Formability of Hybrid Aluminum-Magnesium Compounds

2013 ◽  
Vol 554-557 ◽  
pp. 21-28 ◽  
Author(s):  
Andreas Feuerhack ◽  
Carolin Binotsch ◽  
Birgit Awiszus

In the SFB 692 HALS (High-strength aluminum based lightweight materials for safety components), subproject B-3, the production of an aluminum magnesium compound by a hydrostatic co-extrusion process was investigated. The quality of these semi-finished products, especially the stability and robustness of the interface between the aluminum (AlMgSi1) sleeve and magnesium (AZ31) core, was of particular interest. Previous papers have described the first process optimization steps as the improvement of the die design as well as the numerical methods for identification of important process parameters and the development of a quality model for the interface. This paper describes the formability of such semi-finished products with subsequent forging processes, especially die forging. Therefore, two different die forging strategies were investigated. In the first approach the strand-shaped work piece, with a circular cross-section, was formed along its longitudinal axis with die forging. In the second approach the same geometry was radially formed with die forging. Thereby, the compound was formed in longitudinal direction up to an analytical equivalent strain value of 1.61 and in radial direction up to 1.38. First results showed that the interface of the aluminum magnesium compound is very stable and ductile enough to be forged. Dye penetration tests were performed to prove the stability of the interface in a first step. Then, micro sections were made to investigate the interface metallographically. No cracks or damages were detected with both test methods in the interface of the forged aluminum magnesium compound. Furthermore, numerical simulations were performed to analyze the forging processes in detail. Therefore, a full 3D simulation model was set-up with Forge2011 and the calibration was performed with the press force as well as the geometry aspects. The correlations between experiments and simulations are very well. By means of the calibrated simulation detailed analyses of interface section are performed and the stability of the interface was investigated. This shows that the compound quality reached by the hydrostatic co-extrusion process is very suitable for subsequent forming steps as die forging. The investigations show the potential of such hybrid compounds and clarify their application, especially in the automotive sector.

Author(s):  
Natalia Prodiana Setiawati ◽  
Joko Santoso ◽  
Sri Purwaningsih

The utilization of local food commodities such as corn and cassava with seaweed addition as a dietary fiber source for producing artificial rice through extrusion technology is an  alternative for food diversification. The research was carried out to find out the best composition (rice, corn, cassava, and seaweed) and temperature of extrusion process on making artificial rice and the influence of dietary fibre on sensory properties and physicochemical. The composition of rice, corn, and cassava in proportion  of 1:3:1 with 20% seaweed, Eucheuma cottonii, addition and temperature extruder of 90 °C were selected as the best product for artificial rice. The  sensory evaluation was 8.02±0.21 (people’s preference). In physicochemical properties, dietary fiber significantly affected on low bulk density and starch digestibility. This condition is very good for health especially in maintaining the stability of blood glucose in the body. Keywords: artificial rice, composition, extrusion, seaweed, dietary fibre, temperature


2021 ◽  
Vol 15 (2) ◽  
pp. 137-150
Author(s):  
Susanne Elisabeth Thürer ◽  
Anna Chugreeva ◽  
Norman Heimes ◽  
Johanna Uhe ◽  
Bernd-Arno Behrens ◽  
...  

AbstractThe current study presents a novel Tailored Forming process chain developed for the production of hybrid bearing bushings. In a first step, semi-finished products in the form of locally reinforced hollow profiles were produced using a new co-extrusion process. For this purpose, a modular tool concept was developed in which a steel tube made of a case-hardening steel, either C15 (AISI 1015) or 20MnCr5 (AISI 5120), is fed laterally into the tool. Inside the welding chamber, the steel tube is joined with the extruded aluminum alloy EN AW-6082. In the second step, sections from the compound profiles were formed into hybrid bearing bushings by die forging. In order to set the required forming temperatures for each material—aluminum and steel—simultaneously, a tailored heating strategy was developed, which enabled successful die forging of the hybrid workpiece to the desired bearing bushing geometry. Using either of the case-hardening steels in combination with aluminum, this novel process chain made it possible to produce intact hybrid bearing bushings, which showed both macroscopically and microscopically intimate material contact inside the compound zone.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2169
Author(s):  
Agnieszka Tabaczyńska ◽  
Anna Dąbrowska ◽  
Marcin Masłowski ◽  
Anna Strąkowska

