mm 206 project group 1

7/30/2019 MM 206 Project Group 1

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Characterisation ofGreen Ceramic Tapes

By:- Ugam Alias Vasudev PradeepRohit

Raj A

Vinay

Anuja Ch

Group 1


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INTRODUCTION

Recently Ceramic Tapes have found wide variety of applications, which iswhy we dec ided to take this as a project in order to characterize and findthe properties of the ceramic tapes.


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PREPARATION

Slip Rec ipe

Powder

Solvents

Dispersion

Binder

Plasticizer


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POWDER

The alumina powder used in this work was CT 3000 with average particlesize of 0.5 m and surface area (BET) of 6.92 m2/gm.

Dec reasing particle size results in increasing viscosity because ofincreased particle-particle interaction

Particle shape is also important. Non-spherical particles, especially rods orplates approach each other much more c losely in a suspension than dospherical particles of equal volume.


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SOLVENTS

An azeotropic mixture of trichloro ethylene and ethanol in the proportionof 60:40 volume ratio is used

This azeotropic mixture prevents skin formation during fast drying bymaintaining residual liquid layer at the top.

Also, they are a good compromise between dielectric constant andsurface tension and low boiling point, and an adequate viscosity forhandling and drying


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DISPERSANTS

Sorbitan Trioleate (a c heap non-ionic surfac tant) and Cardanol (naturallyoccurring C15 unsaturated aliphatic chain-substituted phenol) are thetwo dispersants used

The role of a dispersants in a tape casting slip are to hold each and everyindividual particle in the suspension separate so that binder can coat

them individually and to increase solids loading by maintaining moderateviscosities after binder addition.

The molecules that contain hydrophilic groups, such as OH and COOH,which strongly interact with alumina surface, have been determined tobe better dispersants.


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BINDER

Poly vinyl butyral, which is soluble in non-polar media, was used as thebinder.

Binders are added to slips in order to enhance the strength of the greentape for easy handling and storage. The binder remains in the tape,forming organic interparticle bridges, resulting in a strong adhesion after

solvent evaporation.

Being the only continuous phase in the green tape, the binder has thegreatest effec t on green tape properties such as strength, flexibility,plasticity, laminatability, durability, toughness, printability, and smoothness


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PLASTICIZERS

Polyethylene glycol 300 (PEG)(Plasticizer I) and Dioctyl phthalate(DOP)(Plasticizer II) owing to their lower molecular weight, lowerintermolecular contacts, less rigid side groups and reduced number ofpolar groups.

Plasticizers are added to the slip to confer sufficient flexibility to the green

tape for easy handling and storage.

The most important effect of the plasticizer is to reduce the binder Tg atroom temperature or less.


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Schematic of Tape Casting Process


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CHARACTERIZATION

TGA

SEM

EDX

Evaporation

Measurement of viscosity


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ThermoGravimetricAnalysis

(TGA)


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DTA Analysis


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ScanningElectronMicroscope

(SEM)


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ScanningElectronMicroscope

(SEM)


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Scanning Electron Microscope (SEM)

Particle Size as measured from the photograph mentioned above is 0.6min 15k X magnification

As can be clearly seen the microstructure of the ceramic tape is highlypacked with very few voids indicating good quality sample

15kV elec tron excitation voltage was used. This provided high resolution

with a trade off of signal quality.

Back Electron Scattered SEM imaging did not show any contrast as all theelements are within very small range of atomic numbers


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Energy Dispersive X-Ray Spectroscopy(EDX)


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EDX results of all the three samplings of the sample provided the sameelemental proportion.


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ViscosityMeasurementof Slurry

Pascal-second

1/second


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Curve of Weightvs. Drying Time

Curve of Weight v


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Applications of Green Ceramic Tapes

Some potential applications include

1. Solid-oxide fuel cells

2. Multi-layered ceramic packages (MLCP)

3. Multilayered ceramic capacitors (MLCC )

4. Photovoltaic solar applications

5. Laminated composites sensors/actuators

6. Transducers


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Applications of Green Ceramic Tapes


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Thanks for your

Patience

mm 206 project group 1

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