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1

Influence of the Extrusion Cavity Shape on the Ultimate Extrusion Force Value During Pellet Extrusion Through Multiple-Cavity Dies

Górecki Jan, Łykowski Wiktor, Gumeni Maria

Advances in Science and Technology. Research Journal

|

2024

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Vol. 18, no 1

118--128

EN

The article describes the results of experimental research that allowed us to compare the influence of the forming channel shape and its length on the limit value of the force occurring in the process of extruding crystallized carbon dioxide using multi-channel dies. To carry out the research, the authors adopted a method described in the literature, which allows for experimenting using a sublimating material under normal conditions, at a temperature of -78.4°C. Analysis of variance was used for the statistical analysis of the experiment results, which allowed to determine the level of statistical significance of differences between individual populations. Additionally, based on the median and regression values, an attempt was made to fit a function describing the change in the tested values as a function of geometric parameters. This allowed for comparison of the impact of individual variables. The authors did not observe the research results in the available literature, they would discuss the influence of the channel shape of multi-channel systems on the value of the confining force. Therefore, according to the authors, the presented results constitute an important supplement to the available knowledge.

2

Analiza numeryczna procesu wieloetapowego kształtowania odkuwki drążonej z kołnierzem zewnętrznym z wsadu rurowego

Winiarski Grzegorz, Bulzak Tomasz, Wójcik Łukasz

Hutnik, Wiadomości Hutnicze

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2023

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Vol. 90, nr 2

9--15

PL

W artykule przedstawiono nową metodę kształtowania wyrobów drążonych z kołnierzami z wsadu rurowego. Technologia polega na kilkuetapowym wytwarzaniu odkuwki z zastosowaniem technologii przepychania, nowej metody wyciskana z ruchomą tuleją oraz spęczania. Weryfikację zaproponowanej metody kucia na zimno przeprowadzono w oparciu o obliczenia numeryczne wykonane w programie Deform-2D/3D wykorzystującym metodę elementów skończonych. Założono, że materiałem wsadowym jest rura z stali 42CrMo4 o znormalizowanych wymiarach przekroju poprzecznego. Analizie poddano dwa warianty procesu różniące się kinematyką trzpienia. Zastosowano trzpień przemieszczający się z taką samą prędkością jak stempel oraz trzpień nieruchomy. W ramach wyników przedstawiono progresję kształtu odkuwki, rozkłady naprężeń, odkształceń, temperatur, wartości całki Cockrofta Lathama oraz parametry siłowe. Analiza uzyskanych wyników potwierdziła słuszność zaproponowanej metody.

EN

The paper presents a new method of shaping hollow products with flanges from a tubular billet. The technology consists in a multistage forming of the forgings using the extrusion technology, a new extrusion method with a movable sleeve and upsetting. The verification of the proposed cold forging method was carried out on the basis of numerical calculations made in the Deform-2D/3D program using the finite element method. It was assumed that the billet material is a 42CrMo4 steel tube with standardized cross-sectional dimensions. Two variants of the process with different mandrel kinematics were analyzed. A mandrel moving at the same speed as the punch and a stationary mandrel were used. As part of the results, the progression of the forging shape, stress distributions, strains, temperatures, Cockroft-Latham integral values and force parameters were presented. The analysis of the obtained results confirmed the correctness of the proposed method.

3

Numerical analysis of the heating of a die for the extrusion of aluminium alloy profiles in terms of thermochemical treatment

Joachimiak Damian, Judt Wojciech, Joachimiak Magda

Archives of Thermodynamics

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2023

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Vol. 44, no 2

159--175

EN

Thermochemical treatment processes are used to produce a surface layer of the workpiece with improved mechanical properties. One of the important parameters during the gas nitriding processes is the temperature of the surface. In thermochemical treatment processes, there is a problem in precisely determining the surface temperature of heat-treated massive components with complex geometries. This paper presents a simulation of the heating process of a die used to extrude aluminium profiles. The maximum temperature differences calculated in the die volume, on the surface and at the most mechanically stressed edge during the extrusion of the aluminum profiles were analysed. The heating of the die was simulated using commercial transient thermal analysis software. The numerical calculations of the die assumed a boundary condition in the form of the heat transfer coefficient obtained from experimental studies in a thermochemical treatment furnace and the solution of the nonstationary and non-linear inverse problem for the heat conduction equation in the cylinder. The die heating analysis was performed for various heating rates and fan settings. Major differences in the surface temperature and in the volume of the heated die were obtained. Possible ways to improve the productivity and control of thermochemical treatment processes were identified. The paper investigates the heating of a die, which is a massive component with complex geometry. This paper indicates a new way to develop methods for the control of thermochemical processing of massive components with complex geometries.

