Hetero-Modulus Ceramic-Ceramic Composites

Ceramics, Glasses, Composite Materials Part 1. Introduction: Definition, Classification & Application

Professor Igor L. Shabalin

1

Definition of Ceramics 



The word ceramic is derived from the Greek word κεραμικος, which means “potter’s earth” or “pottery” Up until the middle of the 20th century the term covers inorganic nonmetallic materials whose formation was due to the action of heat and the most important of these were the traditional clays, made into pottery, bricks, tiles and the like, along with cements and glass 2






In modern context, the term ceramic covers an extremely broad range of inorganic materials; they contain nonmetallic and metallic chemical elements and are produced by a wide variety of manufacturing techniques Although ceramics are sometimes said to be non-metallic in character, this simple distinction from metals and alloys has become increasingly inadequate and arbitrary as novel ceramics with unusual and non-conventional properties are developed and come into use in high technologies Development of composites as a modern breakthrough in materials engineering is connected mainly with successful combinations of metals or polymers with different ceramic ingredients 3




W. D. Kingery (one of the greatest ceramic materials scientists of the 20th century) gave a following definition of ceramics: “The art and science of making and using solid articles, which have, as their essential component, and are composed in large part of inorganic non-metallic materials” Ceramics or ceramic materials can be really defined as: Solid strong compositions that are formed by the application of higher temperatures, and sometimes other energetic effects, such as high pressures etc, comprising at least one non-metallic chemical element; in other words, what is neither a metal, a semiconductor or a polymer is a ceramic 4

Definition of Ceramics

(comparison with metals and polymers)

Properties

Metals

Polymers

Ceramics

Melting point

Low to high

Low

High

Density

Medium to high

Very low

Low

Elastic modulus

Medium to high

Low

Very high (except graphite and α-BN)

Plasticity

Ductile

Ductile to brittle

Brittle

Chemical stability

Reactive

Very reactive

Non-reactive

5


(comparison with metals and polymers)

6


(comparison with metals and polymers) 





In metals, the inter-atomic (chemical) bonding is predominantly metallic, where delocalized electrons provide the “glue” that holds the positive ion cores together; this delocalization is responsible for properties most associated with metals: ductility, thermal and electrical conductivity etc. In polymers, the bonding within the chains is covalent (strong and directional), while the hydrogen bonding and Van der Waals' forces between the chains are relatively weak; this results to lower melting points, higher thermal expansion coefficients and lower stiffness etc. In ceramics, different types of bonding mechanism can occur:  ionic, e.g. in oxides and silicates (Al2O3, MgO, SiO2 etc.)  covalent, e.g. in non-metallic carbides and nitrides ( SiC, B4C, BN, Si3N4, AlN, Si2N2O, SiO2 etc.)  metallic, e.g. in transition-metal carbides and nitrides etc. and they often co-exist in the same physico-chemical phases 7


(variety of chemical bonding) 

Many compounds in ceramics contain both ionic and covalent bonding. The overall properties of these materials depend on the dominant bonding mechanism. Compounds that are either mostly ionic or mostly covalent have higher melting points than compounds in which neither kind of bonding predominates: Compound

Melting Point, 0C

Covalent, %%

Ionic, %%

MgO

2798

27

73

Al2O3

2050

37

63

SiO2

1715

49

51

Si3N4

1900

70

30

SiC

2830

89

11

8


(variety of chemical bonding) 

The unique phase of β´-sialon Si6-xAlxOxN8-x (0 ≤ x ≤ 4.2) is formed as a solid solution on the basis of β-Si3N4 by the substitution of Si and N atoms for a couple of Al and O atoms; it varies the character of chemical bonding from predominantly covalent to mainly ionic within its range of stoichiometry and in the frame of the same crystallographic structure



The cubic transition-metal carbides (e.g. TiC1-x, ZrC1-x, HfC1-x, VC1-x, NbC1-x, TaC1-x etc.), nitrides (e.g.TiN1-x, ZrN1-x, HfN1-x, VN1-x, NbN1-x, TaN1-x etc.), carbonitrides (MeCxNy) , oxycarbides (MeCxOy), oxycarbonitrides (MeCxNyOz) and some other compounds, so-called “interstitial phases”, show the properties of complex solids combining ionic structure, metallic conductivity and covalent strength 9

Classification of Ceramics (in physical structure terms)



