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Precision Ceramic
      Precision ceramic (Fine Ceramics) is made of high purity inorganic materials that's different from traditional ceramic. Its blank is made with chemical formulation and physical process then it's formed by molding and reinforce its microstructure, chemical and physical properties up to some certain level with high temperature sintering.
Finally it's made into various products with precision machining. Fine ceramic is
featured with 5 major properties:

1. Corrosion resistance:
    Most ceramics are capable of anti-oxidation and chemical corrosion resistant.

2. High temperature resistance:
    Very few other material can withstand high temperature like that of ceramics.
    Some fine ceramics can withstand 1,400° C and still keep good strength. But
    even like the most heat resistant alloy can hardly be used more than 1,100°C.

3. Wear resistance:
    Fine ceramic is well known for its good wear resistance but reversely it's brittle.

4. Light weight:
    Most ceramics are lighter than metals and even lighter by 40% of metals weight.

5. Low friction coefficient:
    Due to its low friction coefficient, high compressive strength and abrasion
    resistance make some fine ceramic parts can be used in mechanical components
    without lubrication.


 

     Although fine ceramics are possessed of all these properties but its low
toughness(high brittleness) is likely to cause user troubles. Therefore our company
has been dedicated to develop fine ceramics of higher toughness.It can be sorted
into four main categories:
 
1. Silicon carbide
     This is commonly used non-oxide ceramic material. Due to its better hardness, heat resistance, oxidation resistance, corrosion resistance and high thermal conductivity than the normal ceramic, silicon carbide is widely used in recent years as the structural item in mechanical engineering and as seals in chemical engineering, and even used in the extreme conditions like strong acid, strong alkali, high abrasion, high temperature, aerospace.
     The normal pressure sintered silicon carbide is composed of α-SiC crystals. Volume density can reach more than 98% of theoretical density (3.1g/cm3). Density is 1/5 of tungsten carbide. Hardness is second only to diamond. Performance of particle abrasion resistance is excellent. S-SiC paired with graphite is a sealing pair of the highest PV value. High purity and normal pressure sintered silicon carbide (>98% SiC) can resist corrosion of all kinds of acid and alkali of chemical media. S-SiC has high strength. Its performance of anti-oxidation and mechanical strength in high temperature is also excellent.
 
2. Zirconia
    In addition to the general properties of fine ceramics like high strength and hardness, high temperature resistant, corrosion resistant of acid and alkali and high chemical stability, Zirconia is even further featured with higher tenacity. This makes it can be used in various industries such as shaft sealed bearings, cutting parts, auto parts and even can be used in human body such as artificial hip joints.

 Zirconia can be sorted into four categories:
 a. Fully Stabilized Zirconia (FSZ)
 
    This is a complete cubic crystal structure with poor mechanical properties.
 b. Zirconia Toughened Ceramics (ZTC)

 
     Its second phase is compounded with other elements (Al2O3, Si3N4, glass,
     etc.) into a composite material in order to improve tenacity and mechanical
     properties.

 c. Partially Stabilized Zirconia (PSZ)

 
     The PSZ is added with Y2O3 that can help tetragonal distribute in the cubic.
     Tetragonal phase is with characteristics of phase transformation toughening,
     so the PSZ has a higher toughness.

 d. Tetragonal Zirconia Polycrystals (TZP)

 
     By adding Y2O3-ZrO2 in the TZP to obtain higher mechanical properties,
     strength, toughness and chemical stability which will be widely used in
     construction and biomedical fields.

3. Alumina Oxide
    The reserve of alumina oxide in the earth is only after the silica and belong to one of ceramic material. The aluminum oxide has a strong link with oxygen, so that aluminum oxide  has the highest hardness and chemical stability and is corrosion resistant against most acidic, alkaline, molten salt solution. The strength of Alumina Oxide is subject to density and microstructure and will reach the highest strength at normal temperature. By raising the temperature to 1000 ˚ C , the strength decreased obviously. Alumina has also low thermal expansion coefficient.


4. Porous Ceramics
     
Porous ceramic is a ceramic of which the material itself has numerous pores by the ceramic sintering technology and is used for a vacuum chuck. 

Recently it is widely used as a basic material for various industrial products like filters, refractories, kiln furnitures, absorbers, acoustic absorbents, light weight structural materials, adiabatic materials, etc.

Especially it is applied for the vacuum absorption technology with high precision and high performance to absorb ultra thin objects which is required recently for production of semiconductor, LED and display.

It is very important for porous ceramic to have high porosity and maintain high strength. Especially in the area of semiconductor and display industry recently rising as an issue, porous ceramic should have even porosity and good surface roughness not to damage the object to absorb.

It is good for porous ceramic to have high porosity but the higher the porosity is, the lower the material strength gets. In addition, when pore density is low the porosity gets lower or the pore size gets bigger at the same porosity. So the material with low pore density also has lower strength. 
 

     All Alumina characteristics (including thermal properties, mechanical properties and physical and chemical properties, etc.) is related to its purity. In general, the higher purity of alumina, the better thermal conductivity. And density of high-purity alumina close to the theoretical density which can make the mechanical properties better.