Ceramic material

 

(57) Abstract:

The invention: the invention relates to the field of military technology and can be used in designs requiring high mechanical strength, in particular in body armor designs. The ceramic material includes the following oxides in wt.%: aluminum oxide 95,025; silicon oxide 1,25; calcium oxide 0,005; iron oxide 0,04; magnesium oxide 0,63; titanium oxide 2,0; yttrium oxide 1,0; sodium oxide of 0.05. table 1.

The invention relates to the field of military technology and can be used in designs requiring high mechanical strength, in particular in body armor designs.

Known corundum ceramic materials having high mechanical strength [1]

In corundum ceramics combine a number of valuable properties, due to which it has found wide application in various fields of mechanics. Corundum ceramics has high strength and dielectric properties, and high chemical resistance.

However, the process of obtaining such ceramics are difficult and labor-intensive, in particular the need to perform sintering at a high temperature of 1800oC. the Introduction of admixtures and additives the properties of ceramics.

Known charge for making agrarias, including silicon carbide, carbide fight, clay refractory, kaolin, aluminium oxide and an additive comprising sodium carbonate and by-products from the production of caprolactam and antioxidant [2]

The lack of charge is low mechanical strength.

Closest to the present invention is corundum ceramic material with a low sintering temperature [3]

Corundum ceramic material, taken as a prototype, has the following composition:

Aluminum oxide 94,02%

The silicon oxide (IV) 2,22%

Calcium oxide is 0.01%

Iron oxide (III) 0,06%

Magnesium oxide (II) 1,14%

The titanium oxide (IV) 2.5% of

The sodium oxide of 0.05%

Calcium oxide and iron oxide (III) are present as impurities in the composition of the starting components.

Ceramic material, taken as a prototype, has the following advantages: reduced the sintering temperature due to the addition of titanium oxide (IV) and magnesium oxide (II), the material has a high technical and economic parameters. This material is used for manufacturing reasons resistors.

The disadvantage of the material is low apparent density ( 3,67 g/cm3), Kotelnich conditions does not provide sufficient mechanical strength, allowing the use of this material, particularly in armored structures. In tough spot-kick and the concentration of the load is the destruction of the elements made of ceramic material. The degree of destruction depends primarily on the properties of the material itself: the sintering temperature, apparent density, environment sintering, the ultimate strength in static bending.

The invention is aimed at improving the strength characteristics of the material by increasing the apparent density and mechanical strength for use in his armored structures.

To achieve this goal ceramic material based on aluminum oxide, containing as mineralizuyushchie additives magnesium oxide (II), silicon oxide (IV), titanium oxide (IV) and mixtures of calcium oxide (II), iron oxide (III), sodium oxide included in the source components, further comprises yttrium oxide (III) in the following ratio, wt.

Aluminum oxide 95,025

The silicon oxide (IV) 1,25

Calcium oxide 0,005

Iron oxide (III) 0.04

Magnesium oxide (II) 0,63

The titanium oxide (IV) 2,0

Yttrium oxide (III) 1,0

The sodium oxide 0,05

Talc pre-sorted, crushed and burned at t 1170oC. All materials were dispersively separately in different mill to a specific surface area of not less than 10000 cm2/year Produced mixing wet grinding in a ball mill MS-60 using distilled water. The prepared slurry was obezvozhivani, dried, screened, progulivali at t 900oC, again sieved, adminicula and the obtained mixture prepared press the powder from which the extruded billet bilateral pressed in hydraulic presses. The task in obtaining a ceramic material with a high apparent density and mechanical strength was achieved by obtaining pieces of material with fine-grained structure, as the crystalline structure is associated with a decrease in strength properties.

As in the prototype, the proposed material is aluminum oxide and the mineralizing additive was introduced in conjunction with tavernost not less than 10000 cm2/g, this helped to produce a mixture of initial components and to create favorable conditions for sintering. The result is a material with a uniform density distribution throughout the volume of the workpiece material.

Precalcination talc at t 1170oC, lower in comparison with the prototype, contributed to the higher reactivity of the components of talc, providing optimal conditions for sintering workpieces material and, eventually, obtain the crystalline structure. The chemistry of the process was the fact that talc greatest lagoudaki when firing is the most intensive in the temperature range 900-1100oC.

In addition, lowering the temperature of the heat treatment of talc increased the efficiency of dispersion, which led to a reduction of the time of grinding.

Compared with the prototype of the content of magnesium oxide (II) in the proposed ceramic material is reduced 1.8 times to 0.63% This is sufficient for the formation on the surface of particles of aluminum oxide spinel, which inhibits the growth of crystals during compaction of the material during firing.

The reduced content of magnesium oxide, which has the ability the ü material.

The titanium oxide (IV) reduced the sintering temperature, while the rapid growth of the crystals. Compared with the prototype of its contents reduced to 2.0% when the sintering temperature is not increased and improved conditions for the formation of the crystalline structure.

In the proposed material unlike the prototype introduced additive oxide yttrium (III) 1,0%

Introduction this Supplement helped to cause the reduction of crystal growth, reduction of intracrystalline porosity and, as a consequence, the increase in apparent density and mechanical strength of the material.

Yttrium oxide enters steklovata, stabilizing the sintering process, allows you to save the fine-grained structure, increasing the density and mechanical strength of samples by reducing the number of pores and microcracks.

Thus, the combination of the above factors causes directional crystallization of the material, in particular a delay of crystal growth, reducing the number of pores and microcracks.

We offer ceramic material unlike the prototype has a new ratio of components and the additive oxide yttrium (III). The obtained ceramic material has characteristics that preds the prototype, a tensile strength on the level with the prototype.

Ceramic material has high strength properties (apparent density and tensile strength in static bending) that it could be used for the manufacture of elements for armored structures, in particular of body armor.

The test results armour blocks of the proposed ceramic material of positive, provide protection from bullets B-32 and ABOUT FSC/CST cartridge of 7.62 x 54 rifle SVD. Survivability armor plates 6-8 shots.

Ceramic material based on aluminum oxide, containing as mineralizing additives titanium oxide (IV) oxide, silicon (IV), magnesium oxide (II) and mixtures of calcium oxide, iron oxide, sodium oxide, characterized in that it additionally introduced the addition of yttrium oxide (III) in the following ratio of components:

Aluminum oxide 95,025

The silicon oxide (IV) 1,25

Calcium oxide 0,005

Iron oxide (III) 0.04

Magnesium oxide (II) 0,63

The titanium oxide (IV) 2

Yttrium oxide (III) 1

The sodium oxide 0.05 to about

 

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7 cl, 3 ex, 1 tbl

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