Pressing Process Research Articles

Enhancing Wear Resistance of Al6061 Composites: Insights from Microstructural and Tribological Investigations with ECAP

This work presents a comprehensive investigation into the microstructural and tribological properties of Al6061 alloy composites reinforced with E-glass fibers and soda–lime particulates, both before and after Equal Channel Angular Pressing (ECAP) processing. The study explores the intricate relationships between reinforcement materials and the aluminum matrix, shedding light on their collective impact on material behavior. Elemental composition analysis via Energy Dispersive X-ray (EDX) reveals crucial elements shaping the properties of these composites, highlighting the dominance of aluminum in the matrix and the contributions of silicon, calcium, sodium, and oxygen from the reinforcement materials. Scanning Electron Microscopy (SEM) and Optical Microscopy (OM) demonstrate refined grain structures, improved reinforcement dispersion, and enhanced interfacial bonding post-ECAP, indicating potential for superior mechanical properties. Furthermore, wear test analysis on these composites, encompassing varying reinforcement percentages and load conditions, unveils consistent trends in wear behavior. Higher reinforcement percentages, particularly with E-glass fibers, lead to reduced specific wear rates, showcasing enhanced wear resistance. Post-ECAP results consistently exhibit lower wear rates, highlighting the positive impact of ECAP on wear resistance. Statistical analysis using Taguchi and Analysis of Variance (ANOVA) techniques underscores the critical role of reinforcement percentage in wear characteristics, with optimal configurations identified for both E-glass fiber and soda–lime particulate composites. These findings offer valuable insights for designing and optimizing materials, emphasizing the importance of reinforcement levels, load, and speed in enhancing wear resistance and optimizing material performance for specific applications.

Process parameters optimization of double‐vacuum‐bag technology for carbon fiber/resin composites

AbstractDouble‐vacuum‐bag (DVB) process, as an effective out‐of‐autoclave (OoA) technology, can manufacture composite materials with low void content and high mechanical properties. Therefore, this paper aimed to achieve low void content, the effects of pressure difference between inner and outer bags, dwelling temperature, and dwelling time on the void of composite laminates were studied based on orthogonal experimental method. The void content and morphology of laminates were statistically analyzed, by observing the microscopic images of the samples on cross‐section. The results show that the pressure difference between the inner and outer bags has a significant impact on the void content and morphology, while the dwelling temperature and dwelling time have little effect. In addition, with the variance analysis and extreme difference analysis, the optimal process parameters were determined as follows: pressure difference between inner and outer bags was 0 MPa, dwelling temperature was 110°C, and dwelling time was 15 min. The void content of composite laminates manufactured under these parameters is 0.07%, less than 1% requirement for aerospace components, and interlaminar shear strength (ILSS) is 110 MPa, which is 54.93% higher than the single‐vacuum‐bag (SVB) process. Generally, the void content and ILSS reached the level of hot press process with 0.6 MPa.Highlights Influence of different DVB process parameters on void were studied. Void content manufactured with the optimal DVB process parameters was less than 1%. ILSS of laminate with the optimal DVB process parameters was equal as hot press process.

Effect of aging on the translucency of lithium disilicate and zirconia reinforced lithium silicate ceramics: An in vitro study

BackgroundTranslucency of dental ceramics have great impact on the esthetic and success of dental restorations. The goal of the study is to investigate the effect of the aging process on the translucency of zirconia-reinforced lithium silicate ceramic material, and lithium disilicate ceramic material made using CAD/CAM and press processes. MethodsThirty disc-shaped specimens with 0.5 mm thickness and 10 mm diameter were fabricated of IPS e.max Press (n = 10), IPS e.max CAD (n = 10), and VITA Suprinity (n = 10) (Vita). All ceramic specimens were fabricated with shade that corresponded to A2 with high translucency (HT) and subjected to measurement of relative translucency parameter (RTP) with a spectrophotometer machine prior to and following thermocycling. The results were analyzed using the one-way ANOVA and Bonferroni methods. To identify any statistically significant change in translucency after thermocycling, paired t-tests were utilized. ResultsThe mean ΔRTP00 after aging was 3.23 ± 0.36, 0.60 ± 0.34, 3.05 ± 0.90 for IPS e.max CAD, IPS e.max Press, and Suprinity respectively. The mean RTP values in IPS e.max CAD and Suprinity decreased significantly after aging (p˂0.05). However, there was no statistically significant difference between the RTP00 values of the IPS e.max Press before and after aging (p > 0.05). ConclusionPrior to aging, there was no difference between the three materials in terms of the translucency parameter. However, the translucency of CAD/CAM lithium disilicate and zirconia reinforced lithium silicate was negatively influenced by aging.