4

A Comparative Study on Ex-Situ & In-Situ Formed Metal Matrix Composites

Gobalakrishnan B., Rajaravi C., Udhayakumar Gobikrishnan, Lakshminarayanan P. R.

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 1

171--185

EN

An attempt has been made to synthesize the aluminium based ex-situ (Al-SiC) and in-situ (Al-TiB2) formed metal matrix composites with varying weight percentage of reinforcement contents such as 4wt.%, 6wt.% and 8wt.%. Synthesized composites were subjected to a cold extrusion process followed by heat treatment according to the ASTM B 918-01 standards. The mechanical properties of in-situ composites were evaluated as per the ASTM guidelines and compared with ex-situ formed composites and base metal properties. Superior properties were noticed in the in-situ formed composites and the mechanical properties such as yield strength, Ultimate tensile strength (UTS) and Hardness for both ex-situ and in-situ composites were found to increase with increasing the reinforcement addition. Cold extruded Al-8 wt.% SiC composite properties such as hardness, yield strength and UTS are 87 RB, 152 MPa, 216 MPa respectively. Whereas, for Al-8 wt.% TiB2 composite, the corresponding properties are 94 RB, 192 MPa, 293 MPa. The morphology of the composites is analysed by Optical and Scanning Electron Microscopic (SEM) whereas presence of reinforcement particles such SiC and TiB2 along with intermetallic phases Mg2Si and Al5FeSi are confirmed by EDX, XRD and Element Mapping analyses.

5

New Methodology for Predicting the Cracking Phenomenon in the Radial Extrusion Process of Hollow Parts with a Flange

Winiarski Grzegorz, Samołyk Grzegorz

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 3

64--72

EN

The selected issue of flange cracking in the radial extrusion process of hollow parts has been discussed in this paper. The researches were carried out based on numerical calculations in the Deform 3D software and experimental tests, which were carried out using pipe billets made of aluminum alloy EN AW 6063. A new methodology has been developed that allows to determine the place and approximate moment of material cohesion loss. This is determined from the results of the FEM calculation only, and does not require calibration tests. The method is based on a detailed analysis of the state of stress, state of strain in the forging, and is focused on identifying zones with an uneven distribution of the mentioned parameters. Determination of characteristic zones with a zero increase in the strain effective value makes it possible to determine, with a high approximation, the maximum (due to the phenomenon of cracking) diameter of the flange. The results of numerical calculations showed a high agreement with the results of experimental tests, in which the maximum diameter of the flange was determined.

6

Evaluation of Density Fields of Numerical Analysis Output of Solid Carbon Dioxide Extrusion Process

Górecki Jan, Lindner Tymoteusz, Wałęsa Krzysztof

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 4

235--248

EN

Efforts to reduce energy consumption and explore alternative energy sources are paramount in production process research. However, a research gap exists regarding the evaluation of density fields in numerical analysis output of solid carbon dioxide (CO2) extrusion. This study aims to address this gap by examining the density fields in the numerical analysis output of the extrusion process for solid CO2, commonly known as dry ice. Dry ice, a by-product of ammonia compounds production, requires efficient management due to its high sublimation rate. Ram pressing is a commonly used method for compressing dry ice, but the resulting product often exhibits non-uniform density fields, presenting challenges for process optimization. To bridge this research gap, an algorithm is verified for determining the percentage share of density fields in the numerical simulation results. By comparing simulations using single- and multiple-cavity dies, the algorithm provides valuable insights into the distribution of density within the extruded solid CO2. In overcoming the limitations of subjective comparative evaluation, this study offers objective measures for assessing and comparing numerical analysis outputs. The findings contribute to a deeper understanding and optimization of the solid CO2 extrusion process, facilitating the production of high-density dry ice products with reduced energy consumption. In conclusion, this research not only bridges the research gap in evaluating density fields but also advances the field of solid CO2 extrusion and waste materials management.

