Hold Time Research Articles

Parameters influence on mechanical properties of resistance spot welding: AISI304L/AISI1005

AbstractWelding dissimilar metals by resistance spot welding offers several advantages, including lighter weight and better mechanical properties for the shipping, aerospace, and automotive industries. The resistance spot welding parameters effects (welding current, squeeze time, welding time, and hold time) on the welding results of AISI 1005 and AISI 304L were investigated in the present research. The joints' tensile shear force, microhardness, and microstructure were examined. The Taguchi design of experiments approach was utilized to analyze the tensile shear force results statistically. A welding current of 7 kA, welding time of 1.4 s, squeeze time of 1.2 s, and hold time of 0.8 s resulted in an optimum tensile shear force of 6.194 kN. Additionally, the nugget zone demonstrated a higher hardness compared to the base metal and heat-affected zones.

Evaluating ATP testing for distribution system monitoring: comparison to HPC, impact of chlorine quenching, and hold time dependency.

Adenosine triphosphate (ATP) assays have a faster turnaround time and higher sensitivity than traditional cultivation methods for microbial monitoring. Challenges implementing ATP testing include incompatibility with chlorine quenching agents and hold time sensitivity, which are not well-studied. Chlorinated distribution system samples were collected from two Canadian utilities, Metro Vancouver (n = 40 samples) and Halifax Water (n = 283). No significant correlations were observed between heterotrophic cell count (HPC) and cellular ATP, suggesting these do not correlate well in waters with low biological activity (median HPC < 2CFU/mL). However, interpretation of HPC and cATP results (based on the HPC guideline of 100CFU/mL and cATP of 10pg/mL) yielded the same conclusion for 95% of samples, suggesting a potential decision-making framework to replace HPC with cATP. Moreover, cATP correlates better with free chlorine (p < 0.04) compared with HPC for one of the studied systems. Importantly, adding chlorine quench (10% sodium thiosulfate) did not produce significantly different cATP results, nor did analyzing at various hold times of 4-, 6-, and 24-h. This study supports the integration of ATP testing into existing sampling procedures for water utilities, as a sensitive, fast, and reliable monitoring method.

Discriminant Power of Smartphone-Derived Keystroke Dynamics for Mild Cognitive Impairment Compared to a Neuropsychological Screening Test: Cross-Sectional Study.

Conventional neuropsychological screening tools for mild cognitive impairment (MCI) face challenges in terms of accuracy and practicality. Digital health solutions, such as unobtrusively capturing smartphone interaction data, offer a promising alternative. However, the potential of digital biomarkers as a surrogate for MCI screening remains unclear, with few comparisons between smartphone interactions and existing screening tools. This study aimed to investigate the effectiveness of smartphone-derived keystroke dynamics, captured via the Neurokeys keyboard app, in distinguishing patients with MCI from healthy controls (HCs). This study also compared the discriminant performance of these digital biomarkers against the Korean version of the Montreal Cognitive Assessment (MoCA-K), which is widely used for MCI detection in clinical settings. A total of 64 HCs and 47 patients with MCI were recruited. Over a 1-month period, participants generated 3530 typing sessions, with 2740 (77.6%) analyzed for this study. Keystroke metrics, including hold time and flight time, were extracted. Receiver operating characteristics analysis was used to assess the sensitivity and specificity of keystroke dynamics in discriminating between HCs and patients with MCI. This study also explored the correlation between keystroke dynamics and MoCA-K scores. Patients with MCI had significantly higher keystroke latency than HCs (P<.001). In particular, latency between key presses resulted in the highest sensitivity (97.9%) and specificity (96.9%). In addition, keystroke dynamics were significantly correlated with the MoCA-K (hold time: r=-.468; P<.001; flight time: r=-.497; P<.001), further supporting the validity of these digital biomarkers. These findings highlight the potential of smartphone-derived keystroke dynamics as an effective and ecologically valid tool for screening MCI. With higher sensitivity and specificity than the MoCA-K, particularly in measuring flight time, keystroke dynamics can serve as a noninvasive, scalable, and continuous method for early cognitive impairment detection. This novel approach could revolutionize MCI screening, offering a practical alternative to traditional tools in everyday settings. Thai Clinical Trials Registry TCTR20220415002; https://www.thaiclinicaltrials.org/show/TCTR20220415002.