Electro-conductive paths that are mechanically resistant and stable during simulated aging cycles are promising, in relation to the non-invasive application in e-textiles in our everyday surroundings. In the paper, an analysis of the influence of electro-conductive filler, as well as ionic liquid on surface resistance is provided. Authors proved that depending on the tested variant, obtained surface resistance may vary from 50 kΩ (when 50 phr of Ag and [bmim][PF6] ionic liquid applied) to 26 GΩ (when 25 phr of Ag and [bmim][PF6] ionic liquid applied). The samples were also evaluated after simulated aging cycles and the stability of electric properties was confirmed. Moreover, it was proved that the addition of ionic liquids reduced the resistance of vulcanizates, while no significant influence of the extrusion process on conductivity was observed.


2011 ◽  
Vol 189-193 ◽  
pp. 1778-1781 ◽  
Author(s):  
Gui Hua Liu ◽  
Yong Qiang Guo ◽  
Zhi Jiang

By using Deform-3D software, the necking extrusion forming processes of integer trailer axle with two different heating means which are Uniform Heating (UH) method and Partly Heating (PH) method with temperature gradient are simulated. The influence of deformation parameters such as friction factor, necking coefficient, different temperature distribution of work-piece on the material flow features, stress and strain field, loading force and deformation process are analyzed in detail. According to the numerical simulation results, using PH method with temperature gradient can improve necking deformation during tube extrusion process.


2013 ◽  
Vol 554-557 ◽  
pp. 630-637 ◽  
Author(s):  
Martin Grüner ◽  
Marion Merklein

Aluminium alloys show a great potential for lightweight constructions due to their high strength and low density but the production of this material is very energy consuming. Also the recycling of aluminium alloys, e.g. chips from the milling process, shows different challenges. Beside contamination by cooling lubricant and oxidation of the surface of the chips the melting and rolling process for new semi finish products needs a high amount of energy. TEKKAYA shows a new approach for recycling of aluminium alloy chips by an extrusion process at elevated temperatures producing different kinds of profiles. A new idea is the production of components directly out of chips using severe plastic deformation for joining of the chips similar to the accumulative roll bonding process in sheet metal forming. In a first approach aluminium alloy chips out of a milling process were uniaxial compressed with different loads inside an axisymmetric tool installed in a universal testing machine. The compressed chip disks subsequently were tested with two experiments to gain information on their stability. First experiment is a disk compression test with the disk standing on its cylindrical surface, giving information on the stability perpendicular to the compression direction. Second experiment is a stacked disk compression test with three disks to investigate the stability parallel to compression direction. During all three tests force and displacement values are recorded by the universal testing machine. These data are also processed to calculate or identify input parameters for the numerical investigations. For numerical simulation ABAQUS in conjunction with the Drucker-Prager-Cap material model, which is often used for sintering processes, seems to be a good choice. By numerical simulation of the experiments and comparison with the experiments input parameters for the material model can be identified showing good accordance. This material model will be used in future numerical investigations of an extrusion process to identify tool geometries leading to high strains inside the material and by this to an increased stability of the parts.


1993 ◽  
Vol 75 (1) ◽  
pp. 458-467 ◽  
Author(s):  
L. B. Wong ◽  
I. F. Miller ◽  
D. B. Yeates

The temporal and spatial coordination of ciliary beat (metachronicity) is fundamental to effective mucociliary transport. Metachronal wave period (MWP) and ciliary beat frequency (CBF) of fresh excised sheep and canine tracheal epithelial tissues were measured with the use of a newly developed alternating focal spot laser light scattering system. MWP was determined from cross correlation of the heterodyne signals from the alternating focal spots. CBF was determined by autocorrelation of the heterodyne signals from each of the spots. MWP and CBF were measured in four sheep tracheal epithelial tissues with the use of longitudinal interfocal spot distances of 6 and 18 microns. In three canine tracheal epithelial tissues MWP and CBF were measured both longitudinally and circumferentially with interfocal spot distances of 5, 15, 65, 87, and 96 microns. For the sheep tracheal epithelial tissues the mean CBF was 5.9 +/- 0.4 Hz (mean of means; range 3.6 +/- 0.5 to 9.9 +/- 1.5 Hz), whereas the mean MWPs for 6- and 18-microns interfocal spot distances were 0.50 +/- 0.1 and 0.47 +/- 0.1 s, respectively. For the canine tracheal epithelial tissues the mean CBF was 4.0 +/- 0.2 Hz (2.0 +/- 0.8 to 7.2 +/- 3.2 Hz), whereas the mean longitudinal MWP was 1.5 s and the mean circumferential MWP was 2.1 s. Geometric combination of the MWP components leads to a derived MWP of 2.6 s with a propagation direction of 54 degrees with respect to the longitudinal axis of the trachea. MWP was found to be episode modulated with 12- to 20-min intervals in the longitudinal direction, but modulation was not as apparent in the circumferential direction. These data suggest that MWP and CBF are regulated by separate intracellular, intercellular, and intraciliary mechanisms.


