Fabrication and Processing of Ceramics

Ceramics melt at high temperatures and show fragile behavior under tension. As a result, the conventional melting, casting and thermomechanical treatment routes are not suitable for the treatment of polycrystalline ceramics. However, inorganic glasses use lower melting temperatures because of the formation of eutectics. As a result, most ceramic products are made from ceramic powders by powder treatment from ceramic powders. The treatment of powder ceramics is very close to that of metals, powder metallurgy. However, there is an important consideration in the formation of ceramics which is more important than in metal forming: it is dimensional tolerance. The post-forming shrinkage is much higher in the ceramic processing because of the large differential between the final density and the density as formed.

Glasses, however, are produced by heating the raw materials to an elevated temperature above which melting occurs. Most commercial glasses are of the soda-lime type, where silica is supplied in the form of common quartz sand, sodium hydroxide (Na2O) in the form of sodium carbonate (Na2CO3), while lime (CaO) is supplied in the form of limestone (CaCO3). Different forming methods – pressing, blowing, drawing and fiber drawing – are widely used in the manufacture of glass products. Thick glass objects such as plates and dishes are produced by pressing, while blowing is used to produce objects such as jars, bottles and ampoules. The drawing is used to form long objects such as tubes, rods, fibers, whiskers, etc.

The treatment of ceramic powders consists of a powder production by grinding / milling, followed by the manufacture of a green product which is then consolidated to obtain the final product. A powder is a collection of fine particles. The synthesis of the powder consists in preparing it for shaping by grinding, grinding, separation of impurities, mixing of different powders, drying to form soft agglomerates. Various techniques such as compaction, strip casting, slip casting, injection molding and extrusion are then used to convert the treated powders into a desired shape to form what is called green ceramic. The green ceramic is then consolidated using a high temperature treatment called sintering or baking.

Yt-stabilized High-purity Zirconia Bead

Yt-stabilized High-purity Zirconia Bead is also known as zirconia ball, zirconia ceramic ball, zirconia bead, ultrafine grinding media, zirconia microball, zirconia grinding ball

Pearl-like luster and a smooth working sphere. It is the top class of grinding media

Applications: Particularly suitable for vertical stirring mills, horizontal roller ball mills, vibrating mills and various high linear speed pin-type sand mills, for wet or dry ultrafine dispersion and grinding of pastes and powders requiring to refuse cross contamination. Its application includes:
1.Wear and corrosion resistant product: coating, textile, pigment, dyeing
2.High strength, high tenacity product: magnetic material, piezoelectric ceramics, dielectric ceramics
3.Pollution prevention: medicine, food, cosmetics
4.Ceramics: electronic ceramics, refractory ceramics, structural ceramics

Features: High strength, high tenacity, high density; sound wear resistance; heat and corrosion resistance; high rigidity; non-magnetic conducting; electric insulation and thermal expansion coefficient close to that of steel. The alumina ceramic ball is subject to little strength and hardness variation even under 600℃. It is baked under high temperature on fixed phase basis by a special shaping process using yttria as the stabilizer.
1.High grinding efficiency: Yt-stabilized TZP zirconia ceramic microball has a specific gravity 1.6 times that of common zirconia beads and ensures higher grinding efficiency under the same conditions
2.Sound fluidity: Yt-stabilized zirconia bead provides sound circular integrity, is smooth on the surface and causes lower abrasion to equipment than any other grinding medium
3.Impact resistant, low abrasion: TZP zirconia ceramic microball has sound tenacity, does not crack or strip in high speed/high concentration machines, with abrasion only 1/2 that of zirconium silicate beads
4.Low service cost: Choosing this product will undoubtedly bring down our cost on media abrasion, power consumption, labor and equipment, and significantly improve your product quality

For more information, please visit http://www.samaterials.com/208-zirconia

What is Hexagon Alumina Ceramic Lining Sheet

Applications: Wear-resistant material for all mechanical equipment exposed to heavy abrasion,material delivery systems, pulverizing systems, ash or dust removing systems in thermal power generation, iron and steel works, smelting, machinery, coal, mining, chemical, cement and harbors.

Features
1.Alumina wear-resistant sheet has high hardness
It Rockwell hardness is HRA80-90, second to only diamond and far better than wear-resistant steel and stainless steel.

2.Alumina wear-resistant sheet has sound wear performance
Its wear resistance is 266 times that of manganese steel and 171.5 times that of high chromium cast iron. From our customer follow-up over the past decade, under the same load, it can extend the equipment service life by at least 10 times.

3.Alumina wear-resistant sheet has light weight

Its density is 3.6g/cm3, just half of iron and steel, which greatly reduces the equipment load.

