Knowledge Resources

Resources

This contains a variety of cross-industry general technical guidelines and basic knowledge.

All Questions

Why Is Low-Temperature Pre-Drying On A Laboratory Hot Plate Necessary? Stabilize Silver Ink For Better Conductivity

Learn why pre-drying silver nanoparticle ink prevents defects like cracks and bubbles, ensuring high-quality sintering and film conductivity.

What Advantages Does A Cold Isostatic Press (Cip) Offer Over Uniaxial Die Pressing? Enhance Your Silicon Carbide Yield

Learn how Cold Isostatic Pressing (CIP) eliminates density gradients and defects in Silicon Carbide, outperforming traditional uniaxial pressing.

What Role Does A Laboratory Hydraulic Press Play In Preparing Ceramic Sputtering Targets? Master Thin Film Precision

Learn how laboratory hydraulic presses ensure high green density and phase purity in NiO and LSMO sputtering targets for magneto-ionic research.

What Role Does The Hot Isostatic Pressing (Hip) Process Play In Grain Boundary Strengthening? Enhance Alloy Stability

Learn how Hot Isostatic Pressing (HIP) strengthens grain boundaries through carbide precipitation and solute segregation to improve creep resistance.

Why Is Hot Isostatic Pressing (Hip) Equipment Necessary For Am Alloys? Ensure 99.97%+ Density And Structural Integrity

Learn how HIP equipment eliminates pores, heals micro-cracks, and increases density in additive manufacturing alloys for safety-critical parts.

Why Is It Necessary To Pre-Press Powder Mixtures With A Laboratory Hydraulic Press? Achieve Superior Sintering Quality

Learn why pre-pressing powder into a high-density green body is essential to prevent shrinkage, cracking, and voids during the sintering process.

Why Must Hpht Sintering Be Used For Cubic Boron Nitride (Cbn)? Ensure Stability And Superhard Performance

Learn why HPHT equipment is essential for cBN fabrication to prevent phase reversion and ensure maximum material density.

What Is The Primary Role Of A Laboratory Hydraulic Press In Ppcmp-Cu Cathode Preparation? Optimize Battery Performance

Learn how laboratory hydraulic presses enhance PPCMP-Cu organic cathodes through precise compaction, density control, and reduced internal resistance.

What Role Does Hot Isostatic Pressing (Hip) Play In Nbtialsizrnx Target Preparation? Ensure High-Entropy Alloy Purity

Learn how HIP densifies and homogenizes NbTiAlSiZrNx targets to eliminate porosity and ensure stable atomic flux for high-quality thin film sputtering.

What Is The Purpose Of Using A Pre-Press Before Hot Pressing Plywood? Optimize Your Veneer Bonding Success

Learn how pre-pressing plywood veneers improves adhesive penetration, prevents layer shifting, and eliminates delamination before final hot curing.

What Role Does An Industrial Hot Press Play In Plywood Fabrication? Optimize Modified Corncob-Filled Adhesives

Learn how an industrial hot press uses 130°C and 1.2 MPa to activate corncob adhesives, ensuring high bond strength and chemical cross-linking.

What Are The Advantages Of Using A Cold Isostatic Press (Cip) Over Conventional Pressing? Achieve Superior Uniformity

Learn how Cold Isostatic Pressing (CIP) eliminates density gradients and improves mechanical integrity in porous titanium preparation.

Why Are Stainless Steel Electrodes Used With Spring-Loaded Devices? Eliminate Contact Resistance For Precise Accuracy

Learn why stainless steel electrodes and spring-loaded pressure are essential for accurate electrolyte membrane AC conductivity measurements.

What Role Does A Laboratory Hydraulic Press Play In Lsgm Electrolyte Pellet Forming? Achieve High Green Density

Learn how laboratory hydraulic presses transform LSGM nanopowders into high-density green bodies for superior ionic conductivity and sintering.

Why Is Manual Grinding With An Agate Mortar Necessary For Lsgm Electrolytes? Unlock High-Density Sintering Results

Learn why manual grinding is critical for breaking LSGM nanocrystal agglomerations to improve green body density and reduce sintering temperatures.

How Do Precision Disk Punches And Laboratory Press Machines Contribute To The Assembly Of Sodium-Ion Batteries?

Learn how precision punches and lab presses optimize electrode geometry, density, and ion transport for high-performance sodium-ion battery research.