Microstructure and mechanical properties of 3D‐printed zirconia bone scaffold: Experimental and computational analysis

AbstractMicroextrusion‐based additive manufacturing of zirconia‐based bioceramics is capable of fabricating design‐specific architectures with high mechanical strength properties and relative density. We developed a novel organic residue‐free binder system for zirconia paste printing (ZP2) with the shear‐thinning properties apropos to microextrusion‐based 3D printing. Based on thermogravimetric analysis, debinding protocol was established followed by high‐temperature heat treatment under four sintering conditions. Quantitative linear shrinkage (32.3%–42.7% ranging from in‐plane to vertical direction), density (83.3%–87.5%), and surface roughness (7.7–13.8 µm from the parallel to the perpendicular to the infill direction) as a factor of sintering conditions (1400°C–1500°C for 3–4 h) were analyzed. Whereas qualitative phase assemblage demonstrated “sintering condition independent” phase stability; grain growth and reduction in porosity were observed in the microstructure with increment in sintering temperature and hold time. Interestingly, at higher temperature and hold time, the compressive (46–72.4 MPa) and tensile strength (16.2–23.1 MPa) properties experienced a trade‐off between grain growth and reduction in porosity. The ZP2 scaffolds sintered at lower temperature and hold time qualified for the bone scaffold applications having interconnected porosities, biologically relevant surface roughness, and human bone mimicking mechanical properties. With a unique finite element analysis recipe, the mechanical behavior of the “life‐like” reconstructed computer aided design (CAD) geometries identical to real 3D‐printed‐sintered ZP2 scaffolds was quantitatively predicted.

Nonequilibrium dynamics and atom-pair coherence in strongly interacting Bose-Fermi mixtures

Theoretical treatments of nonequilibrium dynamics in strongly interacting Bose-Fermi mixtures are complicated by the inherent non-Gaussian nature of the vacuum two-body physics, invalidating the typical Hartree-Fock-Bogoliubov approximation. Here we apply the cumulant expansion to study nonequilibrium Bose-Fermi mixtures, which allows us to explicitly include the missing non-Gaussian quantum correlations, leading to a consistent dynamical theory of a Bose-Fermi mixture near an interspecies Feshbach resonance. We first apply our theory to a study of atom-pair coherence in the gas, which is significantly enhanced by the competing influences of the Fermi sea and Bose-Einstein condensation, in agreement with analytical calculations. Then we study the depletion of a degenerate Bose-Fermi mixture following a quench to the unitary regime, characterizing the resulting depletion of the Bose-Einstein condensate, the deformation of the Fermi surface, and the production of molecules. We find that at early times, the population dynamics scale quadratically with the hold time, and define an associated characteristic timescale set by the parameters of the mixture and the width of the Feshbach resonance. Published by the American Physical Society 2024

Mechanisms of deformation, damage and life behavior of inconel 617 alloy during creep-fatigue interaction at 700 °C

The continuous fatigue tests and creep-fatigue tests with the imposition of strain hold at the peak strain were conducted at 700 °C on Inconel 617 alloy. The strain amplitude of 0.25 %, 0.30 %, 0.35 %, 0.40 %, and hold time of 60 s, 600 s and 1800 s were used. The cyclic deformation behavior and dynamic strain aging (DSA) were discussed. The strain localization, dislocation substructure and precipitation behavior were carefully characterized, which provided physical information to understand the cyclic deformation behavior. The dominant damage mechanism and damage interaction, responsible for the cracking behavior were identified based on the fracture surface observation and secondary cracks morphology. The cyclic life saturation effect was comprehensively elucidated from the perspective of macroscopic mechanical response and microscopic deformation mechanism.

Effect of High-Temperature Operation on Voltage Cycling Induced PEMFC Degradation: From Automotive Customer Drive Cycles to an Accelerated Stress Test

Degradation of the Pt catalyst during load cycling constitutes a major durability issue for proton exchange membrane fuel cells (PEMFCs) in automotive applications. In this study commercial 5 cm2 electrodes were exposed to 20 k voltage cycles between 0.6–0.9 VRHE at temperatures ranging from 75 to 120 °C. The electrochemical surface area (ECSA), the roughness factor (rf), and the oxygen transport resistance were investigated over the course of the test. The degradation was mainly governed by Pt agglomeration and was accelerated with increasing temperature. Interestingly, operation at high temperature (120 °C and 30% RH) caused the same ECSA loss as at standard conditions (90 °C and 90% RH), suggesting that when maintaining dry conditions high-temperature operation is not critical for the durability of the catalyst material. The experimental results were used to validate an existing 0D catalyst degradation model, which was then applied to an automotive customer drive cycle. The calculated degradation over the whole automotive lifetime (excluding startup shutdown and idle events) equals 20 k voltage cycles (0.6–0.9 V, 10 s hold time) at 90 °C and 30% RH, which provides a guideline for the assessment of the suitability of novel catalyst materials for automotive applications.

