Extrusion Conditions Research Articles

Optimization of Extrusion Conditions for Development of High Quality Rice-Lupin-Pumpkin Based Extruded Snack Food

Optimization of Extrusion Conditions for Development of High Quality Rice-Lupin-Pumpkin Based Extruded Snack Food

Effects of different processing methods on phenolic compounds in flaxseed meal

This study examined effects of different processing methods on phenolic compounds in flaxseed meal. The optimal SE treatment was 1.0 MPa for 3 min, and the contents of total flavonoids and phenolic acid were 2.26 times and 1.63 times of the control group, respectively. Notably, erucic acid increased 85.76 %. Optimal extrusion conditions (15 % moisture content, 140 °C, 29 hz) led to the presence of rutin and a 2.81 times increase in protocatechuic acid content over the control. Fermenting with 3 % Bacillus subtilis for 4 days yielded gallic acid in bound form and vanillic acid in free form, with protocatechuic acid increasing 40.65 % compared to the control. Among all the treatments, extrusion produced the highest levels of phenolic compounds in flaxseed meal. Each treatment significantly increased the open ring isomer ester phenol (SDG) compared to the control. Overall, various processing methods impacted the phenolic content and composition in flaxseed meal differently.

Extrusion Parameters Optimization and Mechanical Properties of Bio-Polyamide 11-Based Biocomposites Reinforced with Short Basalt Fibers.

The increasing demand for sustainable materials in high-value applications, particularly in the automotive industry, has prompted the development of biocomposites based on renewable or recyclable matrices and natural fibers as reinforcements. In this context, this paper aimed to produce composites with improved mechanical and thermal properties (tensile, flexural, and heat deflection temperature) through an optimized process pathway using a biobased polyamide reinforced with short basalt fibers. This study emphasizes the critical impact of fiber length, matrix adhesion, and the variation in matrix properties with increasing fiber content. These factors influence the properties of short-fiber composites produced via primary processing using extrusion and shaped through injection molding. The aim of this work was to optimize extrusion conditions using a 1D simulation software to minimize excessive fiber fragmentation during the extrusion process. The predictive model's capacity to forecast fiber degradation and the extent of additional fiber breakage during extrusion was evaluated. Furthermore, the impact of injection molding on these conditions was investigated. Moreover, a comprehensive thermomechanical characterization of the composites, comprising 10%, 20%, and 30% fiber content, was carried out, focusing on the correlation with morphology and processing using SEM and micro-CT analyses. In particular, how the extrusion process parameters adopted can influence fiber breakage and how injection molding can influence the fiber orientation were investigated, highlighting their influence in determining the final mechanical properties of short fiber composites. By optimizing the process parameters, an increment with respect to bio-PA11 in the tensile strength of 38%, stiffness of 140%, and HDT of 77% compared to the matrix were obtained.

Thermorheological properties and structural characteristics of soy and pumpkin seed protein blends for high-moisture meat analogs

This study explored the effects of soy protein isolate (SPI) and pumpkin seed protein concentrate (PSC) blends on the thermorheological properties and microstructure of high-moisture meat analogs. Using a Discovery Hybrid Rheometer, we observed that increasing PSC content weakened SPI network formation, resulting in decreased gel stability and a more porous, less aligned structure. Microstructural analyses (FE-SEM and FT-IR) revealed a correlation between protein network disruption and increased PSC content. Additionally, higher PSC levels reduced overall bonding (ionic, hydrogen, hydrophobic, disulfide), modifying the texture and softening the gel while retaining solid-like characteristics essential for replicating meat textures. Although full high-moisture extrusion conditions were not replicated, the observed trends offer valuable insights into texture development for meat substitutes. Future research using a closed-system rheometer is required to validate these findings and improve precision.