How Do The Processing Effects Of High-Frequency Vibratory Mills Compare To Planetary Mills For Boron-Based Compounds?

Compare planetary vs. vibratory mills for boron-based synthesis. Learn why planetary mills offer superior energy density and higher conversion rates.

Why Is A Hot Isostatic Press (Hip) Required For Mgb2? Master Volatile Synthesis And Stoichiometry

Learn how Hot Isostatic Press (HIP) furnaces suppress magnesium vaporization and ensure chemical purity in superconducting MgB2 synthesis.

What Is The Function Of A Laboratory Press Machine For Boron-Based Compounds? Optimize Your Synthesis Kinetics

Learn how laboratory presses facilitate atomic diffusion and lower synthesis temperatures in boron-based compound preparation.

What Is The Role Of A Planetary Centrifugal Mill In Boride Synthesis? Master High-Efficiency Mechanochemistry

Learn how planetary centrifugal mills use mechanical activation and kinetic energy to synthesize borides and boron carbides at room temperature.

Why Is A Laboratory Hydraulic Press Required For Li-P-S Electrolytes? Achieve Precision In Solid-State Battery Research

Learn how a laboratory hydraulic press enables accurate Li-P-S electrolyte characterization by eliminating porosity and ensuring ionic conductivity.

Why Is A High-Purity Argon-Protected Glove Box Essential For Sns2 Batteries? Ensure Peak Battery Stability

Learn why inert argon environments are critical for Tin Sulfide battery assembly to prevent lithium oxidation and electrolyte hydrolysis.

What Is The Primary Function Of A Laboratory Hydraulic Press For Cof Precursors? Master Precision Pellet Preparation

Learn how laboratory hydraulic presses transform PI-COF powder into high-density discs essential for carbonization and electrical testing.

Why Is A Laboratory Hydraulic Press Typically Required During The Assembly Process Of Supercapacitor Electrodes?

Learn how laboratory hydraulic presses optimize supercapacitor performance by reducing resistance, increasing energy density, and ensuring stability.

How Does A Laboratory Hydraulic Press Contribute To The Manufacturing Of Shape Memory Polymer? Ensure Material Integrity

Learn how laboratory hydraulic presses eliminate defects and program shape memory polymers for reliable bridge plugging performance.

What Is The Purpose Of Heat Treating Li|Glass|Li Batteries At 175°C? Optimize Interfaces With Vacuum Precision

Learn how 175°C vacuum heat treatment optimizes Li|glass|Li battery interfaces by softening lithium to reduce impedance and improve ion transport.

Why Is A High-Purity Inert Atmosphere Glove Box Critical For The Assembly Of Solid-State Symmetric Batteries?

Learn why <1 ppm oxygen and moisture control is vital for solid-state battery assembly to prevent lithium oxidation and electrolyte hydrolysis.

How Does A Laboratory Press Contribute To Vsse/V2Ctx Cell Assembly? Maximize Battery Performance And Stability

Learn how laboratory presses and sealers optimize interfacial contact and hermetic integrity in VSSe/V2CTx coin and pouch cell assembly.

How Do Laboratory Hydraulic Press Machines Contribute To The Standardization Of Earth-Based Materials (Ebms) Research?

Learn how laboratory hydraulic presses standardize Earth-Based Materials (EBMs) through precise compaction for reliable engineering data.

What Are The Primary Applications Of An Automatic Lab Press? Enhance Precision In Sample Prep And Material Testing

Learn how automatic lab presses optimize XRF/FTIR spectroscopy, powder metallurgy, and material research through precise, automated pressure control.

Why Is A Laboratory Press Machine Essential For The Preparation Of Lto/R-Go/H-Bn Composite Anode Electrode Sheets?

Learn how laboratory presses enable 20C high-rate performance by densifying LTO/r-GO/h-BN composites and building stable 3D conductive networks.

Why Is High-Precision Temperature Control Critical For Kapok Fiber Heat-Pressing? Optimize Your Fabric Performance

Learn why precise 170°C control is vital for kapok fiber bonding, preventing thermal degradation and ensuring maximum non-woven fabric strength.

Why Is Fluorine Oil Selected As The Pressure-Transmitting Medium? Achieve Nmr Signal Purity In Shale Gas Research

Discover why fluorine oil is essential for coal-bearing shale gas experiments using 1H-NMR by eliminating hydrogen signal interference.

