar, Pawan Kumar, editor, and Suryawanshi, H. M., editor
- Published
- 2019
- Full Text
- View/download PDF
132. Application of Explosives in Metal Forming
- Author
-
Šunjić, Darko, Buljan, Stipo, Kacprzyk, Janusz, Series Editor, and Karabegović, Isak, editor
- Published
- 2019
- Full Text
- View/download PDF
133. Comparison of Different Upsetting Processes for the Production of Copper Coils for Wheel Hub Engines
- Author
-
Petrell, Daniel, Braun, Alexander, Hirt, Gerhard, Schmitt, Robert, editor, and Schuh, Günther, editor
- Published
- 2019
- Full Text
- View/download PDF
134. Characterisation of the Tensile Bonding Strength of Ti-6Al-4V Hybrid Parts Made by Sheet Metal Forming and Laser Beam Melting
- Author
-
Papke, Thomas, Huber, Florian, Geyer, Georg, Schmidt, Michael, Merklein, Marion, Schmitt, Robert, editor, and Schuh, Günther, editor
- Published
- 2019
- Full Text
- View/download PDF
135. Industry 4.0 and New Paradigms in the Field of Metal Forming
- Author
-
Mladomir Milutinović, Mijodrag Milošević, Jovica Ilić, Dejan Movrin, Milija Kraišnik, Saša Ranđelović, and Dejan Lukić
- Subjects
flexibility ,Industry 4.0 ,metal forming ,smart tools ,Technology - Abstract
Over the last few year, the metalworking sector has been undergoing rapid and radical transformations driven by global competition and the revision of the production focus that is being moved from mass customization to mass individualization. A results of this is introduction of new manufacturing strategies such as Industry 4.0, a concept that combines cyber-physical systems and promote communication and connectivity. Therefore, this concept changes not only the face of the manufacturing systems but also causes transformation of existing business models and the society as a whole. This paper deals with the recent trends and paradigms in the field of metal forming, resulting from the concept of Industry 4.0 and the modern market challenges. The maim attention is paid on the flexibility of manufacturing systems and recent developments in design of smart forming tools.
- Published
- 2021
136. Extraction and Physicochemical Characterization of Cashew Nut-Shell Liquid in Metal Forming
- Author
-
O. I. Sekunowo and G. U. Uduh
- Subjects
Cashew nut-shell ,Liquid ,Lubrication ,Metal forming ,Waste Management, wastewater, landfill leachate, physicochemical process, organic, inorganic, contaminants ,Soxhlet extraction ,Technology ,Geophysics. Cosmic physics ,QC801-809 - Abstract
Effective lubrication during metalworking is critical to mitigating undesirable tool wear and poor surface finish of formed components. This paper investigated the physicochemical characteristics of cashew nut-shell-liquid (CNSL) with a view of determining its suitability for the development of an eco-friendly lubricant used in metal forming. The cashew nut shell oil (CNSO) was extracted by soxhlet method and characterised to determine its physicochemical properties including density, free fatty acid (FFA), and viscosity. In addition, the saponification value, iodine value, pH, flash point and friction coefficient were determined using relevant analytical tools. The results showed that CNSL yield from soxhlet solvent extraction is 45.6%, which is adjudged to be relatively substantial with regard to other extraction processes. Furthermore, the CNSL exhibited critical lubrication characteristics in terms of density (0.94 g/cm3), moisture content (3.96%), acid value (11.32 mg.KOH/g), FFA (3.7%), ester value (127.92 mg.KOH/g), saponification value (139.24 mg.KOH/g), pH value (4.61), iodine value (40.21 gI2/100 g), viscosity at 100 oC (14.12 Pa.s), friction coefficient (0.001) and flash point of 286.63 oC. Given these outcomes in comparison with commercial Chevron soluble oil, it is concluded that CNSL is suitable for use as a viable metal forming lubrication fluid.
