CERAMICS

7th group member :Firda Ramadhena 112122239

Emeral SakinahDinar

Prima Annisa Karunia 112121184

CERAMICS

Ceramic MaterialsCeramic materials are inorganic and non-metallic

materials that can be composed also of metal and non-metal materials. Because it has certain properties that are difficult processed and avoided like the fragility of nature, then this material development is quite slow.

The most important element that ceramic materials can be processed into industrial materials which is good because in general has excellent properties, such as:1. Strong2. Hard3. Stable in high temperature.

By having important properties above, the ceramic materials such as Silicon Carbide (SiC) or Silicon Nitride (Si3N4) can be used as a base turbine and motor. They are formed of materials in ionic and covalent bonding.

Characteristic

Properties and main characteristics of ceramic materials can be summarized as follows:1. Hard2. Fragile3. Has a high melting temperature4. Electical Isolator5. A poor conductor of heat6. Has a stable chemical composition7. Has a high compressive8. Properties retain heat stable

Scope

This material as a raw material for a wide range industries, such as:

1. Household appliances2. Cookers furnace equipment3. Irrigation pipes4. Glassware equipment5. Refractory goods6. Tooling machines7. Electronic materials8. Aviation and armament

Ceramic Phases

Generally ceramic phase has a crystalline structure, only difference with the element of metal crystals, crystalline ceramics do not have much free electrons.

This is because the electrons divided by the adjacent atoms. Or is because the electrons move from one atom to another atom and form ionic bonds. Because the ionic bonds the ceramic material has a high stability.

Atom bonding ceramic materials are stronger than metal, because the chemical reactions take place more slowly.

Tetrahaden crystal SiO4 structure is the basis for the construction of various types of crystalline silicate ceramic materials.

In general, the crystal structure of the ceramic material is more complicated when compared with the crystal structure of the metal.

The picture is a form of cristobalite SiO2 unit.

Crystal Ceramic Material

Wake ceramic crystals that occur from metallic and non-metallic compounds most simple is if the comparison between metallic and nonmetallic elements as 1:1. Examples of these compounds are molecules of MgO. 2 MgO bonding electrons move from the metal to non-metal, thus forming Mg2+ cations and anions O2-.

How the preparation of the main atom can have 3 ways, as the following example:

Crystal Ceramic Build type AZ

WAKE OF CRYSTAL: ZnS Coordination Numbers: 4 Constants Kisi: a = 4 (r + R)

WAKE OF CRYSTAL: NaClCoordination Numbers: 6Constants Kisi: a = (2r + 2R)

WAKE OF CRYSTAL: CsCl Coordination Numbers: 8 Constants Kisi: a = (r + R)

The Number Of Coordinates And Radius Comparison

EXAMPLES OF CERAMIC CRYSTAL STRUCTURE

EXAMPLES OF CERAMIC CRYSTAL STRUCTURE

A. CRYSTAL STRUCTURE OF CESIUM CHLORIDA (CsCl)B. CRYSTAL STRUCTURE OF NATRIUM CHLORIDA (NaCl)C. CRYSTAL STRUCTURE OF ZINK SULPHUR (SnS)D. CRYSTAL STRUCTURE OF FLUROITE. CRYSTAL STRUCTURE OF WURTZITE

COORDINATES OF ATOM CRYSTALCERAMIC MATERIAL

• Ceramic materials disseminated to electromagnetic circuits, this is because the constant dielectric this material is high, even at the moment of the transition elements are almost all semiconductors.

• There are a variety of oxides which acts as an insulator is good, because the valence electrons of the metal atoms move on a permanent basis to the oxygen atoms to form ion O2-

ELECTRON MAGNETIC PROPERTIES OF CERAMICS

examples of phase binair diagram

THE TRANSFORMATION OF COMPOUND CERAMIC

Ceramic Crystal type SiO2 shape : tetrahedder silica can have various forms of alotropi, when the temperature rises, the silica will change from :

The graph of the equilibrium is affected by the pressure and temperature

The transformation from crystalline to the crystalline form of a shift transformation, where the transformation of this form is identical to the reaction martensit. Silica with drastically changed the structure of the Crystal due to distortion of the unit cell on the small contiguous parts or from the nearest neighbor. This kind of transformation also occurs in cristobolite and trydimite.