What Is The Function Of A Laboratory Press Machine In The Preparation Of Simulated Coal-Bearing Shale Specimens?

Learn how laboratory presses consolidate coal and shale powders into geologically accurate specimens by controlling density and porosity.

Why Must Peo/Pvb-Based Lithium-Metal Batteries Be Assembled In A Glovebox? Protect Your High-Energy Research

Learn why <0.8 ppm moisture and oxygen levels are vital for PEO/PVB lithium batteries to prevent anode oxidation and electrolyte hydrolysis.

What Is The Role Of A Laboratory Press Machine In Peo/Pvb Electrolyte Film Prep? Unlock High-Performance Solid-State Battery Research

Learn how laboratory presses enable solvent-free PEO/PVB electrolyte production through thermoforming, molecular dispersion, and densification.

Why Is The Operation Of A Hydraulic Crimper Critical When Assembling Laboratory Coin Cells? Ensure Data Reproducibility

Learn why hydraulic crimpers are vital for coin cell assembly: ensuring hermetic seals, reducing impedance, and eliminating operator variability.

How Do Laboratory Press Machines Ensure The Quality Of Green Bodies? Master Uniform Density For Flawless Sintering

Learn how precise pressure regulation in lab presses prevents cracking and warping by ensuring uniform density in powder metallurgy green bodies.

What Is The Purpose Of Using An Automatic Crimper Machine? Achieve Precise Coin Cell Sealing For Battery Research

Learn how automatic crimpers ensure hermetic seals and repeatable internal pressure for CR2032 cells to produce reliable electrochemical data.

Why Is A Laboratory Hydraulic Press Used For Solid-State Batteries? Achieve Optimal Density And Ion Transport

Learn how laboratory hydraulic presses eliminate voids and reduce interfacial resistance to enhance solid-state battery performance.

Why Must The Handling And Assembly Of Solid-State Battery Materials Be Performed Within An Argon-Filled Glove Box?

Learn why Argon-filled glove boxes are critical for solid-state batteries to prevent degradation of sulfide and lithium materials.

What Is The Critical Role Of A Laboratory Press In Dac Preparation? Achieve High-Density Skeletal Integrity

Learn how high-pressure laboratory presses optimize Alkali-activated Dolomite powder-emulsified Asphalt Composites by reducing porosity and strength.

Why Is Glycerin Preferred Over Paraffin As A Pressing Aid When Forming Tungsten Powder Targets? 2 Key Stability Factors

Learn why glycerin outperforms paraffin as a pressing aid for tungsten targets, preventing material splashing and ensuring uniform thin film quality.

What Is The Role Of A Laboratory Hydraulic Press In Tungsten Sputtering Target Preparation? Expert Insights

Learn how laboratory hydraulic presses and specialized molds consolidate tungsten powder into high-density green bodies for sputtering targets.

What Is The Purpose Of Using Laser-Drilled Rhenium Or Stainless Steel Gaskets In Dac Experiments? Master Ultra-High Pressures

Learn how rhenium and stainless steel gaskets enable ultra-high pressure in DAC experiments through lateral constraint and sealed chambers.

How Does A Laboratory Hydraulic Press Assist In Multi-Anvil Press Experiments? Optimize Sample Pre-Compaction Now

Learn how a laboratory hydraulic press ensures experiment success through pre-compaction, density optimization, and geometric precision.

Why Is An Alumina (Al2O3) Spacer Used In High-Pressure Experiments? Protect Your Data Accuracy

Learn how alumina spacers prevent thermocouple poisoning and chemical interdiffusion for accurate temperature monitoring in high-pressure research.

What Functions Do Mgo Octahedra Serve In Map Experiments? Enhance Your High-Pressure Physics Performance

Learn how chromium-doped MgO octahedra act as a pressure-transmitting medium and thermal insulator in Multi-Anvil Press (MAP) experiments.

What Is The Role Of A Laboratory Uniaxial Hydraulic Press In Hap Green Body Preparation? Master The 25-50 Mpa Range.

Learn how laboratory uniaxial presses consolidate hydroxyapatite (HAp) powder into green bodies with optimal structural integrity and density.