The Electrochemical Performance of The Blended Cathode of LMFP and NMC811

Blended cathodes are one of new approach for enhancing both characteristics of different cathode active materials. In previous study, a blended cathode between olivine structural cathode active materials and layered lock salt cathode active materials are applied to lithium ion cell to realize high thermal stability derived from olivine and large capacity derived from layered rock salt type. The blended cathode between lithium iron phosphate (LFP: LiFePO4) and lithium nickel cobalt manganese oxide (NMC1-x-y, x, y: LiNi1-x-yMnxCoyO2) shows a high stability of crystal structure and large specific capacity. However, an operation voltage of LFP and NMC is 3.3 V and 3.8 V, respectively. The difference in their operation voltage leads to a poor performance of cathode. Recently, lithium manganese iron phosphate (LMFP: LiMn1-xFexPO4 /C) has been expected as a excellent cathode active material due to higher operation voltage and higher energy density than those of LFP. LMFP is prepared by a replacing of Fe by Mn in LFP. The Mn2+/Mn3+ redox can be used, leading to higher operating average voltage of 3.8V with high stability of ordinary olivine structure features (high stability, capacity:170 mA h g-1, long cycle performance). Therefore, the blended cathode between LMFP and NMC has been expected as a new cathode with high performances. The cathode performance depends on the blending ratio between LMFP and NMC. The effect of blending ratio on cathode performance have been reported in previous study. Various NMCs has been widely used as a cathode active material. Recently, a lithium ion battery using high nickel NMC811 cathode have been actively studied, due to its high specific capacity. However, NMC811 cathode has a low thermal stability due to weak chemical bond between Ni and O, elution of Ni and Mn in an electrolyte and a crack formation due to volume expansion and shrinkage during charge and discharge cycles. These problems have to be solved to realize lithium ion battery with NMC811 cathode. In previous study, Both LMFP and NMC cathodes have been made by solid-state process. The blended cathode using cathode active materials made by solid-state reactions shows a concern in a sense of a cathode layer density.In this study, physical properties and electrochemical performance of the blended cathode between LMFP made by hydrothermal-synthesis and NMC811 made by solid-state reaction were investigated by using laminated cells at room and high temperatures.Slurry of the blended cathode was prepared by mixing of PVdF, conductive additive, and two cathode active materials into NMP. The making slurry was coated on carbon coated Al foil and dried at 80 °C for 3hr under vacuum. The fabricated electrodes were evaluated by half-cells and full-cells. The sample name was added based on the blending ratio of LMFP.The morphology of LMFP particles in the blended cathodes was changed by a press process. The specific capacity of the blended cathode of LMFP 20 wt.% was 182 mA h g-1 which was a larger specific capacity than 180 mA h g-1 of NMC811 cathode. The blended cathode of LMFP 20 wt.% exhibited the lowest porosity among various blended cathodes, suggesting that LMFP may play a role in the formation of conductive pathway. In addition, the blended cathode of LMFP 20wt.% exhibited a good cycle performance 80% discharge capacity retention (based on 0.2C)) at room temperature, which was better than that of NMC811 (65% discharge capacity retention). After disassembling the full-cell, the cross-section of the cathode was observed with SEM. Many cracks were observed in the NMC811 particles in the NMC811 cathode. On the other hand, no cracks were observed in the NMC811 particles of the blended cathode, indicating that LMFP could suppress the crack formation in NMC811 particles. This is one of reasons for the high cycle ability of the blended cathode. A cycle performance at 60 °C showed that the discharge capacity of NMC811 cathode decreased during 300 cycles, whereas that of the blended cathode of LMFP 20wt.% also decreased with much better discharge retention. From the cross-sectional SEM images, may cracks in NMC811 were observed in both pure NMC cathode and LMFP 20wt.% blended cathode. However, a less crack formation of NMC811 was confirmed in the blended cathode of LMFP 20wt.%. Based on these results, the effect of the blended cathode can be explained. Firstly, the improvement in specific capacity is due to the conductive pathway of the LMFP. Secondly, the improvement in cycle performance is due to the suppression of crack formation in the NMC811. Figure 1