2000 ◽  
Vol 6 (2) ◽  
pp. 82-86 ◽  
Author(s):  
Vaidotas Šapalas

Two single-span frame tests were carried out. The width of frame is 6m, column's height 4.17m. Frame supports are pinned. Connection between column and beam is rigid. Beam of the frame was loaded with two vertical and one horizontal loads. The stability of tappered columns was analysed in frame plane and in perpendicular plane, according to [1] and [2] methods. All deflections were calculated taking into account support movements. During the first frame test R1-1 the tapered column collapsed at the load 2V=400kN and H=200 kN (vertical and horizontal loads). During the second test R1-2 the tapered column collapsed at the load 2V=390 kN and H=175 kN. In both tests columns collapsed in lateral-torsional buckling way. Because the column's web is very thin at the load 2V=300 kN and H=150 kN the column's web achieved local buckling. But the column was still carrying the load. During both tests at the load 2V=300 kN and H=150 kN the column began to twist in the middle of its height about the longitudinal axis and to bend about the weak axis. In test R1-1, the vertical experimental deflection (in point 6, see Fig 1 a) is about 17.5% smaller than the theoretical one. The horizontal experimental deflection (in point, see Fig 1 a) is about 11.6% smaller than the theoretical one. In test R1-2, vertical experimental deflection (in point 6, see Fig 1 a) is about 21.1% bigger than the theoretical one. The horizontal experimental deflection (in point, see Fig 1 a) is about 29.6% smaller than the theoretical one. In test R1-1, an experimental compression stresses in section A-A (see Fig 2) are about 11.2% smaller than the theoretical one. Experimental tension stresses in section A-A are about 8.65% smaller than the theoretical one. In test R1-2, an experimental compression stresses in section A-A is about 0.43% bigger than the theoretical one. An experimental tension strain in section A-A is about 1.73% smaller than the theoretical one.