CREEP-FATIGUE BEHAVIOR ANALYSIS OF THE 310 NBN STEEL: EXPERIMENTAL AND LIFE PREDICTION

With the increasing challenge of extending the service life of structural steels components subjected to high-temperature environments, there is an urgent need to investigate the mechanisms of creep-fatigue and to develop new steels that can effectively withstand these complex loading regimes. This study examines the creep-fatigue behavior of a novel 310 NbN austenitic stainless steel, enhanced with nitrogen and niobium, under high-temperature conditions. Specimens were subjected to tests at 675°C with varying hold-times of 0, 5, 60, and 600 s. Results indicated that longer hold times significantly increased crack growth rates and reduced cycles to fracture, highlighting a time-dependent crack propagation. Fracture surface analysis revealed a shift from transgranular to intergranular fracture with longer hold-times, indicating predominant creep damage. Predictive models, including the strip-yield model, aligned well with experimental data, emphasizing the critical role of hold-time in designing high-temperature steel components for improved durability.

The Combined Use of High Pressure Processing and Lactic Acid Containing Fermentate on Inactivation of Salmonella, Shiga Toxin-producing E. coli, and Listeria monocytogenes in Raw Pet Foods

Raw meat pet foods can pose health risks to pets and humans. High-pressure processing (HPP) was used in a previous study to demonstrate its effectiveness in achieving a 5-log reduction of Salmonella, E. coli STEC, and L. monocytogenes in commercially available raw pet foods and maintaining the 5-log reduction throughout shelf-life with frozen storage being more effective than refrigerated. L. monocytogenes, being more HPP resistant, could potentially regrow when stored at refrigeration temperatures and required further optimization. Chicken-based raw diet pet food was inoculated with 7–8 log CFU/g cocktails of Salmonella spp., E. coli STEC, or L. monocytogenes and stored at 4 °C for 24 h before the addition of either 0.7% or 1.0% w/v lactic acid fermentate (LAF) and HPP treated at 586 MPa for 2, 3, and 4 min after 24 or 72 h storage at 4 °C. HPP-treated products were stored frozen (−10 to −16 °C) up to 21 days with microbiological analyses on days 1, 3, 5, 7, 14, and 21. All HPP-and LAF-treated samples demonstrated a 5-log reduction of Salmonella spp., E. coli STEC, and L. monocytogenes. Samples without LAF and HPP treated after 24 h storage at 4 °C resulted in an average 4.02 log cfu/g reduction of L. monocytogenes with 2 min HPP hold time while longer HPP hold times at 4 min improved L. monocytogenes reduction by 0.35 log cfu/g. E. coli was found to be more HPP resistant in this study than L. monocytogenes and the addition of LAF had a significant impact on the overall pathogen survival during post-HPP storage. Based on qualitative enrichment data for each pathogen, the use of LAF resulted in more complete inactivation compared to samples without LAF. The use of 1% LAF in combination with 586 MPa for 4 min was found to be most effective for the inactivation of Salmonella spp., E. coli STEC, and L. monocytogenes. The findings are significant as it provides both formulation and processing controls to ensure the safety of raw diet pet foods.

Flash sintering of UO2 pellets for nuclear fuel and wasteform applications

Flash sintering (FS) has been shown to enhance the sintering kinetics in UO2. Using a bespoke AC-FS furnace, high density UO2 pellets, >95% theoretical density (TD) have been produced followed by scale up and Gd2O3 doping trials. Increasing furnace temperature during FS increases pellet density to a plateau, however, increasing hold time and maximum current both increased the density of UO2 samples to >95% TD and grain size to ~4µm, close to conventional sintering (CS). The optimised FS program reduced sintering temperature and cycle time by ~50% compared to CS. Scale up trials showed >96%TD pellets could be achieved for 11.3 and 14.125mm diameter green bodies, demonstrating typical fuel pellet diameters are feasible with FS. Gd doping experiments showed with 1wt.% Gd2O3 addition, a ~92%TD pellet with ~2µm grain size was obtainable, highlighting further optimisation is required for mixed oxide (MOx) materials.