- Published
- 2022
137. Modelling and simulation of hot direct extrusion process for optimal product characteristics: Single and multi-response optimization approach.
- Author
-
Elplacy, F., Samuel, M., and Mostafa, R.
- Subjects
- *
EXTRUSION process , *PRODUCT attributes , *VIBRATION (Mechanics) , *FINITE element method , *TAGUCHI methods , *ALUMINUM alloys - Abstract
The study of eccentricity minimization in cylindrical products helps to reduce the mechanical vibrations and wear of related mechanical parts such as bearings, columns and gears which positively affects in maintenance costs savings and increasing production quality reliability. The main purpose of this paper is to investigate the effect of the eccentricity between the billet material and the die parts on the quality of the final product in the direct extrusion process. The input parameters to produce a cylindrical product shape are optimized in MINITAB based on Taguchi method and ANOVA. The selected material of the billet is the aluminium alloy AA2024, and the die material is Steel H13. The inputs parameters are the temperature, the die angle, the ram speed, and the presumed eccentricity. The finite element model of the process is simulated in DFORM-3D for providing the extrusion information such as the pressure, the effective stress and strain, the final product eccentricity, and the roundness error. The study is carried out on two cases of the presumed eccentricity in addition to a case of zero eccentricity. The single and multi-response optimi- zations are executed to obtain the optimum parameters for the minimum product eccentricity and roundness error. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
138. Experimental and modelling study of interaction between friction and galling under contact load change conditions.
- Author
-
Yang, Xiao, Hu, Yiran, Zhang, Lemeng, Zheng, Yang, Politis, Denis J., Liu, Xiaochuan, and Wang, Li-liang
- Subjects
METALWORK ,DYNAMIC balance (Mechanics) ,ABRASIVE machining ,FRICTION ,ALUMINUM alloys ,ALUMINUM - Abstract
The galling process remains one of the least understood phenomena in metal forming. The transfer of material from a work-piece onto the tool surface can cause an evolutionary increase in friction coefficient (COF) and thus the use of a constant COF in finite element (FE) simulations leads to progressively inaccurate results. For an aluminium work-piece, material transfer, which has history and pressure dependency, is determined by a dynamic balance between the generation and ejection of wear particles acting as a 'third body' abrasive element at the contact interface. To address this dynamic interactive phenomenon, pin-on-disc tests between AA6082 and G3500 were performed under step load change conditions. The COF evolutions, morphologies of the transfer layer and its cross-section were studied. It has been found that contact load change will disequilibrate and rebuild the dynamic balance and high load will increase the generation and ejection rate of third body and vice versa. Moreover, based on the experimental results, an interactive model was developed and presented to simulate the dynamic formation process of the aluminium third body layer under load change conditions, enabling multi-cycle simulations to model the galling distribution and friction variation. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
139. تعیینورق دولیهAA3105-St12بهینهدر فرایندشکلدهي نمویبا استفاده از شبکه عصبیو الگوریتمژنتیکچند هدفه.
- Author
-
حامد دیلمیعضدی, سعیدرضایی, حسن بادپروا, and علیزینالعابدین&#
- Subjects
ARTIFICIAL neural networks ,SHEET metal ,GENETIC algorithms ,GENETIC models ,METALWORK ,ALUMINUM sheets - Abstract
Incremental sheet forming is a flexible forming technology in which the sheet metal is gradually formed by the movement of tools in specified path. Due to the progressively localized deformation of the sheet and concentration of the forces on contact area of tool and sheet metal, the formability of the sheet increases compared with other common forming methods. In this study, numerical simulation of the incremental forming of AA3105-St12 two- layer sheet has been performed to calculate forming force and final thicknesses of the layers. The validity of the simulation results is evaluated by comparing them with those obtained from experiments. Numerical models for estimating the vertical force applied on the tool and the final thicknesses of the layers in terms of the process variables have been obtained using artificial neural network. Multi-objective optimization has been conducted to achieve the minimum force and the minimum thickness reduction of layers using obtained numerical models based on genetic algorithm method. Optimum thickness of the two-layer sheet and the thickness ratio the layers in different states of contact of the aluminum or the steel layers with the forming tool have been determined. [ABSTRACT FROM AUTHOR]
- Published
- 2022
140. SuperMeshing: A New Deep Learning Architecture for Increasing the Mesh Density of Physical Fields in Metal Forming Numerical Simulation.