Chalcopyrite CuFeS2: Solid-State Synthesis and Thermoelectric Properties.

The optimal conditions for synthesizing a pure chalcopyrite CuFeS2 phase were thoroughly investigated through the combination of mechanical alloying (MA) and hot pressing (HP) processes. The MA process was performed at a rotational speed of 350 rpm for durations ranging from 6 to 24 h under an Ar atmosphere, ensuring proper mixing and alloying of the starting materials. Afterward, MA-synthesized chalcopyrite powder was subjected to HP at temperatures between 723 K and 823 K under a pressure of 70 MPa for 2 h in a vacuum. This approach aimed to achieve phase consolidation and densification. A thermal analysis via differential scanning calorimetry (DSC) revealed distinct endothermic peaks at the range of 740-749 K and 1169-1170 K, corresponding to the synthesis of the chalcopyrite phase and its melting point, respectively. An X-ray diffraction (XRD) analysis confirmed the successful synthesis of the tetragonal chalcopyrite phase across all samples. However, a minor secondary phase, identified as Cu1.1Fe1.1S2 (talnakhite), was observed in the sample hot-pressed at the highest temperature of 823 K. This secondary phase could result from slight compositional deviations or local phase transformations at elevated temperatures. The thermoelectric properties of the CuFeS2 samples were evaluated as a function of the HP temperatures. As the HP temperature increased, the electrical conductivity exhibited a corresponding rise, likely due to enhanced densification and reduced grain boundary resistance. However, this increase in electrical conductivity was accompanied by a decrease in both the Seebeck coefficient and thermal conductivity. The reduction in the Seebeck coefficient could be attributed to the higher carrier concentration resulting from improved electrical conductivity, while the decrease in thermal conductivity was likely due to reduced phonon scattering facilitated by the grain boundaries. Among the samples, the one that was hot-pressed at 773 K displayed the most favorable thermoelectric performance. It achieved the highest power factor of 0.81 mWm-1K-1 at 523 K, indicating a good balance between the Seebeck coefficient and electrical conductivity. Additionally, this sample achieved a maximum figure-of-merit (ZT) of 0.32 at 723 K, a notable value for chalcopyrite-based thermoelectric materials, indicating its potential for mid-range temperature applications.

Lipoxygenase activity in tropical fish: Changes during surimi processing and some biochemical characterization in lizardfish (Saurida tumbil).

The lipoxygenase (LOX) activity of major tropical fish used for surimi production, including threadfin bream (TB), lizardfish (LZ), and goatfish (GF), was measured in the gills, skin, and muscle. The highest LOX activity was observed in the LZ samples (p<0.05), with the gills exhibiting the greatest activity at 376.56U/mg (p<0.05). The highest peroxide value was detected in the TB samples, particularly in the gills (p<0.05). Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) were the main polyunsaturated fatty acids in all the tissues and surimi. The total lipid and DHA contents of washed mince reduced considerably after the screw press process. Although LOX activity decreased during surimi production, a residual activity of 21.33U/g was observed in the finished surimi. LOX was partially purified and characterized from LZ gills. The purification was conducted using two successive chromatographic steps, Sephacryl S-200 and diethylaminoethyl (DEAE)-sepharose, resulting in a 3.52% yield and a 22.43-fold increase in purity. The optimum activity was found at 25°C and pH 7.5, with pH stability between 6.0 and 8.5. The relatively high thermal stability at 4°C-10°C suggested that LOX might contribute to fish lipid oxidation during cold storage. The enzyme was thermally inactivated at 60°C. The preferred substrate was EPA. LOX from the LZ gills was inhibited by 1mM ethylenediaminetetraacetic acid and activated by 1mM Fe2+, Na+, and Ca2+. PRACTICAL APPLICATION: Elucidating lipoxygenase activity and lipid oxidation in various tropical fish tissues, as well as understanding the characteristics of LOX, can help take appropriate postharvest actions to afford high-quality surimi.

