bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of Influencing Factors in Machine Hammer Peening with Consideration of Lubricant Influences
Authors: Uhlmann Lars , Mannens Robby , Weiser Ingo Felix , Herrig Tim , Bergs Thomas
Published: July 2022

Lightweight construction and performance requirements in the automotive industry have resulted in increased power density. At the same time, this increases the load on the workpieces. To counteract the resulting wear, either a more wear-resistant material may be applied or the functional surface may be specifically modified against wear. Machine hammer peening (MHP) is a process for such a targeted adjustment of the functional surface and the surface area properties. MHP is a mechanical surface treatment, which increases the wear resistance of the workpieces by introducing residual compressive stresses and work hardening as well as by smoothing or structuring the surface. To ensure an accurate adjustment of the surface properties, the influencing factors (material, process parameters and lubricant) and their interactions must be sufficiently well studied and understood. In particular, the influence of the lubricant on the surface area properties has not yet been adequately investigated. The objective of the work presented in this paper was to provide a deeper insight into the influence of the type of lubricant on the resulting surface properties in terms of roughness, residual stresses and hardness. The lubricant’s influence was investigated using a partial factorial experimental design. Additional factors investigated, besides the choice of lubricant, were stroke, distance of indentation and step over distance. The results show a strong influence of the lubricant selection, especially on the resulting surface roughness. For the same process parameters, a deviation of 540 % in the resulting surface roughness was measured between two surfaces machined with different lubricants.
Comparison of Scan Strategies for Side Roughness Optimization of Al6061-Zr Alloy Produced by Laser Powder Bed Fusion (L-PBF), Benefits and Drawbacks on Different Part Profiles
Authors: Beal Maxime
Published: July 2022

Laser Powder Bed Fusion (L-PBF) is an additive manufacturing process that allows to build parts by solidifying powder bed, layer by layer, with a laser. This approach offers the possibility to build complex geometries. However, due to the succession of layers, the use of powder as raw material and melt pool dynamic, the surface roughness generated through this process is a limitation for some applications. Several works have been conducted to improve surface roughness by improving scan strategies such as contouring, and compensation optimization. However, these improvements are mostly applied on usual materials and on simple geometries. The aim of this work was i) to compare roughness obtained on cubes with high performance aluminium alloy (6061-Zr) and cast alloy (AlSi7Mg), ii) apply roughness optimization strategy on 6061-Zr on cubes and iii) compare typical L-PBF geometries obtained with and without roughness optimization strategies. This study shows that LPBF using Al6061-Zr alloy produces a higher roughness than AlSi7Mg (+16 %). The strategies used allowed the roughness to be reduced (-63 %) as well as obtaining a better circularity and a more homogeneous surface. It was also shown that some strategies have weaknesses for specific geometrical shapes.
Experimental Setup for Fatigue Testing of Additively Manufactured Specimens
Authors: Manco Emanuele , Scherillo Fabio , El Hassanin Andrea , Borrelli Domenico , Caraviello Antonio , Squillace Antonino
Published: July 2022

Poor fatigue life is a huge issue of additively manufactured parts, despite the unique qualities characterizing this manufacturing process (such as low waste of material and geometry freedom). Fatigue life is strongly affected by both surface defects and internal defects, metal AM is characterized by extremely poor surface quality, internal porosities and lack of fusions. For this reason, many researchers investigated methods to improve manufacts quality. The most promising methods are surface finishing treatments and thermal treatments which provide an enhancement of fatigue behavior. A focal point of the research should be evaluating the respective contribution of surface treatments and thermal treatments. In order to evaluate the effectiveness of surface treatment, it is necessary to highlight the surface quality contribution in terms of fatigue life thus a specific testing method is necessary. Rotating beam fatigue test fits this requirement because each point of the specimen’s surface is subjected to the maximum stress. The aim of this work is to present the experimental setup for rotating beam fatigue testing that has been used to evaluate the fatigue behavior of AM SLM IN718 specimens.
Extrusion of Lightweight Aluminum and Magnesium Alloys Structures for Aviation Applications
Authors: Śliwa Romana Ewa , Pawłowska Beata , Balawender Tadeusz , Zwolak Marek
Published: July 2022

The development of light-weight materials and fabricating parts/sub-assemblies of substantially large dimensions has become a major issue for the aerospace industry, which has boosted the development of more advanced materials with high specification properties. Recent aluminum and magnesium alloys developments are based on achieving superior fatigue crack growth resistance, better corrosion resistance, lower density, etc. Standard manufacturing techniques, such as extrusion, ought to be developed in order to find a beneficial solution allowing for structural weight reduction, which is a very efficient means of improving aircraft performance. It is associated with the problem of extrusion profiles with a complex cross-section shape. In this work the formability of aluminum and magnesium alloys in the extrusion process was determined by the upsetting test through specification of the flow stress in relationship to the deformation size and rate. The results of the upsetting test of Al (7075, 2024, 8090, 2099) and Mg ( AZ31, AZ61, AZ80, WE 43) alloys were used in determining the conditions of the extrusion of profiles of various cross section shape and extrusion ratio. The analysis of macro and microstructure of extruded products and their mechanical properties demonstrates strong influence of the shape of extrudate cross section on metal exit speed and extrusion force value. Macro-and microstructure of all the investigated alloys after extrusion are highly homogeneous in terms of the grain size and morphology of the phase components, compared to the macro- and microstructure in the initial state, which justifies the use of them in production of aviation profiles.
Experimental Investigation of Factors Influencing the Determination of the Onset of Yielding by Temperature Measurement
Authors: Vitzthum Simon , Gruber Maximilian , Rebelo-Kornmeier Joana , Hofmann Michael , Volk Wolfram
Published: July 2022

