Ceramic Materials - Science topic

I am analysing my impedance data for ceramic materials, and I'm confused between using:

- A simpler R(QR)(QR) model

- A more complex R(QR(QR)(CR)) model

Example: if the chi-square values after fitting the data are:

- R(QR)(QR): 1.68E-2

- R(QR(QR)(CR)): 2.93E-4

What would be your recommendation for me, ? Thank you.

I am a doctoral student at University Politehnica of Bucharest, currently working on a literature survey regarding optimal metallic and ceramic materials for food packaging. I would like to request permission to reproduce Figure Nano-coating pe aluminiu from your article “Metal-Based Nanoparticles in Food Packaging and Coating Technologies: A Review,” published in *Biomolecules* (2023).

This figure will be included in my Ph.D. thesis, which is non-commercial and strictly academic. Full citation and acknowledgment will be provided.

Thank you for your consideration, and I look forward to your response

I make polycrystalline diamond with tape casting followed by HPHT sintering. When i sintered the samples up till May, the sintering was good. When i sintered the samples in June and July at the same conditions, the sintering was not good. I used the same slurry making conditions, tape casting conditions, debinding conditions, heat treatment conditions, and sintering conditions.

The only changed parameter i can think of may be humidity, as humidity is very high in June, July and August in Korea.

What tests should i perform and at what stages? How to overcome this issue?

Thank you.

I am preparing polycrystalline diamond (PCD) with tape casting. The powder is 8~12 um.

After drying of tapes, I place several tapes in Ta cup without warm-pressing. Next, debinding is carried out. There are no cracks visible with naked eye. SEM analysis shows all the organics are evaporated.

After debinding, WC-Co substrate (4 um average particle size of WC) is placed in cup over debinded tapes. Heat treatment is done in vacuum above 1000 C for surface graphitization to help in sintering.

After that, high pressure high temperature sintering is carried out. When surface is observed after polishing, there are whitish parts on the dark gray diamond surface, mostly in circles. These discolored parts are mostly near the edge of sample, and sometimes inwards too, for example, in the center of a sample. Sometimes, these discolors are distributed throughout the sample.

What may the reason of these discolors?

Additionally, mostly there are also cracks near the edge of sample. What could be the reason for these cracks?

I am working on a project to study the piezoelectric property of a polymer matrix by incorporating ceramic material. While studying the dielectric properties, I see a continuous decrease as the filler loading increases. What could be the reason behind it in terms of dipoles and in relation to their respective properties?

Kindly help.

I usually use PEG-200 and PEG-300 that are in liquid form.

Recently I received PEG-100 from a company that usually do not make PEG-100, and made it once specially for us.

It is not in liquid state, or granules or flakes form, but it is one big solid that looks like in the picture attached.

I tried to melt it up to 100 C, but it did not melt.

How should I use it? My purpose is to use it as a plasticizer for aqueous tape casting, and to mix it with powder, binder and water.

Thank you.

Is this dental material classified as ceramic? Does it contain hydroxyapatites?

I would like to know the void fraction for known powder material properties to estimate a bisque sample's packing density/void fraction. In combination with any geometric &/or Archimedes measurements.

Assuming the density of powder to be 5.03 g/cm3 (correct me if I'm wrong)

This is regarding my research.

I appreciate any help you can provide.

I have measured the sound absorption coefficient in each sample I made using a ceramic mixture. The perforation was done with the same dimensional holes and perforation increased as A-E as follows. I was confused with my reading since it was not as I expected. Is there any physics theory other than sound energy dissipation by walls of holes?

Is there a technological niche in pharmaceutical research that makes NQR or NMR the only measurement methods practically applicable?

Have you any data about the operating costs of CERAMIC membranes over for example 50 years? what about sand filter and polymeric membranes? The use of all of them is after coagulation, but for sand filter we have clarifier. For MF CERAMIC membranes (or polymeric membranes), the filter will act as clarifier. Any data for any types of CERAMIC membranes (MF, UF, ...) can be useful.