Enhanced density and microstructural integrity of binder jetting manufactured ceramics through cold isostatic pressing

Binder jetting (BJ) is a type of additive manufacturing (AM) process that enables fabrication of complex zirconia (ZrO2) ceramic components. However, there are significant challenges in fabricating ceramic parts with high relative density and superior performance. In this study, cold isostatic pressing (CIP) process was integrated into BJ, successfully producing high-performance ZrO2 ceramics. Comprehensive study was conducted on ZrO2 granules, binder, and their interactions. In addition, effects of CIP process on relative density and mechanical properties of sintered samples were investigated. Results indicate that CIP process significantly enhances green body density and reduces spacing between particles, thereby facilitating subsequent densification during ceramic sintering. Moreover, debinding followed by CIP treatment yields superior mechanical properties compared to the methods where CIP was performed prior to debinding, as it prevents defect formation during debinding. Subsequently, differences in performance between ZrO2 ceramics treated with and without CIP were compared at various sintering temperatures. After sintering at 1400 °C, relative density and flexural strength of ZrO2 ceramics reached 98.75 ± 0.19 % and 1047.80 ± 88.45 MPa, representing significant improvements of 53.24 % and 100-fold increase compared to those without CIP treatment, respectively. These findings indicate that proposed method is highly promising for fabrication of high-density and high-performance ZrO2 components.

Efficiency of Ceramic Composite Filter Produced Using Nano Particulate Carbonaceous Material

Millions of people have no access to safe water. This has led to continued incidence of waterborne diseases with severe cases of complications and sometimes death. Attempts to use silica sand-based materials for the production of filters by researchers are still evolving. In this study a novel hybrid clay-nanoparticulate agro-waste blend water filter with appropriate pore size and flow rate for contaminant-free water filtration was produced. The composite filters were produced using hydraulic pressing and sintering process. Four different ratios of clay, activated carbon and nanoparticle coconut shell (60:30:10, 60:20:20, 60:10:30, and 60:0:40 wt %) were mixed and fired at 700 °C, 750 °C, 800 °C, 850°C, 900 °C, 950 °C, and 1000 °C respectively at the rate of 75 °C/hr. E. Coli, Total Coliform, and turbidity tests were carried out on the influent water collected from Lagos Lagoon, and effluent water samples were filtered using the produced samples. The result of water tests revealed that all the filters produced removed between 86.81 % to 99% Escherichia Coliform (E. coli), and 81.81% to 93.31%% total coliform in the water sample. The blend of 60:10:30 fired at 850 °C and 900 °C showed improved properties with a flow rate value of 2.83 l/hr and 2.77 l/hr. In conclusion, the study established that synthesis of nanoparticle coconut shell and activated carbon is a suitable material for producing clay composite filters that can purify water to Nigerian Standards for Drinking Water Quality (NSDWQ) acceptable level.

Numerical Studies of Influencing Factors on the Homogeneity of the Powder Mixture during the Powder Spreading Process of Powder Bed Fusion–Laser Beam/Metal