7

The influence of calcium carbonate and its modifications on the extrusion process and selected properties of polypropylene cast films

Kloziński Arkadiusz, Szczepańska Małgorzata, Jakubowska Paulina, Samujło Bronisław, Barczewski Mateusz, Lota Grzegorz

Polimery

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2022

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Vol. 67, nr 10

509--521

EN

The effect of unmodified and stearic acid-modified calcium carbonate (5, 10, 20 and 30 wt%) on selected properties (tensile strength, puncture resistance, haze and gloss) and processability of polypropylene films (MVR, extensional viscosity) was investigated. The composites were obtained in the twin-screw extrusion process with cold granulation, and the films in the single-screw extrusion process, using a flat die head (so-called cast films) and a chill roll type cooling and pull-back device. It has been shown that stearic acid is an effective modifier of polypropylene processing properties both under shear and tensile flow conditions (lower extensional viscosity of films containing modified calcium carbonate).

PL

Zbadano wpływ dodatku 5, 10, 20 oraz 30 % mas. niemodyfikowanego imodyfikowanego kwasem stearynowym węglanu wapnia na wybrane właściwości użytkowe (wytrzymałość na rozciąganie, odporność na przebicie, zamglenie, połysk) iprzetwórcze folii polipropylenowych (MVR, lepkość wzdłużna). Kompozyty otrzymano w procesie dwuślimakowego wytłaczania z granulacją na zimno, a folie w procesie jednoślimakowego wytłaczania, przy użyciu głowicy płaskiej (tzw. cast films) oraz urządzenia chłodząco - odciągającego typu chill roll. Wykazano, że kwas stearynowy jest efektywnym modyfikatorem właściwości przetwórczych folii polipropylenowych zarówno w warunkach przepływu ścinającego, jak i rozciągającego (mniejsza lepkość wzdłużna folii zawierających modyfikowany węglan wapnia).

8

Forming of a bimetallic element for the resistance element soldering method

Schrek Alexander, Vanko Branislav, Sejč Pavol

Journal of Metallic Materials

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2022

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Vol. 74, no. 2

8--20

EN

The joining of sheet metal parts produced in the material combination of Fe-Fe, Fe-Al as well as Fe-thermoplastic and Al-thermoplastic can be realized by the Resistance Element Soldering (RES). Extruded bimetallic elements were used to form the overlap joint. The semi-finished product for extrusions was a Cu 99.9 tube with dimensions φ6 × 0.5 mm and length 9 mm, filled with Sn60Pb40 solder. “T” shaped overprints were produced in two ways. Simulation in the ANSYS software environment was chosen to optimize, select the appropriate forming process, and design the geometry of the functional parts of the forming tool, allowing to use only one extrusion forming operation. The results of the simulations are the magnitudes of stresses and strains, and different head shape geometries of the bimetallic element extrusions of the three proposed forming methods. The task was to achieve extrusions without defects of the Cu tube shell, such as corrugations and wrinkles. The geometry was observed and compared by macroanalysis of extrusion sections made on a laboratory forming tool.

PL

Łączenie części metalowych wykonanych z połączenia materiałów Fe-Fe, Fe-Al oraz termoplastycznych Fe i Al można wykonać metodą lutowania oporowego (RES - Resistance Element Soldering). Do wykonania połączenia zakładkowego użyto wytłaczanych elementów bimetalicznych. Półfabrykatem do wytłaczania była rura Cu 99,9 o wymiarach φ6 × 0,5 mm i długości 9 mm, wypełniona lutem Sn60Pb40. Nakładki w kształcie litery „T” wykonywano na dwa sposoby. W celu optymalizacji, doboru odpowiedniego procesu formowania i zaprojektowania geometrii funkcjonalnych części narzędzia kształtującego wybrano symulację w środowisku oprogramowania ANSYS, co pozwala na użycie tylko jednej operacji kształtowania przez wytłaczanie. Wynikiem symulacji są wielkości naprężeń i odkształceń oraz różne parametry geometryczne kształtu głowic wytłoczonych elementów bimetalicznych z trzech proponowanych metod kształtowania. Celem było uzyskanie wytłoczek pozbawionych wad powłoki rury z Cu, takich jak pofałdowania i zmarszczki. Parametry geometryczne obserwowano i porównywano za pomocą makroanalizy produktów wytłaczania wykonanych w laboratoryjnym narzędziu kształtującym.

