Increase Of Extrusion Speed Research Articles

A novel combo‐transmission system of cold energy and electricity for aluminium profile production: Using liquid nitrogen and superconductor technologies

AbstractAluminium production needs the most energy‐intensive technologies among all the metal processing sectors. During the process of aluminium profile extrusion, the whole production line needs bulk electricity, and the mold inside the extrusion equipment needs robust cold energy for rapid cooling of the metal surface. This paper presents a new combo‐transmission that can simultaneously deliver cold energy together with electricity to the aluminium profile extrusion line. Thanks to the superiority of virtually zero loss and compact size, the powerful superconducting cable is used to replace the conventional copper cable. The entire superconducting cable assembly is fully installed into a cryogenic pipeline and cooled by liquid nitrogen at 77 K. In addition to keeping a favourable cryogenic environment for the superconducting cable, liquid nitrogen can also provide a large amount of cold energy for cooling the metal surface. For a typical 100 MN aluminium extrusion production line, the design and optimization of 10 kA class superconducting cable with the pipeline cooling system for aluminium production are presented in detail. The simulation results and comparisons show that the total energy loss of superconducting transmission is about 46% of conventional copper cable, and the energy saved in a year can be up to about 240.6 MWh. Moreover, the net profit increases almost linearly along with the increases of the extrusion speed when the liquid nitrogen cooling is applied to the 100 MN production line. For the case of 23% increase in extrusion speed, the net profit can be up to 1.48 M$ in a year. Overall, the novel design, technical evaluation, and economic analysis of the combo‐transmission system (cold energy + electricity) can provide a promising solution for future high‐dense aluminium production sectors.

Effect of extrusion speed on microstructure and mechanical properties of Mg-Al-Ca-Sn alloy

Low-temperature and high-speed extrusion of wrought magnesium alloy is an urgent problem. Mg-2.5Al-2Ca-1Sn alloys were extruded at 260 °C with different ram speeds (2.0, 4.0 and 6.0 mm s)−1. The effects of extrusion speed on the microstructure and mechanical properties of the alloys were systematically investigated. It’s worth noting that all the three extruded alloys were fully dynamic recrystallized (DRXed). With the increase of extrusion speed from 2 mm s−1 to 6 mm s−1, the DRXed grain size are increased from 1.25 μm to 1.94 μm, average second phase particles are augmented from 0.79 μm to 0.89 μm and the volume fraction of second phase increases from 6.4% to 18.6%. All the three extruded samples show excellent comprehensive mechanical properties because of fine grain size, fully recrystallization and homogeneously dispersed second phase particles. The tensile yield strength (TYS) and ultimate tensile strength (UTS) decreased from 285 MPa, 304 MPa to 217 MPa, 264 MPa while the elongation increased from 11.4% to 20% when the ram speed rose from 2.0 mm s−1 to 6.0 mm s−1.

Extrusion of Unhomogenized Castings of 7075 Aluminum via ShAPE

Extrusion of unhomogenized castings of the 7075 aluminum (Al) alloy has been accomplished using shear assisted processing and extrusion (ShAPE). The simultaneous plastic deformation and heat generation during ShAPE rapidly fracture and dissolve interdendritic and intragranular secondary phases of Al-Zn-Mg-Cu, accomplishing homogenization in seconds rather than many hours in a furnace before extrusion. ShAPE thereby eliminates the energy-intensive and time-consuming homogenization step required to prepare as-cast microstructures for conventional extrusion. Concurrently, extensive grain refinement occurs due to gradient activation of dynamic recrystallization during ShAPE, which facilitates a threefold increase in extrusion speed compared to the conventional extrusion method. Evident enhancement of the mechanical properties of ShAPE + T6 samples is achieved, compared to the ASTM standard values for conventional extrusion products. The microstructural evolution pathway, involving the processes of grain refinement and secondary particle dissolution, is explained using scanning and transmission electron microscopy.

Effects of extrusion speed of continuous extrusion with double billets on welding performance of 6063 Al alloy

During continuous extrusion, the welds were formed at the confluence of two billets. Influences of extrusion wheel rotational speed on micromorphology and properties of welds of 6063 Al alloy were investigated through microstructure observation, tensile test, and SEM analyses. Welding parameters were analyzed using finite element simulation. Results indicated that metal welding was remarkably affected by oxide on outer surface of the double billets during continuous extrusion. Degree of oxide breakage on the welding surface increased due to the evident increase in effective strain rate with increasing extrusion speed. The high temperature induced by increased extrusion speed accelerated the formation of metallurgical bonding. A portion of weld seam lines slowly disappeared, and the proportion of the welding interface that failed to reach metallurgical bonding was also gradually reduced. Tensile strength and elongation of the weld specimen increased with the increase of extrusion speed.

