Low-temperature Extrusion Research Articles

Influence of extrusion parameters on microstructure, texture and mechanical properties of a low Mn and high-Ca containing Mg-2.9Zn-1.1Ca-0.5 Mn magnesium alloy

A newly developed low Mn and high-Ca containing magnesium alloy, Mg-2.9Zn-1.1Ca-0.5 Mn (wt.%) based alloy was processed by low-temperature extrusion. The average recrystallized grain size decreased from 1.64 to 0.58 μm with a decrease in the extrusion speed from 1 to 0.01 mm s−1, but increased to 2.11 μm with increasing extrusion temperature from 270 to 350 ℃. The finest and uniform recrystallized grain structures with substantial nano-sized MgZn2 precipitates and α-Mn particles were obtained in the 270 ℃/0.01 mm s−1 sample. The texture intensity including basal (0002), prismatic type I (10−10) and prismatic type II (11–20) decreased accompanied by increasing the deformation temperature or extrusion speed. The weakest texture intensity for the 270 ℃/1 mm s−1 sample was derived from high degree of recrystallization, inhomogeneous recrystallized grain structure and the precipitates. Superior uniaxial tensile strength (yield strength of ∼352.5 MPa, ultimate tensile strength of ∼382.3 MPa and elongation of ∼7.1%) were achieved in the 270 ℃/0.01 mm s−1 sample. The improved yield strength was mainly ascribed to fine grain strengthening and precipitates strengthening relative to dislocation strengthening and back stress strengthening. A positive slope of work-hardening rate (dθ⁄dσ > 0) extruded at 270 ℃/0.01 mm s−1 was related to the sharp basal texture and insufficient slip. High θ value at stage IV after extrusion at 270 ℃/1 mm s−1 with abundant dimples and weak texture contributed to high ductility. Massive micro-cracks formed along the twins in the coarse deformed grains led to the failure during tension.

Development of high-performance Mg–Zn–Ca–Mn alloy via an extrusion process at relatively low temperature

In general, Mg alloys are difficult to process at low temperature (below 200 °C), due to the limited slip systems. High-temperature deformation easily results in the grain growth, which seriously restricts the improvement of mechanical properties. In this study, we report a subsequent low-temperature extrusion technology for ultra-fine grained (UFG) Mg–Zn–Ca–Mn alloys processed through equal channel angular pressing (ECAP), and successfully fabricate the extruded alloy with high yield strength (∼332.8 MPa) and superior ductility (∼17.9%) through grain refinement and texture modification. The initially fine-grained structure in the as-ECAPed alloy is beneficial to improving its low-temperature deformability, because the compatibility stress at grain boundaries can effectively promote the activation of the non-basal slip systems. Although the strength is dramatically increased, the alloy extruded at 100 °C exhibits the poor ductility, which can be ascribed to the dislocation accumulation behavior. With increasing extrusion temperature, the yield strength is remarkably increased at very small expense of ductility, because of the grain refinement, stacking faults, recovery of basal texture and fine secondary phase particles. The dislocations formed during the extrusion can be rapidly annihilated through a dynamic recrystallization process, which contributes to the improved ductility.

Mechanistic investigation of a low-alloy Mg–Ca-based extrusion alloy with high strength–ductility synergy

High strength–ductility synergy is difficult to achieve in Mg alloys. Although high strength has been achieved through considerable alloying addition and low-temperature extrusion, these techniques result in low ductility (2%–5%). In this work, a novel low-alloy Mg–Ca-based alloy that overcomes this strength–ductility trade-off is designed. The alloy has an excellent tensile yield strength (∼425 MPa) and exhibits a reasonably high elongation capacity (∼11%). A microstructure examination reveals that a high density of submicron grains and nano-precipitates provides the alloy high strength, and the leaner alloy additions and higher extrusion temperatures initially improve ductility. As a result, the density of residual dislocations is reduced, and the formation of low-angle grain boundaries (LAGBs) is enhanced. With fewer residue dislocations, it becomes less probable for the newly activated mobile dislocations to be impeded and transformed into an immobile type during the subsequent tensile test. The LAGBs function as potential sites to emit new dislocations, thus enhancing the dislocation–multiplication capability. More importantly, they can induce evident sub-grain refinement hardening and guarantee that the alloy achieves high strength. The findings lead to a controllable Mg alloy design strategy that can simultaneously afford high strength and ductility.

