Cast stone material

FIELD: chemistry.

SUBSTANCE: invention relates to artificial fused silicate ceramic materials, particularly cast stone compositions, and is meant for making bulletproof armoured plates (boards) of bulletproof vests. Besides the defence industry, the invention can be used in construction, ore dressing and other industries. The disclosed stone cast material has components in the following ratio, wt %: SiO₂ 43-45; Al₂O₃ 15-16; CaO 9-17; FeO 5-8; MgO 8-9; Fe₂O₃ 3-5; TiO₂ 1-1.5; K₂O and/or Na₂O 2.5-4; Cr₂O₃ 2-2.5 and CaF₂ 1.5-2. Owing to use of cheap technologies, raw material and optimum content of additives, the stone cast material has a lower cost. Availability of dissipative properties which meet GOST R 50744-95 "Armoured garments. Classification and basic requirements" attests to its suitability for making bulletproof armoured plates of bulletproof vests.

EFFECT: obtaining material which is suitable for making bulletproof armoured plates of bulletproof vests, as well as elements which combine bulletproof properties with the capacity to scatter and absorb radioactive and infrared radiation.

3 tbl, 2 dwg

The invention relates to synthetic fused silica materials, in particular to the compounds of stone casting, and is intended for the manufacture of pulsewith armor plates (slabs), flak jackets and military equipment, which combines the function of protection against radiation and obscurity due to the absorption of infrared radiation. In addition to the defense industry, the invention can be used in the construction, mining and other industries.

Politisite armour plate, which is inserted "hard" elements multilayer of armoured plates have the armor, since the third class protective structure prometida determined in accordance with GOST 50744-95 "Prometida. Classification and General requirements". Material pulsewith armor plates absorbs and scatters (dissipeared) energy small arms bullets.

Traditionally politisite armour plates are made of metallic materials - high strength carbon and alloy steels, alloys based on titanium or aluminum. At the present time for this purpose use ceramic materials. Such important properties of ceramic materials, as in 2-3 times lower density than metal materials, high hardness, elastic modulus, melting point (decomposition) and registering the strength when heated, enable their use for the manufacture of pulsewith armor plates of armor.

Highest protective properties have impact-resistant ceramic materials based on boron carbide B₄C, significantly reducing the weight of armor protection, and also on the basis of titanium diboride TiB₂with the highest hardness and elastic modulus. However, the high cost of production technologies constrain their mass application for protection from ballistic lesions. Relatively cheap aluminum oxide Al₂O₃considered to be the most promising for mass production of armor ceramics based on it, produced by conventional technology, to protect manpower.

Known patent RU 2331038 (IPC F41H 5/04, F41H 1/02, publ. 10.08.2008), dedicated to the design of the armor element for protection vest, where the material of the armor plate (plate), absorbing the impact energy of the bullet, use a ceramic composition based on aluminum oxide Al₂O₃and ceramic materials reinforced with ceramic fibers made of Al₂O₃, Al₂O₃·2SiO₂or TiO₂. Through the use of simple and composite materials the authors of the patent RU 2331038 solve one task - reduction of 1.7-2.5 times the weight characteristics of the armor plates.

General shortcomings ceramic watch, the ski materials, produced using traditional technology, including the processing of raw materials - production of powders, preparation of the ceramic material by mixing, molding, drying and sintering at high temperatures, are: the presence of some residual porosity, always lingering in the material; the need to use scarce and expensive raw materials and/or complex and expensive technology and equipment to achieve high density, strength and other indicators, which considerably increases the cost of the resulting ceramic material.

The lack of stone casting in patent RU 1433939 is the presence of residual porosity of 0.35 to 0.4%, which does not allow to use it as material pulsewith armor plates of armor.

Known stone casting with improved heat resistance described in patent RU 2349557 (IPC C03C 3/00, publ. 20.03.2009)that contains components in the following ratio, wt.%: SiO₂50,0-52,0; Al₂O₃4,0-5,0; Fe₂O₃10,5-11,9; FeO 0,4-1,0; CaO 3,1-4,5; MgO 9,0-11,0; TiO₂0,6-1,0; Na₂O 2.0 to 2.5; K₂O 3,5-4,0; F₂4,2-4,3; ZrO₂2.8 to 3.5; B₂O₃5,0-6,0.

Also known stone casting with improved heat resistance described in patent RU 2341485 (IPC C04B 30/00, publ. 20.12.2008)that contains components in the following ratio, wt.%: SiO₂47,5-52,5; Al₂O₃12,0-16,0; Fe 2O₃6,0-9,0; FeO 0.5 to 1.0; CaO of 6.0-8.0; MgO 12,0-16,0; Na₂O 0,5-1,0; K₂O 5,0-7,0.