- Author
-
Qingfeng Xu, Zhenguo Nie, Handing Xu, Haosu Zhou, Attar, Hamid Reza, Nan Li, Fugui Xie, and Xin-Jun Liu
- Subjects
- *
DEEP learning , *METALWORK , *FINITE element method , *COMPUTER simulation , *DENSITY - Abstract
In metal forming physical field analysis, finite element method (FEM) is a crucial tool, in which the mesh-density has a significant impact on the results. High mesh density usually contributes authentic to an increase in accuracy of the simulation results but costs more computing resources. To eliminate this drawback, we propose a data-driven mesh-density boosting model named SuperMeshingNet that uses low mesh-density physical field as inputs, to acquire high-density physical field with 2D structured grids instantaneously, shortening computing time and cost automatically. Moreover, the Res-UNet architecture and attention mechanism are utilized, enhancing the performance of SuperMeshingNet. Compared with the baseline that applied the linear interpolation method, SuperMeshingNet achieves a prominent reduction in the mean squared error (MSE) and mean absolute error (MAE) on the test data. The well-trained model can successfully show an improved performance than the baseline models on the multiple scaled mesh-density, including 2 ×, 4 ×, and 8 ×. Enhanced by SuperMeshingNet with broaden scaling of mesh density and high precision output, FEM can be accelerated with seldom computational time and cost with little accuracy sacrificed. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
141. Characterization of sheet metal components by using an upsetting test with miniaturized cylindrical specimen.
- Author
-
Hetz, Peter, Kraus, Martin, and Merklein, Marion
- Subjects
SHEET metal ,STRAIN hardening ,STANDARDIZED tests ,COMMERCIAL product testing ,METALWORK - Abstract
Especially for safety-relevant components local characterization of the mechanical properties is necessary for product testing. For sheet metal parts with a complicated geometry conventional specimens for standardized tests cannot be extracted due to size limitations. Thus, a novel extraction procedure of miniaturized upsetting specimens is investigated. Taking a miniaturized upsetting specimen out of the sheet component allows for the first time the characterization of sheet metals in a standardized upsetting test under uniaxial compression stresses. Furthermore, this enables the analysis of strain hardening behavior of components and a direct validation of finite element simulations based on the true stress. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
142. Metal forming driven surface engineering of thin profile wires for high precision industrial filtration screens.
- Author
-
Muszka, Krzysztof, Kwiecien, Marcin, Perzynski, Konrad, Majta, Janusz, and Madej, Lukasz
- Subjects
METALWORK ,AUSTENITIC steel ,STAINLESS steel ,WEAR resistance ,RESIDUAL stresses ,PEARLITIC steel ,WIRE ,LASER peening - Abstract
Screens made of drawn and spot-welded stainless steel precise profile wires are widely used to separate particles from fluids during various industrial applications. Increased durability and surface quality of these products are critical in maximising their wear resistance and extending the screen service life. Therefore, the paper discusses the development of metal forming technology considering the surface quality and residual stress level of austenitic and lean-duplex steel profile wires for the production of high-quality industrial screens. It is shown that surface engineering driven by metal forming is a key factor in extending the life and performance of these products. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
