Hot-pressing Process Research Articles

A Comparative Study of Airbag Covers for Automotive Safety Using Coconut Shell Fiber/PP Composite Materials

In this study, we compared the physical properties of coconut fiber/polypropylene (PP) composite materials with coconut fiber as a reinforcing agent, produced through a hybrid injection molding process and a layered hot-pressing process. Through comparative experiments, the mechanical properties of both the hybrid injection-molded and layered hot-pressed materials were validated. The results indicated that, when using a coconut fiber content of 5%, the layered hot-pressed composite material exhibited optimal comprehensive performance. Specifically, its tensile strength reached 25.12 MPa, showing a 37.6% increase over that of pure PP materials of the same brand and batch. Its tensile modulus was 1.17 GPa, representing an 11.4% decrease. Additionally, its bending strength was 35.94 MPa, marking a 49.8% increase, and its bending modulus was 2.69 GPa, which is nearly double that of pure PP materials. Furthermore, through Creo modeling and an ANSYS simulation analysis, it was verified that this material could be applied to airbag covers in the field of automotive safety. This study confirmed that layered hot-pressed coconut fiber/PP composite materials exhibit superior mechanical properties to traditional materials and injection-molded composite materials, making them more suitable for airbag covers.

Waste ramie fiber/EVA composites with wideband sound-absorbing performance with mixing and foaming process

Increasing noise pollution and ramie fibers waste resource problems need to be solved urgently. In order to resolve the problems, the porous sound-absorbing composites with high sound-absorbing performance were prepared by using waste ramie fibers as reinforcement materials, vinyl acetate copolymer (EVA) as matrix materials, azodicarbonamide(AC) as foaming agent, ZnO as auxiliary foaming agent, and dicumyl peroxide (DCP) as cross-linking agent, which were mixed in a two-stick mixer according to a certain ratio and then hot-pressing process. The process conditions were optimized using single factor analysis. Under the optimal process conditions, the sound-absorbing composites had a maximum sound absorption coefficient (SAC) of 0.72, an average SAC of 0.37, and a noise reduction coefficient (NRC) of 0.41. The sound absorption performance grade reached level III, and the sound absorption performance was excellent in the frequency range of 600 ∼ 6300 Hz. The introduction of foaming agents made the composites with more pores, and the average SAC of foamed composites increased by 346 %(compared with the unfoamed composites). Then, the sound-absorbing mechanism was analyzed. This study presents a novel approach to the recycling and reusing of the waste ramie fibers. It also provides a theoretical and experimental basis for the development of sound-absorbing composites with wider sound absorption band, larger (sound absorption coefficient) SAC and wider application, which is of great significance for sound absorption in the building fields.

The influence of the hot-pressing process on the mechanical properties of continuous aramid fiber-reinforced PA12 composites

Abstract Hot-pressing post-treatment can effectively improve the mechanical properties of composite specimens. In order to improve the impact resistance of continuous aramid fiber-reinforced nylon 12 (CAF/PA12) composites, the effect of hot-pressing parameters on the interlaminar shear strength of the composite was studied. The effects of hot-pressing temperature, hot-pressing time, and hot-pressing pressure on the interlaminar shear strength of composite formed specimens were studied by single factor test. Based on the optimized parameters of hot-pressing, the influence of hot-pressing on low-speed impact performance was analyzed. The results shown that the interlaminar shear strength first increased and then decreased with the increase of hot-pressing temperature and pressure. With the extension of hot-pressing time, the interlaminar shear strength continued to increase. When the hot-pressing parameters were 170°C, 30 min, and 600 kPa, the shear strength and specimen quality were the best. Under this hot-pressing process, the low-speed impact performance was increased by 36.0%. In this paper, the research content of the hot-pressing process of composite materials was expanded, which provided a reference for the research of impact resistance of continuous aramid fiber-reinforced PA12 composite materials.

Effect of Pressure on Ce-Substituted Nd-Fe-B Hot-Deformed Magnets in the Hot-Pressing Process.