In addition, it is known stone casting construction with improved durability (patent RU 2303017, IPC C04B 32/00, publ. 20.07.2007)comprising components in the following ratio, wt.%: SiO₂50-54; Al₂O₃2-4; Fe₂O₃2-4; CaO 16-20; MgO 4-6; K₂O 1.8 to 2.3; MnO 0,7-1,2; Cr₂O₃1.5 to 2.5; NiO 6-10; ZrO₂3-7.

A common shortcoming of these inventions by patents RU 2349557, EN 2341485 and EN 2303017 is that the composition of each of the presented materials helps to improve only one of the properties or heat resistance, or strength, while for manufacturing pulsewith armor plates of armor you want, stone casting, having a set of improved properties.

The closest analogue on the components is glass fused material having as a main crystalline phase spinel. The material obtained from various waste (including ash), as well as mine tailings and has the following chemical composition, wt.%: SiO₂38-62, Al₂O₃14-32, Fe₂O₃the 2.5-10, MgO 6-24. TiO₂1-24, CaO 1-8, K₂O 0-2,5, Na₂O 0-0,6, Cr₂O₃0-3. The composition of the charge is CaF₂, ZnO, ZrO₂CeO₂and other optional components. This material dedicated to superior quality products is sufficient for the production of armor (ballistic protection) (see US 2010/0242715, CL F41H 5/02, epubl, only 21 C., (I), see p.8-9, table 2, composition, paragraph[0095], [0102]).

The disadvantage of this material is that it contains part of the oxides of zinc, cerium and zirconium, which are rare, and is only one function of puletasi, does not protect against energy impact or locations.

The task of the invention is to develop a material - inexpensive stone casting, suitable not only for making pulsewith armor plates of armor, but also for the manufacture of protective elements, combines bulletproof with the ability of the scattering and absorption of radiation and infrared radiation.

The technical result is achieved by the fact that the stone casting, comprising silicon oxide SiO₂aluminium oxide Al₂O₃, calcium oxide CaO, iron oxide (II) FeO, magnesium oxide MgO, iron oxide (III), Fe₂O₃, titanium oxide TiO₂the oxide and potassium (K₂O and/or sodium oxide Na₂O, chromium oxide (III) Cr₂O₃and calcium fluoride CaF₂contains ingredients in the following ratio, wt.%:

Lower cost claimed stone casting reach through the use of less expensive technologies for stone casting in comparison with traditional technologies to produce high-strength ceramic materials or metal alloys, as well as through the use of non-deficient complex natural raw materials and optimization of content additionally introduced additives.

For example, according to Pervouralsk plant mining equipment estimated market price of 1 ton of manufactured stone casting is 13 thousand rubles, while the price of the most common alumina ceramics is about 2 thousand roubles (prices are calculated based on the average economic performance of producers).

The feedstock for production of stone casting are basic and ultrabasic rocks and/or ash-slag waste anthropogenic origin (blast-furnace slag, fuel ash, and others). In particular, the raw material for the manufacture of the inventive stone casting is hornblendite ore deposits Isoscope district of Sverdlovsk region - rock of basic composition are modified by the introduction of additional additives fluorspar (containing calcium fluoride CaF₂) and chromite (FeCr₂O₄).

Additional additive fluorspar CaF₂helps reduce the melting temperature and melt viscosity, increasing its fluidity, which improves the casting properties of the melt and improves the manufacturability of production. I.e. this additive serves as a flux. The use of less than 1.5 wt.% fluorspar in conjunction with the composition used hornblendite ore Deposit is insufficient reduces the viscosity of the melt, which impairs its technological properties. It was established experimentally that the optimal number of additional input fluorspar CaF₂1.5-2 wt.%.

Additional additive refractory chromite (FeCr_{2 O4) provides additional centers of crystallization during solidification of the melt and gives it a more uniform and dense structure, increasing such physico-mechanical properties of stone casting, as the hardness, strength, dissipativity. The addition of chromite (FeCr2O4) helps speed up the process of crystallization during cooling of the melt. It was established experimentally that the optimal number of additional input additives chromite (FeCr2O4) is 2-2,5 wt.%. The amount of additive stimulates the development of the pyroxene structure of a material that solidifies with the formation of dissipative channels, which provide dissipation not only the kinetic energy of motion of the striking element, but also the effects of radiation and infrared radiation. Introduction less than 2 wt.% chromite (FeCr2O4) leads to lower physical-mechanical properties of the resulting stone casting.}

As to achieve the desired results, the impact of additional additives is enough no more than 2 wt.% fluorspar CaF₂and not more than 2.5 wt.% chromite (FeCr₂O₄), then a further increase of their content is inappropriate, including due to the increase in the cost of the resulting stone casting.

Figure 1 shows the absorption spectrum of the sample material.

On IG - the image of the microstructure of the sample with the dissipative channels.

The technology of stone casting comprises: melting a pre-prepared mixture of rocks and/or waste products (toxins) and the relevant supplements thereto subsequent casting of the melt into molds, fungus products, annealing and cooling.