143. Severe plastic deformation by Constrained Backward Flowforming.
- Author
-
Ghiotti, Andrea, Bruschi, Stefania, Simonetto, Enrico, Magro, Tommaso, and Madej, Lukasz
- Subjects
MATERIAL plasticity ,PARTICLE size distribution ,MANUFACTURING processes ,HYDROSTATIC pressure ,GRAIN ,SHEET metal - Abstract
The last decades have seen several attempts to develop Severe Plastic Deformation (SPD) processes to manufacture parts with Ultra-Fine Grained (UFG) microstructure without additional thermal processing. However, they remained mostly focused on producing small components, often in the micro-scale range, thus limiting the technological and environmental impact of SPD techniques. The paper introduces a new approach to produce large size UFG metal sheets which main innovation lies in a constrained flowforming process that allows obtaining large deformations under high hydrostatic pressure. Metal sheets with isotropic grain distribution and average grain size of 4 μm were manufactured by this process chain and their mechanical properties assessed. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
144. W-Temper forming of B-pillar from 7075 aluminum alloy.
- Author
-
Gronostajski, Zbigniew, Jaśkiewicz, Karol, Kaczyński, Paweł, Skwarski, Mateusz, Polak, Sławomir, Krawczyk, Jakub, Chorzępa, Władysław, and Trzpis, Przemysław
- Subjects
MATERIALS testing ,ALUMINUM alloys ,METALWORK ,ALUMINUM - Abstract
The work concerns the possibility of producing B-pillars from the 7075 aluminum alloy. First, extensive material tests were carried out. The as-delivered sheets (T6 temper) were heated up to 500 °C and solution heat-treated to dissolve the phases in the aluminum matrix. Then, the foot of the B-pillar was stamped from water-cooled and conductively-cooled blanks. When the initial process parameters were established, stamping tests of B-pillars were carried out. The strength and hardness of the manufactured elements were tested. The selection of process parameters allowed to obtain a product with an appropriate strength, similar to the strength of the T6 temper. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
145. The role of entrapped lubricant in asperity flattening under bulk plastic deformation.
- Author
-
Nielsen, Chris V., Zwicker, Maximilian F.R., Spangenberg, Jon, Bay, Niels, and Martins, Paulo A.F.
- Subjects
MATERIAL plasticity ,COMPRESSIBILITY ,METALWORK ,COMPRESSION loads ,DEFORMATIONS (Mechanics) ,TRIBOLOGY - Abstract
The load bearing capacity of entrapped lubricant and resulting diminished asperity flattening are studied with a new specimen design that allows for both compression and biaxial bulk deformation of the subsurface material. Numerical simulations considering the experimental compressibility curve for the trapped oil support the analysis and show how incomplete filling of the valleys affect asperity flattening depending on the asperity flank angle. Finally, the new specimen design also allows quantifying the differences in friction when bulk deformation of the subsurface material is carried out with and without trapped oil in the valleys between asperities. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
146. Experimental Pressure-Forming
- Author
-
Daniel Elkin
- Subjects
making research ,tooling provision ,metal forming ,construction technology networks ,autonomous development ,Architectural drawing and design ,NA2695-2793 - Abstract
This paper describes improved pressure forming techniques, metal-forming methods related to industrial processes, but suited to lower capitalisation contracting or do-it-yourself (DIY) fabrication settings. Working from literature and previous research, the author describes advancements to the tooling’s capabilities, compared to other research vectors for double-axis curvature metal forming. These works connect fabricators’ situational constraints to value constructs that surround making’s particularity as research, and to values driving autonomous development construction networks. This paper asks: what values drive, and what value is added by, improving such sub-optimal fabrication processes? Given industrial and digital processes’ extensive capabilities, are there contexts where intermediate technologies are particularly suited? How do those contexts constrain technical researchers’ ability to add value through tooling improvement? This paper presents recent technical research, and projects a method to integrate that research into autonomous development fabrication contexts within the Hong Kong Special Administrative Region (HKSAR) and China’s Great Bay Region.