Effect of extrusion on physicochemical and functional properties of cladode flour from Opuntia cochenillifera and Opuntia ficus-indica

In this study, the physicochemical and functional properties of flours obtained from mature cladodes of two nopal species, Opuntia cochenillifera (OC) and Opuntia ficus indica (OF), subjected to different extrusion conditions, varying moisture (20 % and 26 %) and temperature levels (120 °C, 140 °C and 160 °C) were evaluated. The results showed significant differences in chemical composition, physical, functional and phytochemical properties between the two species. OC had a higher ash and ether extract content (29.27 % and 1.28 % respectively), while OF had more protein and carbohydrates (7.83 and 55.31 % respectively). The expansion index was higher (1.06 – 1.27) in OF, especially under high temperature extrusion and low moisture conditions. Bulk density decreased with increasing extrusion temperature, and color was significantly altered by temperature and moisture, with greater changes observed in OF. Functional properties such as oil absorption capacity, water absorption capacity, and water solubility index, were significantly affected by the extrusion process in both species of nopal. In terms of dietary fiber, extrusion increased (4.99 to 10.38 %) the soluble fiber content and decreased (36.91 to 32.30 %) the insoluble fiber content in both species. However, OC had a higher percentage of soluble and total dietary fiber. Phenolic compounds, flavonoids and antioxidant activity were significantly affected by the extrusion process in most treatments, although some maintained or improved these properties. These results highlight the influence of species and extrusion conditions on the properties of nopal flours, providing valuable information for the development of nopal-enriched food products, thereby optimizing their nutritional and technological properties.

Optimization of Non-Thermal Treatment Methods and Extrusion Temperature on Quality of Rice Pasta Enriched with <i>Cirina butyrospermi</i>

Food security remains a critical global challenge, necessitating the exploration of sustainable and nutrient-rich food alternatives such as edible insects. This study investigated and optimized the effect of treatment methods (boiling, ultrasound, and a combined boiling and ultrasound treatment) on Cirina butyrospermi and extrusion temperature (70℃, 80℃ and 90℃) on some quality (crude protein, in-vitro protein digestibility, calcium, zinc, iron, cooking time, water uptake ratio, lightness, and colour change) of rice pasta. The effect of treatment methods on Cirina butyrospermi powder and extrusion temperature on crude protein ranged from 15.85 to 18.27%, in-vitro protein digestibility (80.42-88.55%), calcium (48.53-56.25 mg/100g), zinc (2.42-3.56 mg/100g), iron (3.34-5.13 mg/100g), cooking time (8.50 - 19.50 min), water uptake ratio (1.15 - 1.90), lightness value (4.19 - 50.73) and colour change (4.47 - 51.13), respectively. The combined boiling and ultrasound treatment on Cirina butyrospermi powder and higher extrusion temperature gave rice pasta the highest protein, calcium, zinc, and iron content while lower extrusion temperature along with boiling treatment, increased in-vitro protein digestibility. Optimum conditions for desirable rice pasta were achieved at 80°C extrusion temperature with combined boiling and ultrasound treatment. Conclusively, exploring edible insects like Cirina butyrospermi under an accurate treatment method and extrusion condition could aid in the development of nutrient-rich rice pasta.

Influence of Twin Screw Extrusion Conditions on MWCNT Length and Dispersion and Resulting Electrical and Mechanical Properties of Polycarbonate Composites