Before loading into the furnace raw materials are crushed, sieved, dosed in the required quantities and mix, receiving the charge. For melting of the charge is used mine, bathrooms, rotary, and electric furnaces. The most common tank furnaces. Melt receive at a temperature of 1400 to 1500°C. During the melting temperature as a result of chemical interaction of the components of the charge, the formation of silicates and aluminosilicates of calcium, magnesium and iron. During the continuous casting of products of the melt enters Kobylniki, in which creating a supply of a homogeneous mass with a temperature of 1180...1250°C. the Cooling of the melt before casting in the form it is necessary to reduce shrinkage defects (cracks, shells) and education appropriate product structures. Next, the melt is poured into earthen, metal or silicate form, heated to 600...700°C, and slowly cooled. A gradual decrease in temperature favors the precipitation of crystalline phases from the melt. Then sformovannye stone casting is placed in a tunnel, or chamber of the furnace, or in a special furnace where it is subjected to annealing is maintained at a temperature of 800...900°C for a certain period of time, and slow cooling. Annealing helps reduce thermal stresses associated with the cooling and crystallization, increase resilience to get stone casting shock loads.

Examples of practical implementation of the invention discussed below.

Table 1 shows the experimental compositions No. 1-5 stone casting specifying oxide content component.

Specified in table 1 of prescription formulations No. 1-5 manufactured tiles (plates) stone casting of size 100×100×15 mm according to the following technological scheme. Before loading into the furnace raw materials - hornblendite ore deposits together with additional additives fluorspar CaF₂and chromite (FeCr₂O₄) grind, sift, metered in the desired ratio and mixed together to receive a charge. The mixture is loaded into an electric furnace and at a temperature of 1400 to 1500°C receive the melt processing time 1-2 hours Then the melt enters the kopilnika for obtaining a homogeneous mass with a temperature of 1180...1250°C. Next, the melt is poured into a flat metal shape with a size of 100×100×15 mm, heated to 600...700°C, and slowly cooled. Then plates of stone casting is placed in a muffle furnace and annealed at a temperature of 800...900°C for 12-16 h After annealing stone casting is gradually cooled.

Received stone casting (part # 3) on traditionally used methods identified the following indicators of physico-mechanical properties: a density of 2.9 g/cm³that is thinned compressive strength of 450 MPa, the tensile bending strength of 50 MPa, a hardness of 15 GPA, the impact strength of 2.5 kJ/m².

Made of plates of stone casting compositions No. 1-5 of size 100×100×15 mm was subjected to field tests in accordance with the requirements of GOST P 50744-95 on bulletproof - property elements armour protection to resist through-penetration welded elements or fragments. Table 2 shows the list used in this regulated weapons, their characteristics and test conditions.

Table 3 shows the results of tests made of plates of stone casting compositions No. 1-5 on bulletproof.

From table 3 it can be seen that the most successfully tested plate stone casting made from composition No. 3. The specified material in the pool the resistance corresponds to 6 class protective structure prometida, determined by ballistic table is given in GOST P 50744-95, depending on the means of destruction.

Stone molding composition No. 2 corresponds to the 5-class protective structure prometida, because this material has stood the test of firing bullets with steel cores - breaking plates are not available, but the breakout is recorded when shooting from a sniper rifle SVD (2) employing bullets with heat-treated core.

In the General case, the test result is "no penetration" means that when a bullet enters the experimental plates offer stone casting see their destruction in the place of contact of the bullet and the plate is the formation of a large number of small fragments. When the bullet moves or small pieces on plate no, indicating that dissipation of energy bullets plate stone casting, i.e. the bullet does not already possess sufficient energy to penetrate the plate stone casting and injure the soft tissues of the person.

More research and comparison data on the properties of similar materials suggest about the durability of the material under conditions of radiation and the ability to absorb infrared radiation range 400-1400 cm^-1(figure 1).

In addition, research has shown that material properties dostigajut is due to the formation without zirconium spinel and pyroxene minerals, as a result of growth of crystallites allow the material system of dissipative channels (figure 2).

Thus, the results of field tests of the proposed stone casting compositions No. 2 and 3 indicate its compliance with the requirements of GOST P 50744-95, in addition, developed the material has a low cost by using inexpensive technology, feedstock and optimization of the content of additives, i.e. developed material suitable for the manufacture pulsewith armor plates of armor and military equipment, which combines the function of protection against radiation and obscurity due to the absorption of infrared radiation.

Stone casting, comprising silicon oxide SiO₂aluminium oxide Al₂O₃, calcium oxide CaO, iron oxide (II) FeO, magnesium oxide MgO, iron oxide (III), Fe₂O₃, titanium oxide TiO₂the oxide and potassium (K₂O and/or sodium oxide Na₂O, chromium oxide (III) Cr₂O₃and calcium fluoride CaF₂, characterized in that it contains the ingredients in the following ratio, wt.%: