Development of Ceramic Materials with Extreme Mechanical Properties Dr. László A. Gömze H-3515 Miskolc-Egyetemváros, Hungary Tel. +36-30-7462714 EUROMAT

Development of Ceramic Materials with Development of Ceramic Materials with Extreme Mechanical Properties Extreme Mechanical Properties

Dr. László A. GömzeDr. László A. Gömze

H-3515 Miskolc-Egyetemváros, HungaryH-3515 Miskolc-Egyetemváros, HungaryTel. +36-30-7462714Tel. +36-30-7462714

EUROMAT 2005 Conference PRAGUE

Dr. GÖMZE A. László, [email protected]; +36-30-7462714Department of Ceramics and Silicate Engineering, University of Miskolc



ABSTRACTABSTRACT

Mechanical properties of ceramicsMechanical properties of ceramics

Factures influence on mechanical properties of Factures influence on mechanical properties of ceramicsceramics

Microstructure and Morphology of technical Microstructure and Morphology of technical ceramicsceramics

Distribution of pressure stresses in ceramic Distribution of pressure stresses in ceramic powders during their compactingpowders during their compacting

Ceramic items with extreme mechanical Ceramic items with extreme mechanical properties properties



MECHANICAL PROPERTIES OF CERAMICSMECHANICAL PROPERTIES OF CERAMICS

STRENGTH STRENGTH Pressure strength (Rp)Pressure strength (Rp)Shearing strength (Rs)Shearing strength (Rs)Bending strengt (Rb)Bending strengt (Rb)Tensile strength (Rh)Tensile strength (Rh)

HARDNESSHARDNESSMicro-hardness (HVmi)Micro-hardness (HVmi)Macro-hardness (HVma)Macro-hardness (HVma)

RHEOLOGICAL PROPERTIES (RHEOLOGICAL PROPERTIES (ii, E, Eii, , 00, , ))




FACTURES, INFLUENCE ON MECHANICAL FACTURES, INFLUENCE ON MECHANICAL PROPERTIES OF TECHNICAL CERAMICSPROPERTIES OF TECHNICAL CERAMICSChemical composition (CChemical composition (Ccc))

Shapes (SShapes (Sgg) and grain sizes (G) and grain sizes (Gss) of used ) of used ceramic powdersceramic powders

Distribution of grain shapes and sizes in Distribution of grain shapes and sizes in forming dies (Dforming dies (Dgg))

Distribution of pressure stresses in ceramic Distribution of pressure stresses in ceramic bidies during their compacting (Dbidies during their compacting (Dpp))

Temperature (TTemperature (Tss) and atmosphere (S) and atmosphere (Saa) of ) of sinteringsintering



PRESSURE STRENGTH AND MICRO PRESSURE STRENGTH AND MICRO HARDNESS AS FUNCTION OF INFLUENCE HARDNESS AS FUNCTION OF INFLUENCE

FACTURESFACTURES

Rp = f(CRp = f(Ccc, D, Dgg, D, Dpp, G, Gss, S, Saa, S, Sgg, T, Tss););

HVmi = f(CHVmi = f(Ccc, D, Dgg, D, Dpp, G, Gss, S, Saa, S, Sgg, T, Tss))



THE TIPICAL SHAPES AND DISTRIBUTION OF THE TIPICAL SHAPES AND DISTRIBUTION OF ATOMIZER POWDERS IN FORMING DIESATOMIZER POWDERS IN FORMING DIES



INFLUENCE OF POWDER GRAIN SIZES AND INFLUENCE OF POWDER GRAIN SIZES AND THEIR DISTRIBUTION ON MICROSTRUCTURE THEIR DISTRIBUTION ON MICROSTRUCTURE

AND MORPHOLOGY OF FIRED CERAMIC AND MORPHOLOGY OF FIRED CERAMIC ITEMSITEMS



DISTRIBUTION OF PRESSURE STRESSES IN DISTRIBUTION OF PRESSURE STRESSES IN CERAMIC POWDERS DURING THEIR CERAMIC POWDERS DURING THEIR

COMPACTING WITH UNIAXIAL TECHNOLOGYCOMPACTING WITH UNIAXIAL TECHNOLOGY

DL

fppc

4exp

11 [MPa]



PRESSURE DISTRIBUTION IN FORMING DIES PRESSURE DISTRIBUTION IN FORMING DIES WITH TRUNCATED CONE SHAPESWITH TRUNCATED CONE SHAPES

L

dDd

dDdDfdDdfpp

btc

2

22

3

2212exp

11

[MPa]



PRESSURE DISTRIBUTION IN FORMING DIES PRESSURE DISTRIBUTION IN FORMING DIES WITH RECTANGULAR PRISMATIC SHAPESWITH RECTANGULAR PRISMATIC SHAPES

ab

bafL

pprp2exp

11 [MPa]



PRESSURE DISTRIBUTION IN FORMING DIES PRESSURE DISTRIBUTION IN FORMING DIES WITH REGULAR HEXAGONAL PRISMATIC WITH REGULAR HEXAGONAL PRISMATIC

SHAPESSHAPES

a

Lf

pphp

3

34exp

11 [MPa]



PRESSURE DISTRIBUTION IN FORMING DIES PRESSURE DISTRIBUTION IN FORMING DIES WITH TRUNCATED PYRAMID SHAPESWITH TRUNCATED PYRAMID SHAPES

LabAB

ba

ababABABf

bBaAf

pp

b

tp

3

2

coscos4

exp

11

[MPa]



PRESSURE DISTRIBUTION IN FORMING DIES PRESSURE DISTRIBUTION IN FORMING DIES WITH SPHERICAL SEGMENT OF SHAPESWITH SPHERICAL SEGMENT OF SHAPES

L

rRr

rRf

rR

fpp

b

s

3

cossin4exp

11

22

[MPa]



PRESSURE DISTRIBUTION IN FORMING DIES PRESSURE DISTRIBUTION IN FORMING DIES WITH QUARTERED TORUS SHAPESWITH QUARTERED TORUS SHAPES

L

rRr

rrRRfrRfrpp

bqt

20

200

200

2000

6

28331046exp

11

[MPa]



THE REQUIRED „MINIMUM” VALUE OF THE REQUIRED „MINIMUM” VALUE OF DEVELOPED PRESSURE STRESS IN DEVELOPED PRESSURE STRESS IN

CERAMIC BODIES DURING THEIR FORMING CERAMIC BODIES DURING THEIR FORMING IN DIES WITH CYLINDRICAL SHAPESIN DIES WITH CYLINDRICAL SHAPES

kr

D

Lf

cm p

e

pp

4[MPa]




CERAMIC BODIES DURING THEIR FORMING CERAMIC BODIES DURING THEIR FORMING IN DIES WITH TRUNCATED CONE SHAPESIN DIES WITH TRUNCATED CONE SHAPES

krb

tcm p

LdDd

dDdDfdDdf

pp

2

22

3

2212exp

[MPa]




CERAMIC BODIES DURING THEIR FORMING CERAMIC BODIES DURING THEIR FORMING IN DIES WITH SPHERICAL SEGMENTS OF IN DIES WITH SPHERICAL SEGMENTS OF

SHAPESSHAPES

kr

b

sm p

LrRr

rRf

rR

f

pp

3

cossin4exp

22

[MPa]



THE SYMBOLS USED IN MATHEMATICAL THE SYMBOLS USED IN MATHEMATICAL EQUATIONSEQUATIONS

a, A, b, B, r, r0, R, R0, d, D, a, A, b, B, r, r0, R, R0, d, D, , , , , and and - are - are geometrical parametersgeometrical parameters

ff, , fb –friction ratiofb –friction ratioss

p – p – the the outside pressure, developed by outside pressure, developed by pressingpressing puncherspunchers

L – distance from the contact surface of pressing L – distance from the contact surface of pressing punchers to the examined place in ceramic powderspunchers to the examined place in ceramic powders



INFLUENCE OF THE PRESSURE STRESSES INFLUENCE OF THE PRESSURE STRESSES ON THE MICROSTRUCTURE AND ON THE MICROSTRUCTURE AND

MORPHOLOGY OF FIRED ALUMINA CERAMIC MORPHOLOGY OF FIRED ALUMINA CERAMIC ITEMSITEMS

UNDER PRESSED POWDERSUNDER PRESSED POWDERS WELL PRESSED POWDERSWELL PRESSED POWDERS



OPTIMUM PRESSED POWDERSOPTIMUM PRESSED POWDERS

INFLUENCE OF THE PRESSURE STRESSES INFLUENCE OF THE PRESSURE STRESSES ON THE MICROSTRUCTURE AND ON THE MICROSTRUCTURE AND

MORPHOLOGY OF FIRED ALUMINA CERAMIC MORPHOLOGY OF FIRED ALUMINA CERAMIC ITEMSITEMS

WELL PRESSED POWDERS WITH WELL PRESSED POWDERS WITH OPTIMUM GRAIN SIZE DISTRIBUTION OPTIMUM GRAIN SIZE DISTRIBUTION

IN FORMING DIEIN FORMING DIE



CONCLUSIONCONCLUSION

1.1. THE FAILURES AND MISTAKES MADE DURING THE FAILURES AND MISTAKES MADE DURING COMPACTING OF CERAMIC ITEMS CAN NOT BE COMPACTING OF CERAMIC ITEMS CAN NOT BE CORRECTED WITH SINTERING AND OTHER CORRECTED WITH SINTERING AND OTHER TECHNOLOGICAL OPERATIONSTECHNOLOGICAL OPERATIONS

2.2. THE VALUES AND DISTRIBUTION OF PRESSURE THE VALUES AND DISTRIBUTION OF PRESSURE STRESSES ARE THE MAIN FACTURES WHICH STRESSES ARE THE MAIN FACTURES WHICH INFLUENCE ON PRESSURE STRENGTHES OF INFLUENCE ON PRESSURE STRENGTHES OF TECHNICAL CERAMIC ITEMS MADE FROM AL2O3 TECHNICAL CERAMIC ITEMS MADE FROM AL2O3 POWDERSPOWDERS

3.3. WE ARE THE FIRST WHO COULD DESCRIBE THE WE ARE THE FIRST WHO COULD DESCRIBE THE MATEMATICAL EQUATIONS OF PRESSURE MATEMATICAL EQUATIONS OF PRESSURE DISTRIBUTION IN CERAMIC BODIES DURING THEIR DISTRIBUTION IN CERAMIC BODIES DURING THEIR COMPACTING IN DIES OF DIFFERENT COMPACTING IN DIES OF DIFFERENT GEOMETRICAL SHAPESGEOMETRICAL SHAPES



THANK YOU FOR YOUR ATTENTIONTHANK YOU FOR YOUR ATTENTION

Documents

Development of Ceramic Materials with Extreme Mechanical Properties Dr. László A. Gömze H-3515 Miskolc-Egyetemváros, Hungary Tel. +36-30-7462714 EUROMAT