9

Influence of multi extrusion die process on mechanical and chemical behavior of 2024-T3 alloy

Razooqi Ahmed Ibrahim, Abbas Naseer M., Ghazi Sara Saad

International Journal of Applied Mechanics and Engineering

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2022

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Vol. 27, no. 3

163--170

EN

In this paper, a cold multi-pass extrusion process for a 15mm in diameter solid 2024-T3 aluminum alloy rod was carried out using three dies to obtain three different diameters of 14mm, 13mm, and 12mm. The microstructure, hardness, and corrosion behavior were investigated before and after the extrusion process. Load-Displacement data were recorded during each extrusion process. The electrochemical corrosion test was made in a 3.5 wt.% NaCl solution using potentiostat instrument under static potentials test. Corrosion current was recorded to determine the corrosion rate for specimens. The results showed that the extrusion load increased with the number of extrusion passes, which is also seen in hardness test results. In addition, the corrosion rate decreased with the increase in the number of extrusion passes. This is due to severe plastic deformation, which generates a fine grain structure of (AlCu) and (AlCuMg) components.

10

Research on the Microstructure of Laser Beam Welded Sc-Modified AA2519-F Extrusion

Kosturek Robert, Śnieżek Lucjan, Grzelak Krzysztof, Wachowski Marcin

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 2

773--778

EN

In this paper, the microstructure of laser beam welded Sc-modified AA2519-F has been taken under investigation. The welded joint has been produced using Fanuc 710i industrial robot equipped with YLS-6000 6 kW laser beam source. The welding speed and laser power were equal to 0.75 m/min and 3.2 kW, respectively. The investigation involved microstructure observations with the use of both light microscope and scanning electron microscope with energy dispersive spectroscopy (EDS) analysis of chemical composition and microhardness distribution measurements. It has been stated that laser beam welding allows to obtain Sc-modified AA2519-F weld of good quality, characterized by the presence of an equiaxed grain zone containing scandium-rich precipitates adjacent to the fusion boundary.

11

UV Degradation Influence on the Selected Physical Properties of Extruded PVC/Ceramic Composites

Tor-Świątek Aneta, Garbacz Łukasz

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 3

282--294

EN

This paper presents a study of PVC-ceramic composites obtained by twin-screw extrusion. Properties such as colour, wettability, tensile strength, elongation at break and impact tensile strength were studied. Moreover, the composite samples were subjected to UV degradation process and the influence of the composite composition therefore the degradation process on the mentioned properties has been determined. The study showed the dependence of the ceramic content in the material and its granulation on the individual properties. The research showed a significant influence of degradation on the colour and wettability of samples containing ceramic filler with granulation 0.25-0.5 mm, and in the case of tests of mechanical properties, this influence is the greatest for samples with filler with grain size 0.5-1.25 mm. Additionally, the aging process significantly influenced obtained results.

12

Microstructure and Hardness of Cold Forged 42CrMo4 Steel Hollow Component with the Outer Flange

Szala Mirosław, Winiarski Grzegorz, Bulzak Tomasz, Wójcik Łukasz

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 4

201--210

EN

For decades, steel has been a crucial structural material. Mainly low-alloy steel grade ISO 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 semi-globular 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.

13

Introduction to modelling the correlation between grain sizes of feed material and the structure and efficiency of the process of co-rotating twin-screw extrusion of non-flammable composites with a pla matrix

Fiedurek Kacper, Szroeder Paweł, Macko Marek, Raszkowska-Kaczor Aneta, Borowicz Marcin, Puszczykowska Natalia

Acta Mechanica et Automatica

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2022

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Vol. 16, no. 4

301--308

EN

Co-rotating twin-screw extrusion is an energy consuming process that is generally not fully optimised to a specific polymer. From the point of view of the efficiency of the extrusion process, the starting material should be characterised by small grain sizes in comparison to the screw channel area, small surface area to volume ratio and small internal friction between the pellets. To develop a model describing the effect of polylactide (PLA) grain size on the extrusion efficiency, a series of experiments with a twin-screw extruder were carried out during which the energy consumption; torque on shafts and temperature of the melt on the extruder die were monitored. As feed material, both the neat PLA with different grain sizes and the PLA with expandable graphite fillers and phosphorous-based flame retardants were used. Morphology and dispersion quality of the composites were examined using scanning electron microscopy (SEM); flammability, smoke production, mass loss and heat release rates were tested using cone calorimetry; and melt flow rate was determine using a plastometer. Moreover, the thermal properties of the obtained composites were determined using differential scanning calorimetry (DSC). The results show that the choice of the starting material affects both the efficiency of the extrusion process and the flame retardancy properties of the composite materials.