Influence of extrusion conditions on microstructure and mechanical properties of Mg-2Gd-0.3Zr magnesium alloy

In general, different extrusion conditions will affect the microstructure of magnesium alloys and further determine the mechanical properties. The effects of extrusion parameters and heat treatment processes such as extrusion speed, pre-forging, annealing time, extrusion ratio and cooling rate on the microstructure, texture evolution and tensile properties of Mg-2Gd-0.3Zr alloys were investigated in this study. Compared with the as-cast alloy, the extrusion process significantly refines the grains and exhibit the rare earth texture. With the increase of extrusion speed and annealing time, the growth of recrystallized grains is accelerated, leading to the increase of elongation. Large pre-forging deformation achieves to refine the grains by promoting recrystallization nucleation, resulting in increased strength of Mg-2Gd-0.3Zr alloy. Decreasing the extrusion ratio or increasing the cooling rate will introduce coarse un-DRXed grains, which transformed the texture into the basal texture. In particular, the effect of rapid cooling on refining the recrystallized grains is also obvious. Different extrusion conditions influence the mechanical properties of the Mg-2Gd-0.3Zr alloy through the grain size, proportion of non-recrystallization region and texture type.

Influence of Manufacturing Parameters and Post Processing on the Electrical Conductivity of Extrusion-Based 3D Printed Nanocomposite Parts.

The influence of manufacturing parameters of filament extrusion and extrusion-based Additive Manufacturing (AM), as well as different post processing techniques, on the electrical conductivity of 3D printed parts of graphene nanoplatelets (GNP)-reinforced acrylonitrile butadiene styrene (ABS) has been analyzed. The key role of the manufacturing parameters to obtain electrically conductive filaments and 3D printed parts has been demonstrated. Results have shown that an increase in extrusion speed, as well as lower land lengths, induces higher extrudate swelling, with the consequent reduction of the electrical conductivity. Additionally, filaments with lower diameter values, which result in a higher surface-to-cross-section ratio, have considerably lower electrical conductivities. These factors tune the values of the volume and surface electrical conductivity between 10−4–100 S/m and 10−8–10−3 S/sq, respectively. The volume and surface electrical conductivity considerably diminished after 3D printing. They increased when using higher printing layer thickness and width and were ranging between 10−7–10−4 S/m and 10−8–10−5 S/sq, respectively. This is attributed to the higher cross section area of the individual printed lines. The effect of different post processing (acetone vapor polishing, plasma and neosanding, which is a novel finishing process) on 3D printed parts in morphology and surface electrical conductivity was also analyzed.

Computer Simulation Study on Microstructure Evolution of Super Alloy During Tube Extrusion Deformation

In view of the evolution law of the dynamic recrystallization of super alloy IN690 during tube extrusion forming process, a method of combining finite element software and organization evolution model is put forward to simulate the microstructure evolution of the deformation process. First, a computer simulation geometry model for tube extrusion process of super alloy IN690 is established. Secondly, model of the dynamic recrystallization microstructure evolution and material properties and extrusion process parameters are determined. Thirdly, the functions of the microscopic organization simulation in the calculation software are developed secondly, and the related UGRAIN subroutine is compiled. Finally, the computer simulation of the microstructure evolution in the tube extrusion deformation process is carried out, and the ideal results are obtained, and the influence of process parameters on the dynamic recrystallization and grain size is analyzed. The results show that with the increase of extrusion deformation temperature, the area of fully dynamic recrystallization increases, and the average grain size of the tube increases. With increase of extrusion ratio, the area of fully dynamic recrystallization increases and the average grain size decreases. With increase of extrusion speed, the area of fully dynamic recrystallization decreases and the average grain size increases. The simulation results of the average grain size are in agreement well with the experimental results, and the relative error is less than 12%.