Fiber engraving for bioink bioprinting within 3D printed tissue engineering scaffolds

In this work, we describe a new 3D printing methodology for the fabrication of multimaterial scaffolds involving the combination of thermoplastic extrusion and low temperature extrusion of bioinks. A fiber engraving technique was used to create a groove on the surface of a thermoplastic printed fiber using a commercial 3D printer and a low viscosity bioink was deposited into this groove. In contrast to traditional extrusion bioinks that rely on increased viscosity to prevent lateral spreading, this groove creates a defined space for bioink deposition. By physically constraining bioink spreading, a broader range of viscosities can be used. As proof-of-concept, we fabricated and characterized a multimaterial scaffold containing poly(ε-caprolactone) (PCL) as the thermoplastic polymer and a gelatin-based bioink. A 7.5 w/v% gelatin methacryloyl (GelMA) bioink loaded with either 5 w/v% poly(lactic-co-glycolic acid) (PLGA) microparticles containing fluorescent albumin or mouse fibroblasts (1 ​× ​106 ​cell/mL) was printed at 24 ​°C. The structure of the composite scaffolds had no significant decrease in porosity or mechanical properties as compared to the PCL control scaffolds, demonstrating the engraving technique did not significantly compromise the mechanical or structural integrity of the scaffold. The encapsulated PLGA microparticles were homogeneously distributed in the GelMA and remained in the scaffolds after incubation in PBS for 24 ​h ​at 37 ​°C. In addition, the viability of the fibroblasts encapsulated in the GelMA bioink and printed in the grooves of the PCL scaffolds was confirmed after 24 ​h of incubation. Overall, this work provides a new methodology for the preparation of 3D printed scaffolds containing a robust thermoplastic structure in combination with low viscosity bioinks.

Functional and physical properties of naked barley-based unexpanded extrudates: effects of low temperature

ABSTRACT The purpose of this study was to provide a new approach to producing a slowly-digestible snack with sensory appeal suitable for people with hyperglycemia. The study was based on naked barley supplemented with other functional components and used low-temperature extrusion technology. The effects of the extrusion temperature (Et = 65–85°C), feed moisture (Fm = 25–35%), and screw speed (Ss = 60–80 rpm) were studied systemically, aiming at minimizing the glycemic index and maximizing the radical scavenging rate while obtaining a good texture and pleasant sensory characteristics. The best response was obtained with an Et of 74.24°C, Fm of 35%, and Ss of 80 rpm. Under these conditions, barley extruded with multiple grains showed a lower degree of gelatinization (70.17%), lower glycemic index (29.37), higher radical scavenging rate (53.66%), and higher sensory evaluation (86) compared to those of extrudates with only naked barley. The present study suggests that the low-temperature extrusion method can effectively produce snacks with a high radical-scavenging rate, slow digestion characteristics, and high market acceptance.

Enhanced Precipitation and Recrystallization in a Mg-Zn Alloy During Low-Temperature Extrusion

Lightweight magnesium (Mg) alloys have great potential to be used in a variety of structural applications. However, Mg’s hexagonal crystal lattice and the limited number of deformation slip systems create fundamental challenges during forming. Furthermore, the selection and amounts of alloying additions can lead to complex phases and transformations or location-sensitive precipitate reactions (i.e., in grain or grain boundary regions). Mg-Zn alloys are promising candidates for applications requiring high strength due to their high hardening response. In this study, we processed solution treated Mg-3Zn (wt.%) using equal channel angular extrusion (ECAE) along the Bc route at 150 oC. The microstructure of the extruded material showed two distinct regions. The grain interior showed a dense distribution of nano precipitates. The grain boundary region contains recrystallized ultrafine grains with some reprecipitation occurring inside them. We employed the Lukác-Balík strain hardening model to estimate the dislocation density evolution during the processing, and we linked these dislocations to the high density of precipitates seen in the grain interiors.