With the increasing demand for Nd-Fe-B magnets across various applications, the cost-effective substitution of Ce has garnered significant interest. Many studies have been conducted to achieve the high magnetic properties of Nd-Ce-Fe-B hot deformation magnets in which Nd is replaced with Ce. We propose a method to improve magnetic properties of the Ce-substituted Nd-Ce-Fe-B hot-deformed magnets by optimizing the hot-pressing process. This study investigates the microstructure and properties following hot deformation of Ce-substituted Nd-Ce-Fe-B magnets fabricated at a constant temperature and different pressures (100-300 MPa) during the hot-pressing process. The results highlight the influence of pressure from previous hot-pressing processes on grain alignment and microstructure during hot deformation. Magnets subjected to hot pressing at 200 MPa followed by hot deformation achieved superior magnetic properties, with Hci = 8.9 kOe, Br = 12.2 kG, and (BH)max = 31 MGOe with 40% of Nd replaced with Ce. Conversely, precursors prepared at 100 MPa exhibited low density due to high porosity, resulting in poor microstructure and magnetic properties after hot deformation. In magnets using precursors prepared at 300 MPa, coarsened grains and a condensed h-RE2O3 phase were observed. Incorporating Ce into the magnets led to insufficient formation of RE-rich phases due to the emergence of REFe2 secondary phases, disrupting grain alignment and hindering the homogeneous distribution of the RE-rich phase essential for texture formation. Precursors prepared under suitable pressure exhibited uniform distribution of the RE-rich phase, enhancing grain alignment along the c-axis and improving magnetic properties, particularly remanence. In conclusion, our findings present a strategy for achieving the ideal microstructure and magnetic properties of hot-deformed magnets with high Ce contents.

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.

Cr-Diamond/Cu Composites with High Thermal Conductivity Fabricated by Vacuum Hot Pressing.

Chromium-plated diamond/copper composite materials, with Cr layer thicknesses of 150 nm and 200 nm, were synthesized using a vacuum hot-press sintering process. Comparative analysis revealed that the thermal conductivity of the composite material with a Cr layer thickness of 150 nm increased by 266%, while that with a Cr layer thickness of 200 nm increased by 242%, relative to the diamond/copper composite materials without Cr plating. This indicates that the introduction of the Cr layer significantly enhanced the thermal conductivity of the composite material. The thermal properties of the composite material initially increased and subsequently decreased with rising sintering temperature. At a sintering temperature of 1050 °C and a diamond particle size of 210 μm, the thermal conductivity of the chromium-plated diamond/copper composite material reached a maximum value of 593.67 W∙m-1∙K-1. This high thermal conductivity is attributed to the formation of chromium carbide at the interface. Additionally, the surface of the diamond particles in contact with the carbide layer exhibited a continuous serrated morphology due to the interface reaction. This "pinning effect" at the interface strengthened the bonding between the diamond particles and the copper matrix, thereby enhancing the overall thermal conductivity of the composite material.

Solution temperature influence on CRSS of the secondary γ′ phase in nickel-based superalloy FGH4096

Nickel-based superalloy components are capable of being manufactured by direct hot isostatic pressing (HIP) process with near-net shape and nearly 100 % raw materials utilization. However, they cannot be applied directly, due to the poor mechanical properties of HIPed components. Fortunately, heat treatment can improve the properties via regulating the microstructure. Therefore, the effects of varied solution temperatures on the tensile properties of FGH4096 nickel-based superalloy disk at room and high temperatures were studied. The results revealed that the disk after sub-solution treatment (1130 °C) has higher tensile properties (room temperature yield strength: 1194 MPa, elongation: 15.5 %; high temperature yield strength: 1075 MPa, elongation: 10.5 %). The antiphase boundary (APB) shear stress, Orowan bypass stress, stacking faults (SF) shear stress, and micro-twins (MT) shear stress affected by the size and distribution of the secondary γ′ phase were calculated. The results show that the main strengthening mechanism at room temperature is APB shear, and the APB shear stress of solution treatment at 1190 °C is the highest. The high temperature strengthening mechanism is due to SF shear and MT strengthening effects. The difference in SF shear stress between various solution temperatures is minimal. 1190 °C has a higher MT strengthening effect than 1090 °C. This is consistent with the actual result that the tensile properties at 1190 °C are superior to those at 1090 °C. The conclusion is that the combination of high strength reflected by several critical resolved shear stresses and considerable plasticity reflected by the MT strengthening effect can lead to a comprehensive improvement in alloy tensile properties.