The processing conditions were varied during the production of polycarbonate-based composites with the multiwalled carbon nanotubes (MWCNTs) Baytubes® C150 P (Bayer MaterialScience AG, Leverkusen, Germany), by melt mixing with an extruder on a laboratory scale. These included the screw design, rotation speed, throughput, feeding position and MWCNT content. Particular attention was paid to the shortening of the MWCNT length as a function of the conditions mentioned. It was found that there is a correlation between the applied specific mechanical energy (SME) during the melt mixing process and MWCNT dispersion, which was quantified by the agglomerate area ratio of the non-dispersed nanotubes based on optical microscopic analysis. The higher the SME value, the lower this ratio, which indicates better dispersion. Above an SME value of about 0.4 kWh/kg, no further improvement in dispersion was achieved. The MWCNT length, as measured by the quantitative analysis of TEM images of the MWCNTs dissolved from the composites, decreased with the SME value down to values of 44% of the original MWCNT length. At a constant loading of 3 wt.%, the tensile strength and tensile modulus were almost independent of the SME, while the elongation at break and notched impact strength showed an increasing trend. The variation in the feeding position showed that feeding the MWCNTs into a side feeder led to slightly better electrical and mechanical properties for both types of MWCNTs studied (Baytubes® C150 P and Nanocyl™ NC7000 (Nanocyl S.A., Sambreville, Belgium)). However, feeding into the hopper led to better CNT dispersion with Baytubes® C150 P, while this was the case with Nanocyl™ NC7000 when feeding into the side feeder. The screw profile had an influence on the dispersion, the MWCNT length and the electrical resistance, but only to a small extent. Distributive screws led to a greater shortening of the MWCNT length than dispersive screws. By varying the MWCNT content, it was shown that a greater MWCNT shortening occurred at higher loadings. Two-stage masterbatch dilution leads to stronger shortening than composite production with direct MWCNT incorporation.

Hot Melt Extruded High-Dose Amorphous Solid Dispersions Containing Lumefantrine and Soluplus

Over the last 15 years, a small number of paediatric artemisinin-based combination therapy products have been marketed. These included Riamet® and Coartem® dispersible tablets, a combination of artemether and lumefantrine, co-developed by the Medicines for Malaria Venture and Novartis. Disappointingly, patient compliance, requirement for high-fat meal, and sporadic drug dissolution behaviours following administration still result in considerable challenges for these products. The first and foremost barrier that needs addressed for successful delivery of the artemether/lumefantrine combination is the poor solubility of lumefantrine within the gastrointestinal fluids. In this work, amorphous solid dispersions of lumefantrine within Soluplus®-based matrices have been manufactured using hot melt extrusion as a potential formulation strategy to achieve enhanced dissolution and apparent solubility. The drug loading capacity of Soluplus® to accommodate amorphous lumefantrine, whilst ensuring improved in-vitro dissolution performance, was investigated. The extrusion process employed a variety of processing parameters, including various temperature profiles and different production scales. The influence of variation in extrusion conditions upon the physical stability of manufactured amorphous solid dispersions was also examined. This allowed for a greater understanding of the role of extrusion processing conditions on the performance of supersaturated amorphous solid dispersions during dissolution and storage. This may allow for the design and manufacture of drug enabled formulations with lower drug dosing and thus a lower risk of adverse effects.

Structural, physicochemical and technofunctional properties of corn gluten meal modified by extrusion

This study aimed to evaluate the influence of sample moisture, extrusion temperature, and extruder screw speed on the hydration properties of corn gluten meal (CG), optimize process condition for the highest protein solubility at pH 7 (PS7) and WAC, and assess the effect of the optimized extrusion process on the structural, chemical, physical, and technofunctional properties of CG proteins. Extrusion was carried out at different sample moisture (20%–40%), temperatures (120–160 °C), and screw speeds (33–117 rpm) using a complete factorial design with two central points. All extrusion conditions resulted in reduced hydration properties. Extrusion with 20% sample moisture, 120 °C and 117 rpm resulted in the lowest loss of water absorption capacity and protein solubility at pH 7 (optimized condition). After optimized extrusion, the GC became darker and showed greater activity and protein emulsifying capacity and lower foaming capacity. Furthermore, CG proteins had reduced solubility at different pHs. Changes in technofunctional properties resulted from changes in protein structure after extrusion. The new protein structure is stabilized by non-covalent bonds (hydrogen bonds and hydrophobic interactions) and disulfide bonds. Extruded corn gluten has the potential to be used as an ingredient in bakery, emulsified meat products, salad dressings, vegetable pates, and desserts.