(1) Single crystals of appreciable size (e.g. ruby laser crystal)



(2) Polycrystalline (glassfree) aggregates (e.g. finegrained pure alumina, 5000x, thermally etched)



(3) Polycrystalline aggregates produced by heat-treating glasses of special composition (e.g. glass-ceramics for laser gyroscope) to be continued

1




(4) Crystalline or glassy filaments (e.g. E-glass for glass-reinforced polymers)



(5) Polycrystalline aggregates bonded by a glassy matrix (e.g. silica refractory bricks for glass furnaces)



(6) Glass (non-crystalline) of appreciable size (e.g. sheets of “float” glass) to be continued

1




(7) Composites, multiphase systems (some examples): 

 







(a) polymer matrix (PM), longitudinal glass fibre orientation, 500x (b) PM, transverse orientation (t.p.), 500x (c) ceramic matrix 80%ZrB2 – 20%SiC, 1000x (d) ceramic matrix Si3N4+5% 3Al2O3·2SiO2 (mullite) – SiC fibre, 100x (e) ceramic matrix β´sialon – α-BN, 4000x, SEM (f) carbon – carbon (t.p.), 1000x 1

a

b

c

d

e

f

Difference between Crystalline Solids and Glasses (glass-transition temperature )

Solidification of glasses is gradual, through a viscous stage (viscosity is increasing with decreasing temperature), without a clear melting temperature  The specific volume does not have an abrupt transition at a fixed temperature but rather shows a change in slope at glass-transition temperature Tg 

1

Particularities of Glasses (glass specific temperatures)

Melting point (102 P), below this temperature glass is liquid  Working point (104 P), glass is easily deformed  Softening point (4×107 P), maximum temperature at which a glass piece maintains shape for a long time  Annealing point (1013 P), relax internal stresses due to diffusion processes  Strain point (3×1014 P), above it, fracture occurs before plastic deformation Glass forming operations – between softening and working points 1 P (poise) = 0.1 Pa·s 1 

Classification of Ceramics

(in chemical composition terms) 

(1) Oxides: 



(1.1) Simple oxides e.g. ThO2 (Tm = 3300 °C), MgO (2825 °C), UO2 (2810 °C), ZrO2 (2710 °C), CaO (2630 °C), BeO (2570 °C), Cr2O3 (2290 °C), Al2O3 (2050 °C), ZnO (Tdec=1975 °C), Fe2O3 (1740 °C), SiO2 (1715 °C), SnO2 (1127 °C), TiO2, Ta2O5 and other (1.2) Complex oxides e.g. ferrites Fe3O4 or FeO·Fe2O3, (Ba,Sr)Fe12O19 or (Ba,Sr)O·6Fe2O3, (Zn,Mn)Fe2O3 or (Zn,Mn)O·2FeO; titanates BaTiO3 (1625 °C), BaTi4O9, Ba2Ti9O20, ZrxSn1-xTiO4 SrTiO3 (2080 °C), PbZrxTi1-xO3 (PbZr0.52Ti0.48O3); niobates LiNbO3 or Li2O·Nb2O5; cuprites Nd2-xCexCuO4, La2-xBaxCuO4, YBa2Cu3O7-x, Bi2Sr2CaxCux+1O2x+6 (Bi2Sr2CaCu2O8, Bi2Sr2Ca2Cu3O10) Tl2Ba2Ca2Cu3O8, HgBa2Ca2Cu3O8 and other 1



(1) Oxides: 



(1.3) Silicates (complex oxide phases containing SiO2) e.g. mullite Al6Si2O13 or 3Al2O3·2SiO2 (Tm = 1850 °C); steatite (or talc) Mg3Si4O10(OH)2 or 3MgO·4SiO2·H2O; zircon ZrSiO4 or ZrO2·SiO2 and other (1.4) Aluminosilicates (complex oxide phases containing SiO2 and Al2O3) e.g. feldspars KAlSi3O8 or K2O·Al2O3·6SiO2, K2Al2Si8O20 or K2O·Al2O3·8SiO2; kaolinite (porcelain) Al2(Si2O5)(OH)4 or Al2O3·2SiO2·2H2O; montmorrilonite Al5(Na,Mg)(Si2O5)6(OH)4 or (Na,Ca)x(Al,Mg)2(Si4O10)(OH)2·nH2O; cordierite Mg2Al4Si5O18 or 2MgO·2Al2O3·5SiO2 and other to be continued