The cooling of the material during elastic tensile loading is well known as the thermoelastic effect. It is already known that the temperature minimum at the elastic-plastic transition can be used for the determination of the onset of yielding. Conceivable parameters for this have already been presented and investigated. Within this study factors influencing the specimen temperature during tensile loading and unloading are experimentally analyzed to improve the determination approach and the understanding of it. Furthermore, the robustness and repeatability of the measurement and evaluation procedures are analyzed. Therefore, cyclic tensile tests with the mild steel DC06 and the high strength steel CR590Y980T (DP1000) are performed with four PT1000 sensors applied on the specimen. The temperature behavior during elastic loading, elastic-plastic elongation and elastic unloading is separately evaluated. Different strain rates are investigated to better understand the strain-dependent heat development and its influence on the temperature-dependent evaluation. In this way, correlations between strain rate and thermal conduction due to prevailing temperature differences are found and their influence on the temperature-based determination of the onset of yielding is analyzed. Therefore, the yield stress at temperature minimum YSTmin as well as an additional yield stress at zero plastic strain YS0 are evaluated for all experiment settings. In a comprehensive experimental study, the standard deviations are compared and thus conclusions can be drawn about the robustness of the determination methods.
Anomaly Detection during Thermoplastic Composite Infusion: Monitoring Strategy through Thermal Sensors
Authors: Le Bot Philippe , Lebreton Grégoire , Siddig Nihad , Couarraze Pierre , Fouché Olivier , Sébastien Camille , De Fongalland Antoine , Cara Fabien , Gérard Pierre
Published: July 2022

Vacuum assisted resin infusion (VARI) processes are widely used for the fabrication of large composite parts. For some years now, wind blades are designed with thermoset composite materials, however, recyclability is often the missing brick. The recent advent of thermoplastic materials such as ELIUM©, developed by ARKEMA, shows the possibility to consider the manufacture of very large parts such as wind turbine blades with recyclable constituents [1]. The French institute IRT Jules Verne is leading the research project ZEBRA, with a consortium of industrials, focusing on different thematics of the manufacturing of wind turbine blades, including process monitoring. In the objective of evaluating the possibility for anomaly detection during the ELIUM© infusion process, an infusion test bench was developed, equipped with different sensors including infrared camera, thermocouples and heat flow sensors. In this work, the thermal sensors are evaluated by the study of several infusion scenarios of plates fabricated under different process conditions and material parameters. Artificial anomalies are imposed into the process to evaluate the potential of these sensors to detect the induced disturbances. A numerical process modelling is developed, compared to the sensor outputs and used to achieve a better understanding of some effects observed during the process.
Influence of Plastic Deformation on the Hydrogen Embrittlement Susceptibility of Dual Phase Steels
Authors: Drexler Andreas , Helic Besim , Silvayeh Zahra , Sommitsch Christof , Mraczek Klemens , Domitner Josef
Published: July 2022

The susceptibility of advanced high-strength steels (AHSS) to hydrogen embrittlement (HE) limits the broad utilization of these materials for body-in-white (BIW) components. The considerable decrease of both ductility and toughness due to local hydrogen accumulation inside of formed components may cause unpredictable time-delayed failure. In particular deep-drawn and punched AHSS components are prone to hydrogen absorption. This work investigates the influence of plastic deformation on hydrogen absorption of dual phase (DP) steels. For that purpose, tensile samples were machined out of three commercial 1.2 mm-thick DP sheets with ultimate tensile strengths of 626 MPa, 826 MPa and 1096 MPa. Samples were uniaxially pre-strained to 2 %, 5 %, 10 %, 15 % and 20 %. After pre-straining the samples were electrochemically charged with hydrogen, and the actual hydrogen contents were determined using a thermal desorption analyser (TDA). Before and after charging, the hardness of the samples was measured and the uniaxial quasi-static tensile properties were determined. In order to quantify the influence of plastic deformation on HE, slow strain rate tests (SSRT) were performed. The results of the tests were correlated with the fraction of martensite determined for each of the three steels.
Comparison of Conventional and Conformal Cooling Channels in the Production of a Commercial Injection-Moulded Component
Authors: Kariminejad Mandana , Kadivar Mohammadreza , McAfee Marion , McGranaghan Gerard , Tormey David
Published: July 2022