Research on ballistic properties of UHMWPE hybrid laminates impregnated with shear thickening fluid

In this paper, a technology of impregnating ultra-high molecular weight polyethylene (UHMWPE) with shear thickening fluid (STF) was proposed to prepare composite laminates, and the ballistic properties of laminates with hybrid configurations were studied. Firstly, two kinds of STFs were prepared using silica particles of 20 nm and 500 nm. Then, STF-impregnated UHMWPE composite laminates were prepared using the hot-press lamination process. Finally, a ballistic experimental study of different combinations of laminates was carried out using a two-stage light gas gun. The results of the study show that the energy absorption rate of the hybridized laminate with the 20 nm + 50 nm configuration scheme is enhanced by more than 9.3 % compared to the laminate impregnated with the single STF. The laminate’s back face deformation depth (BFD depth) after impregnation with shear thickening fluid is only 66.8 % of that of pure UHMWPE laminate. The research work can provide new ideas and references for designing and developing new protective equipment.

Enhancement of thermal–mechanical performances via a selective CNTs configuration in laminated CNTs/AZ31B composite

Magnesium alloy is an excellent lightweight material. While the alloying process improves mechanical properties, it often reduces material thermal conductivity. An effective way to balance these two properties is to add CNTs. In this paper, a novel laminated CNTs/AZ31B composite was fabricated by introducing CNTs with selective configuration. First, the specific configuration of CNTs was built onto AZ31B sheets with a reticle mask using the electrophoretic deposition process. Then, the CNTs/AZ31B composite was obtained by the hot-pressing process. The effect of deposition factors on composite forming quality was studied to seek a satisfactory interlayer binding. Finally, the mechanical and thermal properties of CNTs/AZ31B composites with different CNTs content and deposition orientations were tested. The results show that the mechanical and thermal properties of CNTs/AZ31B composites were noticeably anisotropic. By adding 0.5 wt% CNTs, the tensile strength and Young’s modulus of the CNTs/AZ31B composite were effectively enhanced by 30.3 % and 10.5 %, respectively. Meanwhile, the thermal conductivity of the composites increased to 84.2 W/ (m·K) when adding 0.25 wt% CNTs, with heat conduction and dissipation performance enhanced. The studies of tensile fracture and CNT-Mg interfaces of CNTs/AZ31B composite show that CNTs can act as a shortcut of heat flow and load transfer.

Molecular dynamics simulation study of Zr interposer promoting Cu-Cu low-temperature hybrid bonding

With the development of the microelectronics industry, microelectronics packaging technology continues to develop towards higher integration and smaller size. To overcome the problem that the micro-bump size of solder cannot meet the fine pitch bonding, Cu-Cu direct bonding has become one of the most promising methods in advanced packaging technology. However, since the temperature required for Cu-Cu direct bonding is approximately 400 °C, currently Cu-Cu direct bonding is mostly achieved through a hot-pressing process. Such high temperatures will lead to reduced alignment accuracy, damage to device performance, and increased equipment requirements. In order to overcome these problems, this study proposed to use active metal Zr as the interposer material to improve the Cu-Cu atomic diffusion ability and reduce the Cu-Cu direct bonding temperature. The research results indicated that the interposer structure of Zr with (111), (11-2), and (1-10) surfaces contribute to promote Cu-Cu diffusion and bonding at low temperatures. Among them, the Zr (11-2) structure had the strongest promoting effect. Due to the tight arrangement of atoms in the densely packed crystal plane, the diffusion ability of atoms is significantly weakened during the bonding process of the densely packed crystal plane. Therefore, the Zr (001) structure can only promote bonding process under specific crystalline surface of Cu, and the bonding ability was very weak. The application of this research result will have a beneficial effect on the reliability and manufacturability of three-dimensional integrated packaging.