1



(2) Carbides: 





(2.1) Non-metallic carbides e.g. SiC (Tdec=2830 °C) and B4C (2450 °C) (2.2) Metallic carbides e.g. TaC (Tm = 3985 °C), HfC (3930 °C), NbC (3600 °C), TiC (3070 °C), WC (2780 °C), UC (2550 °C), UC2 (2480 °C) and other

(3) Nitrides: 



(3.1) Non-metallic nitrides e.g. BN (Tdec=2200-3000 0C, structurally isoelectronic to carbon), Si3N4 (1900-2600 °C) and AlN (1800-2400 °C) (3.2) Metallic nitrides e.g. HfN (Tm = 3400 °C), TaN (3080 °C), ZrN (2955 °C), TiN (2950 °C) and other 1

to be continued



(4) Complex (mixed) oxides, carbides and nitrides phases (oxynitrides, carbonitrides etc): 





(4.1) Sialons e.g. α´-sialon MexSi12-m-nAlm+nOnN16-n (Me = Li, Mg, Ca, Sr, Y, RE, 0.1 ≤ x ≤ 0.9); β´-sialon Si6-xAlxOxN8-x (0 ≤ x ≤ 4.2); cubic spinel sialon Si6-xAlxOxN8-x (0 ≤ x ≤ 2.8); O´-sialon Si2-xAlxO1+xN2-x (0 ≤ x ≤ 0.2) and other (4.2) Non-metallic compounds e.g. carbide Ti3SiC2, oxynitrides Si2ON2, γ-Al2x+1O3xN (1 ≤ x ≤ 3), Al9O3N7, Al7O3N5, Al6O3N4, φ-spinel Al22O30N2 and other (4.3) Metallic compounds e.g. mixed carbides Me´1-xMe´´xCy, carbonitrides MeCyN1-y, oxycarbonitrides MeCxNyOz (Me ´,Me´´= Ti, Zr, Hf, V, Nb, Ta, 0 ≤ x ≤ 1, 0 ≤ y ≤ 1) and other to be continued

1



(5) Borides: 





(5.1) Transition-metal borides e.g. diborides HfB2 (Tm = 3350 °C), ZrB2 (3245 °C), TiB2 (3225 °C), TaB2 (3100 °C); hexaborides LaB6 (2715 °C), SmB6 (2580 °C); dodecoboride ZrB12 (2680 °C) and other (5.2) Alkali-earth-metal borides e.g. diboride MgB2 (800 °C); hexaboride CaB6 (2235 °C) and other

(6) Silicides e.g. Hf5Si3 (Tm = 2600 °C), WSi2 (2160 °C), MoSi2 (2020 °C), Ti5Si3 (2410 °C), TiSi2 (1760 °C) and other to be continued

1



(7) Phosphides e.g. BP (Tm = 3350 °C), UP (2850 °C), AlP (>1000 °C), (Al,In,Ga)P and other



(8) Halcogenides and halides e.g. CaS (Tm = 2525 °C), US (2500 °C), CuMeX2 and CuMe2X4 (Me = Ni, Fe, V, Ir, Rh, Co, Cr and X = S, Se, Te), SrF 2 (1480 °C), CaF2 (1400 °C), NaCl (800 °C) and other



(9) Intermetallides e.g. HfRe2 (Tm = 3160 °C), Nb3Sn (2650 °C), Nb3Ge, Sm2Co17 (1620 °C), SmCo5 (1590 °C), Sm2(Co,Fe,Cu,Zr)17, Nd2Fe14B, TiNi (1580 °C) and other to be continued

2



(10) Carbon: 





(10.1) Perfect sp3-structures: diamond (cubic) and lonsdaleite (hexagonal) allotropies (10.2) Intermediate sp2/sp3-structures: diamond-like carbon, coke, char, carbon black, amorphous carbon, turbostratic graphite, vitreous carbon, vitreous carbon foam, molded carbon, pyrolytic carbon, low-modulus carbon fibre, carbon – carbon composite and other (10.3) Perfect sp2-structures: graphite (hexagonal and rhombohedral allotropies), natural graphite, molded graphite, pyrolytic graphite, highmodulus graphite fibre and other to be continued

2


(in chemical composition terms) 





(10.4) sp-structures: carbynes in different forms (10.5) Nanostructures e.g. buckminsterfullerene, fullerites, carbon nanotubes (SWCNT, MWCNT), horns, cones etc.