Microstructure and mechanical properties of hot extruded Mg-8.89Li-0.96Zn alloy

Abstract The numerical simulation and experiments were conducted to study the hot extrusion of Mg-8.89Li-0.96Zn alloy. The extrusion process was modelled based on finite element method, and the effects of extrusion speed on the distribution of flowing velocity, effective strain rate, and temperature were clarified. Moreover, the extrusion experiments were carried out at varied extrusion speeds, and both the microstructure and mechanical properties of the extruded alloy were examined. The results showed that the flowing velocity, effective strain and temperature increased with the increase of extrusion speed, and the deformation is more severe in the edge of the extruded plate than that in the center. The grain size is smaller and the degree of dynamic recrystallization is higher in the edge zone. With the increase of extrusion speed, the average grain size in the edge zone increased, while the grain size in the center zone firstly decreased and then increased. When the extrusion speed is 0.5 mm/s, the specimen exhibited the best ultimate tensile property and elongation due to its uniform grain size and relatively more recrystallized grains. The hardness increases from the center to the edge due to the decreasing grain size.

Effects of extrusion speed and printing speed on the 3D printing stability of extruded PEEK filament

In fused deposition modeling (FDM) using polyether-ether-ketone (PEEK), the dimensions of extruded filaments are unstable and there is insufficiency dimensional agreement between the fabricated part and design model. The present study presents the effects of the extrusion speed and printing speed on the microstructure and dimensions of an extruded PEEK filament in 3D printing. The extrusion process characterization including extrusion force and extrusion resistance was measured for the understanding of the evolution of extrusion process with the increase in extrusion speed. The relationship between the extrusion speed and the diameter of the extruded filament was established by measuring the diameter of the extruded filament at different extrusion speeds in freeform extrusion. Furthermore, PEEK was stably printed in an experiment with increasing printing speed and it was revealed that the control algorithm that mathematically replaces the nozzle diameter with the diameter of the extruded filament is feasible and effective. During PEEK FDM, the melt pressure in the chamber directly affects the surface morphology and extrusion diameter of the extruded filament, and higher melt pressure is beneficial to reducing surface defects of the extruded filament. A fluctuating extrusion force is the main constraint on the stability of extrusion. The optimized control algorithm between the extrusion speed and the diameter of the extruded filament improve the stability of PEEK FDM and improves the dimensional accuracy and surface morphology of printed PEEK parts. Furthermore, this study could be applied to reveal the instability of extrusion and select a set of suitable printing parameters during FDM.

High strength Mg-9Al serial alloy processed by slow extrusion

The AZ91-0.5Ca alloy was extruded at 250°C with slow extrusion speed (0.03, 0.3, 3mm/s) in the current study. The results showed that both the volume fraction and average grain size of DRXed grains increased with the increase of extrusion speed. Furthermore, numerous fine Mg17Al12 phase were observed in the DRXed regions of the extruded alloys, the amount of which decreased by increasing extrusion speed. The decrease of extrusion speed led to the improvement of yield strength and ultimate tensile strength, however, at the expense of elongation. As the extrusion speed decreased to 0.03mm/s, the yield strength, ultimate tensile strength and elongation of present alloy were ~347.8MPa, ~402.2MPa and ~9.1%, respectively, which were superior to the present commercial Mg-Al serial alloys. Detailed reasons are given and analyzed.

Effect of ultra-slow extrusion speed on the microstructure and mechanical properties of Mg-4Zn-0.5Ca alloy

The Mg-4Zn-0.5Ca alloys extruded at 280°C by different ultra-slow extrusion speed (0.01, 0.05, 0.1 and 0.5mms−1) were investigated in present study. The results show that both the volume fraction and average size of DRXed grains increase with the increase of extrusion speed, which is different from that depicted by present Z parameter. To fit the extrusion conditions with low temperature and ultra-slow extrusion speed, a more accurate estimate/measurement of the actual temperature in the expression of the Z parameter is needed in the further study. Even though the amount of precipitates decrease with the increasing extrusion speed, the increasing amount of DRX regions lead to the decreased intensity of basal plane texture. Superior mechanical properties with the yield strength of 324.5MPa, ultimate tensile strength of 371.1MPa and elongation to failure of 7.9% are achieved in present Mg-4Zn-0.5Ca alloy extruded at the speed of 0.01mms−1. As the extrusion speed increased from 0.01 to 0.5mms−1, the strength decreases which is accompanied with the increase of elongation.