In my undergraduate research, i am planning to investigate effective pore size and the effect of sound absorption in directional pores in ceramic material. So I am planning to obtain a porous ceramic sample with a diameter of 5 cm with 1 cm thickness. what should be stating pore size if they are in cylindrical type

Considero que las mujeres que han empleado el material cerámico para sus creaciones artísticas tienen un doble estigma, su género y el material que emplean.

Supongo que la larga tradición cerámica dentro del estado español y su indudable vinculación con la artesanía es un alegato que descarta a las personas que emplean este material apartándolas de la inclusión dentro del Arte.

For dating purposes, to calculate the annual radiation dose in ancient ceramics, the contribution of natural radiation from radionuclides which includes 40K, 238U, and 232Th of the environment (sediment) and inside the ceramic material should be considered. How to calculate the annual radiation dose in ceramics, when there are significant contribution of U, Th, K from both ceramics and sediments. Even the contribution of ceramics is greater.

We are using glass and iridium substrate for the deposition of Y2O3 by PLD. Under the same deposition conditions, the Y2O3 was successfully deposited on glass substrate but we did not found thin film on the Iridium substrate. We also confirmed it by SEM images and found only few particles of Y2O3 on iridium substrate but on glass substrate it was a complete thin film with reasonable coverage. We are looking for the expert opinion for understanding/resolving this issue or any other deposition technique suitable for the deposition of Y2O3 on iridium substrate.

How can I determine the best RPM and balls to powder ratio for wet Ball Milling?

Where can I see data on all mechanical properties of hydroxyapatite materials?

What is the effect of the particle size of raw material in the preparation of ceramic material via Solid state reaction method? If we are using powder of raw material in the nanometric range, Can it will result in the single phase formation or leads to segregation at the boundary?

Hello dear researchers

I am beginner in Abinit software, I made a simulation of piezoelectric properties and I got its two errors. Please if you have any idea how I can solve them please.

-----------------------------------------------------------------------------

ddb_piezo : WARNING -

Acoustic sum rule violation met : the eigenvalues of accoustic mode

are too large at Gamma point

Increase cutoff energy or k-points sampling.

The three eigenvalues are: 2.589265E-05 2.380597E-05 2.589265E-05

ddb_piezo : WARNING -

Unstable eigenvalue detected in force constant matrix at Gamma point

The system under calculation is physically unstable.

-----------------------------------------------------------------------------

Actually zinc ferrite are ceramic materials and it exhibits their magnetic properties between paramagnetic and ferromagnetic. Can you explain simply the actual application of ZnFe2O4 in the medical field.

Hello all,

I hope you are doing well!

I am currently doing research in the field of additive manufacturing with technical ceramics, and I have two separate questions specifically regarding silicon dioxide (SiO2).

1. In 3D printing with SiO2, I use a slurry mixture which is composed of SiO2 powder, deionized water, DARVAN C-N (for dispersant) and CELLOSIZE Texture F4M (for binder). The CELLOSIZE Texture F4M is cold-water dispersible hydroxypropyl methylcellulose which is primarily used to control viscosity within the slurry. My main issue is when I add the binder into my SiO2 slurry and mix it, the slurry almost becomes a non-Newtonian liquid within 20 seconds, in that sudden impact hardens the overall slurry and after the impact it immediately goes back to a viscous state. Could you please point me to any research regarding this issue? Additionally, I've tried the same binder on alumina and silicon carbide (other technical ceramics) and haven't faced this issue. I've also experimented with modifying different speeds of mixing, gradual increments of adding the binder, and mixing in a vacuum environment; however, none of these helped. Could it be that methylcellulose reacts chemically with SiO2, and a different binder should be used?

2. For sintering ceramics, I've read that ~80% of the melting temperature is a good baseline for experimentation. My goal is to increase part density and flexural strength. Could you please point me to any research regarding selecting a sintering schedule (time and temperature) for silica specifically? I've read through literature suggesting ~1300C for around 8 hours with a heating rate of 5C/min; however, I'm curious if a lower temperature such as 900C for a longer sintering time or a higher temperature of 1500C for a shorter sintering time would vary the final part density and flexural strength significantly. I'm currently only experimenting with single-stage sintering.

I appreciate all your help and insight.