Cooling channels are critical in injection mould tooling as cooling performance influences component quality, cycle time, and overall process efficiency. Additively Manufactured moulds allow the incorporation of cooling channels conforming to the shape of the cavity and core to improve heat removal. These conformal channels can reduce the cycle time, reduce mould temperature, and enhance the temperature uniformity on the mould's surface, leading to improved quality of the moulded components and reduced wastage in the production. The design of such channels is more challenging than conventional channels; thus, Computer-Aided Engineering (CAE) has a significant role within the design process. In this paper, a novel design for conformal cooling channels for the production of a commercial component from an industrial partner is investigated. This component had issues of high cycle time and a high defect rate due to residual stresses, resulting in component shrinkage. First, the existing conventional drilled cooling channels in the mould were simulated in Autodesk Moldflow Insight to evaluate temperature distribution and cycle time. Based on the temperature distribution, conformal cooling channels were designed in Solidworks, addressing the problem areas. Next, a simulation of fluid flow in the conformal channels was conducted in ANSYS-Fluent to ensure equal flow distribution in the entire circuit, iteratively arriving at an optimal configuration. Finally, the results of the new conformal channels, including mould temperature and cycle time, were compared with conventional cooling channels in simulation. The results showed a significant reduction in cycle time and improvement in the temperature distribution, thereby minimising residual stresses and shrinkage.
Synthesis of ZnO and CuO Nanowires by Thermal Oxidation on Metallic Substrates
Authors: Arafat Mahmood Md. , Haseeb A.S.M. Abdul , Rozali Shaifulazuar , Brabazon Dermot , Rahman B.M.A. , Grattan Ken T.V. , Naher Sumsun
Published: July 2022

In this research work, brass (Cu - 37.2 wt% Zn) and Cu (99.9 wt%) wires having diameters of 200 μm were thermally oxidized in N2 containing 5% O2, at a flow rate of 200 sccm and in the ambient atmosphere respectively, to support the growth of nanowires. The oxidation temperature was varied from 300 to 600 °C and the as-grown nanowires were characterized by field emission scanning electron microscope (FESEM) equipped with energy dispersive X-ray (EDX) spectroscope, and transmission electron microscope (TEM). Results show that ZnO and CuO nanowires are formed on brass and Cu wires, respectively. The ZnO nanowires are branched and CuO nanowires are straight with tapered morphology. ZnO nanowires having hexagonal wurtzite structure grow along the <1 1 0> directions whereas, CuO nanowires have monoclinic structure. A diffusion based stress induced model is proposed to explain the growth mechanism of the nanowires. Thermal oxidation process is a suitable platform for synthesizing ZnO and CuO nanowires, which can be used in in-situ device fabrication.
Prediction of Solid-State Phase Transformations for the Ti-6Al-4V Alloy
Authors: Andrade Carlos M. , Neto Diogo M. , Oliveira Marta C.
Published: July 2022

Ti-6Al-4V alloy is the most relevant titanium alloy, finding applications in multiple high-value industries. The production of Ti-6Al-4V components by selective laser melting is particularly challenging, due to the highly localized heat input and large temperature gradients, which affect the material’s microstructure and final mechanical properties. The main objective of this work is to develop a metallurgical framework able to describe the solid-state phase transformations of Ti-6Al-4V during processing. The predicted volume fraction of each solid phase is used to estimate strains induced by the thermal cycle and the phase transformations independently. The presented numerical model considers a single finite element subjected to heat fluxes that impose two sequential heating/cooling cycles, replicating the laser movement. The numerical results emphasize the importance of predicting phase volume fraction fields for an accurate estimation of the material’s volume change. In fact, changing the heating/cooling rates resulted in completely different final microstructures and a 0.5% difference on the material’s volume change relative to its initial volume, which would correspond to a stress increment of approximately 200 MPa if the linear elastic material was fully constrained.
Effects of Temperature on Deep Drawing of an Aluminum Alloy for Different Yield Criteria and Hardening Models
Authors: Demirkol Rasih Hakan , Darendeliler Haluk
Published: July 2022

In this study, the influences of temperature variation in deep drawing process are investigatedby changing the temperatures of the whole blank, a part of the blank, the punch and die fordifferent yield criteria and hardening models. Von-Mises criterion with isotropic, kinematic and combinedhardening and, Hill48 and Yld2003 yield criteria with isotropic hardening are considered toform the constitutive relations. Circular, square and complex shaped parts made of AA5754 materialare used in the numerical analyses. The local heating simulations are conducted for circular blanksand the drawability of the parts are evaluated by using the Johnson-Cook failure criteria. Hot formingand quenching and local heating analyses are also carried out for a complex shaped part. The resultsobtained by the finite element analyses for different constitutive equations are compared with eachother and experimental results according to thickness strain distribution, punch force variation andrim shape of the deformed blanks.
Integrated Thermomechanical Characterization of Metals Using the Virtual Fields Method
Authors: Rossi Marco , Lattanzi Attilio , Morichelli Luca
Published: July 2022