Physical and sensory characteristics of cheese-flavored expanded snacks obtained using butyric acid and cysteine as aroma precursors: Effects of extrusion temperature and sunflower oil content

Pre-extrusion flavoring with butyric acid and cysteine, as aroma precursors, was used for production of cheese-flavored expanded corn-based snacks. The effects of extrusion temperature and sunflower oil sprinkled over the snacks on the physical and sensory characteristics of the products were evaluated. Both variables had influence on the expansion ratio, density, luminosity, yellow chromaticity and chroma, as well as on oil flavor, cheese odor, cheese flavor, salty taste, and umami taste (descriptive). Cheese flavor intensity (consumers) and oil odor and cereal flavor (descriptive) were influenced by sunflower oil, while yellow color, crispness and hardness (descriptive) were influenced by extrusion temperature. In terms of overall acceptability, all snacks, excepting that obtained at low extrusion temperature (91.8 °C) or that with no oil addition, showed similar acceptability. In this way, snacks with low oil content (i.e. 3.5%) may be considered as so preferred as snacks with 20.5% of sunflower oil. Therefore, the pre-extrusion flavoring with aroma precursors is feasible and a promising technology, because it allows the production of snacks with desirable physical and sensory characteristics, as well as better nutritive value, due to the low incorporation of lipids into the snacks sprinkled with the sunflower oil.

Strength properties and structure of CuCrZr alloy subjected to low-temperature KOBO extrusion and heat treatment

KOBO extrusion of metals and alloys strongly activates the point defect generation processes, as a result of which they reach a concentration exceeding the equilibrium level by many orders of magnitude. This leads to significant acceleration of diffusion phenomena which in heat-treatable alloys may cause disturbance of the thermodynamic equilibrium between the solid solution decomposition and dissolution of precipitates. In this work, measurements of mechanical and electrical properties and structural observations Cu1Cr0.1Zr alloy subjected to low-temperature KOBO extrusion at different stages of multi-variant heat treatment were conducted. In addition, the geometry of the extruded alloy’s flow zone was analyzed and the obtained results made it possible to assess the effectiveness of experimental procedures, including product formation with high extrusion ratio λ, aimed at achieving of high and thermally stable functional properties of the material.

Embedding Ultra-High-Molecular-Weight Polyethylene Fibers in 3D-Printed Polylactic Acid (PLA) Parts.

This study aims to assess whether ultra-high-molecular-weight polyethylene (UHMWPE) fibers can be successfully embedded in a polylactic acid (PLA) matrix in a material extrusion 3D printing (ME3DP) process, despite the apparent thermal incompatibility between the two materials. The work started with assessing the maximum PLA extrusion temperatures at which UHMWPE fibers withstand the 3D printing process without melting or severe degradation. After testing various fiber orientations and extrusion temperatures, it has been found that the maximum extrusion temperature depends on fiber orientation relative to extrusion pathing and varies between 175 °C and 185 °C at an ambient temperature of 25 °C. Multiple specimens with embedded strands of UHMWPE fibers have been 3D printed and following tensile strength tests on the fabricated specimens, it has been found that adding even a small number of fiber strands laid in the same direction as the load increased tensile strength by 12% to 23% depending on the raster angle, even when taking into account the decrease in tensile strength due to reduced performance of the PLA substrate caused by lower extrusion temperatures.

Effects of extrusion temperature on microstructure, mechanical properties and in vitro degradation behavior of biodegradable Zn-3Cu-0.5Fe alloy.

Zn-based alloys as biodegradable materials for cardiovascular stents have drawn more and more attention in recent years. However, the hot plastic deformation of Zn-based alloys does not get enough attention. In this study, Zn-3Cu-0.5Fe alloy was prepared and then hot extruded at 140, 180, 220 and 260 °C. Effects of extrusion temperature on the microstructure, mechanical properties and degradation behavior were investigated. Nano-scaled particles precipitated during extrusion and the quantity decreased with the increasing of extrusion temperature. As the extrusion temperature increased from 140 to 260 °C, the grain size increased from 1.15 to 4.38 μm, the yield strength and ultimate tensile strength increased from 203 ± 3.23 and 221 ± 1.56 MPa to 269 ± 2.65 and 302 ± 8.01 MPa, increased by 32.5% and 45%, while the degradation rate was decreased gradually from 62.8 ± 0.72 μm/year to 49.9 ± 3.35 μm/year, decreased by 20.5%. In addition, the degradation behavior changes from a relatively uniform degradation mode to a localized degradation mode with the increase of the grain size. Dislocation gliding is replaced by grain-boundary movement and dynamic recrystallization (DRX) in the room temperature tensile deformation process. Lower extrusion temperature is beneficial for higher elongation and degradation rate as well as relatively uniform degradation mode, which is better suitable for the clinical application of cardiovascular stents.