Thanks & Regards,

Sam Choppala

I am looking for a metal/ceramic material that has good wear resistance in corrosive gases (HF: 750 ppmv, HCl: 200 ppmv, N2: 70 %, O2 % 18 %, remaining constituents are SO2, H2SO4 (1%), SO3, CO2, H2O) at operating temperatures of 450 C. pH ~1.

Can you be specific on what grade of alloys or class of ceramics I should be looking at? I am sure if there is an application, some material is used for it.

Dear all

Hope you are doing well!

What are the best books in Materials Science and Engineering (Basics and Advanced)? Moreover, what are the best skills (or materials topic related) that materials scientists have to develop and to acquire?

Thanks in advance

^_^

I want to Create Surfaces/sets from wireframe 2D Sketch in .Iges format to do a 2D analysis of a Ceramic material. I am using ANSYS Workbench to create a mesh for my geometry. The .jpg file is attached. The .iges file imported from a different source where the sketch had been created in wireframe 2D, contains splines and lines, the closed splines and lines represent the crystals and the rest is the matrix. The crystals had been indicated with C and matrix with M in the image respectively.

Could you provide some information on how should two surfaces/sets can be generated in ANSYS so that meshing can be done afterward?

Hello everyone,

I'm currently doing some DTA analysis on two phases of the same ceramic material, one is fully crystalline and the other fully amorphous.

When I work with the crystalline one I have a melting peak, with a clear area I can integrate if I want to.

But when I'm working with the amorphous one, I don't have a peak anymore but more like a transition, with no distinct area (similar to a reversed glass transition in a way).

Why don't I have a proper melting peak on my amorphous material ?

The same heating rates have been used, with really closed mass for the samples.

Thank you for your help,

Julien

For different purposes, molten metals will be in contact with a ceramic material. For example a furnace nozzle guides the melt flow to the mold is usually made from a thermo-chemical resistant ceramic.

- However, in the case of Mg metal, chemical reactions and temperature drop are very fast.

- Beside, mechanical strength and elongation must be high enough to suffer mechanical shocks.

- Moreover, machinability and density of a ceramic material must be good enough to form in the desired shape.

I will highly appreciate if you let me know your answers and reasons in this regard.

#Magnesium

#Oxidation

#Flamability

#

Best regards,

I have synthesized a titanium-based ceramic material (Titanium Carbide) by high-temperature synthesis. But I am getting Oxide peaks while performing XRD analysis. Is there any way to remove the unwanted oxides from my sample? If so how to do it. Kindly enlighten me

For O1s, there are two peaks, 529.6ev and 533.3ev.

529.6ev can be corresponding to Zr-O. But 532.3ev, I don't know how to explain it.

Consult relevant literature, there are two explanations.

The first, It may be Si-O, but there is no Si element in my material.

The second, It may also be chemically adsorbed oxygen, but is this possible in ceramics materials?

I am puzzled by the analysis, hope I can get an answer about it.

Thank you

Thermal behavior of ceramic materials

Consider a small tube made of polymer or ceramic (inner diameter of about 3mm, outer diameter of about 1cm, and 5cm length), inside which a high-gas pressure should be generated in a short time (few microseconds). How can we measure the maximum gas pressure that the tube can withstand before it breaks or deforms, even before starting the actual experiment?

My goal is to create a layer of Lead Zirconate Titanate, or other piezoelectric material, deposited on the surface of a PFTE Teflon tube. What are some good methods to accomplish this task?

Why does a Cole-Cole plot display a downward slope?

After plotting the E'' vs E', there is a particular composite that has the opposite trend of others. Attached is the image. Thank you

Dear all,

I am investigating the corrosion resistance of ceramic coating (deposited by PVD process) on Stainless steel samples using Gamry Instrument with parameters OCP (77.78 mV conducting before tafel curve), then scan rate = 1 mV/s, Potential = -0.5 to 0.5 Vs OCP in 0.5M NaCl environment. During starting of tafel curve, there is overloading error within 3-5 minutes and also coating was seen peeled off at the point of contact/interface between solution and Coating having area .022 cm2.

Kindly suggest the best possible solutions to overcome this problem.