In this paper, the possibility of characterizing the thermomechanical behavior of metals using the virtual fields method (VFM) and suitable specimens with heterogeneous strain and temperature fields was demonstrated using simulated experiments. The used geometry is a double-notched tensile test with a Gaussian distribution of temperature over the surface. The chosen constitutive model is the Johnson-Cook hardening law coupled with the Hill48 anisotropic yield criterion. First the VFM strategy and the simulated experiments are described. Then the results are presented showing three case studies, (i) only the effect of the temperature is identified, (ii) the whole set of constitutive parameters is identified at the same time, (iii) a two-step identification is performed. The potentiality of the method as well as the main problems are discussed extensively.
Tactile Perception in the Sensory Comfort of Fabric Samples
Authors: Abreu Maria José , Martins Etienne , Nagamatsu Naomi , Amaral Wanderlayne
Published: July 2022

This investigation aims to present the process of development of the attributes that will form the textile lexicon of the northeast region of Brazil for the assessment of textile tactile comfort. For this purpose, the following were adapted: ISO 11035:1994 Sensory analysis – Identification and selection of descriptors for establishing a sensory profile by a multidimensional approach; and ISO 8586:2012 Sensory analysis – General guidelines for the selection, training and monitoring of selected assessors and expert sensory assessor’s standards concerning the areas of food and cosmetics. Three panels of naive assessors from three different cities in northeastern Brazil were invited to touch 8 samples of fabrics with different textures and compositions. Initially, they generated 322 terms. Afterwards, in a second phase, they qualitatively eliminated terms with the same meaning. In the third phase, they grouped the terms through similarity analysis, which resulted in 23 terms. Then, the terms that were most cited by the assessors were analyzed and, as a result, 4 terms were eliminated. Finally, similarities were evidenced in the haptic perceptions that were perceived by the different panels, due to their cultural proximity and the fact that they come from the same region of a country with continental dimensions, as well as the transformation of human subjectivity into objective parameters provided by the textile lexicon.
Influence of the Anisotropic Behavior on Equibiaxial Paths
Authors: Salles Felipe F. , Oliveira Marta C. , Neto Diogo M. , Alves José Luis , Menezes Luis Filipe , Fernandes José Valdemar
Published: July 2022

Marciniak and Nakajima tests are commonly used in building FLD's, since they allow covering all regions from uniaxial to almost equibiaxial strain paths. In this work, the deviation from equibiaxial strain paths is analyzed as function of the material anisotropic behavior. The numerical results show that material with present equibiaxial stress and strain paths, while for the ones with the paths are neither equibiaxial in stress nor strain. Moreover, it is shown that despite the similarities between the two tests, they present different sensitivity to the control of the blank holder force and to the friction coefficient. Namely, the stress and strain paths in the Marciniak specimen center are more sensitive to the control of the blank holder force. On the other hand, the stress and strain paths in the Nakajima specimen center are more sensitive to the friction coefficient. The deviation from the equibiaxial strain path indicates that the stress ratio is also not necessarily 1.0, meaning that the stress triaxiality and the Lode parameter also present some deviation from the reference values for an equibiaxial stress state. This should be taken into account when analyzing forming limit results.
A Preliminary Investigation of Energy Consumption for Turning Ti6Al4V EBM Cylindrical Parts
Authors: Cozzolino Ersilia , Astarita Antonello , Borrelli Rosario , Franchitti Stefania , Lopresto Valentina , Pirozzi Carmine
Published: July 2022

Sustainability is becoming a central pillar of manufacturing and Additive Manufacturing (AM) processes, thanks to their potentialities, seem to open a new path to reduce the environmental footprint. However, the surface finishing of AM parts is hardly ever adequate for high performances applications so post-process treatments are required. Thus, the assessment of sustainability should inevitably consider both steps. In this study, a Ti6Al4V cylindrical sample was firstly manufactured by Electron Beam Melting (EBM) and then machined by turning as post-treatment process. Surface roughness was measured either before and after the machining process both along the direction parallel and that perpendicular to the axis of the cylindrical sample and a Ra reduction of 84.14% and 95.74% were obtained, respectively. To evaluate the goodness of the machining process from the sustainability perspective, the Specific Energy Consumption (SEC) was calculated to evaluate the unit energy consumption for removal the mass unit. Moreover, power trends during the two turning passes have proved to be useful in understanding the different stages of the machining process, the cutting forces involved, and the amount of material removed.
Comparison of Friction Extrusion Processing From Bulk and Chips of Aluminum-Copper Alloys
Authors: Rath Lars , Suhuddin Uceu F.H. , Klusemann Benjamin
Published: July 2022

Friction extrusion processing describes the extrusion of metallic materials via severe plastic deformation imposed by friction-induced heat and shear strain. The process features relative rotational movement between die and feedstock material, resulting in complex shear introduction affecting local thermal and material flow conditions. While the processing of powders, chips and bulk material for improvement of extrudate properties has been studied independently, this work focuses on the direct comparison between the friction extrusion of bulk material and chips of AlCu10 under identical processing conditions. Analysis of machine response and microstructure in the extruded wires allows for first conclusions, identifying characteristics and requirements for friction extrusion processing from different feedstock materials.
Formability Experiments for Unidirectional Thermoplastic Composites
Authors: Brands Dennis , di Genova Luca G. , Pierik E. Rens , Grouve Wouter Johannes Bernardus , Wijskamp Sebastiaan , Akkerman Remko
Published: July 2022

