Archive for the ‘Ceramic Materials’ Category

Jet cutting is used for cutting the abrasion of the water at a pressure of 6,000 atmospheres


Water jet cutting, free rein to creativity

Emerging in the United States in 1974 and first used in the aerospace field, the technique of water jet cutting is used for cutting the abrasion of the water at a pressure of 6,000 atmospheres.

This, at a rate of 1.200 cm / sec. and mixed with abrasive grit, is capable of cutting through a Cartesian robot axes moved on, run by a numerical control system, thickness of 150 mm on any Read the rest of this entry »


Ceramic building materials are divided into porous and dense


Artificial materials kilns

Artificial kilns and Materials (ceramics) is prepared by firing at 900-1300 ° C molded and dried clay mass. As a result of firing the clay mass is converted into an artificial stone, which has good strength, high-density composition, water resistance, water resistance, frost resistance and durability. Raw materials for ceramics is clay, with inputs in it, in some cases, emaciated additives. These additives reduce the shrinkage of the product during drying and firing, increase porosity, reduce the average density and thermal conductivity. As additives use sand, crushed ceramics, slag, ash, charcoal, sawdust. The firing temperature depends on the temperature of the melting of clay. Ceramic building materials are divided into porous and dense. Porous materials have a relative density of up to 95% and water absorption of not more than 5% of their compressive strength does not exceed 35 MPa (bricks, drain pipes). Dense materials have a relative density greater than 95%, water absorption of less than 5%, compressive strength of 100 MPa, and they have the Read the rest of this entry »


The property of water-saturated material to withstand alternate freezing and thawing


Frost resistance of building materials.
Frost resistance – the property of water-saturated material to withstand alternate freezing and thawing. Quantitatively, the estimated frost brand. For the brand is accepted the largest number of cycles of freezing to -20 ° C and thaw at a temperature of 12-20 ° C, samples of material which can withstand without reducing the compressive strength of more than 15% after the test, the samples should not have visible damage – cracks, spalling (loss of mass of no more than 5%).

The mechanical properties of building materials

Elasticity – the spontaneous recovery of original shape and size after the termination of an external force.

Plasticity – the property to change the shape and size under the Read the rest of this entry »


Thermal conductivity – a material property to transfer heat from one surface to another..

Thermophysical properties of materials.
Thermal conductivity – a material property to transfer heat from one surface to another.

The formula relates the thermal conductivity of Nekrasov λ [W / (m * C)] with a bulk density of the material, expressed in relation to water: λ = 1,16 √ (0,0196 + 0,22 γ2) -0,16. With increasing temperature, the thermal conductivity of most materials increases. R – thermal resistance, R = 1 / λ.
Heat c [kcal / (kg * C)] – the amount of heat that must be reported 1 kg of material to raise its temperature by 1C. For stone materials heat capacity varies from 0.75 to 0.92 kJ / (kg * C). With increasing humidity increases the heat capacity of materials.

Fire resistance – ability of material to withstand prolonged exposure to high temperature (1580 ° C and above), the material softens and is Read the rest of this entry »


Search




Categories
Bookmarks

Tag Cloud


Fatal error: Call to undefined function circum_add_code() in /home/virtuald/public_html/wp-content/themes/earthbiz/sidebar1.php on line 99