High-Resistant Starch Based on Amylopectin Cluster via Extrusion: From the Perspective of Chain-Length Distribution and Structural Formation.

Resistant starch (RS) has the advantage of reshaping gut microbiota for human metabolism and health, like glycemic control, weight loss, etc. Among them, RS3 prepared from pure starch is green and safe, but it is hard to achieve structural control. Here, we regulate the crystal structure of starch with different chain-length distributions (CLDs) via extrusion at low/high shearing levels. The change in CLDs in extruded starch was obtained, and their effects on the fine structure (Dm, dBragg, dLorentz, degree of order and double helix, degree of crystal) of RS and its physicochemical properties were investigated by SAXS, FTIR, XRD and 13C NMR analyses. The results showed that the RS content under a 250 r/min extrusion condition was the highest at 61.52%. Furthermore, the crystalline system induced by high amylopectin (amylose ≤ 4.78%) and a small amount of amylose (amylose ≥ 27.97%) was favorable for obtaining a high content of RS3-modified products under the extruding environment. The control of the moderate proportion of the A chains (DP 6-12) in the starch matrix was beneficial to the formation of RS.

Effect of different extrusion parameters on the microstructure and mechanical properties of Mg-4Sm-3Gd-2Yb-0.5Zr alloy

The effect of different extrusion parameters on the microstructure and mechanical properties of Mg-4Sm-3Gd-2Yb-0.5Zr (SGY2) alloy was investigated. It was observed that under different extrusion parameters, unDRXed grains of SGY2 alloy exhibited a pronounced basal plane texture, specifically <011¯0>//ED, while the texture of DRXed grains was relatively dispersed. Under the condition of 420 °C and an extrusion ratio of 9.4 (420 °C-ER9.4), the basal plane texture strength of unDRXed grains in SGY2 alloy was the highest. Furthermore, SGY2 alloy at different extrusion parameters exhibited recrystallization mechanisms mainly characterized by continuous dynamic recrystallization (CDRX), with some DRXed grains and deformed grains experiencing discontinuous dynamic recrystallization (DDRX). Additionally, at the 420 °C-ER9.4, the second phase particles in the as-extruded SGY2 alloy were smaller in size and exhibited a dispersed distribution. Under this condition, a significant amount of dislocation accumulation, dislocation bypassing, and dislocation tangling phenomena were observed in the SGY2 alloy. The primary deformation mechanism of unDRXed grains in the SGY2 alloy at the 420 °C-ER9.4 may involve prismatic plane 〈a〉, pyramidal plane 〈a〉, and pyramidal plane 〈c + a〉 slip, thereby activating a significant amount of dislocations. Compared to other extrusion conditions, this condition is more prone to activate non-basal plane slip. The as-extruded SGY2 alloy exhibited superior mechanical properties, with ultimate tensile strength (UTS) and yield strength (YS) of 332 MPa and 278 MPa, respectively. This is mainly attributed to the extremely fine grains, with many DRXed grains having grain sizes smaller than 1 µm, and higher density grain boundaries produced under this condition. Additionally, the unDRXed grains contain a high density of dislocations with small Schmid factor (SF), thus effectively inhibiting basal plane slip and strengthening the alloy to some extent. Similarly, the increased presence of second phase particles will also contribute to strengthening the alloy matrix through precipitation hardening.