Reliable composite forming experiments are required to characterize composite formability, to aid material development, and to validate process simulations models. Due to practical reasons, however, typically a limited amount of forming configurations is studied. The objective of this study is, therefore, to develop a methodology for obtaining controlled forming results in a wide range of configurations. Press forming experiments using a dome geometry were used to explore the formability of two commercial unidirectional thermoplastic composite materials. A variety of forming configurations was employed by changing the blank dimensions and layup. The observation of wrinkling defects was simplified by leaving an additional 3 mm tool gap. Blank width and layup had the most influence on the wrinkling severity, followed by blank thickness and length. Quasi-isotropic layups were found to produce wrinkles in nearly all cases, confirming a difficulty in general to form double curved parts. The size and number of wrinkles in these layups were found to change with the stacking sequence. Cross-ply layups showed better formability, but significant wrinkles were still observed depending on the orientation of the blank relative to the layup. The formability experiments using a dome geometry provided a reliable methodology for controlled forming results in many configurations using a generic toolset. Additionally, a comprehensive comparison of formability for two commercial thermoplastic UD materials in a variety of scenarios was provided.
Hot Spinning of Cutting Blades for Food Industry
Authors: Engemann David , Homberg Werner
Published: July 2022

The spinning process is a flexible incremental forming process for the manufacturing of axially-symmetric sheet metal or tubular components with functionally graded properties. It is characterized by the utilization of universal tooling geometries and quite low forming forces. The process has a high potential to reduce material waste, to extend the forming limits and to achieve more complex geometries as well as favorable part properties [1]. Current research work at the Chair of Forming Technology (LUF) is focused on innovative flow-turning processes that have a high potential for producing flat components with excellent geometrical and mechanical properties while keeping process times short [2]. In combination with process-integrated local heat treatment, the new spinning process is predestined for the efficient forming of ultra-high-strength steel or tailored materials. Due to the desired field of food industry only food-safe materials such as special stainless steels are being investigated. This paper presents an innovative machine layout as well as an adequate process design for the production of high-performance circular knives with optimized mechanical hardness. In this context, particular attention is paid to various areas of temperature control as well as process-related challenges during the process.
On the Anisotropic Mechanical Response of Ti6Al4V Sheet at High Strain Rates
Authors: Corallo Luca , Verleysen Patricia
Published: July 2022

In traditional sheet metal forming processes, a thin sheet metal is deformed at relatively low speeds. However, more and more the speed of production processes is increased, very often to take advantage of the beneficial implications that high strain rates can have on the formability of certain metals. In this work, the effect of strain rate on the anisotropic behavior of Ti6Al4V is investigated performing tensile tests in different orientations, namely 0o, 45o and 90o, with respect to the rolling direction (RD), and in-plane shear experiments along RD. Three nominal strain rates, i.e., , 0.5 and 1000, are considered. A novel high-speed bulge (HSB) test developed at Ghent University, designed to deform sheet metals in nearly equibiaxial loading conditions at high strain rates, is used for the dynamic bulge test. The experimental results, presented in this paper, clearly show the need of including the effect of strain rate, and eventually temperature, into the formulation of the yield function in order to correctly model and predict deformation processes performed at high speed.
Modelling of Ceramic Particle Motion during Semi-Solid Forming of Aluminium Matrix Composites via CFD-DEM Four-Way Coupling
Authors: Speth Marco , Heine Johannes , Riedmüller Kim Rouven , Liewald Mathias
Published: July 2022

Today, aluminium matrix composites (AMC) are widely used for the manufacturing of lightweight, yet highly stressed components in automotive, aeronautic and electrical engineering. In order to achieve particle distributions as homogeneous as possible within these component’s volumes and thus ensure optimum component properties, efforts are being made to simulate the manufacturing process prior to production. In this paper, AMC with extremely high particle fractions of more than 25 vol.% are considered in particular, as their processing still poses significant technological challenges. To model the particle motion in a computational fluid dynamics (CFD) simulation of the semi-solid forming process of this type of materials, a Lagrangian multiphase approach combining CFD and discrete element method (DEM) was used. Here, the DEM allowed all particle-particle interactions to be considered. Thus, different parameters influencing particle agglomeration, particle distribution as well as particle interaction with the cavity can be investigated during a numerical study. More specifically, the influence particle parameters such as cohesion forces and the influence of the forming speed onto the particle distribution in the final component ́s volume was analysed. The simulations were performed for a symmetric disc geometry. A forming tool was already available for this geometry, with which components could be manufactured to validate the simulation results. In the end, the study shows that by using four-way CFD-DEM coupling, simulation predictability for the semi-solid forming process of AMC could be significantly improved.
FEM Analysis of the Skin Contamination Behavior in the Extrusion of a AA6082 Profile
Authors: Negozio Marco , Pelaccia Riccardo , Donati Lorenzo , Reggiani Barbara
Published: July 2022