High-speed indirect extrusion of Mg–Sn–Al–Zn alloy and its influence on microstructure and mechanical properties

This investigation into the effect of indirectly extruding Mg–7Sn–1Al–1Zn (TAZ711) alloy at high exit speeds on the microstructure and tensile properties found no evidence of surface cracking, not even at the maximum speed tested of 27 m/min. This high-speed extrudability is attributed to the relatively high incipient melting temperature of the alloy (535 °C), which results from the formation of a thermally stable Mg2Sn phase. All extruded samples exhibited a completely recrystallized (DRXed) structure consisting of coarse DRXed grains with few particles in combination with relatively fine DRXed grains containing numerous fine precipitates. With an increase in extrusion speed, the total amount of Mg2Sn precipitates decreased and the size and quantity of coarse DRXed grains increased due to a rise in temperature during extrusion. This has the effect of reducing the strength of the extruded alloy through a reduction in precipitation and grain-boundary strengthening, yet the elongation of the extruded alloy remains essentially the same due to a loss of ductility caused by the increase in DRXed grain size.

Microstructures of an AZ61 wrought magnesium alloy fabricated by a novel SPD process using thermomechanical simulation

Abstract Extrusion-shear (ES), a novel severe plastic deformation (SPD) method which includes initial forward extrusion and a subsequent one step shearing process, has been developed to fabricate fine grained AZ61 Mg alloys in a Gleeble 1500D thermomechanical simulator for the first time. The effects of the ES process on the grain refinement of an as cast magnesium alloy were investigated at different extrusion speeds and the microstructures of the as processed billet and rods were investigated at right, central and left positions. It was found that the extrusion force caused by the ES process at 5 mm × s−1 is about 5 times of that caused at an extrusion speed of 1 mm × s−1. Besides, the increase of extrusion speed could improve the deformation stress. The ES extrusion causes serve plastic deformation and improves the dynamic recrystallization during the process. The results confirmed that the ES process can be used to refine the grains effectively and to produce serve plastic deformation. The microstructural investigation showed that grain sizes are finer in the bottom parts than in the other parts of the rod.

A Finite Element Analysis on the Effect of Location of Holes, Die Pockets and Extrusion Speed in Multi-hole Extrusion Process

Extrusion process has proved its potential in bulk metal forming process since the industrial development. The better product quality, mechanical property and the strength of the extruded products are the advantages in extrusion process. Multi-hole extrusion is used where pressure required for extrusion is in excess of press capacity. It is used for the production of small and precise products such as parts used in automobiles, health-care and aviation industries. The different process parameters affect the extrusion process and quality of the extruded products. In the present investigation, finite element analysis is carried out to study the effect of loaction of holes on the die, die pockets and the extrusion speed on the extrusion load, efective strain and the extruded product length. Extrusion load is found to increase with increase in extrusion speed. The die pockets help in reducing the extrusion load. The effective strain, which provides the information about the work hardening of the material during the extrusion process is dependentof the above said process parameters. The extruded product lengths become more uniform when die pockets are made. The selection of process parameter is based upon the required quality of the product.

Effects of extrusion speed on the microstructure and mechanical properties of ZK60 alloys with and without 1 wt% cerium addition

The effects of extrusion speed on the microstructure and tensile properties of the ZK60 and ZK60-1Ce alloys were investigated by performing indirect extrusion at three ram speeds (0.3, 1.0 and 3.0mm/s). All of the extruded alloys showed a bimodal microstructure consisting of equiaxed fine recrystallized (DRXed) grains and elongated coarse unDRXed grains. With increasing extrusion speed, the exit temperature increased due to deformation heating, resulting in a larger grain and a higher DRXed fraction. The yield and ultimate tensile strengths and elongation at RT decreased with an increase of extrusion speed. The ZK60-1Ce alloys exhibited a finer grain size, a higher DRXed fraction, and weaker texture intensity than the ZK60 alloys at the same extrusion speed due to the inhibition of grain growth by the pinning effect and the promotion of DRX by particle-stimulated nucleation. The yield and ultimate tensile strengths at room and elevated temperatures were increased by the addition of Ce, while elongation was decreased due to cracking at the Mg–Zn–Ce particles.