Why Use Graphite Foil In Alloy 825 Compression Tests? Achieve Uniaxial Stress And Prevent Barrelling

Learn why graphite foil and lubricants are critical for Alloy 825 tests to eliminate friction, prevent barrelling, and ensure accurate stress data.

Why Is Precise Pressure Control From A Laboratory Press Machine Necessary For Zinc-Ion Battery Electrode Preparation?

Learn why precise pressure control is vital for electrode densification, reducing impedance, and ensuring battery stability in zinc-ion research.

What Advantages Does An Automatic Laboratory Press Provide For Pet Enzymatic Degradation Studies? Enhance Data Accuracy

Learn how automatic laboratory presses standardize PET sample preparation, ensuring consistent surface area and density for accurate enzymatic studies.

What Are The Advantages Of Using A Laboratory Hydraulic Press For Ceramic Preforms? Precision Density Control

Discover why high-precision hydraulic presses outperform gel-casting for ceramic preforms through superior density control and structural strength.

What Function Does A Laboratory Hydraulic Press Serve In The Forming Process Of Gd2O2S:tb Phosphor? Essential Pre-Pressing Guide

Learn how laboratory hydraulic presses create high-density green compacts and remove air to optimize Gd2O2S:Tb phosphor synthesis.

How Does A Dedicated Cooling Device Influence The Properties Of Peek Composite Materials? Unlock Peak Performance

Learn how dedicated cooling devices regulate PEEK crystallinity to eliminate internal stress, prevent warping, and enhance mechanical durability.

How Does A Laboratory Heated Press Contribute To The Fabrication Of Peek Composite Sheets? Ensure Peak Structural Integrity

Learn how heated presses enable structural densification, eliminate voids, and enhance bonding in PEEK composite fabrication at 380°C.

Why Does Hot Pressing Achieve Higher Density In Al/Ni-Sic? Superior Densification Via Thermo-Mechanical Coupling

Learn how simultaneous heat and 840 MPa pressure achieve 100% theoretical density in Al/Ni-SiC composites compared to traditional sintering.

What Are The Technical Advantages Of Using A Hot Isostatic Press (Hip) To Treat Sintered Al/Ni-Sic Samples?

Unlock 98% density in Al/Ni-SiC samples with Hot Isostatic Pressing. Learn how HIP eliminates micro-pores and stabilizes mechanical properties.

What Role Does A Lab Hydraulic Press Applying 840 Mpa Play In Al/Ni-Sic Cold-Press Sintering? Achieve Peak Densification

Learn how 840 MPa of pressure drives plastic deformation and eliminates porosity in Al/Ni-SiC composites to create high-density green compacts.

How Does A Laboratory Hydraulic Press Influence Supercapacitor Electrode Performance? Boost Esr And Density Now!

Learn how precise hydraulic pressing optimizes supercapacitor electrode density, reduces ESR, and enhances mechanical durability for research.

What Role Do Industrial Loading Systems Play In Laboratory Performance Testing? Maximize Structural Connection Reliability

Learn how laboratory hydraulic presses validate structural designs, simulate traffic loads, and optimize connection geometries through precise force.

What Is The Function Of High-Efficiency Grinding Equipment In Green Algae Extract Preparation? Maximize Surface Area

Learn how high-efficiency grinding enhances green algae nanoparticle synthesis by increasing surface area and optimizing phytochemical extraction.

What Is The Role Of Alumina Grinding Balls In The Mixing Process Of La-Gd-Y Rare Earth Oxide-Alumina Ceramic Powders?

Learn how alumina grinding balls enable atomic-level dispersion and mechanical activation for high-performance La-Gd-Y rare earth ceramic powders.

Why Is A Lab Press Machine Essential For Evaluating Hybrid Hydrogels? Master Precise Mechanical Testing

Learn how lab press machines standardize sample preparation and provide precise compression data for hybrid hydrogel performance evaluation.

Why Is A Laboratory Hydraulic Press Required For Nasicon Electrolytes? Achieving High-Precision Green Body Molding

Learn why precision pressure is critical for NASICON green body molding to eliminate voids, prevent sintering cracks, and ensure high conductivity.

Why Are Gold-Palladium (Au80Pd20) Alloy Capsules Selected For Magma Simulation? Ensure Chemical & Physical Fidelity

Learn why Au80Pd20 alloy capsules are essential for magma research, offering chemical inertness and strength to retain volatiles under pressure.