Regulating integral alignment of magnetic MXene nanosheets in layered composites to achieve high-effective electromagnetic wave absorption

The integral structure design is equally crucial to the regulation of electromagnetic components in microwave absorbing materials. In this work, magnetic MXene/polyvinylidene fluoride composites with integral nacre-like structure were prepared by successive hot-pressing process to realize the layered arrangement of Ni anchored MXene (Ni@MXene). The order degree of Ni@MXene from random to orientation can be adjusted by gradually changing compression ratio. Interestingly, increasing the orientation degree of Ni@MXene effectively improves the dielectric constant, minimal reflection loss (RLmin) and effective absorption bandwidth (EAB) of the layered composites. This is attributed to the improved loss ability by increasing the contact areas between Ni@MXene and vertically incident electromagnetic waves, inducing multiple scattering/reflection effect, and the formation of localized conductive pathways. As a result, the layered composite with optimal layered structure delivers the best electromagnetic microwave absorption performance with a RLmin of −69.8 dB and an EAB of 4.77 GHz. Besides, increasing the orientation degree can also optimize the mechanical properties of the layered composites, with the maximum tensile strength and toughness of 32.6 MPa and 115.0 MJ m−3, respectively. Therefore, this work proves the adjustability of absorption performance by changing the distribution of absorbents, and integrates the structure and function for microwave absorption materials.

Investigation of oil palm fiber reinforced polylactic acid composite extruded filament quality

This study examines the quality of Polylactic Acid (PLA) filament reinforced with Oil Palm Fiber (OPF) for additive manufacturing applications. The research aims to create a composite filament that leverages the advantages of PLA, a biodegradable polymer, and OPF, a natural fiber from the oil palm tree, to enhance mechanical strength, dimensional stability, and printability. The methodology involves crushing the PLA filament and OPF to the desired size using a crusher machine, blending them in different ratios (e.g., 90:10 and 80:20 PLA to OPF), and using a hot-pressing process to bond the components. The resulting pelletized composites are then extruded into filaments using an extruder machine. The quality of the produced filament is assessed based on diameter consistency, surface smoothness, and printability, considering compatibility with 3D printers. The study reveals that composition ratios and processing parameters impact filament quality, leading to challenges such as diameter variations, rapid hardening, breakage, and extruder die clogs. Future recommendations were suggested to optimize compositions, refine processing, explore advanced extrusion, and investigate fiber distribution and bonding for improved filament properties. This research offers valuable insights for creating high-quality OPF-reinforced PLA filaments for additive manufacturing, advancing understanding of filament quality factors, and proposing ways to enhance composite filament performance across applications.

Structural and shielding effectiveness properties of (NiFe2O4/chopped strands) composites for 6.5–18 GHz applications

In this research, a mixed oxide technique was employed to create composite materials comprising NiFe2O4-chopped strands, aimed at evaluating their structural properties and microwave shielding effectiveness. The composites, produced through a hot-pressing process with varying proportions of NiFe2O4 and chopped strands, were integrated with epoxy to enhance their shielding capabilities. X-ray diffraction confirmed the formation of single-phase NiFe2O4, free from secondary phases. Scanning electron microscopy analysis corroborated the presence of cubic crystalline NiFe2O4, without microstructural impurities. The microwave shielding performance of the composites was assessed within the 6.5–18 GHz frequency range using a network analyzer (NA), revealing a minimum shielding effectiveness of − 36.34 dB at 16.56 GHz for a 1.3 mm thick sample. These findings demonstrate the successful fabrication of NiFe2O4-chopped strands composites with tunable microwave shielding properties, achieved by adjusting the NiFe2O4 content, allowing for tailored performance across various frequency bands.

천연섬유 열가소성 복합재료 제조 및 특성 연구

In this study, a natural fiber thermoplastic composite material was prepared by applying the natural fibers jute and kenaf as reinforcement materials and polypropylene (PP) and high-density polyethylene (HDPE), which are thermoplastic resins, as matrix materials. The natural fibers were surface-treated to activate the interface between them and the thermoplastic resins. Differential scanning calorimetry analysis of the thermoplastic resins was performed to apply the hot-pressing process, and changes in hot-pressing process conditions were observed. The tensile and bending strengths as well as moisture absorption rate of the composite materials to which jute and kenaf were applied were compared and analyzed to confirm the possibility of replacing the glass fiber composite with the natural fiber composite for use as a small-ship material. In addition, for application to ship decks, a sandwich-structured composite material was manufactured and analyzed by applying polyvinyl chloride foam to the natural fiber composite material.