14

Influence of extruder plasticizing systems on the selected properties of pla/graphite composite

Kaczor Daniel, Bajer Krzysztof, Domek Grzegorz, Madajski Piotr, Raszkowska-Kaczor Aneta, Szroeder Paweł

Acta Mechanica et Automatica

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2022

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Vol. 16, no. 4

316--324

EN

Twin-screw extrusion is a crucial method for the direct inserting of carbon micro- and nanomaterials into a polymer matrix using a dry procedure. The study aimed to determine the influence of the parameters of the twin-screw extruder plasticizing system on the dispersion homogeneity and distribution of graphite filler in the polylactide polymer matrix and overall quality of the composite. As a filler, a graphite micropowder with a 5 μm lateral size of platelets was used at concentration of 1 wt.%. Three configurations of screws with different mixing intensity and various types segments were considered in the extrusion experiments. Morphology and chemical structure of the obtained composites were examined using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy – attenuated total reflectance (FTIR-ATR) and Raman spectroscopy. Differential scanning calorimetry (DSC) and melting flow rate measurements (MFR) were used to asses thermal and rheological properties of the composites. Samples of the polylactide/graphite composites were also subjected to mechanical tests. The results show that the selection of the mechanical parameters of twin-screw extruder plasticizing system plays a key role in the preparation of the homogeneous PLA/graphite composites. Incorrect selection of the screw geometry results in poor mixing quality and a significant deterioration of the mechanical and thermal properties of the composites. Optimised mixing and extrusion parameters can be the starting point for the design of efficient twin-screw extruder plasticizing system for fabrication of PLA composites with carbon nanotube and graphene fillers.

15

An introduction of the planetary roller extruder technology on the example of the wood-plastic composites production

Sąsiedzki Tad

Modelowanie Inżynierskie

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2021

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T. 42, nr 73

42--47

EN

Planetary roller extruder with his excellent mass temperature control, homogenization and dispersion is used not only in the plastics industry, but in a wide range of physical processes like continuous mixing, reactive chemical processes as polymerization and decomposition, for example in the process of recycling. ENTEX developed in last few years new improved technical solutions for example for better degassing, higher torque transmission, laboratory applications and direct extrusion. With these new solutions we create significant cost savings due to reduction of energy consumption and reduction of production costs by simplifying production process. We can also improve final product quality by reducing the thermal and mechanical load on the material on the example of WPC composite (Wood-Plastic-Composites).

PL

Rynek kompozytów WPC stale rośnie i otwiera potencjał dla nowych producentów i nowych technologii. Również firma ENTEX Rust & Mitschke GmbH podjęła wyzwanie i oferuje swoją technologię mieszalnika planetarnego do wyżej wymienionych zastosowań. Ze względu na dużą powierzchnię styku, wysoce wydajne i precyzyjne możliwości ogrzewania lub chłodzenia przetwarzanego materiału oraz modułową budowę wytłaczarka planetarna jest w stanie uzyskać do 78% wypełnienia wiórkami drzewnymi w polimerze przy zachowaniu najwyższej jakości produktu końcowego.

16

Analyzing mechanical behavior of ABS-SiO2 polymer-based nanocomposite based on ANOVA method

Afzali Mohammad, Asghari Vahid

Composites Theory and Practice

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2021

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R. 21, nr 3

61--69

EN

The fabrication of polymer-based nanocomposites by means of twin extruders is a typical method for manufacturing lightweight and high-strength structures. However, selection of the optimal parameters for this process to study the material characteristics is important. The primary aim of the present study was to ascertain the optimum extruder temperature and nanosilica content in an acrylonitrile-butadiene-styrene matrix composite. The response surface methodology was based on two factors and three levels. The identification of the effect of the parameters on the fatigue behavior of the fabricated composite was comprehensively analyzed. The results were analyzed using scanning electron microscopy (SEM). The obtained results revealed that up to 4% nano-SiO2 improves tensile strength and reduces the impact toughness. On the other hand, an increase in the extrusion temperature yields a higher impact toughness and lower tensile strength. The optimization results showed that 2.5% nanosilica and the extrusion temperature of 225°C result in the maximum tensile strength of 41 MPa, and impact toughness of 30 KJ/m2.