Recent studies have focused on the alloying of nitrogen (N) in high‐alloy stainless steels by powder bed fusion–laser beam/metal (PBF‐LB/M). However, N‐induced pore formation remains a challenge. To overcome this, a combined PBF‐LB/M and hot isostatic pressing (HIP) process is developed. AISI 304L stainless steel powder was mixed with silicon nitride (Si3N4) powder and processed by PBF‐LB/M, allowing partial retention of Si3N4. This helps to maintain sufficient N content while reducing pore formation. The microstructure is then homogenised by HIP. A major challenge of this process is to maintain the homogeneity of the deposited powder mixture on the powder bed to ensure a consistent N content in the final products. This study combines experimental and numerical methods to address this issue: scanning electron microscopy is used to characterize the microstructure and map the local N content, while various numerical studies based on the discrete element method are carried out to investigate the effects of layer thickness, substrate surface roughness, and powder properties on the intermediate product. The numerical approach effectively predicts the N content distribution and homogeneity on the powder bed. The models are validated with experimental data and optimal process conditions for PBF‐LB/M are identified.

Tunning Pr to achieve ultra-high magnetic properties of anisotropic nanocrystalline (Sm,Pr)Co5 magnets

In this study, we reported on the bulk anisotropic nanocrystalline Sm1-xPrxCo5 (x = 0.2–0.6) magnets aimed at achieving excellent energy products. Through a combination of advanced processing techniques, including melt spinning, hot pressing, and hot deformation process, bulk magnets with a fine nanocrystalline structure were successfully synthesized. The results revealed that the substitution of Pr strengthened the c-axis texture and the saturation magnetization, facilitating the enhancement of remanence (Mr) and maximum magnetic energy product [(BH)max]. However, Pr substitution decreased the coercivity (Hci) due to the reduced magnetocrystalline anisotropy field. Excellent magnetic properties are obtained for Sm0.4Pr0.6Co5 magnets with the (BH)max of 23.2 MGOe and Hci of 11.8 kOe. The prepared (Sm,Pr)Co5 magnets with different Pr contents have essentially the same microstructure with RECo5 main phase grains of about 400 nm in diameter and fine dispersed rare earth-rich nanoprecipitates. Our findings can provide reliable reference for manufacturing nanocrystalline permanent magnet materials and promote the development of rare earth permanent magnet new materials.

PEMBUATAN PART BRACKET PIPE MAIN L/SIDE 844A7-I7000 MENGGUNAKAN MESIN STAMPING PRESS

This practical work report explains the process of making the Bracket Pipe Main P/Side 844A7-17000part using a stamping press machine and operating procedures for the stamping press machine at PT Persada Selaras Indonesia. The aim is to find out directly the process of making the Bracket Pipe Main P/Side 844A7-17000 part, and to know how to operate the stamping press machine. The process of making the Bracket Pipe Main P/Side 844A7-17000 consists of several stages starting from checking the material using SPHC-PO, checking the product design, the Stamping Press process with four stages of the production process (blanking, bending 1 and forming, bending 2 and restrike, &amp; Piercing). Apart from that, this report discusses how to operate a stamping press machine starting from the machine inspection stage to setting up the stamping press machine. Through this practical work report, it is hoped that readers will gain insight into the process of making the Bracket Pipe Main P/Side 844A7-17000 and the company's contribution to maintaining product quality.

PEMBUATAN BRACKET FINISH PANEL MOUNTING D74 MENGGUNAKAN MESIN PRESS STAMPING PUX 100

This practical work report describes the process of making part bracket finish panel mounting type d74 using PUX 100 stamping press machine and the operating procedures of stamping press machine at PT Persada Selaras Indoensia. The aim is to know directly during the process of making part bracket finish panel mounting type d74, and to know how to operate the stamping press machine. The manufacturing process of bracket finish panel mounting type d74 consists of several stages starting from material checking using SPC440, product design checking, Stamping Press process with four stages of production process (blanking, forming, bending, &amp; Pierching). In addition, this report discusses how to operate the stamping press starting from the machine inspection stage to the stamping press machine setting. Through this practical work report, it is hoped that readers can gain insight into the process of making bracket finish panel mounting type d74 parts and the company's contribution in maintaining product quality. Keywords : Stamping Press, SPC440, Production Process

Improved mechanical properties and thermal conductivity of laser powder bed fused tungsten by using hot isostatic pressing