(11) Boron e.g. boron and B - SiC fibre or whiskers to be continued

2



(12) Composites: 



(12.1) Metal – Ceramic hard alloys, e.g. WC-Co, WC-TiC-Co, WC-TiC-TaC-Co, TiCMo-Ni, Ti(C,N)-Mo-Ni and other; cermets, e.g. Al2O3-(Mo,Ni,Cr,Cu,Al), ZrO2-(W,Mo,Ni,Fe), UO2-Al, WC-Al, TiC-(Fe,Ni), B4C-Cu, (Ti,Cr)B2-(Fe,Ni), ZrN(W,Mo), BN-Al, MoSi2-Al and other; dispersion-strengthened metals, e.g. Ni, Mo, Nb, Al, Be, Ti, Co, stainless steel and different alloys with dispersion of ceramic (oxide, carbide, boride etc.) particles; different metal matrices with oxide, boron, carbon, SiC, BSiC, B4C, BN fibre or whiskers (12.2) Polymer – Ceramic e.g. ceramic (oxides, silicates, carbon black, graphite) powders or glass microspheres with thermosetting synthetic resins; fibre glass with different synthetic resins; carbon fibre with different synthetic resins

2

to be continued


(in chemical composition terms) 

(12.3) Ceramic – Ceramic different ceramic matrices with aluminosilicate, silicate, oxide, carbon, SiC, B-SiC, B4C, Si3N4, BN fibre or whiskers oxide – carbon refractories, e.g. MgO – C, Al2O3 – C, SiO2 – C, ZrO2 – C, mullite 3Al2O3·2SiO2 – C, forsterite 2MgO·SiO2 – C and other

to be continued

2


(in chemical composition terms) hetero-modulus ceramics – the combination of ceramic matrix with high Young‘s modulus E = 300-600 GPa and the inclusions of a dispersed phase with significantly lower E = 15-20 GPa, such as sp2-structured graphite or graphitelike, hexagonal BN

2

Classification of Ceramics (in application terms)

(1) Pottery (made from traditional clays)  (2) Bricks, tiles, earthenware pipes (heavy clay products)  (3) Coarse-grained refractories (fire-bricks, silica, alumina, basic, neutral and other)  (4) Cement and concrete  (5) Glass and vitreous enamels  (6) Technical (advanced, fine, engineering, special) ceramics 

2

Application of Technical Ceramics (thermal properties)



Thermal insulation (hightemperature furnace linings): Porous oxides and silicates, e.g. SiO2, 3Al2O3·2SiO2 , Al2O3  Oxide and silicate fibre, e.g. SiO2, 3Al2O3·2SiO2 , Al2O3, ZrO2  Carbon, graphite fibre and fabric and other 

2

to be continued




Refractoriness (hightemperature furnace linings and crucibles for insulation and containment of molten metals and slags): 





Oxides and silicates, e.g. MgO, Al2O3, SiO2, 3Al2O3·2SiO2, 2MgO·SiO2 and other Oxide (sialon) – carbon refractories, e.g. MgO – C, Al2O3 – C, 3Al2O3·2SiO2 – C and other Molded graphite and carbon and other 2

to be continued




Thermal conductivity (heat sinks for electronic packages): AlN  BeO and other 

to be continued

2

Application of Technical Ceramics (thermo-mechanical properties)



Thermal protection (aerodynamic-heated surfaces of re-entry flying apparatus and thermally stressed parts of liquid and solid propellant rocket engines):    

Porous oxides e.g. SiO2 Polymer – ceramic composites Carbon – carbon composites Hetero – modulus ceramics to be continued

3

Application of Technical Ceramics (electrical and dielectric properties)