Thank you

What is the best cement, and the temperature required to ensure a good bond ?just normal alumina ceramics. I wish to bond two pieces thoroughly which would withstand high temperatures say 800  to 900 deg C.

In the (electro-) conducting materials, as I know, there is an energy gap between the valence band (VB) and the conduction band (CB) that can be brought to or near-to the Fermi level by doping (p-type or n-type dopant).

But ( My question is ), If I want to design a (semi- or super-) conductor's materials (inorganic or polymeric) , Which properties would I look for? and, also, Which characterizations would I consider for the properties' investigations? What are the requirements for the materials' property (with regard to its band structure) to achieve the considered structure-property relationships (or requirements ) for the preparation of the conducting materials?

Fluxing agents like the oxides of alkali metals are used as fluxing agent in ceramic body mix for reducing melting. How fluxing agent works during sintering of ceramic body?

Good afternoon everyone, I want to make a calculation of the optical properties of a perovskite-type ceramic material, but I present the following questions that I would like to help me clarify:

1. In order to do the calculation of the optical properties, I must first do the minimization calculation?

2. My great doubt is referring to some INCAR parameters when I am going to calculate the optical properties, they are: IBRION =? ISIF =? LORBIT =? LREAL =? LWAVE =? NSW =? PREC =? 3. Can I calculate the optical properties with PAW-GGA?

I appreciate your attention and I look forward to your comments

regards

I came across an article that uses heat treatments to determine whether or not the surface charge introduced by contact electrification on a ceramic material is due to electron-transfer mechanism or ion-transfer mechanism. I was wondering if ions can be removed using heat or what other method can be used.

On a synthetic graphite tube production line, this type of defect, similar to scales or the beginnings of cracks (cf. photos), appears regularly, including on unimpregnated tubes, just out of the oven (on the photos, these are tubes that have been impregnated and then brushed with traces of resin at the bottom of the scale). We noticed that our graphite had an abnormally high Fe content (a supplier problem). Do you think that these defects can come from a cast iron inclusion (the carbon of the graphite + Fe) formed locally during the graphitization process? Can such an inclusion at this scale (0.5-2mm) lead to surface flaking? If not, do you have any ideas on the origin of these defects?

Thank you very much for your answers and time,

A french materials engineering trainee in need of knowledge

I want to make slurry for aqueous tape casting of alumina (500 nm avg. particle size) using PVA binder and PEG plasticizer, but I am not being able to optimize the contents.

1. In what quantity range (wt% or vol%) should I use alumina to get high relative density?

2. In what range (wt% or vol% w.r.t total composition or w.r.t alumina) should I use PVA binder? Should the PVA added be in solid granules form or aqueous solution, and hence will that quantity represent binder active matter or binder solution?

3. Should PEG added be in aqueous solution form?

4. Is optically high grade PET film ok as substrate for tape casting? Can the tape be detached from this substrate easily? (I could not be able to detach yet).

Thank you so much~

I'm working with a dielectric ceramic material. I plotted tangent loss V's frequency and it doesn't show any peak which corresponds to the relaxation mechanism. What does this mean? How to interpret the data?

I am trying to calculate the theoretical density of my ceramics materials. I use the formula below to calculate the theoretical density: Theoretical density = (Molecular weight x No. of molecules per unit cell) / (Volume of unit cell x Avogardo's number). The issue is how to calculate the Z number? I found that the value of Z even changes as the original materials is doped. please see the attached image of PDF infor for LaFeO3 and La0.8Ca0.2FeO3. The value of Z change from 4 to 2. So, my question is how to exactly calculate the Z value? And why does the value of Z change?

I will be very appreciated if someone could help me out.

Thanks in advance!

I am conducting research into additive manufacturing metal matrix composites at the university of Wolverhampton (UK) but I am struggling to locate this information. any help would be appreciated. if you have written a paper that includes this information that would be a bonus also.

For a PbO-SiO₂ glass, PbO is a network modifier for up to 30-40%, but it becomes a network former at higher concentration. Why?

It's something I've seen as trial and error, but to make it a little more technical I haven't seen a route for this process. Does anyone have ideas for this route?

I'm talking about the case of rotational reometers.