In this study, the microstructure evolution, mechanical properties and thermal conductivity of laser powder bed fused tungsten subjected to the subsequent hot isostatic pressing (HIP) processes with natural cooling (NC) and ultra-rapid quenching (URQ) were investigated. The results showed that the relative density was significantly improved after HIPping regardless of the cooling rates. The HIP-URQ treatment led to a near defect-free component with increased recrystallization and reduced dislocation density. The enhanced comprehensive mechanical properties, including the ultimate compressive strength of 1180 MPa without sacrificing microhardness was achieved for the HIP-URQ sample. Furthermore, the highest thermal conductivity of 168.6 W/(m·K) related to the densification behaviour and microstructure evolution during the HIP treatments was reported.

Modern Approaches to Mathematical Modeling of the Process of Direct Pressing of Tablets

Modern Approaches to Mathematical Modeling of the Process of Direct Pressing of Tablets

Influence of Equal Channel Angular Pressing Processing on the Microstructure, Hardness and Corrosion Resistance of Al-Si Alloy

In this study, the impact of heat treatment and Equal Channel Angular Pressing (ECAP) processing routes on refining the microstructure, hardness, and corrosion resistance of Al-7.5% S alloy in a 3.5% NaCl solution was examined. The alloy underwent T5 and T6 heat treatments, followed by ECAP processing via routes A and Bc in a mold with a channel angle of 120° at room temperature. The results indicate that dendritic α-Al grains transformed to globular and fiber shapes after processing routes Bc and A, respectively. Both processing routes fragmented coarse and brittle Si particles into smaller sizes in the eutectic phase. The use of a combination of heat treatment and the Equal Channel Angular Pressing (ECAP) process significantly improved the hardness and corrosion resistance of the samples. The hardness of the heat-treated samples increased considerably from 68 to 116 and 129 HV after three and four passes, respectively. Reducing the area ratio between the noble silicon particles and the less noble eutectic aluminum phase greatly enhances the resistance of alloy to pitting corrosion.

Role of combinative In and Sm additions in tailoring the discharge performance of extruded AZ31 alloys as anodes for seawater batteries

The discharge behaviors of AZ31 alloys, modified by the addition of In and Sm elements in conjunction with equal channel angular pressing (ECAP) processing, were systematically explored. The incorporation of In suppressed the formation of cathodic second phases. In contrast, Sm promoted the precipitation process and therefore led to higher microstructure uniformity following ECAP processing. The solid-solution In contributed to the activated dissolution of Mg matrix and the inhibited hydrogen evolution during discharge, while Sm was beneficial for the uniform dissolution and the alleviation of chunk effect. The results indicated that the 12-pass ECAP processed AZ31-In-Sm anode revealed the most enhanced discharge performance with a discharge voltage of 0.889 V and a utilization of 66.94% at 100 mA cm−2. This improvement can be primarily attributed to the combined effects of the decreased precipitations of cathodic phases by In addition and the enhanced microstructure homogeneity by Sm addition, collaborated with significant microstructure refinement.

Lightweight and thermally insulating carbon-bonded carbon fiber/graphite composite with enhanced in-plane heat-leading functionality for efficient thermal protection materials

Non-ablative thermal protection materials are subjected to localized high-density heat flux, facing extreme temperatures and uneven temperature distribution. Heat dredging is expected to enhance thermal protection efficiency and alleviate its resistance to temperature pressure. In this study, the function of in-plane (IP) heat leading is innovatively incorporated to increase the thermal-protection efficiency of carbon-bonded carbon fiber (CBCF) composites. The modified composite is prepared by a one-step integrated filter press process in which continuous flexible graphite paper (FGP) is used as the heat-leading layer. The typical micromorphology, mechanical response, thermal-insulation and heat-leading performance are determined. The CBCF/FGP composites with a 0.1 mm thick heat-leading layer exhibits a density of 0.22 g/cm3. The compressive strength increased by 160 % in the IP direction while remaining consistent in the through-the-thickness direction relative to that of the pure CBCFs. The thermal conductivity in the insulation and heat-leading directions at room temperature are 0.061 W/mK and 21.14 W/mK, respectively, indicating significant anisotropy with an approximately 350-fold difference. The incorporation of FGP effectively enhances the IP heat-leading capabilities of CBCF composites, potentially improving their thermal-insulation efficiency when combined with different matrix materials.