ƩS COVID-19 is a rapid high throughput and sensitive one-step quadruplex real-time RT-PCR assay

Real-time reverse transcription polymerase chain reaction (RT-PCR), a standard method recommended for the diagnosis of coronavirus disease 2019 (COVID-19) requires 2–4 h to get the result. Although antigen test kit (ATK) is used for COVID-19 screening within 15–30 min, the drawback is its limited sensitivity. Hence, a rapid one-step quadruplex real-time RT-PCR assay: termed ƩS COVID-19 targeting ORF1ab, ORF3a, and N genes of SARS-CoV-2; and Avocado sunblotch viroid (ASBVd) as an internal control was developed. Based on strategies including designing high melting temperature primers with short amplicons, applying a fast ramp rate, minimizing hold time, and reducing the range between denaturation and annealing/extension temperatures; the assay could be accomplished within 25 min. The limit of detection of ORF1ab, ORF3a, and N genes were 1.835, 1.310, and 1 copy/reaction, respectively. Validation was performed in 205 combined nasopharyngeal and oropharyngeal swabs. The sensitivity, specificity, positive predictive value, and negative predictive value were 92.8%, 100%, 100%, and 97.1%, respectively with 96.7% accuracy. Cohen’s Kappa was 0.93. The newly developed rapid real-time RT-PCR assay was highly sensitive, specific, and fast, making it suitable for use as an alternative method to support laboratory diagnosis of COVID-19 in outpatient and emergency departments.

Transient characteristics of carrier transport in an isotopically enriched 28Si/SiGe undoped heterostructure

An isotopically enriched 28Si/SiGe undoped heterostructure is a promising platform for Si-based qubits due to the long coherence time by reducing 29Si isotopes with non-zero nuclear spins. Carriers in the buried Si quantum well (QW) of the Si/SiGe heterostructures could tunnel to the oxide/Si interface, increasing charge noise and leading to charge instability. In this work, we investigate the tunneling effects on carrier distribution and transport properties in an isotopically enriched 28Si/SiGe undoped heterostructure and its transient characteristics by controlling the hold time of gate biasing under different drain biases. By holding the gate bias for a longer time, the drain is reduced since more carriers in the buried QW tunnel to the oxide interface. Furthermore, under a larger drain bias, more carriers can move across the Si/SiGe heterojunction to the oxide interface and are trapped, resulting in a stronger current reduction, which is explained by a lucky electron model.

Rapid 24 GHz microwave sintering of alumina – yttria-stabilized zirconia ceramic composites

Samples of alumina – 3 % yttria-stabilized zirconia (YSZ) composites were sintered in rapid processing regimes using 24 GHz microwave heating at rates of up to 200 °C/min and zero hold time. The final relative density was 96–99 % for the samples containing 1.5 and 7.5 wt % YSZ and 98–99 % for the samples containing 13 wt % YSZ. The microwave sintering kinetics were compared for the processes carried out by direct and susceptor-assisted microwave heating. Under direct microwave heating, the effect of an intense microwave electromagnetic field with an estimated absorbed power density of up to 130 W/cm3 resulted in a shift of the shrinkage curves by about 100 °C towards lower temperatures compared to the case of susceptor-assisted heating. The grain size of the samples sintered by direct microwave heating decreased with an increasing heating rate. The mechanical properties were slightly higher for the materials sintered under susceptor-assisted microwave heating. The samples containing 13 wt % YSZ exhibited a microhardness of about 20 GPa and a fracture toughness of about 7 MPa m1/2.

