Ceramics are products obtained by utilizing the heat energy of the appropriatemixtures of the elements found in the form of compounds in the nature.TRADITIONAL CERAMICSCeramics are used in many places today. In this section we will examine thetraditional ceramics and production processes. In the beginning, the materialmust be in the form of plastic paste.
RAW MATER?AL• When the ceramics are processed, mechanical energy applicationssuch as impact compression are used to reduce the particle size.• Two general grinding operations are categorized:Crushing and grinding• In this part, it may not be enough to reduce the size of the materialonce. After a few steps, the desired amount of reduction can beobtained. We can call it primary crushing, secondary crushing.• Reduction ratio is between 3 and 6.• After crushing, grinding of small pieces is called grinding.• Grinding is the process of pulverizing small pieces after crushing• It is a phenomenon that wears out in harsh environments with freemovement or comes to the end of the collapse.
• It is made up of three basic components: clay, silica and feldspar.• Kilin’s main raw hides juicy aluminum silicates (Al2O3,SiO2,H2O), whichin small amounts contain TiO2,Fe2O3,MgO,CaO,Na2O.• The clay in the traditional ceramics, before it hardened providesworkability and is the main component of the material.• Silika, also called flint or quartz (SiO2), has a high melting temperatureand provides resistance to conventional ceramics.
SHAPING PROCESSESPower and water ratio determine the shaping methods1. Slip casting is a mixture of clay and water. (It contains 25% -40%water.)2. If the plastic contains 15% -25% water in the clay, it is the plasticshaping methods.3. Semi dry press has low softness and moist clay (10% -15% water).
4. In dry pressing, the clay is basically dry and not soft (it contains lessthan 5% water).SLIP CASTINGSuspension of ceramic powders in water is poured into a liquid die,called a slip. The water coming from the mixture is absorbed into theliquid to form a hard solid layer on the mold surface.
The slipcomposition is 25% to 40% waterv? DRAIN CASTINGv? SOLID CASTINGPLASTIC FORMINGPlastic Forming Initially the mixture is usually a plastic that contains 15% -25% water. It can be done manually or mechanically. In order to have a softconsistency in manual construction, more water is used.
Manual shapingmethods have a long history and are still used today.Manuel method (hand modeling)Mechanized method (jiggering, plastic pressing, extrusion)Ø? Hand modeling clay is brought to desired shape and ceramic productproduction takes place. It is applied by hand molding or by throwing itinto the wheel of the potter.1. Jiggering briefly, plastic pressing can be called as a method.
Platescan be used to produce identical products such as glass bowls.Ø? Plastic pressing is the method of shaping the plastic is applied betweenthe upper and lower layers in the molds. The clay is removed from thepores when the vacuum is drawn. Subsequently, the mold sections areopened with a positive air pressure to prevent the part from sticking.
This method provides faster production than jiggering.Ø? Extrusion compression of clay is called extrusion in order to producelong sections with uniform cross-section. Products are hollow bricks,shaped tiles, drain pipes, pipes.WATERWater is a material with important factor when traditional ceramics are formed.
The water, which varies according to its quantity, must be removed before thefire. because it adds a certain volume to the piece, if it can not be removed,the volume of the piece becomes smaller than the desired size.DRYINGThe drying process has two stages.First stage is drying is rapid.
The water is evaporated into the air in thesurface and the water in the interior is transported to the surface by capillaryaction. At the same time, there is a risk of cracking due to the change in thevolume.The second part of the content is reduced to the area contacted by theceramic beads and the volume difference shrinks. Drying heat treatment isrequired to sinter the ceramic materials.
At this stage the water should not beremoved very quickly.