On crashworthiness design of hybrid metal–composite battery-pack enclosure structure

Considering the crashworthiness and lightweight of the battery-pack enclosure structure (BPE), this article demonstrates multi-objective optimization design of BPE subjected to extrusion conditions by using a validated numerical model and an analytical approach. BPE is made with a unique combination of three materials: a high-strength steel (HSS) surrounding enclosure, an aluminum below enclosure, and a carbon fiber-reinforced polymer (CFRP) upper enclosure. First, the constitutive model of BPE material was determined based on the results obtained in material testing, meanwhile, the structural extrusion analysis of the initial BPE was performed and validated by the published experimental data. Second, a contribution analysis method based on modified TOPSIS (MTOPSIS) is adopted to screen the design parameters of the optimal structure. Based on this, the mass of the BPE and the maximum extrusion deformation of the BPE are employed as objectives to establish an optimization mathematical model. Furthermore, improved multi-objective particle swarm optimization (IMOPSO) has been exerted as the optimization algorithm to conduct optimization design, the results show the optimization model has a better optimization level and fitting ability. Finally, the performance comparison results before and after model optimization show the crashworthiness performance can be improved significantly, while the lightweight performance of BPE is ensured.

Exploring off‐flavour compounds in soy‐based meats: Mechanisms and removal methods

AbstractPlant‐based meat is projected to address world‐wide meat shortage and supply–demand imbalances, potentially promoting the growth of sustainable diet choices. Soybean is a key ingredient to produce this alternative food, but the off‐flavours that naturally occur in soy can hinder its widespread acceptance among consumers. This review extensively elaborates on the primary compounds responsible for off‐flavours, their formation mechanisms, and removal techniques. Lipoxygenase oxidation–reduction, oleosins removal, adjustment extrusion conditions, and β‐cyclodextrin treatment were discussed. Fermentation mechanisms, solvent extraction, enzymes hydrolysis, flavouring, and controlling storage conditions were summarised. The most crucial, safe, and effective techniques were enzyme restriction, β‐cyclodextrin treatment in conjugation with phospholipase A2, and modification of the extrusion condition. The reviews provide a systematic summary of the development and prevention methods for the undesirable flavour of soy protein isolate and soy‐based meat products.

Nova abordagem para as batatas fritas: Produtos alimenticios a partir da batata e o arroz extrudidos

This study aimed to craft an extruded product resembling conventional French fries, utilizing rice as the primary ingredient, and incorporating potato blends to enhance physicochemical and sensory attributes during frying. Mashed potatoes, rice flour, and additives were processed using a twin-screw extruder, followed by frying at 160°C for 2.15 minutes in three stages. In stage I, four formulations were assessed, with the formulation comprising 70% mashed potato, 30% rice flour, and 0.1% salt displaying superior acceptability and minimal oil absorption (8%). Stage II compared vacuum application to non-vacuum conditions, revealing enhanced sensory acceptability with vacuum due to improved texture and firmness. Combining optimal conditions, stage III yielded the best formulation of 70% mashed potatoes, 30% rice flour, 0.1% salt, and 48% moisture. Extrusion conditions result in heightened sensory evaluation across sensorial parameters. This study pioneers a novel avenue for producing healthier rice-based French fry alternatives via extrusion technology, ameliorating frying attributes.

A multidisciplinary approach to investigate the influence of process parameters on interlayer adhesion in material extrusion additive manufacturing

This study investigates the influence of deposition conditions in material extrusion (MEX) on fracture toughness, with a specific focus on the interlayer adhesion. A full factorial experimental design was employed, varying three key parameters: the deposition strategy, the extrusion multiplier, and the extruder speed. Fracture toughness was assessed using double cantilever beam tests, following ASTM D5528 standards. Additionally, the study explores the influence of load direction through various deposition strategies, including 0/90 and ± 45 orientations. To gain deeper insights, real-time thermal analysis was conducted during deposition, utilizing an infrared thermal camera. This allowed to investigate the effect of deposition conditions on temperature history. Subsequent examination of fracture surfaces post-testing was performed using optical and scanning electron microscopy. The findings reveal compelling evidence of the significant impact of the extrusion multiplier, printing speed, and deposition orientation on interlayer adhesion. In addition, the results indicated the presence of crystalline phase after deposition which was due to partially melting during depositions involving high material flow. This was due to the adoption of a semicrystalline filament. The adoption of the multidisciplinary approach enabled a better understanding of some phenomena occurring during the deposition (e.g., formation/existence of crystalline phase) that influence the adhesion behavior. These results underline the capability of such broad approach to analyze the influence of the processing conditions on the interlayer adhesion. Consequently, the developed analysis procedure represents a pivotal approach to study and optimize the MEX process and filament characteristics especially for semicrystalline polymers.