Excellent mechanical properties obtained by low temperature extrusion based on Mg-2Zn-1Al alloy

A newly developed low Al containing magnesium alloy, Mg-2Zn-1Al based alloy (wt.%) shows excellent mechanical properties. The alloys with superior high strength and considerable ductility (the maximum of tensile strength reaches 332 MPa and corresponding elongation is 23.1%) were produced by electromagnetic casting and extrusion at relatively low temperatures (110 °C, 170 °C, 210 °C, and 250 °C) with an extrusion ratio of 17.4:1. Effects of extrusion temperature on the evolution of microstructure, mechanical properties and extruded texture were investigated by OM, SEM, TEM, and EBSD analysis. The microstructures of the alloy extruded at low temperatures mainly consist of the equiaxed dynamically recrystallized grains, elongated grains, and regions without dynamic recrystallization. And there are only equiaxed dynamically recrystallized grains in the alloy extruded at 250 °C. The increasing extrusion temperature results in grain coarsening and strength reduction. When the extrusion temperatures are 110 °C and 170 °C, the average grain size reaches submicron level of 0.65 μm and 0.89μm, respectively. Because the higher extrusion temperature makes the dynamically recrystallized grains rotate in a favorable direction, the basal texture enhances with the rise of extrusion temperature. The high strength is mainly attributed to the structure of extremely refined grains. High ductility benefits from a large amount of basal slip, activation of non-basal slip, and grain boundary movement under the action of tensile stress.

High ductility induced by un-DRXed grains in a Mg–Zn–Mn–La–Ce alloy

An approach of achieving high ductility as well as respectable high strength for low-Zn-containing wrought Mg alloy is presented in this paper. A low-cost and industry-compatible Mg–2Zn–0.3Mn–0.2La–0.1Ce alloy with highest yield strength (YS) of 289 MPa, ultimate tensile strength (UTS) of 300 MPa and excellent elongation (EL) of 32.7% is developed by traditional indirect extrusion. The microstructure and macro-textures of this alloy under various extrusion temperatures are characterized by OM, EBSD and XRD analysis. High quantity of dispersed elongated un-DRXed grains with various orientations form at relatively low extrusion temperatures, and many of them possess high basal Schmidt Factors (SFs) toward transverse directions. TEM analysis reveals a large number of networked dislocations passing through the deformation bands along transverse directions within the un-DRXed grains, which suggests the integral deformation (bending) is achievable by dislocation motion. It is believed that the high ductility along extrusion direction is induced by the bendable elongated un-DRXed grains during tensile deformation by embodying the easy-to-failure regions, preventing the subsequent generation of micro-cracks and accommodating the stress concentration.

High strength TiCp/Mg-Zn-Ca magnesium matrix nanocomposites with improved formability at low temperature

A novel TiCp/Mg-4Zn-0.5Ca nanocomposite was successfully developed by using the ultrasonic-assisted semisolid stirring method, and then extruded at the speed of 0.01 mm/s with low extrusion temperatures of 270, 230 and 190 °C, respectively. The experimental results indicated that ultrasonic-assisted semisolid stirring could be able to realize the uniform distribution of nano-sized TiCp in the nanocomposite. The external addition of TiC nanoparticles refined the grain dimension of the matrix alloy and improved the morphology of eutectic Ca2Mg6Zn3 phases. The particle stimulated nucleation caused by TiCp provided large driving force for the dynamic recrystallization at the low temperature of 190 °C, leading to high volume fraction of recrystallized grains and formability of TiCp/Mg-4Zn-0.5Ca nanocomposite. The smallest grain size of ∼0.34 μm obtained at 190 °C was caused by two factors, one was due to the temperature reduction, the other was attributed to the coordination pinning effect of nano-scale TiC particles with MgZn2 precipitates. The elongation of the present nanocomposite extruded at 270 °C was improved by 158.2% than the level in as-extruded matrix alloy. This could be ascribed to that the addition of TiC nanoparticles could act as nucleation sites for the recrystallization, and thus coordinate the deformation of matrix. The tensile strength increased as the extrusion temperature decreased, YS of ∼355.3 MPa, UTS of ∼385.7 MPa and EL ∼10.2% were obtained for the TiCp/Mg-4Zn-0.5Ca nanocomposite extruded at 190 °C. The excellent mechanical properties were associated with combining effects of the addition of TiC nanoparticles, grain refinement and a large amount of precipitated MgZn2 phases.