Dear Colleagues,

The term of bending strength and flexural strength are interchangeably used to measure the strength of ceramic materials. I am aware about the bending strength. Ceramic materials are brittle in nature and lack of plasticity. Hence, bending strength is difficult to count preciously in ceramic materials. However, there are numerous papers measured bending strength of several ceramic materials.

Flexural strength is another frequent used strength measurement for ceramics.

1-What are the main differences between these terms?

2- Why these strengths are important to measure separately?

3-are these strengths can be related to other strengths such as compressive strength of ceramics?

4- is there any difference in the relationship of porosity, microstructure features, density and other parameters relation with bending strength and flexural strength separately?

Thank you very much for your kind contribution and assistance.

Yours sincerely,

Zhwan

Ceramic materials like Chromium oxide and Aluminium oxide have high melting point. The combustion flame can reach up to 3000 centigrade. However, The velocity of particle may not allow ceramic powder to melt completely.

But I want to know can we coat these materials by optimizing process parameters like flow rate of fuel gas, air and powder feeder?

Essentially every published review paper on the MAX phases includes Sc2InC in its listings of 'known MAX phases'. However, most of these reviews either: 1) specifically do not reference Sc2InC, while all other phases are referenced, or 2) point the reader in the direction of an earlier review paper.

This paper-trail can be tracked back to the seemingly original source - L. E. Toth, W. Jeitschko and C. M. Yen, The superconducting behavior of several complex carbides and nitrides, Journal of the Less-Common Metals, 10 (1966) 29-32. However this source refers only to Sc2InC as a "personal communication" between W. Jeitschko and E. Parthe. As far as I am aware there are no further reports on the physical synthesis of this phase.

Does anybody know if the origins of this phase go back any further, what the personal communication entailed, or if a publication or any other report has in fact been published regarding this phase which has slipped through my review of the literature?

Thank you in advance.

Hi everyone,

I would like to know that which ceramic material (oxide, carbide, nitride etc.) is non-toxic to humans and possess best Anti-bacterical and Anti-viral properties?

Thank you in advance.

With best regards

I am working on ballistic simulation. The first issue is how can i control hourglass for ceramic materials. Because if hourglass exceeded 10% of internal energy, the simulation will be invalid.

Type 4 or Type 6 , which is better for ceramic ?

And the second question ,if sliding energy is negative but still under control , does it matter for simulation results?

Thank you for your attention and look forward for the answers

I have just started to work with MS and need help with CASTEP module.

Can anyone suggest an "accurate" lab technique for measuring thermal conductivity (TC) of molten nitrate salt-based nanofluids, doped with Al2O3 metal oxide nanoparticles at various volume fractions (ranging between 0.5% to 5%). The main issue here is to measure fluids/salts TC at high temperatures (ranging from 250-500 ºC). Also for this type of testing what would be the best fit for the sensors insulation?

Can anyone share a complete poling process of pyroelectric ceramic materials including equipment name and source?

I have never done that before but I need to purchase equipment to perform a polling process. After polling, what type of test should I do to see that the polling was successful and what equipment I need?

It will be helpful if anyone can give a list of processes and equipment requirements.

Thanks.

Difference between Pyrolysis, Carbonization, Graphitization in Composites?- Clear and Specific

Don't copy the sentences from internet sources please.

Dear researchers ;

I find difficulties to calculate the weight contents (mass%) of kaolin, talc, and alumina corresponding to the ratio of MgO:SiO2:Al2O3. Could you help me please ? 

Thanks for any answers !

Best regards

To measure flexural strength of CAD CAM ceramic materials,is it necessary to prepare the samples as crowns on prepared teeth or can we just use blocks of predetermined dimensions. There are studies which have used the latter method. I am curious to know if it makes any difference in the results in using the above two methods of preparing the specimens. Kindly suggest.

Dears, I am looking for an efficient software (preferably free) to carefully analysis the porosity, phase composition percentage , clearly distinguish between phases, grain size for EACH ELEMENT, grain size distribution and other parameters related to the microstructure analysis to related them to hardness, fracture toughness and strength of advanced ceramics materials? Thank you very much for your kind cooperation in advance. Yours sincerely, Zhwan

In my case, after successive doping in my sample (bulk), one of the peaks starts splitting into two. what could be the reason behind this?