Electrical conductivity (heating elements and electrodes for furnaces): SiC  ZrO2  MoSi2  Graphite  Carbon – carbon composites and other 

to be continued

3




Ferroelectricity (piezoelectric, capacitor and microwave dielectrics): BaTiO3, BaTi4O9, Ba2Ti9O20  SrTiO3  PbZrO3  PbZr0.52Ti0.48O3  LiNbO3  LiTaO3  NaNbO3  Tb2(MoO4)3 and other 

to be continued

3




Low-voltage electrical ceramic insulators: Porcelain Al2(Si2O5)(OH)4 or Al2O3·2SiO2·2H2O  Steatite Mg3Si4O10(OH)2 or 3MgO·4SiO2·H2O  Forsterite Mg2SiO4 or 2MgO·SiO2  Cordereite Mg2Al4Si5O18 or 2MgO·2Al2O3·5SiO2  Corundum Al2O3  Celsian BaAl2Si2O8 or BaO·Al2O3·2SiO2 and other 

to be continued

3




Insulators in electronic applications (substrates for electronic packaging and electrical insulators in general, include insulations in hostile environments e.g. spark plugs, ion rocket engines etc.): Al2O3  AlN  BeO  Borosil SiO2 – BN  SBN β´-sialon – α-BN and other 

3

to be continued




Ion-conducting (sensors and fuel cells): Al2O3  Zr0.92Y0.08O1.96  NiO – (Zr,Y)O2  LaCrO3  Ce0.8Gd0.2O1.9  δ-Bi2O3 and other 

to be continued

3




Semiconducting (electronic devices, thermistors and special heating elements): Oxides of Fe, Co, Mn, Ni, Ti, Sn  Titanates of Ba, Pb  Halcogenides  Diamond and other 

to be continued

3




Non-linear I – V characteristics (current surge protectors, varistors): ZnO (Bi, Co, Mn -doped)  SiC and other 

to be continued

3




Gas-sensitive conductivity (gas sensors):      

ZnO SnO2 SiO2 SiC Si3N4 Carbon nanotubes and other to be continued

3

Application of Technical Ceramics

(magnetic and superconductive properties) 

Hard (permanent) magnets: 



Ferrites e.g. (Ba,Sr)Fe12O19 or (Ba,Sr)O·6Fe2O3 Intermetallides e.g. YCo5, SmCo5, Sm2Co17, Sm2(Co,Fe,Cu,Zr)17, Nd2Fe14B

to be continued

3


(magnetic and superconductive properties) 

Soft magnets (transformer cores and magnetic tapes):  



Oxides γ-Fe2O3, Cr2O3 Ferrites e.g. (Zn, Me)Fe2O4 or (Zn, Me)O·Fe2O3 (Me = Mn, Co, Mg) and other Rare-earth garnets e.g. Y3Fe5O12 or 3Y2O3·5Fe2O3 and other

to be continued

4


(magnetic and superconductive properties)



Superconductivity (wires and SQUID magnetometers):      

   

Nd2-xCexCuO4 Ba0.6K0.4BiO3 La2-xBaxCuO4 La1.6Sr0.4CaCu2O6 YBa2Cu3O7-x Bi2Sr2CaxCux+1O2x+6 (Bi2Sr2CaCu2O8, Bi2Sr2Ca2Cu3O10) Tl2Ba2Ca2Cu3O10 HgBa2Ca2Cu3O8 Nb3Sn, Nb3Ge MgB2 4

to be continued

Application of Technical Ceramics (optical properties)

 Transparency

(different windows, lenses, cables for optical communications): 









Window (soda-lime) glass, wt.%: SiO2 – 72, Na2O – 14, CaO – 10, MgO – 2, Al2O3 – 1 Light bulbs: SiO2 – 74, Na2O – 16, CaO – 5, MgO – 4, Al2O3 – 1 Optical flint: SiO2 – 50, PbO – 19, BaO – 13, K2O – 8, ZnO – 8, Na2O – 1 PyrexTM: SiO2 – 81, B2O3 – 12, Na2O – 4, Al2O3 – 2 Fused silica: SiO2 – 99 4

to be continued




Translucency and chemical inertness (heat- and corrosionresistant materials, e.g. for sodium vapour lamps and other devices): Al2O3 (LucaloxTM)  MgO  Y2 O 3  BeO and other 

to be continued

4




Non-linearity (e.g. for switching devices for optical computing): Oxides e.g. TeO2  Niobates and tantalates e.g. LiNbO3, LiTaO3, KNbO3  Borates e.g. β-BaB2O4, LiB3O5, CsLiB6O10, K2Al2B2O7, Nd-doped YAl3(BO3)4 and YCa4O(BO3)3  Germanates e.g. Bi4Ge3O12, Bi12GeO20  Tellurides e.g. Cd0.96Zn0.04Te, Hg0.8Cd0.2Te and other 

to be continued

4




Infra-red transparency (IR laser windows): Halides e.g. CaF2, SrF2, MgF2, NaCl  Halcogenides e.g. ZnS, ZnSe and other 

to be continued

4

Application of Technical Ceramics (optoelectronic properties)