Exfoliated graphite/acrylic composite film as hydrophobic coating of 3D-printed polylactic acid surfaces

Three-dimensional (3D) printers utilize polylactic acid (PLA) as feedstock filament due to its renewability, low extrusion temperature, and good mechanical properties. One major drawback of 3D-printed PLA products is their limited application in harsh environments due to their low hydrolytic resistance. We developed exfoliated graphite (EG)/acrylic composite films as protective coatings of 3D-printed PLA surfaces. This paper reports on the water contact angles (WCAs) and weight change behavior of 3D-printed PLA surfaces coated with EG/acrylic composite films under humid exposure. We obtained hydrophobic films (WCA > 90°) after adding EG platelets to the acrylic resin. Moreover, the films retain their hydrophobicity after a long humid exposure. The films also reduce the water absorption of 3D-printed PLA surfaces. The addition of stearic acid in the coating formulation further enhances the water resistance of the films. In conclusion, the hydrophobic EG/acrylic composite films improve the hydrolytic resistance of 3D-printed PLA surfaces. The use of EG over defect-free graphene to create hydrophobic polymeric films will need to be considered in future studies.

Processability of SS316L powder - binder mixtures for vertical extrusion and deposition on table tests

ABSTRACT Metal injection molding (MIM) feedstocks are mixtures made of a solid metal powder and a viscous polymeric binder. Vertical extrusion of MIM feedstock has seldom been investigated in the scientific literature, but it is the enabling technology for extrusion-based additive manufacturing processes (EAM). The EAM process adopts the movement of an extruder, relative to a build table, to deposit thin strands (roads) of the mixture and grow a 3D object, layer by layer. EAM may find applications for the consumer as well as industrial products. This paper addresses some of the challenges involved in achieving a consistent flow of molten feedstock mixture and discusses the consequences of the main process parameters on the extrusion-based manufacturing process. This work also relates the rheological behaviour of feedstock to the extrusion process, aiming at the dimensional stability of parts. An experimental study was performed on SS316L feedstock with a water-soluble binder system, by varying the percentage powder content of the mixtures, the extrusion temperature, the extrusion rate, the deposition table speed and the nozzle shape. The study evidences and explains why higher powder loading values and lower extrusion temperatures are the most useful conditions in order to obtain a stable flow with reduced swelling/shrinking phenomena.

Effect of processing temperature and foaming agent loading on properties of polylactic acid/kenaf fiber composite foam

The focus of this study was to investigate the effect of processing temperature and foaming agent loading on physical and mechanical properties of the foamed polylactic acid (PLA)/kenaf fiber (KF) composites. The foamed polymer composites made from PLA, KF and azodicarbonamide (ADC) were prepared via extrusion and compression molding. The temperature profile used for extrusion was set at 170, 185, 180, 175˚C (high temperature profile) and 165, 170, 175, 160˚C (low temperature profile). ADC loadings were varied at 0, 1, 3 and 5 phr. The density of the foamed composites exhibited a decreasing trend with the increasing of ADC loading. The morphology was analysed by Field Emission Scanning Electron Microscope (FESEM) and the results revealed the bigger size in the PLA/KF foamed composites extruded with high temperature. Tensile strength, strain @ break and Young modulus of the foamed composites decreased accordingly with respect of foaming agent content. The mechanical strength was positively affected when the lower extrusion temperature was used for extrusion.

Effects of extrusion variables on corn-mango peel extrudates properties, torque and moisture loss

ABSTRACT Effects of extruder parameters (barrel temperature: 75–175°C; screw speed: 76–100 rpm) and feed formulations (feed moisture: 15–21%; mango peel powder: 0–33.33%) on the extrudate properties, moisture loss, and the mixing torque during extrusion was studied. Feed formulations containing high moisture and mango peel powder produced less expand and hard extrudates. The torque decreased as the barrel temperature, screw speed and mango peel powder content increased. Low temperature extrusion increased the moisture loss of extrudates. Increasing the mango peel powder reduced the extrudate expansion, but the post-drying subjected to the extrudate produced improved texture.