In the extrusion of aluminum alloys, the skin contamination lead to the scraping of the profile extent in which this defect occurs. In order to optimize the scraping process, extrusion companies and die makers can either perform time-consuming and expensive analyses to experimentally determine the evolution of the defect or rely on predictive methods. Recently, numerical methods, as the Finite Elements, are increasingly used to predict the evolution of the skin contamination, but their accuracy is still uncertain. In this work, an AA6082 aluminum profile of industrial complexity is analysed and the data collected used to validate an innovative method for the prediction of the skin contamination evolution developed using the commercial FEM code Qform®. In addition, the results are used to assess the prediction accuracy of an industrial empirical formula often used by operators.
Fabrication of Billet from Aluminum Alloys AA 2011-T3/7075 Chips through Friction Stir Consolidation
Authors: Latif Abdul , Ingarao Giuseppe , Di Lorenzo Rosa , Fratini Livan
Published: July 2022

Recently evolving Solid-State Recycling (SSR) techniques have shown promising features to recycle metals scraps more efficiently compared to remelting-based approaches. Among these SSR methods, Friction Stir Consolidation (FSC) has been successfully tested to transform metals chips directly into semi or final solid products. Therefore, researchers explored FSC critical process parameters and their subsequent effects on quality in terms of the mechanical and metallurgical properties of the billet. All the previous studies of FSC were limited to developing billet of mono materials. Therefore, in this research, an attempt was made to go beyond the idea of recycling; in fact, a billet of two dissimilar aluminum alloys AA 7075 and AA 2011-T3 out of chips was obtained. The mechanical and metallurgical properties were assessed through the Vickers hardness measurements and microstructure analysis. The experimental results of this research illustrate that the FSC process is a feasible approach to develop a billet of dissimilar materials with achieving quality closer to the corresponding billet of mono-material.
Innovative Online Measurement and Modelling Approach for Property-Controlled Flow Forming Processes
Authors: Kersting Lukas , Arian Bahman , Vasquez Julian Rozo , Trächtler Ansgar , Homberg Werner , Walther Frank
Published: July 2022

The production of complex multi-functional, high-strength parts is becoming increasingly important in the industry. Especially with small batch size, the incremental flow forming processes can be advantageous. The production of parts with complex geometry and locally graded material properties currently depicts a great challenge in the flow forming process. At this point, the usage of closed-loop control for the shape and properties could be a feasible new solution. The overall aim in this project is to establish an intelligent closed-loop control system for the wall thickness as well as the α’-martensite content of AISI 304L-workpieces in a flow forming process. To reach this goal, a novel sensor concept for online measurements of the wall thickness reduction and the martensite content during forming process is proposed. It includes the setup of a modified flow forming machine and the integration of the sensor system in the machine control. Additionally, a simulation model for the flow forming process is presented which describes the forming process with regard to the plastic workpiece deformation, the induced α’-martensite fraction, and the sensor behavior. This model was used for designing a closed-loop process control of the wall thickness reduction that was subsequently realized at the real plant including online measured feedback from the sensor system.
Deep-Drawing of Commercially-Pure Niobium Sheet
Authors: Chen Kelin , Kim Minki , Carriere Paul , Penney James , Gopal Matavalam Nanda , Kutsaev Sergey , Korkolis Yannis P.
Published: July 2022

Pure Niobium is a material of interest for high-energy-physics applications including superconducting accelerators. Cold-rolled sheets of Nb exhibit significant plastic anisotropy. Here we report on the mechanical and forming properties of 99.95% pure, 1.02 mm thin, cold-rolled sheet. Uniaxial tension, biaxial tension and disc compression experiments are performed, the first two at multiple angles to the rolling direction of the sheet. The material is very ductile (uniform elongation ~30%), and exhibits significant plastic anisotropy (e.g., the R-values range from 1.2 in 45o to 2.5 in 90o). The results are used to calibrate the Yld2000-2D anisotropic yield function, with an exponent of 6 as Nb is BCC. They are also used to extract the hardening curve beyond the limit load in uniaxial tension. Deep-drawing experiments are performed using a die of 27.6 mm dia. and a punch of 25.4 mm dia. Blanks of various diameters are used. The successfully drawn cups exhibit significant earing. The experiments are simulated using Abaqus/Standard and shell elements. It is shown that a properly calibrated material model enables the numerical simulations to match the experiments.
Study on the Effect of Anisotropy on Plastic Flow Localization of Third Generation Advanced High Strength Steel
Authors: Butuc Marilena , Vincze Gabriela , Santos Rafael , Pereira António , dos Santos Abel , Amaral Rui
Published: July 2022