17

The extraordinary effect of very low content of hybrid carbonaceous reinforcement on the microstructural and mechanical properties of 7075 aluminum alloy

Ezatpour H. R., Torabi Parizi M., Ebrahimi G. R.

Archives of Civil and Mechanical Engineering

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2021

|

Vol. 21, no. 2

263--286

EN

Until recently, the strengthening efficiency of carbonaceous reinforcements in aluminum-based matrix nanocomposites (AlMNCs) was lower than expected. The intrinsic characteristics of matrix and carbonaceous reinforcements and fabrication technique, which affected the microstructural characterization, played main roles in determining the performance of Cs/AlMNCs. In this study a novel strategy was developed via flake powder metallurgy followed by slurry blending combined with rheocasting and hot-extrusion processing to prepare hybrid AA7075-matrix composite reinforced with CNTs + GNPs. No Al4C3 phase was detected in Raman spectrums, while uniform dispersion of carbonaceous hybrid reinforcements with minimal structural damage was observed. There were ~ 9% and 39% decrease in the average grain size of the as-casted and extruded CNTs + GNPs/AA7075 composites, respectively, compared to AA7075 alloy. In the extruded CNTs + GNPs/AA7075 composite, plate precipitates were predominant and some lath-like dynamic precipitates were observed at the GNPs/AA7075 interfaces. The micro-hardness, tensile yield strength (TYS), ultimate tensile strength (UTS) and uniform elongation (UE) of the CNTs + GNPs/AA7075 composite were improved by ~ 17%, 51%, 7% and 20% compared to AA7075 alloy. An ultra-high yield strengthening efficiency of carbonaceous hybrid reinforcements in AA7075 alloy up to 3950 was obtained, where load bearing was the main strengthening mechanism and carbonaceous reinforcements illustrated bridging and pulling-out in the fracture surfaces of composite.

18

The Influence of Geometrical Parameters of a Tool on its Wear in Selected Technological Processes

Nowotyńska Irena

Advances in Science and Technology. Research Journal

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2021

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Vol. 15, no 2

198--207

EN

Forecasting the durability of tools for various technological processes, determining the dominant destructive mechanisms or their impact on the "life time" of the tool is very important. In the paper presents the research on tools wear of different geometric parameters in selected plastic working processes were presented. Numerical calculations of the tool wear in the process of forward extrusion and drawing were carried out using the MSC MARC program, based on the Finite Element Method. In order to determine the amount of wear of dies and drawing dies, the Archard model was applied. The model was implemented in the FEM-based program. As a result of the research, the areas on the surface of tools, which are particularly exposed to significant wear were determined, depending on their geometry.

19

Development of a testing station for empirical verification of the algebraic model of dry ice piston extrusion

Górecki Jan

Acta Mechanica et Automatica

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2021

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Vol. 15, no. 3

107--112

EN

Efficient use of resources is a very important consideration for every production process, especially where waste materials are used as raw materials. One example of these kinds of processes is dry ice extrusion. Based on the subject literature, it can be observed that the machines available in the market that are used to compress dry ice are characterized by high working force value. This leads to low efficiency of resource consumption, in regards to both electrical energy and carbon dioxide. This paper presents a proposed design of a test stand used for measuring compression force as a function of piston displacement in the course of the dry ice extrusion. The first part of the article presents the testing methodology and test stand design. The second part presents the results of measurement of compression force as a function of piston displacement with three different die types. The results of the study allowed to establish the difference between the values of the measured limit force and the values calculated with an analytical model. The test stand design and the results presented in this paper are important for further research and development works in the area of efficient extrusion and compaction of dry ice.

20

Numerical analysis of three-stage the forming process hollow forgings with an outer flange

Wójcik Łukasz, Bulzak Tomasz, Winiarski Grzegorz, Szala Mirosław

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2020

|

nr 62 (134)

142--147

EN

This article presents the results of computer simulations used to investigate the forming of a hollow coldworked forging with an outer flange. Numerical simulations were performed in Deform 2D/3D using a calculation module for axial-symmetric cases. A ϕ57×12.5 mm tube-shaped billet from 42CrMo4 grade steel was used. The forming process involved two and three stages, consisting of extrusion the shaft portion and forging the flange. The objective of this research was to determine the accuracy of the forming process used to produce the hollow part. This technology was analyzed using the effective strain distributions, the Cockcroft-Latham fracture criterion values, and the forming force progression. The results showed that it was possible to use this three-stage process to forge elements from a tube-shaped billet.