Investigating extrusion impact on functional, textural properties, morphological structure, and molecular interactions in hulless barley-based extruded snacks supplemented with mung bean.

The effect of varying extrusion conditions on the functional properties of hulless barley-mung bean (70:30) extruded snacks was investigated using response surface methodology with feed moisture (FM), barrel temperature (BT), and screw speed (SS) as process variables. Results revealed significant impacts on functional characteristics with varying extrusion conditions. Bulk density (BD) of extruded snacks ranged from 0.24 to 0.42 g/cm3, showing that lower FM and higher BT results in lower BD while it increased with increasing FM, SS, and BT. The expansion ratio (ER) of extruded snacks ranged between 2.03 and 2.33, showing BT and SS had a desirable positive effect, whereas increasing FM led to decreased ER. Increasing BT and SS depicted a negative effect on water absorption index, whereas FM showed positive effect, which ranged between 4.21 and 4.82 g/g. A positive effect on water solubility index was depicted by BT and SS, which ranges between 9.01% and 13.45%, as higher SS and BT led to starch degradation and increased solubility suggesting better digestibility. The hardness of extruded snacks ranged from 32.56 to 66.88 Newton (N), showing increasing FM increased hardness, whereas higher SS and BT resulted in lowering the hardness. Scanning electronic microscope (SEM) analysis revealed structural changes in extrudates in comparison with nonextruded flour, indicating starch gelatinization and pore formation affected by varying processing parameters. Shifts in absorption bands were observed in Fourier transform infrared spectroscopy (FT-IR), suggesting structural changes in starch and protein. Understanding the effects of extrusion parameters on product properties can help tailored production to meet consumers' preferences and the development of functional snacks with improved nutritional quality.

Investigating Degradation in Extrusion-Processed Bio-Based Composites Enhanced with Clay Nanofillers

This research investigates the extrusion-based fabrication and characterization of nanocomposites derived from bio-sourced polypropylene (PP) and poly(butylene succinate) (PBS: a biodegradable polymer derived from renewable biomass sources such as corn or sugarcane), incorporating Cloisite 20 (C20) clay nanofillers, with a specific focus on their suitability for electrical insulation applications. The research includes biodegradation tests employing the fungus Phanerochaete chrysosporium to evaluate the impact of composition and extrusion conditions. These tests yield satisfactory results, revealing a progressive disappearance of the PBS phase, as corroborated by scanning electron microscopy (SEM) observations and a reduction in the intensity of Fourier transform infrared spectroscopy (FTIR) peaks associated with C-OH and C-O-C bonds in PBS. Despite positive effects on various properties (i.e., barrier, thermal, electrical, and mechanical properties, etc.), a high clay content (5 wt%) does not seem to enhance biodegradability significantly, highlighting the specific sensitivity of the PBS phase to the addition of clay during this process. This study provides valuable insights into the complex interplay of factors conditioning nanocomposite biodegradation processes and highlights the need for an integrated approach to understanding these processes. This is the first time that research has focused on studying the degradation of nanocomposites for electrical insulation, utilizing partially bio-sourced materials that contain PBS.