Perovskite intermediate phase FAPbBr3·DMSO assisted in-situ growth of FAPbBr3 polycrystalline wafer for X-ray detection and imaging

Polycrystalline perovskite wafers featured in customizable in dimensions and thickness, represent a frontier in mass production of X-ray detectors. Nevertheless, inherent low crystallinity, elevated defect density, and grain boundaries in polycrystalline wafers typically impair the detection performance. Herein, a novel hot-pressing approach employing the perovskite intermediate phase FAPbBr3·DMSO was demonstrated to improve the quality and X-ray detection performance of polycrystalline perovskite wafers. The in-situ growth of FAPbBr3 wafers were promoted via dimethyl sulfoxide (DMSO) vapor released from the decomposition of FAPbBr3·DMSO phase during the hot-pressing process, resulting in compact morphology, large grain size, superior crystallinity and diminished defect density. The resulted wafers exhibit a high ion activation energy (Ea) of 0.45 eV and a substantial mobility-lifetime product (μτ) of 7.41 × 10−4 cm2 V−1. These advancements equip FAPbBr3 wafer-based detectors with remarkable sensitivity of 3694.6 μC Gyair−1 cm−2, low detection limit (LoD) of 43.8 nGyair s−1, and stable operational performance, comparable to that of single-crystal alternatives. Moreover, the detectors exhibit exceptional X-ray imaging capabilities with a spatial resolution of 4.41 lp mm−1. Thus, the thermally induced decomposition characteristic of perovskite intermediate phase presents a novel avenue for the amelioration of polycrystalline perovskite wafers, heralding a leap forward in X-ray detection performance.

Highly durable and efficient anion exchange membrane water electrolyzer using one-step fabrication of the integrated electrode by the hot-press process

Herein, we develop a commercial-scale anion exchange membrane (AEM) water electrolyzer with exceptional durability that employs a Co oxide anode and commercial Pt/C cathode. The anode of the AEM water electrolyzer was developed using a simplified one-step hot-pressing process utilizing a single-phase Co oxide to achieve a uniform electrode surface and simplify the fabrication process. The Co oxide electrode obtained at the optimal hot-pressing temperature of 250 °C, exhibited excellent durability and catalytic activity compared to electrodes synthesized at other temperatures. This can be attributed to its spinel structure and the presence of Co3+ as the primary active site for the oxygen evolution reaction. The AEM water electrolyzer demonstrated remarkable performance, with a high hydrogen production efficiency of 79.46% and ultra-low degradation rate of only 2 mV kh−1 during a long-term durability test of 1000 h at 50 °C. These results indicate the exceptional potential of the AEM water electrolyzer comprising a Co oxide anode as a promising technology for efficient and sustainable production of high-purity hydrogen.

Building a Layer-Structured Aluminum/Graphene Composite with Significant Improvement in Electrical Conductivity.

Aluminum (Al) and its alloys are widely used in various fields due to their excellent physical properties. Although many efforts have been made to fabricate an Al-based composite, they usually results in a significant decrease in electrical conductivity. Herein, a special layer-structured Al/graphene (Gr)/Al composite was successfully designed and fabricated through a facile method using the ultrasonic spraying of graphene powder with alumina removal and a subsequent vacuum hot-pressing process. The as-obtained Al/Gr/Al composite presents a significantly enhanced electrical conductivity of 66% IACS, which is much higher than that of other reported Al-based composites, while it still maintains similar mechanical properties. This work provides a new strategy for the development of highly conductive Al-based composites, which would be very useful and important for practical applications.