- Published
- 2020
- Full Text
- View/download PDF
147. Study on the main influencing factors of shear strength of nano-silver joints
- Author
-
Hui Yang and Wenhui Zhu, PhD
- Subjects
Nano-silver ,Shear strength ,Materials testing ,Metal forming ,Influencing factors ,Mining engineering. Metallurgy ,TN1-997 - Abstract
This article investigates the factors affecting the shear strength of nano-silver joints. Experiments were performed under different sintering temperatures, pressures, and time, different sintered layer thicknesses, different shear rates, and shear temperatures, and the effects of various parameters on joint strength were obtained. It is found that the joint strength can be increased when the sintering temperature, pressure, time and shear rate are increased. The maximum shear strength of the interconnection bond is measured at room temperature 25 °C and 150 °C, and the gap is large. Increasing the temperature will reduce the bond strength Reliability is reduced. The effects of some of these parameters and particle size on joint strength were further studied and analyzed.
- Published
- 2020
- Full Text
- View/download PDF
148. Numerical Investigation of Step Size Effect on Formability of 2024-T3 Aluminum in Incremental Forming
- Author
-
Tyler J. Grimm, Filipe Colombini, and Ihab Ragai
- Subjects
incremental forming ,finite element simulation ,SPIF ,fomability ,metal forming ,Production capacity. Manufacturing capacity ,T58.7-58.8 - Abstract
Incremental forming (IF) is an advanced manufacturing process in which a forming tool locally deforms sheet material into a desired geometry through successive passes at incremental depths. An inherent benefit to the IF process is its formability improvement over conventional stamping; however, further enhancements will enable the forming of increasingly complex geometries. To progress the IF process towards heavy industrial use, the modeling of such processes must be further developed. Single point incremental forming (SPIF) of AA2024-T3 was modeled herein utilizing explicit formulations. The model geometry featured a nominally rectangular-shaped clamping region. A friction factor was experimentally determined and utilized within the model, which is a novel addition to this work. Formability was determined and forming limit diagrams were composed. It was found that the present model shows greater formability and underestimates plastic strain compared to experimental testing. The generation of forming limit diagrams for this material processed by IF is also a novel addition to this field.
- Published
- 2023
- Full Text
- View/download PDF
149. Hybrid Wire-Arc Additive Manufacturing of Conformal Cooling Channels: A Feasibility Study
- Author
-
Pragana, João P. M., Bragança, Ivo M. F., Silva, Carlos M. A., and Martins, Paulo A. F.
- Published
- 2023
- Full Text
- View/download PDF
150. A Review on Friction and Lubrication in Automotive Metal Forming: Experiment and Modeling.
- Author
-
Lee, Kijung, Moon, Chanmi, and Lee, Myoung-Gyu
- Subjects
- *
METALWORK , *FRICTION , *FRICTION materials , *SHEET metal work , *FINITE element method , *SURFACE roughness , *BOUNDARY lubrication , *MECHANICAL properties of condensed matter - Abstract
Metal forming or shaping processes, such as sheet metal forming and bulk forming, are widely used in many industries including automotive industry. Before computational simulations were widely used in the field of metal forming industry, the trial-and-error based empirical approach was conventionally applied to the optimization of the metal forming process and product. The most commonly employed numerical approach in the metal forming process for robust process optimization is the finite element analysis. Friction, one of the parameters that significantly affect the accuracy of numerical analysis, depends on several variants such as surface quality, contact pressure, lubrication, deformation, and the forming environment. Despite the complexity and difficulty of identifying friction mechanisms, accurate friction models are essential and hence have been proposed by numerous researchers. In this paper, the friction models in the previous studies are reviewed by categorizing them into the boundary lubrication condition and mixed-boundary lubrication condition according to their evaluative influences on friction. Since friction models have been proposed based on the contact theories, an overview on the contact models is also included in this paper. In addition, the contribution of several parameters on the friction such as surface roughness and material properties of the tool, adhesion, contact pressure, sliding speed, bulk deformation is also discussed. This review paper aims to provide an understanding and insight into the friction modeling and simulation along with associated friction experiments. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.