Optimization of germinated cowpea flour ratios and extrusion conditions on the nutritional composition and sensory quality of Ethiopian emmer wheat-based extruded porridge

Childhood malnutrition is a major problem in developing countries, particularly in Ethiopia. This study aimed to create nutritious emmer wheat and cowpea extruded porridge with optimal macronutrient levels and sensory quality. Utilizing Design-Expert software, the effects of cowpea blending ratios (10–25 %), barrel temperatures (80–120 °C), and feed moisture content (22–26 %) were analyzed using a three-factor, three-level Box-Behnken design. Significant impacts on nutritional characteristics were observed, leading to the identification of optimal extrusion conditions (cowpea blend: 20.17 %, moisture content: 25.91 %, barrel temperature: 117.20 °C). Blending emmer wheat with cowpea flour significantly enhanced the porridge's color, taste, and aroma. The highest color intensity (4.36 %) was at 10 % cowpea and 22 % moisture processed at 100 °C. The best taste (4.41 %) was with 25 % cowpea and 22 % moisture at 100 °C, while the highest aroma was in blends with 10 % and 25 % cowpea at 100 °C. The control had the best mouthfeel (4.36 %), but a blend with 25 % cowpea, 24 % moisture, and 80 °C barrel temperature had the highest overall acceptability (4.31 %). The study highlighted the potential of these protein-rich porridge products to address protein-energy malnutrition, particularly in Ethiopia, by introducing awareness about the unique nutritional composition of Ethiopian emmer wheat and underutilized cowpea, thus creating a new market for nutritious food options.

Effect of extrusion conditions on microstructural characteristics and mechanical properties of SEN6 magnesium alloy

This study investigates the influence of extrusion conditions on the microstructure and tensile properties of Mg–6Al–0.3Mn–0.3Ca–0.2Y (SEN6) alloy, which is processed at various extrusion temperatures and ratios. An increase in both the extrusion temperature and ratio facilitates dynamic recrystallization during hot extrusion by enhancing thermal and strain energies, increasing the area fraction of recrystallized grains within the extruded material. As either the extrusion temperature or ratio increases, lattice rotation within the recrystallized grains intensifies, resulting in a stronger basal texture in the extruded material. During extrusion, the undissolved Al2Y, Al8Mn4Y, and Al2Ca particles within the billets are partially fragmented and realigned along the extrusion direction. However, the quantity, size, and dispersion of these particles are largely unaffected by variations in extrusion temperature and ratio. The tensile yield strength of the extruded material shows a positive correlation with increasing extrusion temperature and ratio, predominantly due to enhanced texture hardening. Specifically, the tensile yield strength of the material extruded at 400 °C with an extrusion ratio of 25 is 23.2 MPa higher than that of the material extruded at 300 °C with an extrusion ratio of 10. Despite the presence of non-recrystallized grains in materials extruded at the lower extrusion ratio of 10, compression and double twins form uniformly throughout the material during tension, as the widths of non-recrystallized grains are similar to those of recrystallized grains. Consequently, all extruded materials exhibit high tensile elongations, exceeding 20%.

Simulation of taper heating and variable pressing rate to improve extrusion performance for high-strength aluminum alloys

The main process parameters of direct and indirect extrusion of aluminum alloys were studied using FE-modeling in this article. The subject of the study was the use of billets taper heating and variable pressing rate as compared to the standard extrusion conditions. Extrusion of AA2024 grade alloy and experimental Al-2%Cu-1.5%Mn-1%Mg-1%Zn alloy was considered. The flow stress-on-strain dependences within the 350 °C–450 °C range at strain rates of 0.1–10 s−1 were determined for the experimental alloy. Considering the time of billet transportation to the extrusion equipment, its optimum temperature gradient was determined to be 500 °C at the front end and 140 °C at the tail end. Direct extrusion of taper heated billets at the variable rate and elongation of 7 allowed increasing the process performance by 5.6 times (from 1.8 mm s−1 to an average of 10 mm s−1, in case uniformly heated billets are extruded at the constant rate). In case of pressing at high elongations (15 and 25), the performance increase was about 2 times. It was found that the use of taper heating, both in case of grade alloy and model alloy extrusion, in all the considered conditions, allows achieving a significant increase in performance. However, these results are considered to be most effective in case of direct extrusion at small elongation ratios.