Is this caused by strain in structure ?

plz give answer with reference...

I calculated activation energies for intermediate stage of sintering for alumina+tetragonal zirconia composite and alumina+cubic zirconia composite via non-isothermal CHR method in microwave hybrid sintering, and compared them. The particle sizes of both as-received zirconia were same. A+tZ shows slightly higher activation energy as compared to A+cZ, but the densification of A+tZ is also higher. Can someone please guide? Because if densification is higher, then the activation energy for sintering should be lower, but that's not the case here. Is some unusual factor of sintering kinetics involved here?

May you know any methods/software/ or techniques capable of refining a series of similar XRD patterns? I am talking about Rietveld refinement.

1. Proper surface finish 

2. Better bonding of ceramics with adhesives

Respected Sir,

As we know, the ceramics are brittle in nature, if we add polymer and ceramics in piezo ceramics, then the material behaves as flexible. What is the main reason behind it?

Kindly share your valuable answers,

Thanks and best regards.

Please list down the best best Scientists/Researcher in the field of Solid State Electrolyte/Solid-state batteries for Li/Na-ion batteries.

For refractory brick we measure the refractoriness with Orton cone (standard cone)

What should be the PCE value (theoritical) for the refractory having following chemical analysis.

Al2O3 : 74%

Fe2O3 : 0.6%

SiO2: 24%

Na2O + K2O : 0.25%

In my ceramic sample which is highly fragile and porous, structure is destroyed on doing FESEM during placing on the stab holder, even charging of the sample take place even at low magnification.

Why we don't put the rogowoski current sensor in a metallic enclosure? Because for a metallic case (grounded), the sheath thickness will be small as compared to a floating ceramic enclosure.

I am need of a good electrical insulator, which can resist temperature up to around 1200-1400 degree centigrade.

I know Teflon (Polytetrafluoroethylene (PTFE)) which has a melting point of 327 degree C.

Actually I need a insulator which can resist high temperature, it should be electrical insulator and moreover should have adhesive property like that of araldite.

How to convert the fracture toughness to strength?

For a tetragonal zirconia, is it 210 GPa?

And for cubic?

As, Titanium Nitride has a complex structure and it is also transition metal nitride, literature says it is a ceramic material but it still has high electrical conductivity like metals.... Why is that?

and also can you please help me in helping precisely finding the band gap of TiN? Does it have a band gap as it behaves like metal?

Thank you

When indented by a Vickers diamond pyramid, a crack is formed as shown in the figure. What is the distance from the corner need to measure, 1 or 2?

We use Vickers indentation method for estimation of the fracture toughness. We use the following formula, Fig. 1. The calculation requires the average length of cracks. If there is only one 8 μm crack (Fig. 2), then we take the average 8 μm? Or (8+0+0+0)/4 = 2 μm?

Ceramic coating is provided on the metal to improve its wear resistance. There are many ceramic materials are available and seems not easy to choose best one which can fulfill our requirement. What criteria should we use to select the best material?

This question is to those who are experts in metals and metallic coatings.

For a particular application, I have to add very small quantities(ppm/micro gram level) of an inorganic ceramic material into metallic parts (steel,brass etc.) during their formation.Is this possible?If not, any other way to mix the ceramic particles with something and give a permanent layer coating outside?Like thermal spray or galvanization.

While fitting Cole-Cole plot to equivalent circuit model using C, R, Q; different circuit models are changing with different temperature range. The sample has grains and grain-boundaries

C= capacitor

R= Resister

Q= constant phase element.

Actually I was working on a piezoelectric project and I kept the 99.9% pure bismuth oxide powder at 800 C for 4 hours. When I opened the furnace, the bismuth oxide got sintered and took the form of the crucible. I almost placed 100 g of Bi2O3 in the furnace and now the weight of the solid sintered product is roughly the same. I would like to know if there is any way by which I could recover the powdered Bi2O3 without contaminating it?

I could make almost 10 batches with this amount so I don't want to discard it.

P.s. I have planetary ball mill (with Zr medium) and mortar and pestle.