The aim of this work is to analyze the effect of the anisotropy on the formability of the third generation of advanced high strength steel (3genAHSS) from experimental and theoretical point of view. The reference material is the USS CR980XG3TM️ AHSS, a 3genAHSS 980T/600Y-retained austenite bearing-high elongation steel grade. A careful experimental work on the selected 3genAHSS characterization has been performed. The anisotropy factors and the yield stresses have been identified from tensile tests at several orientations with respect to the rolling direction. The experimental forming limit diagram under linear strain paths has been determined using Nakajima tests and the Erichson test for the equibiaxial stretching, respectively. The Marciniak-Kuczynski analysis is used to simulate the onset of localized necking through an advanced sheet metal forming limit model. YLD00-2d yield condition gives the initial shape of the yield locus. Swift strain–hardening power law is used to describe the strain hardening of the material. The effect of the anisotropy on the forming limits of 3genAHSS steel is analyzed. It was achieved proper reproducibility of the experimental tendencies of anisotropic factor distribution and the yield stress as a function of the tensile loading axis by the selected constitutive equations. A good accuracy of the FLDmodel on the prediction of the experimental results is found.
Effects of natural surfactants on the spatial variability of surface water temperature under intermittent light winds on Lake Geneva
Authors: Foroughan Mehrshad , Lemmin Ulrich , Barry David Andrew
Published: July 2022

The spatial variability of lake surface water temperature (LSWT) between smooth and rough surface areas and its potential association with the natural surfactant distribution in the surface microlayer were investigated for the first time in a lake. In spring 2019, two different field campaigns were carried out in Lake Geneva to measure: i) the enrichment factor of fluorescent dissolved organic matter (FDOM) as a proxy for biogenic surfactants, and ii) LSWT and near-surface water temperature profiles while simultaneously monitoring water surface roughness in both cases. Results indicate that, under intense incoming short-wave radiation and intermittent light wind conditions, the atmospheric boundary layer (ABL) was stable and the accumulation of heat due to short-wave radiation in near-surface waters was greater than heat losses by surface cooling, thus creating a diurnal warm layer with strong thermal stratification in the water near-surface layer. A threshold wind speed of 1.5 m s-1 was determined as a transition between different dynamic regimes. For winds just above 1.5 m s-1, the lake surface became patchy, and smooth surface areas (slicks) were more enriched with FDOM than rough areas (non-slick) covered with gravity-capillary waves (GCW). Sharp thermal boundaries appeared between smooth and rough areas. LSWT in smooth slicks was found to be more than 1.5°C warmer than in rough non-slick areas, which differs from previous observations in oceans that reported a slight temperature reduction inside slicks. Upon the formation of GCW in non-slick areas, the near-surface stratification was destroyed and the surface temperature was reduced. Furthermore, winds above 1.5 m s-1 continuously fragmented slicks causing a rapid spatial redistribution of LSWT patterns mainly aligned with the wind. For wind speeds below 1.5 m s‑1 the surface was smooth, no well-developed GCW were observed, LSWT differences were small, and strong near-surface stratification was established. These results contribute to the understanding and the quantification of air-water exchange processes, which are presently lacking for stable Atmospheric Boundary Layer conditions in lakes.
Faults and lineaments of the Quebec City, Charlevoix and Saguenay-Lac St-Jean regions, Québec
Authors: Lamontagne M , Brouillette P
Published: July 2022

This Open File contains the interpreted brittle lineaments and a compilation of mapped faults of an area bound by latitudes 46.5N and 49.75N and longitudes 69.5W and 74W. The study area includes the north shore of the St. Lawrence River in Québec from
slightly north of Trois-Rivières to slightly north of Tadoussac, which includes most of the watersheds of the St-Maurice and Saguenay rivers and the Lac Saint-Jean. The study area includes a seismically active region known as the Charlevoix Seismic Zone (CSZ). The CSZ is an area where at least
five earthquakes of magnitudes between 5.5 and 7 have occurred in the past and where hundreds of smaller earthquakes are recorded yearly. Our study is an attempt to provide a homogeneous coverage of the brittle structures through an integration of visually interpreted lineaments and mapped faults.
The possible relationships between these brittle faults and earthquakes will be examined in upcoming studies. Lineaments were observed mostly from the Digital Elevation Model (DEM) of the Canadian National Topographic Data Base (NTDB) at a scale of 1:250 000. The DEMs illuminated from two directions
were used to first visually recognize lineaments and second, to georeference their surface expressions in a Geographic Information System (GIS). Since the final goal was to better map the brittle faults that could be reactivated in earthquakes, the conspicuous ductile structures were not considered
in this study and the more questionable ones were re-evaluated subsequently against known geological information. The whole region of interest is southeast of the Grenville Front, and all ductile structures are related to the Grenville orogeny (about 1 billion years ago). The recognition of brittle
structures is based on the observation that they are essentially linear in plan view. On the other hand, the ductile structures are generally curved, enhance contact between different Grenvillian lithologies, or present a distinct structural pattern. Only lineaments with a length greater than 5 km
were included. After a first detection pass, lineaments at a more regional scale were drawn by interpolating between segments of lineaments. These interpolated segments corresponded to areas where the topography was subdued and where no conspicuous trace existed. The interpreted lineaments were then
compared with the geological maps of the province of Quebec which often did not distinguish between brittle faults and ductile shear zones (or even at times, boundaries of geological units). Our final product is a 1:500,000 scale map that can be used in the future to better understand the
seismotectonics of this region.
Modified tangential Peeyush's technique
Authors: Shivhare Peeyush , Kumar Ajay , Parihar Ajay , Haidry Naqoosh , Sah Neha , Singh Ankur
Published: July 2022

Introduction:

Zygomatic arch (ZA) fractures are common in facial trauma. The imaging techniques for the ZA include submentovertex (SMV) and jug handle (a variation of the SMV view) views. These radiographic techniques require neck hyperextension to make the canthomeatal line parallel to the film receptor. Most of the time, these patients will be having cervical injuries also which makes these imaging techniques challenging.