Enhancing Ni–Ti shape memory alloy diffusion bonding with Ti/Ni reactive multilayer foils

This study investigates the utilization of Ti/Ni reactive multilayer foils as an energy source for facilitating the joining of Ni–Ti shape memory alloys through diffusion bonding. Multilayered samples were prepared using a 10-cycle accumulative roll bonding (ARB) process to be used for the bonding process. Diffusion bonding employing reactive multilayers was conducted over a temperature range of 600 °C to 900 °C, at 5 MPa pressure, with a 1-h hold time. Additionally, a comparison was made with a diffusion-bonded Nitinol sample at 900 °C without a reactive multilayer. Materials characterization and testing involved scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), shear strength testing, and differential scanning calorimetry (DSC), which were conducted on the bonded samples. The findings underscored the advantages of using reactive multilayers for diffusion bonding. These benefits included the formation of TiNi and the induction of a shape memory effect in the joint region, alongside a 1.5 times shear strength compared to identical diffusion bonding conditions without reactive multilayers. Moreover, employing reactive multilayers in the diffusion bonding of Nitinol holds promise for significantly reducing the energy needed to achieve robust and seamless bonded boundaries in the joining area.

(Invited) Dynamic Operation of Solid Oxide Electrolyzers

Electrolysis of steam to generate hydrogen is expected to be a highly dynamic operation if renewable resources such as wind and solar are used as the electrical power input. Rapid fluctuation of input power and intermittent operation of the solid oxide electrolysis stack will result in transient operating conditions at the cell level. All operating variables such as temperature, steam content, voltage, flow rate, etc. may change rapidly in these conditions.To address this situation, this work operates Ni/YSZ-supported and metal-supported cells under highly dynamic conditions, with individual variables isolated. The cells are remarkably robust to dynamic operation. A safe range is found for each operating variable, with accelerated degradation observed outside that range in certain cases. For example, cycling Ni/YSZ-supported cells between 1.3 V and 1.6V at 750°C and 50:50 H2O:H2 is tolerated well, but increasing the upper voltage to 1.7 V and higher leads to increased degradation. Additionally, Steam:hydrogen ratio is cycled between 3:97 and 75:25. Temperature is cycled between 150 and 800°C. Operation is cycled between fuel cell and electrolysis modes, with synchronized steam content. Metal-supported cells tolerate steam cycling, voltage cycling, temperature cycling and redox cycling, and results for button cells and 50 cm2 planar cells will be reported. In many cases, hold times are 1 minute, allowing thousands of cycles to be accumulated over hundreds of hours of operation.Figure 1. Dynamic cycling of a Ni/YSZ-supported button cell at 750C. (Top) Cycling between 1.3 and 1.7V with 1 min holds and 50/50 H2/H2O. (Bottom) Cycling between various steam contents at 1.3 V. Figure 1

A comparison of phage susceptibility testing with two liquid high-throughput methods.

Phage therapy is a promising antibacterial strategy, especially given that drug-resistant bacterial infections are escalating worldwide. Because phages are not active against all strains of a given species, phages being considered for therapeutic use would ideally be tested against bacterial isolates from individual patients prior to administration. Standardized, clinically validated phage susceptibility testing (PST) methods are needed for assessing in vitro phage activity. This study compared two high-throughput liquid-based PST assays. The first, using the Biolog Omnilog™, assessed changes in microbial respiration leading to color changes based on a tetrazolium dye. The second, Agilent BioTek Cytation 7, assessed changes in optical density. Both used 96-well microtiter plate formats. A total of 55 diverse phages with activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, or Enterococcus faecalis were studied against their respective susceptible bacterial hosts and non-susceptible controls, with susceptibility defined based on plaque assay. PST was performed by both assays in replicates, with results compared in terms of hold times (time through which bacterial growth is inhibited by phage compared to controls). Coefficients of variance and interclass correlation coefficients were used to assess inter- and intra-assay reproducibility. Based on a ≤50% coefficient of variance cutpoint, 87% of Biolog and 84% of Agilent assays were considered valid for susceptible bacteria, with 100% considered valid for non-susceptible bacteria by both systems. Using a 8 h hold time cutpoint, 100% of the results matched between the two assays. The interclass correlation coefficient showed 26% excellent agreement, 35% good agreement, and 17% moderate agreement between the two assays for susceptible isolates and 100% excellent agreement for non-susceptible isolates. Overall, the assays compared provided good/fair statistical reproducibility for the assessment of phage susceptibility.