Active laser medium: Cr-, Ti-doped sapphire Al2O3  Nd-, Er-, Yb-, Nd/Ce-, Ho/Cr-, Tm-, Cr4+-, Dy-, Sm-, Tb-, Ce-doped rareearth garnet Y3Al5O12  Nd-doped orthovanadate YVO4  Silicate and phosphate glasses doped with laser active ions and other 

to be continued

4




Jewellery (natural and artificial gemstones):      

SiO2 (Mn-doped) – amethyst (1) Be3Al2(SiO3)6 (Cr-doped) – emerald (2), aquamarine (3) 6 4 Cubic ZrO2 (4) Al2O3 (Cr-doped) – ruby (5), sapphire (6) Zircon ZrSiO4 (7) Diamond (8) and many 7 5 other

1

2

to be continued

4

8

3

Application of Technical Ceramics (nuclear properties)



Fission reactors:       

Nuclear fuel (UO2, UC, PuO2, (U,Pu)O2, UO2 – BeO, UC2 – C) Fuel cladding (graphite, SiC, Si3N4) Neutron moderators (graphite, BeO, BeC2, ZrO2) Control assistance (B4C, Sm2O3, Gd2O3) Neutron radiation shield (B4C, HfO2, Sm2O3, Gd2O3) Thermal insulation (Al2O3, SiO2) Electrical insulation in active zone (Al2O3, MgO) 4

to be continued

Application of Technical Ceramics (nuclear properties)



Fusion reactors:    

Tritium breeder materials (Li2O, LiAlO2, Li2SiO3, Li2ZrO3) Reactor lining (graphite, SiC, Si3N4, SiC – C, TiC – SiC – C) Plasma restriction (Al2O3, SiC, B4C) Windows for plasma heating (Al2O3, BeO) to be continued

4

Application of Technical Ceramics (chemical properties)



Catalysts, filters, purification of gases, molecular sieves: Synthetic and mineral zeolites (Me´,Me´´,…,Me(i))On·xAl2O3·ySiO2·zH2O, Me(i) = Li(+), Na(+), K(+), NH4(+), Mg(2+), Ca(2+), Sr(2+), Ba(2+) e.g. natrolite Na2O·Al2O3·3SiO2·2H2O or Na2Al2Si3O8(OH)4,  Honeycomb structures for catalyst support e.g. cordierite Mg2Al4Si5O18 or 2MgO·2Al2O3·5SiO2 and other 

to be continued

5




Anticorrosion protection (heat exchangers, chemical equipment in corrosive environments): SiC  Si3N4  Sialons  Borides e.g. TiB2, (Ti,Cr)B2, ZrB2 and other 

5

to be continued




Biocompatibility (artificial joint prostheses, cardiac valve replacement, prosthodontics etc.):       

Al2O3 Sialons ZrO2 Hydroxyapatite Ca5(PO4)3(OH) Glass-ceramics Vitreous carbon Carbon – carbon composites 5

to be continued

Application of Technical Ceramics (mechanical properties)



Hardness (cutting and stamping tools, die molds): WC – Co  WC – TiC – Co  WC – TiC – TaC – Co  TiC – Mo – Ni  Ti(C,N) – Mo – Ni  Al2O3  SiC – Al2O3  Si3N4  Sialons  Cubic BN  Diamond and others 

5

to be continued




Hardness (abrasives): SiO2  Al2O3  Aluminosilicates  Al2O3 – ZrO2  SiC  Zircon ZrSiO4  Cubic BN  Diamond and others 

to be continued

5




High-temperature strength retention (stators and turbine blades, ceramic engines etc.):    

 

Si3N4 Sialons SiC – C Whisker- and fibrereinforced ceramic matrices Carbon – carbon composites Different ceramic coatings to be continued 5




Wear resistance (bearings, brake-shoes etc.):    

 

Si3N4 Sialons SiC – C Whisker- and fibrereinforced ceramic matrices Carbon – carbon composites Different ceramic coatings to be continued

5

Application of Technical Ceramics (physico-mechanical properties)



Military use (body and technical armour, piercing ammunition of projectiles etc.): B4C  WC – Co  Different cermets  Carbon fabric  Carbon – carbon composites  Different ceramic coatings and other 

5

To be continued