Influence of stacking sequences of woven jute-carbon hybrid composites: Diffusion mechanism and mechanical characterization

In this study, different stacking orders of carbon-jute fiber mats were used to fabricate the composites and hybrids. The impact of different stacking orientations on mechanical properties was investigated experimentally. The experimental results were verified by finite element analysis (FEA). In addition, the impact of the fiber orientation on the loading direction was also investigated. Four layers of fabrics were piled to fabricate the composites by hand-layup with the cold press process. A NaCl solution was used to create a corrosive medium (pH 8), and the composites and hybrids were immersed in that medium, and their mechanical properties were compared. In this research, it has been found that the laminates with the stacking sequence of type-C (C/J/J/C) show the best result among other composites. Jute composites where all the fibers are in the loading direction possess a high strain compared with the other composites and hybrids. On the scanning electron microscope (SEM) image, delamination, buckling of fiber, fiber pullout, and voids were observed. In addition, the kinetics of the diffusion mechanism were also investigated, and it was found from the experimental results that the composites and hybrids immersed in pH 8 absorbed water via Fickian diffusion.

A profound study of damage behavior for Al 2024-T3 alloy worksheet produced by constrained groove pressing in the superior practical condition

Constrained groove pressing (CGP) process is one of the most efficient and novel methods of severe plastic deformation to manufacture ultra-fine sheet metal. The present research work is related to the study of CGP process of 2024-T3 Aluminum alloy sheet. The empirical and numerical simulation of CGPed- specimens have been examined at both room and elevated temperatures. In order to simulate the constrained groove pressing process in Abaqus software, the Johnson–Cook material model has been employed. The geometrical variables of the CGP process include the teeth number, teeth angle, and sheet thickness, and the criterion for the superiority of the numerical test is the maximum reduction of two equivalent strain and equivalent force factors, simultaneously. To determine the weight’s coefficients of the target factors and select the superior test, the Shannon’s Entropy and Simple Additive Weighting (SAW) methods have been used, respectively. After validating the numerical findings, the variation of damage parameter, stress triaxiality and the equivalent plastic strain distribution in the superior practical condition have been evaluated in detail. Based on the Entropy-SAW hybrid technique, the weight’s coefficients of equivalent strain and equivalent force target factors were computed to, in turn, 0.38 and 0.62. Also, the results revealed that the CGP process could not be performed at room temperature based on high damage evolution. But, at elevated temperature, the damage parameter (D) doesn't exceed 0.26. Also, the maximum stress triaxiality and equivalent plastic strain (PEEQ) at this process temperature reached to 0.5 and 0.1, respectively.

Bi-Directional Prediction Model for Hot Pressing Production Parameters and Quality of High-Performance Bamboo-Based Fiber Composites Based on cHGWOSCA-SVR

In the hot press process of high-performance bamboo-based fiber composites, there is a highly nonlinear relationship between the production parameters of hot press and the quality parameters of the finished boards. Consequently, it is challenging to accurately predict the quality of the boards based on the given production parameters, and it is equally difficult to preset the production parameters to achieve the desired board quality. The current approach relies on manual experience, which may result in subpar board quality and material waste. To address these issues, this paper proposes a bi-directional prediction model based on cHGWO-SCA-SVR, using the collaboration-based hybrid GWO-SCA optimizer to optimize the relevant parameters of the SVR, and then accurately predicting the production parameters and the quality of the finished boards in both directions. Finally the cHGWO-SCA-SVR prediction model achieves an average of 0.9591 for the forward prediction model and lower MAE and MSE values compared to other models; for the reverse prediction model, it attains an average of 0.9553 and lower MAE and MSE values compared to other models. The results demonstrate the superiority of the cHGWO-SCA-SVR prediction model in comparison with other existing models, proving its significance in guiding the production of high-performance bamboo-based fiber composites by hot compression.