Why Is Confining Pressure Essential For Evaluating Grouting? Ensure Realistic Rock Sealing Performance

Learn how laboratory hydraulic systems simulate subsurface stress and confining pressure to accurately test grout sealing and gas leakage prevention.

How Do Laboratory-Grade Precision Pressure Regulating Valves Assist In Optimizing Grouting Process Parameters?

Learn how precision pressure valves optimize grouting by mapping diffusion kinetics and identifying the ideal balance of sealing and efficiency.

What Are The Primary Functions Of A Hydraulic Manual Pump Within A Rock Grouting Experimental System? Simulate Stress.

Learn how hydraulic manual pumps generate confining pressure and simulate underground stress environments in rock grouting experiments up to 10 MPa.

What Role Does A High-Tonnage Laboratory Press Play In Simulating Rock Strata Fracturing? Enhancing Mining Safety

Learn how high-tonnage laboratory presses use Brazilian splitting and UCS testing to simulate rock fractures and optimize mining safety solutions.

Why Is Precise Pressure Control Critical For Ha/Cord/Zro2 Composites? Master Green Body Formation And Sintering Success

Learn why precise laboratory hydraulic press control is essential for HA/Cord/ZrO2 composites to prevent sintering cracks and ensure density.

How Are High-Precision Laboratory Presses Utilized In Ths Material Modification? Boost Energy Storage Efficiency

Learn how high-precision presses transform THS powders into stable pellets to prevent caking and ensure stable reaction kinetics for energy storage.

How Does High-Precision Pressure Control In A Lab Press Influence Kbr Pellet Quality For Hdmi Dye Research?

Discover how precise pressure control eliminates defects in KBr pellets, ensuring accurate ESIPT data for HDMI dyes.

What Is The Function Of A Laboratory Press Machine In Kbr Pellet Preparation? Optimize Hdmi Dye Characterization

Learn how a laboratory press creates transparent KBr pellets to eliminate light scattering and stabilize HDMI fluorescent dyes for spectroscopy.

Why Is A Laboratory Press Required To Prepare Insoluble Polysulfide Samples For Atr-Ir? Optimize Your Sample Preparation

Learn why a laboratory press is vital for ATR-IR analysis of insoluble polysulfides, ensuring perfect crystal contact and high-quality spectra.

Why Is A High-Precision Laboratory Press Machine Essential For Ftir? Optimize Cellulose Hydrogel Analysis

Learn how high-precision laboratory presses enable accurate FTIR analysis of functionalized cellulose hydrogels by ensuring optical transparency.

What Role Does A Uniaxial Lab Press Machine Play In The Initial Stage Of Preparing Porous Alumina Green Bodies?

Learn how uniaxial lab presses transform alumina powder into stable green bodies, providing essential shape and strength for advanced processing.

What Is The Role Of A High-Precision Laboratory Hydraulic Press In Cement Formulation? Master Your Material Testing

Learn how high-precision hydraulic presses standardize cement samples, eliminate density gradients, and validate mechanical strength for research.

How Does A Laboratory Hydraulic Press Assist In The Ftir Characterization Of Biochar? Optimize Spectral Data Quality

Learn how laboratory hydraulic presses create transparent KBr pellets from biochar to ensure accurate FTIR analysis and clear spectral data.

Why Is A Cold Isostatic Press (Cip) Required Before Sintering Nd:cyga Blocks? Ensure Defect-Free Density.

Learn why Cold Isostatic Pressing is essential for Nd:CYGA blocks to eliminate density gradients and prevent cracking during sintering.

Why Is Pressure Maintenance Performance Critical For Precision Laboratory Hydraulic Presses In Geological Research?

Learn why stable pressure maintenance is vital for geological samples to ensure uniform density and accurate natural simulations.

Why Is A Paterson Press Typically Utilized For Rheological Experiments On Magma? Simulate Deep Earth Conditions

Learn how the Paterson press simulates extreme magma chamber conditions to measure stress responses and define frictional lock-up in real magma.

What Is The Importance Of Using A High-Precision Laboratory Press For Modified Mortar? Master True Material Behavior

Discover how high-precision laboratory presses isolate true material performance through servo-control and stable loading for modified mortar testing.