Investigating the effect of fused deposition modeling processing parameters using Taguchi design of experiment method

Fused Deposition Modeling (FDM) is an Additive Manufacturing (AM) technique that fabricates parts layer upon layer. The recent development of AM technologies is driving FDM from rapid prototyping to rapid manufacturing. However, building end-user functional parts using FDM proved to be a challenging task, which is due to having many processing parameters that may influence the parts’ quality. It is challenging to use full factorial Design of Experiments (DOE) to investigate the influence when there are many processing parameters, especially when the processing parameters are not expected to behave linearly. In addition, to fully exploit the accurate processing parameters influence a large number of sample sets are required. In this paper, Taguchi’s DOE is used to investigate the main effects of four processing parameters in the FDM process, those are the infill percentage, infill pattern, layer thickness, and extrusion temperature. The processing parameters influence is expressed in terms of the mechanical properties and dimensional accuracy of FDM parts fabricated. The material under interest is PLA filament fabricated using a commercial FDM 3D printer. In the presented work, we used Taguchi’s L9 array that had 9 runs with 3 repeated specimens for each, hence a total of 27 specimens were fabricated using varying processing parameters. The dimensions of the fabricated specimens were compared with the 3D CAD model and then tested according to the ASTM D638 standard. The results showed that for generally better dimensional accuracy, a lower extrusion temperature, smaller layer thickness, lower infill percentage, and hexagonal infill pattern were required. In addition, current FDM fabrication process usually generates parts with larger dimensions as compared to the CAD model. On the other hand, to increase the strength of FDM parts, a higher extrusion temperature, an optimized layer thickness, a triangular infill pattern, and a higher infill percentage are required. Ductility can be improved by switching to rectilinear infill pattern and by increasing the layer thickness.

An Insight into Stabilization Mechanism of a Solid Dispersion of Indomethacin/Partially Hydrolyzed Polyvinyl Alcohol Prepared by Hot-Melt Extrusion.

We examined the effect of hot-melt extrusion condition on the physical stability of the solid dispersion prepared using partially hydrolyzed polyvinyl alcohol (PVOH). The hot-melt extrusion of indomethacin (IMC) and PVOH mixed at the weight ratio of 3 : 7, 5 : 5 and 7 : 3 was performed either at 170 or 190°C to prepare the IMC/PVOH hot-melt extrudate (HME). Differential scanning calorimetry represented that IMC was mixed with PVOH on a scale of several tens of nanometer in all the HMEs with different weight ratio. 13C solid-state NMR measurement revealed that an intermolecular interaction was formed between a carboxylic group of IMC and a hydroxy group of PVOH in the HMEs. The intermolecular interaction in the HMEs was stronger at the higher extrusion temperature. At the low IMC loading, the IMC molecules could be mixed with the amorphous PVOH at the molecular level, and the remained PVOH without interaction formed the crystal phase. On the other hand, at the high IMC loading, most PVOH could be amorphized by the interaction with IMC, and the excess IMC which did not interact with PVOH formed the IMC-rich domain. The IMC/PVOH HME at the weight ratio of 7 : 3 extruded at higher extrusion temperature showed higher physical stability of amorphous IMC compared with that extruded at lower extrusion temperature. The hot-melt extrusion process at higher temperature provided the rapid melting of PVOH crystal phase, resulted in the homogeneous mixing with IMC and the formation of stronger intermolecular interaction.

Smart Fertilization Based on Sulfur–Phosphate Composites: Synergy among Materials in a Structure with Multiple Fertilization Roles

Sulfur is currently a bottleneck for agronomic productivity. Many products are based on the application of elemental sulfur (S°), but the ability of the soil to oxidize them is variable and dependent on the presence of oxidizing microorganisms. In this work, a composite was designed based on a matrix of S° prepared by low-temperature extrusion, reinforced by rock phosphate particles acting as P fertilizer, and with encapsulation of Aspergillus niger as an oxidizing microorganism. This structure was shown to be effective in significantly increasing S° oxidation while providing P by rock phosphate dissolution in an acid environment. X-ray absorption near-edge structure (XANES) spectra provided information about P fixation in the soil after dissolution, showing that the composite structure with A. niger modified the nutrient dynamics in the soil. This fully integrated material (a smart fertilizer) is an innovative strategy for eco-friendly agronomic practices, providing high nutrient delivery with minimal so...