Size: 12*3mm,12*6mm,12*9mm,12*13mm, or cusomer required size

For more information, please visit http://www.samaterials.com/152-ceramic-material

 

How to Use Evaporation Boats

 In order to yield the greatest performance of evaporation boats,achieve the longest service life.Please read the following:

1.Align the clamp on both sides and keep the surface bright and clean.
2.Make sure good electric contact and heat conduction on end face and side face by graphite paper.
3.At the first time of heating the new boat,please put a length of aluminium wire in the centre of cavity for easily confirming the temperature of boats.
4.The contact point of aluminium wire should be in the length of 1/3 boat or 2/5.
5.The first heating of new boat should not be so fast that will effect deflation.
6.For the first time of new boat ,the speed of transmitting aluminium wire should be gradually increased from normal 75 percentage and the power should be gradually induced for the greatest area of spreading molten aluminium.
7.The time for heating new boat should be 15 minutes,and operate the evaporation as above method of transmitting aluminium at beginning.
8.Please stop transmitting aluminium wire and turn off the power supply after 30-60seconds at the end of evaporating each rolls .
9.About 2 minutes after power off,the evaporation boat cooled to dull red ,turn off vacuum.

For more information, please visit http://www.samaterials.com/123-evaporation-materials

The Overview of Wear Resistant Alumina Ceramic

Wear resistant ceramic sheet is AL2O3 as main raw material, rare metal oxide as flux, special corundum ceramic by high temperature calcination.

The performance characteristics of wear resistant ceramic sheet:

1 Hardness of Rockwell, hardness is second only to diamond, far more than wear resistant steel and stainless steel wear resistance.

266 times 2 excellent wear resistance of the wear resistance of the equivalent of 171.5 times of manganese steel, high chromium cast iron. According to our more than ten years of customer tracking survey, in the same working conditions, can extend at least ten times the service life of equipment.

3 light weight its density of 3.5g/cm3, only half of steel, can greatly reduce equipment load.

4 strong adhesive, good heat resistance and wear resistant ceramic sheet is adhered to the inner wall of the equipment by heat resistant adhesive. Under 350 DEG C, it can run for a long time without aging, and the inorganic binder used for sticking type products can withstand temperature of 750 DEG C. Adhesive temperature resistance and adhesion performance indicators in the country far ahead.

5 suitable for a wide range of thermal power, steel, metallurgy, machinery, coal, mining, chemical, cement, port enterprises such as coal, coal pulverizing system, feeding system, ash, dust removal system and all wear large mechanical equipment, different needs of different types of products can be according to.

For more information, please visit http://www.samaterials.com/199-alumina

 

Key Features of Some Advanced scientific Ceramics

Aluminium Oxide:

Aluminium oxide widely known as alumina is called as workhorse in the world of advanced technical ceramics. It is full of certain unique mechanical and electrical features like corrosion resistance and wear resistance. The thermal shock resistance of the material is relatively less. Our industry demonstrates its use in a number of area like medical, chemical and wear applications. It performs a significant role in electrical insulator for numerous electronic applications such as electronic substrates as well as spark plug insulators.

Zirconium Oxide:

Among all the ceramic material Zirconium oxide possesses the greatest fracture toughness. The distinct feature of mechanical properties, toughness and corrosion resistance make it recognised as a suitable material for medical use and for certain wear applications. The thermal expansion of Zirconium oxide coefficient is very closely resembled to steel, so it is very well used in a steel bore. The feature of this material is derived from an exact composition phase. It is highly influenced by the environmental conditions. So a small change in the external factor can make the material unstable and can be a reason of lose of its mechanical properties. The high weight and relatively less hardness property often limit its use in wear applications.

Fused Silica:

Fused silica is an outstanding thermal insulator. It has basically zero thermal expansion. The chemical resistance to molten metals of Fused silica is excellent however it suffers from a very low strength. You can find its applicability not only in numerous refractory and glass applications, but also in the field of missiles application.

Silicon Nitride:

Silicon nitride is the best ceramic material which has the perfect proportion of thermal, mechanical and electrical attributes of any superior technical ceramic material. The superb quality of toughness along with its high makes it the material of choice intended for automotive as well as bearing applications.

Boron Nitride:

It is also known as white graphite. This hexagonal boron nitride is chalky white in colour. Usually it has very poor mechanical properties. In inert atmospheres, it has an excellent temperature resistance. Therefore it is useful for a high-temperature insulator. However it is used in a combination with TiB 2 in lots of aluminium and ferrous metallurgical applications.

Tungsten Carbide:

The next metal is the Tungsten carbide. It is a combination of high percentages of either cobalt or nickel. Tungsten carbide is a ceramic metals used very commonly in the applications like cutting tools and several other metal-forming tools. Pure tungsten carbide is very strong and wears resistance. Thus it is used in abrasive water jet nozzles, while its heavy weight often limits many of its applications.

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