Synergistic reinforcement of Cu/Ti3SiC2/C laminated-like composites with the bimodal and highly oriented graphite flake and graphene nanoplatelets

This study describes the preparation of bimodal reinforced Cu/Ti3SiC2/C laminated-like composites using flake powder metallurgy and vacuum hot-press sintering process. The objective was to accurately modulate the formation of oriented reinforcement network in two-dimensional carbon materials. The powders used in the five designed composites were flake Cu powder (45–60 μm), Ti3SiC2 (1–5 μm), graphite flakes (GFs, 120 μm) and graphene nanoplatelets (GNPs, 15 μm). Among them, the proportions of Ti3SiC2 (10 wt %) and GFs (3 wt %) remained unchanged, GNPs accounted for 0 wt %, 0.5 wt %, 1.0 wt %, and 1.5 wt %, and Cu powder accounted for a decreasing proportion. Formation mechanisms of GFs and GNPs in oriented networks were quantitatively analyzed using the alignment model. Additionally, the related strengthening and failure mechanisms were investigated. According to the study, the bimodal laminated-like Cu/Ti3SiC2/C composites with 0.5 wt% GNPs added showed the best overall performance. Specifically, it exhibited a hardness of 125.7 HV, tensile strength of 276.3 MPa, thermal conductivity of 207.8 W m−1 K−1, and electrical conductivity of 23.6 MS/m. The network enhanced by the two-dimensional carbon material achieves efficient and orderly load transfer and dissipation mechanisms, optimizing stress distribution and enhancing fracture resistance, resulting in improved mechanical properties. In addition, the formation of the oriented reinforcement network optimizes the orientation arrangement of the reinforcing particles, which somewhat mitigates the scattering of thermoelectric carriers by structural defects in the composites, and the enlarged mean free-range improves the migration efficiency of electrons and phonons. Therefore, the erection of bimodal laminated-like structure achieves the goal of optimizing the properties of the composites.

Production of porous titanium structures by combining hot isostatic pressing and solid-state foaming

The Hot Isostatic Pressing (HIP) process is based on the combined action of high levels of pressure and temperature. In general, such a process is used for reducing or eliminating microporosities in the component, especially when it is produced by additive manufacturing (AM) or casting. In the present work HIP is used for compacting TI6Al4V-ELI powders by means of a pressurized Argon gas acting at high temperature on a sealed can under vacuum in which Argon is previously inflated; thus, a subsequent Solid-State Foaming (SSF) heat treatment allows to produce a Titanium foam without any melting by exploiting gas entrapment. Samples extracted from billets produced setting different HIP parameters (size of Titanium particles and pressures) have been investigated in this work by means of heat treatments in furnace for the SSF: the temperature was kept constant (1020 °C), but the duration was varied in the range 1 - 6 h; the samples were finally analysed by Light Microscopy. Finally, the Response Surface Method (RSM) was used to determine the conditions able to increase both the size and the percentage area of the pores in order to fully control both the involved processes (HIP and SSF). Experimental results revealed that the porosity determined by the SSF is strongly affected by HIP parameters and by the SSF duration: the highest dimension of Ti particles and the highest level of Argon pressure determined the largest values of porosity, in terms of both percentage and pore dimension. The investigated process for producing porous titanium structures can be properly and efficiently combined with manufacturing processes able to create highly customised parts, not only in terms of geometry but also in terms of porosity.

Effect of Hot-Pressing Process on Mechanical Properties of UHMWPE Fiber Non-Woven Fabrics.

In order to investigate the influence of a hot-pressing process on the mechanical properties of ultra-high molecular weight polyethylene (UHMWPE) fiber non-woven fabrics with stretch and in-plane shear, UHMWPE non-woven fabric samples were prepared by adjusting the temperature, time, and pressure of the hot-pressing process, and mechanical property tests were carried out so as to clarify the influence of the hot-pressing process on the mechanical properties of the samples. The results show that the hot-pressing process mainly affects the silk-glue bonding strength of the samples; in the test range, with the increase in hot-pressing temperature and time, the tensile strength and in-plane shear strength of the samples increase and then decrease, and the best mechanical properties are obtained at 130 °C and 7 min of hot pressing, respectively; at 130 °C, the in-plane shear strength is 39.94 MPa and the tensile strength is 595.43 MPa; at 7 min, the in-plane shear strength is 63.0 MPa and the tensile strength is 643.30 MPa; with the increase in the hot-pressing pressure, the in-plane shear strength of the samples increases and then decreases, and the highest is 52.60 MPa, achieved at 8 MPa; in the range of 5-8 MPa, the tensile strength of the specimens did not change significantly, and increased significantly at 9 MPa, reaching a maximum strength of 674.55 MPa.