Transformation between silica and tridimite, with the cristobolite transformation of the renewal (recontructive). Recontructive transformation, requiring splitting of bonding between atoms and formed a major change in crystal structure. The transformation this form requires greater energy, the growing of grains crystals, and runs slower than on the transformation of the shift.

THE TRANSFORMATION OF COMPOUND CERAMIC

THE TRANSFORMATION OF COMPOUND CERAMIC

The CaO-SiO2-Al2O2 tertiary phase diagram

THE TRANSFORMATION OF COMPOUND CERAMIC

The transformation of the shift gives rise to a linear expansion-shaped dimensions and for sufficiently large compared to the sislika that occurred on the glass, look at pictures 2.8.2 below :

CRYSTAL DEFECTS

POINT DEFECTS HANDICAP LINE DISABLE FIELDS

POINT DEFECTS

• Defects occur on events intersial or subtitusional, which is the replacement of one atom to another.

• Example: a ceramic compound at equilibrium NiO-MgO or orthosilikat compounds such as : (Mg,Fe)2 SiO4 here ions mg or fe acts of mutual substitution.

HANDICAP LINE

• This form of Disability line defect known as very popular name is “dislocation”. Like many of the defects occur in compounds such as LiF, Al2O3 and crystal MgO.

• Although at high temperatures, a ceramic material retains the properties of the ' brittle ' before the case shifts atoms to be plastis deformation.

DISABLE FIELDS

For example the events binding molecules of gas into the surface of the material and this can serve meredusir energy surface. Of foreign ions on certain ceramic compounds will be attracted to composition from the surface of the Crystal field and certainly will change the composition of the material.

PROCESS TECHNOLOGY

VISCOSITY THEORY

FINE PARTICLE (POWDER)

PRESSINGSLIP CASTINGEXTRUSIONJIGGERINGSINTERING

homogenization

manufacturing process

formation technique

TECHNIQUE FOR MANUFACTURING SHEET AND PLATE GLASS

a) Rolling b) Floating the glass on molten tin.

Figure (a): Stating the process of rolling and heat treatment to end with annealling.

Figure (b): The pool of glass with hot and cold process and continues to annealling.

How glass is made?

PROCESSES FOR SHAPING CERAMIC CRYSTALINE

a. PRESSING b. ISOTATIC PROCESSING c. EXTURSION d. JIGERRING e. SLIP CASTING

GRINDING

Until 20 years ago, ceramic material only known on the electrical energy industry, because as an excellent insulator. Now known and processed certain advantages such as: hard, refractory, insulation and has a stable chemical composition. Hard materials are processed because of violence and brittleness higher than metal, has now managed to take the place as a superior components for :

a. CUTTING TOOLSb. MECHANICAL PARTS.

CERAMIC MATERIALS FOR HIGH TEMPERATURE HEAT EXCHANGES

Operation process of heat exchanges with temperatures above 1000˚ C requires a material with excellent mechanical properties. The properties include: strength of materials in high temperature, High heat impact, creep and heat fatigue resistance. The Material has mechanical properties above are just generally owned by: ceramic monooksida. To get the materials ready for use must be processed by sintering, both normal sintering and hot presure pressurized sintering.

Ceramic materials are resistant to heat load caused by the effects of heat flows from one side of the wall to the other side of the heat exchange.

FISTON CERAMIC ENGINE.

In 1989 Isuzu Motor Co. Ltd., announced that it will begin to enter the market a passenger vehicle which is driven by a piston engine of the ceramic material.

presented a comparison of output/thermal efficiency on Ceramic Methanol engines