2021 ◽  
pp. 100-108
Author(s):  
В.И. Токарев ◽  
Н.В. Бабоченко

В статье представлены на рассмотрение характеристики стабильности работы стреловых грузоподъемных средств на колесном шасси в форме математических выражений. Математические выражения представлены в виде не громоздких зависимостей от конкретно заданных параметров. Качество движения зависит от возрастания линейных размеров, масс, моментов инерции, а также скоростей и других механических параметров грузоподъемных средств. Достижение стабильности работы выносных стреловых грузоподъемных средств достигается путем распределения нагрузки между утлегарью (выносной стрелой грузоподъемного средства) и опорными колесами колесного шасси. Считаем, что при существовании ряда концепцией со своими теориями. возможно определение стабильности работы стрелового грузоподъемного средства на колесном шасси. Нами установлено, что возможно обеспечить стабильность работы путем выбора целесообразных значений механических составляющих всех звеньев рабочего механизма для спланировано составленных рабочих ситуаций. В зависимости от возможного размещения грузоподъемного устройства показатели стабильности работы меняются и это подтверждают составленные нами математические выражения, которые приводятся в статье. Установлено, что путем варьирования различными вариантами положений и массой составляющих элементов конструкции грузоподъемного средства, а также графически определяя возможные варианты перемещения груза в зависимости от заданной длины утлегарьи, имеет место выражение, позволяющее определить ряд значений масс, безопасно поднимаемых грузоподъемным средством. Нами получены значения необходимых для графических построений грузовых характеристик грузоподъемного средства, выражающие зависимость между массой груза и вылетом утлегарьи с весом ее элементов. Реакции в шарнирах утлегарьи и усилия в ее составляющих звеньях возможно установить из данных грузовой характеристики. Стремление обеспечить максимальную стабильность работы грузоподъемного средства накладывает ограничения на контроль за несколькими подвижными операциями одновременно, что неблагоприятно сказывается на эффективности рабочего процесса. Установили, что обеспечение стабильности работы в поперечной и продольной плоскостях грузоподъемного средства является необходимым компонентом безопасной эксплуатации. По зависимостям для определения показателя грузового равновесия возможно определение предварительного места установки выносных опор грузоподъемного средства. Как подтверждают полученные результаты, стабильность работы грузоподъемного средства в продольном направлении определяется аналогично стабильности работы в поперечном направлении и для номинальной массы груза при наибольшем вылете утлегарьи и выставленных выносных опорах. В итоге отметим, что показателем грузового равновесия служит отношение удерживающего момента относительно ребра опрокидывания, создаваемого весом грузоподъемного средства на колесном шасси с учетом уменьшающих его дополнительных внешних нагрузок и влияния уклона площадки к опрокидывающему моменту, создаваемому рабочим грузом. The article presents for consideration the characteristics of the stability of the boom lifting equipment on a wheeled chassis in the form of mathematical expressions. Mathematical expressions are presented in the form of not cumbersome dependencies on specified parameters. The quality of movement depends on the increase in linear dimensions, masses, moments of inertia, as well as speeds, and other mechanical parameters of the lifting equipment. Achievement of the stability of the outboard boom lifting device is achieved by distributing the load between the jib boom (outboard boom of the lifting device) and the support wheels of the wheeled chassis. We believe that with the existence of a number of concepts with their theories, it is possible to determine the stability of the boom lifting device on a wheeled chassis. It has been found that it is possible to ensure the stability of work by choosing the appropriate values of the mechanical components of all links of the working mechanism for planned working situations. Depending on the possible placement of the lifting device, the stability indicators are changed, and this is confirmed by the mathematical expressions we compiled, which are given in the article. It has been established that by varying the positions and the mass of the constituent elements of the structure of the lifting device, as well as graphically defining the possible options of the load moving, depending on the given length of the jib boom, an expression takes place that makes it possible to determine a number of values of the masses safely lifted by the lifting device. There have been obtained the values of the cargo characteristics of the lifting device necessary for graphic constructions, expressing the relationship between the weight of the cargo and the overhanging of the jib boom with the weight of its elements. The reactions in the joints of the jig boom and the forces in its constituent links can be established from the data of the load characteristics. The desire to ensure maximum stability in the operation of the lifting device imposes restrictions on the control of several mobile operations at the same time, which adversely affects the efficiency of the work process. It has been established that ensuring the stability of operation in the transverse and longitudinal planes of the lifting device is a necessary component of safe operation. According to the dependencies for determining the indicator of cargo balance, it is possible to determine the preliminary installation site of the outriggers of the lifting device. As the results obtained confirm, the stability of the operation of the lifting device in the longitudinal direction is determined similarly to the stability of the operation in the transverse direction and for the nominal weight of the load with the greatest overhanging of the jib boom and the set outriggers. As a result, we note that the ratio of the holding moment relative to the overturning rib created by the weight of the lifting device on the wheeled chassis, taking into account the additional external loads that reduce it and the influence of the platform slope to the overturning moment created by the working load, serves as an indicator of the cargo balance.


2021 ◽  
Author(s):  
Riccardo Pelacci ◽  
Marco Negozio ◽  
Barbara Reggiani ◽  
Lorenzo Donati ◽  
Luca Tomesani

Liquid nitrogen cooling is widely used in the extrusion industrial practice in order to increase the production rate, to reduce the die temperature and to avoid defects on the profile exit surfaces resulting from an excessive heating. However, the efficiency of the cooling is deeply affected by position and design of the liquid nitrogen channel so that numerical modelling is gaining an increasing industrial interest in relation to the possibility offered to optimize the channel design without expensive and time-consuming experimental trials. In this work, a numerical FE model developed within COMSOL Multiphysics® is proposed and validated against experimental trials performed in industrial environment. The model combines the 3D simulation of the extrusion process with a 1D model of the cooling channel thus allowing the testing of a number of different solutions at the die design stage. The global aim of this work is the assessment of the liquid nitrogen cooling efficiency in the extrusion of an industrial aluminum profile and the proof of the potentials offered by numerical models to get an optimized channel design in terms of cooling efficiency, die thermal balancing and reduction of liquid nitrogen consumption.


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