Damage prediction for magnesium matrix composites formed by liquid-solid extrusion process based on finite element simulation

A damage prediction method based on FE simulation was proposed to predict the occurrence of hot shortness cracks and surface cracks in liquid-solid extrusion process. This method integrated the critical temperature criterion and Cockcroft & Latham ductile damage model, which were used to predict the initiation of hot shortness cracks and surface cracks of products, respectively. A coupling simulation of deformation with heat transfer as well as ductile damage was carried out to investigate the effect of extrusion temperature and extrusion speed on the damage behavior of C sf/AZ91D composites. It is concluded that the semisolid zone moves gradually toward deformation zone with the punch descending. The amplitude of the temperature rise at the exit of die from the initial billet temperature increases with the increase of extrusion speed during steady-state extrusion at a given punch displacement. In order to prevent the surface temperature of products beyond the incipient melting temperature of composites, the critical extrusion speed is decreased with the increase of extrusion temperature, otherwise the hot shortness cracks will occur. The maximum damage values increase with increasing extrusion speed or extrusion temperature. Theoretical results obtained by the Deform™-2D simulation agree well with the experiments.

Ram extrusion of high‐density polyethylene and polypropylene in solid state: Process conditions and properties

AbstractHighly oriented high‐density polyethylene (HDPE) and polypropylene (PP) were obtained by solid state extrusion near, but below, the melting temperature. Draw ratios of 6 and 11 were obtained using properly designed dies, preformed billets and lubrication for different extrusion temperatures. Orientation induced significant changes in properties and morphology that are related to the final draw ratio. The draw ratio was observed to decrease with an increase in extrusion speed due to the molecular relaxation occurring because of local heating during deformation. An increase in the degree of crystallinity was observed for the oriented polymers as well as a large improvement in the tensile modulus. Significant molecular relaxation and elastic recoil were observed during processing. Extrusion speed strongly increases the extent of relaxation, and, consequently, reduces many of the mechanical properties.

Production of New Cellulosic Filament Spun from Cellulose/aqueous NaOH Solution. (part 4). New Spinning Process of Cellulose Filament Production from Alkali Soluble Cellulose Dope-Net Process.

In wet spinning of cellulose filament, a new coagulation method (net process) which can suppress tension on the filament at low level was successfully devised. An employment of this method for the spinning of new cellulose filament from caustic soda solution made it possible to spin at up to 200 m/min. This process includes a cylindrical shaped spinning funnel used for the viscose rayon and a net, as a supporter of coagulating filament, which runs as the same speed of winding roller. Using this method, we can principally spin the filament at any high speed, because of less hydraulic resistance arising from coagulant, Important factors to obtain high spinning speed and good mechanical properties of as-spun cellulose filament were found to be as follows: (1) Lowering draft ratio by an increase of extrusion speed at spinnerets; (2) reducing the hydraulic resistance at early stage of coagulation by shortening the distance from spinnerets to inlet of the funnel; (3) reducing the hydraulic resistance in the funnel by minimizing the velocity difference between coagulant flow and take-up speed of the filament; (4) drawing the never dried filament by 1.2-1.3 after coagulation. Using the spinning apparatus designed to satisfy these conditions, we obtained the cellulose filament with comparable mechanical properties to commercially available viscose filament at the same spinning speed as that of the viscose (100 m/min).

超塑性Ｚｎ‐２２ｗｔ％Ａｌ合金の盛り上げ変形挙動に及ぼす超音波振動の影響

Superplastic Zn-22wt%Al alloy was extruded by close-die sets with three types of punch to which ultrasonic oscillations are applicable. The extrusion load(W)is related to the extrusion speed(V)by the equation W∝Vm". The values of m" generally 0.4 to 0.5 are comparable to those of strain rate sensitivity index m in superplastic deformation in tension or compression. In the extrusion condition in which severe frictional restraint arrises, however, m" decreases down to 0.3 or less. If ultrasonic oscillations are applied, the extrusion load decreases, and m" does not decrease even in the extrusion condition described above. Application of ultrasonic oscillations is effective to flatten the top shape of specimens and to increase the extrusion speed at a constant load. The degree of extrusion load and increase of extrusion speed by applying ultrasonic oscillations are mainly due to the decrease of frictional constraint.

Experiments in the cold extrusion of rods of non-circular section

Experiments in the extrusion of pure lead and tellurium lead rods of circular, square, rectangular triangular and I section form are described. These investigate the effects of section shape and punch speed on the necessary extrusion load, and on the nature of the flow of metal within the extruded rod. It is shown that, for a given reduction in area, the load is independent of section shape for all but re-entrant shapes and increases with increase in extrusion speed.