What Is The Mechanism Of A Laboratory Hydraulic Press With A Precision Spring Device? Precision Uniaxial Testing

Learn how the hybrid mechanism of hydraulic force and precision springs enables controlled, low-pressure increments for delicate material testing.

What Is The Function Of Wc Piston Components? Achieve High-Pressure Precision In Uniaxial Resistivity Testing

Learn how tungsten carbide pistons provide the rigidity and compressive strength needed for accurate uniaxial resistivity measurements on thin films.

What Role Does A Laboratory Hydraulic Press Play In Pt(Bqd)2 Powder Preparation? Optimize Your Material Research

Learn how laboratory hydraulic presses consolidate Pt(bqd)2 powder into dense compacts for hydrostatic testing and resistivity measurements.

What Is The Function Of A Laboratory Hydraulic Press In Multiphysics Simulation? Precise Material Characterization

Learn how laboratory hydraulic presses provide the high-precision specimen preparation required for accurate multiphysics material simulation.

What Are The Process Advantages Of A Hot Extrusion Press Compared To Forging Equipment? Boost Structural Uniformity

Learn why hot extrusion presses outperform forging for high aspect-ratio components, offering superior grain refinement and creep resistance.

What Is The Primary Function Of A Laboratory Press In Hdpe Sample Prep? Optimize Your Solid-State Nmr Results

Learn how laboratory presses transform raw HDPE pellets into thin sheets for solid-state NMR, ensuring sample uniformity and signal sensitivity.

How Does The Biaxial Pressing Process Improve The Bottom Hardness Of Magnesium Block Samples? Optimize Your Compaction

Learn how biaxial pressing enhances the microhardness and densification of magnesium blocks by reorienting particles and eliminating core porosity.

How Do The Mold Material And Structure Influence The Pressing Of Long-Shaped Magnesium Blocks? Optimize Uniform Density

Learn how mold material and wall friction impact the density and hardness of long magnesium blocks in laboratory pressing processes.

What Role Does A Laboratory Manual Hydraulic Press Play In Magnesium Powder Compaction? Achieve Precise Densification

Learn how laboratory manual hydraulic presses transform magnesium powder into stable green compacts through controlled plastic deformation.

Why Is An Isostatic Press Utilized For Al2O3/Al16Ti5O34 Ceramic Precursor Rods? Achieve High-Density Uniformity

Learn how isostatic pressing eliminates density gradients and prevents cracking in Al2O3/Al16Ti5O34 ceramic rods during high-temp sintering.

What Role Does A Coin Cell Crimper Play In Solid-State Batteries? Essential Pressure For Ionic Conductivity

Learn how high-precision pressure molding devices eliminate voids, reduce interfacial resistance, and enable ion transport in solid-state batteries.

Why Is A Laboratory Glovebox Necessary For Assembling All-Solid-State Batteries? Ensure Ultra-Pure Inert Environments

Learn why high-purity argon gloveboxes are critical for preventing lithium oxidation and electrolyte hydrolysis in solid-state battery research.

What Are The Technical Advantages Of Using A Vacuum Hot-Press Sintering Furnace For Ti(C,N)-Based Cermets?

Unlock superior densification and purity in Ti(C,N) cermets using vacuum hot-pressing to lower sintering temperatures and prevent grain growth.

Why Is Graphite Paper Placed In The Mold For Sintering Ti(C,N) Cermets? Optimize Your Lab's Material Processing

Learn why graphite paper is essential in Ti(C,N) cermet sintering to prevent mold adhesion, extend tool life, and ensure superior surface quality.

What Functions Does A High-Purity Graphite Mold Perform In Ti(C,N) Sintering? Optimize Your Cermet Production

Learn how high-purity graphite molds ensure uniform heating and pressure transmission for high-density Ti(C,N)-based cermets during sintering.

What Role Does Cold Isostatic Pressing (Cip) Play In Forming Thermoelectric Materials? Ensure Structural Integrity.

Learn how Cold Isostatic Pressing (CIP) eliminates density gradients and prevents cracking in thermoelectric materials vs. uniaxial pressing.

What Is The Function Of Using Flexible Graphite Paper Or Graphite Foil As A Liner? Enhance Vacuum Hot Pressing Results

Learn how flexible graphite foil improves thermal conductivity, protects molds from diffusion, and simplifies demolding in vacuum hot pressing.