Aims and Objectives:

This observational study aimed to estimate the efficacy of modified tangential Peeyush's technique (MTP technique) as an alternative to SMV view in patients with ZA fracture along with neck pain.

Materials and Methods:

A digital panoramic radiography machine and other standard equipment for radiography were used. Twenty patients with clinically diagnosed ZA fracture were selected and imaged using two different techniques, i.e., technique A (canthomeatal line to be about 30°–45° in relation to image receptor) and technique B (MTP technique). Images obtained with both techniques were evaluated for the presence of ZA fracture. The results were tabulated and compared.

Results:

Technique A showed partial visualization of ZA in 55% of the cases, whereas ZAs were not visualized in 45% of cases. ZA was evident in 100% of the sample selected in technique B (MTP technique).

Conclusion:

Modified Peeyush's tangential technique can be applied in patients having ZA fracture with neck pain.
Endsocopic Internal Maxillary Artery Cauterization in a Patient with Severe Posterior Epistaxis
Authors: Mainasara Mohammed Garba , Shofoluwe Nurudeen Adebola , Shuaibu Iliyasu Yunusa , Mohammed Ibrahim Babatunde , Dotiro Chitumu , Abdullahi Amina Muhammad
Published: July 2022

Epistaxis from the posterior superior region of the nasal cavity might be fatal in some cases. It is particularly severe in an individual with hypertension, arterial aneurysm of traumatic origin, and bleeding from posterior lateral nasal artery, which is frequently difficult to reach and ligate directly on a bleeding area. Certain cases have been reported in which the bleeding could be stopped only by ligating/embolization of the external carotid artery or the internal maxillary artery at its branching off from the external carotid artery. Despite the multiple anastomoses, the effect of such ligation or cauterization is effective if properly done. We present a case of a 25-year-old young man with a 3-month history of recurrent epistaxis resulting from an internal maxillary artery aneurysm following trauma. The clinical presentation, diagnosis, and successful endoscopy treatment of posterior epistaxis are presented.
Alveolar ridge split and expansion with simultaneous implant placement in mandibular posterior sites using motorized ridge expanders – modified treatment protocol
Authors: Manekar Varsha S , Shenoi S. R. , Manekar Sunil , Jhon Janice
Published: July 2022

Purpose:

“The purpose of the study is to evaluate alveolar ridge split and expansion (ARSE) with simultaneous implant placement in mandibular posterior implant sites using motorized ridge expanders.”

Background:

The ARSE is used in the management of horizontally deficient (narrow) alveolar ridge with optimum bone height available. The ARSE procedure in the posterior mandible has limited application as per literature. The successful cases reported are with extensive procedure of the osteo-mobilization with four corticotomies on buccal side. The authors presented the study of mandibular posterior implant sites using motorized ridge expanders. The ARSE performed here was by only crestal osteotomy simple osteo-condensation and immediate implant insertion.

Materials and Methods:

The study was prospective type. The sample size was 15 patients and 31 implant sites. The study population included partially edentulous patients between 18 years and 60 years indicated for implant-supported prosthesis. The outcome variables studied included gain in ridge width, cervical bone loss, success of implant, and survival rate. Successful surgical outcome was evaluated by Buser's criteria. The data collected was evaluated by differential statistics.

Conclusion:

The minimally invasive technique of one-stage ARSE performed with motorized ridge expander and insertion of implant in the same operative procedure decreases the morbidity, treatment time, number of surgical procedures, and the risk of complications, thereby, increasing patient acceptance. In this study, the authors have used this technique in the posterior mandible for narrow ridges (minimum 3 mm) and obtained promising results. The survival rate of the implants was 100% and the gain in ridge width was 3.2 mm. The author has also recommended the protocol according to bone density of mandible.
The Next Generation Intelligent Automation: Hyperautomation
Authors: Madakam Somayya , Holmukhe Rajesh M , Revulagadda Rajeev Kumar
Published: July 2022

One of the buzzwords in the technological world is “Hyperautomation”. Hyperautomation is the new technological phenomenon in which it can bring intelligent automation processes using Robotic Process Automation (RPA), Artificial Intelligence (AI), Machine Learning (ML) and other technologies. It has a good amount of business applications; that is why many tech giants and start-ups are putting huge investments to reap the fruits of Hyperautomation. The data was collected from different secondary sources from 1-4-2020 to 31-7-2021. The rationale of this conceptual manuscript is to explain the definitions, concepts, technologies and models behind Hyperautomation. This study also emphasis in-depth benefits of hyper automation specifically in Banking & Finance sector. Moreover, the study also presents some of the industry test cases