Numerical investigation of flash formation and asymmetrical cooling in resistance projection welding

In resistance projection welding, the softened material is squeezed out from the joint area. The two workpieces being joined together often have different geometries, leading to asymmetrical cooling. The flash formation and asymmetrical cooling are not well quantified in the literature. This study developed a coupled electrical-thermal-mechanical model with adaptive remeshing and glued contact activation techniques for projection welding of steel fitting to a steel shell. The model was used to calculate the evolution of temperature distribution in the fitting and shell for welds made under two different hold times. The cooling rates were then inputted into a literature model to predict the joint hardness values, which correlated well with the experimental data. Additionally, the main factors for the accurate prediction of flash shape and size were the use of temperature-activated glued contact and high-temperature flow stress. Specifically, a combination of no glued contact and low flow stress can lead to an overprediction of the flash geometry.

Normative values of neck extensor endurance test in young adults

BackgroundNeck extensor muscles frequently exhibit poor performance in individuals with neck pain. The Deep Neck Extensor Endurance Test (NEET) is commonly used to assess the isometric holding time of the neck extensor muscles. Establishing normative values for this test may assist clinicians in the development of rehabilitation programs. ObjectivesTo identify the average holding time of the NEET in healthy young adults without neck pain. DesignNormative research. Methods440 young adults (172 males and 268 females; age: 18–28 yrs) satisfied eligibility criteria were recruited for participation in this study. The average of hold-time scores for 2 attempts was recorded and used for data analysis. ResultsThe data were not normally distributed; therefore, descriptive data were expressed in terms of median and interquartile range. Demographic data including age, gender, height, weight, Body Mass Index, International Physical Activity Questionnaire expressed as the mean with 95% confidence interval (CI) and range. The average holding time of healthy young adults for NEET was 43.1 (95% CI 38.8 to 46.6), men produced an average hold time of 47.1 (95% CI 46.1 to 51.9) and women produced 40.7 (95% CI 39.9 to 44.0). ConclusionThe holding time of NEET for healthy young adults was 43 seconds. Forty-seven seconds was average hold time for males and for females, it was 40 seconds.

Vertebral Column Height Andpredisposition To Low Back Pain- Observational Study

Background and purpose: Research was done to find out the relationship between lumbar lordosis and radiologic variables, lumbar lordosis and clinical variables, which showed that lordosis itself, do not have any predisposition to low back pain. Weak abdominal muscles are also associated with low back pain. As no previous study was done to correlate vertebral column height and low back pain, this study is intended to analyze whether these variables are predisposed to low back pain. Case description (Subjects): 200 subjects were approached through systematic convenient sampling which included 100 people (50 males and 50 females) with back pain and 100 people (50 male and 50 female without back pain). Intervention and methods: Subjects for the study were assessed according to the following parameters; vertebral column height, abdominal girth measurement, bilateral SLR, hip waist ratio, VAS scale. Results: Pain scores correlated significantly to the length of spinal segment mainly cervical spine (p=0.05) and lumbar spine (p=0.01) and also to bilateral SLR hold time (p=0.01). The bilateral SLR correlates significantly to a Total spine length and length of thoracic spine (p=0.01) while there was no correlation between bilateral hold time and length of cervical spine. Conclusion: This study has found that the length of the spinal column should be given due importance when assessing the risk of developing low back pain.

Rapid preparation of Si3N4 ceramics with high thermal conductivity and low dielectric loss by fast hot-pressing (FHP) sintering

A series of Si3N4 ceramics with MgO and Y2O3 as sintering additives were successfully prepared by fast hot-pressing (FHP) sintering at the sintering temperature of 1700 °C, with the hold time of only 10 min and the whole sintering process of 36 min. The sintering behavior, densification process, microstructure, crystalline phase composition, bond composition, thermal conductivity and dielectric properties were systematically investigated. FHP reduces the sintering temperature and sintering time of Si3N4 ceramic compared to traditional solid-state method. The results of a series of tests have shown that the densification of Si3N4 ceramics and the phase transition from α-Si3N4 to β-Si3N4 can be facilitated by appropriate levels of additives, resulting in a dense, homogeneous and non-porous microstructure. Additionally, based on test results in this work, Si3N4 -4 wt.% Y2O3 -2 wt.% MgO exhibit the highest thermal conductivity of 78.16 W/mK, the dielectric constant of 8.50 and the dielectric loss of 5.52 × 10−4. The Si3N4 ceramics investigated in this work exhibit excellent properties for use of power semiconductor device packages, microwave devices, and power electronics. And also demonstrate the potential of FHP in laying the foundation for the further preparation of higher performance Si3N4 ceramics.