Method for oxidation defence of articles from composite carbon-containing material and article defenced by this method

FIELD: chemistry.

SUBSTANCE: invention refers to the method for oxidation defence of the article made from composite carbon-containing material and having the residual open inner pores. The said method includes at least one stage of composite material impregnating to depth with the impregnating composition containing at least one metal phosphate in the solution and titanium diboride in the form of the powder with particle size in the range from 0.1 mcm to 200 mcm. The invention refers also to the article obtained by the aforementioned method. Invention is developed in related items of invention formula.

EFFECT: invention provides the article oxidation defence at temperatures more than 1000°C, particularly in the presence of carbon oxidation catalyst and in wet conditions.

10 cl, 12 dwg, 9 ex, 3 tbl

 

The technical FIELD

The invention relates to providing protection against oxidation products made of composite material containing carbon, in particular of products made from thermostructural composite material containing a reinforcement of carbon fiber, compacted matrix, which is at least partially comprised of carbon.

PRIOR art

Thermostructural composite materials are characterized by good mechanical properties and ability to retain these properties at high temperatures. However, in oxidizing environment, this ability to retain good mechanical properties at high temperatures depends on the availability of effective protection against oxidation. However produced such material, they inevitably have residual internal pores, which open, allowing oxygen present in the environment, enter the internal area of the material.

In addition, in some applications, in particular in the brake discs of carbon-carbon (C/C) composite materials used in aviation, protection against oxidation must remain effective even in the presence of oxidation catalysts (present in the de-icing substances, which are processed landing the band), and in the presence of moisture (during landing and taxiing on a wet runway).

To date, a well-known application of protections based on aluminum phosphate, or, more broadly - based individual phosphates of metals or their combinations, such as the phosphates of aluminum and zinc. The coating on the product to be protected, must be monitored in relation to quantitative and geometric distribution, for example, in order to avoid applying a protective composition to certain areas of products, such as the friction surfaces of the brake discs on which the presence of the protective composition may damage the tribological properties of the material. To improve the penetration of the protective composition into the product it is preferable to use a wetting agent, which is applied in advance, or mixed directly with a protective composition, and the composition is applied like paint. As examples can be cited, for example, reference the following patent documents: US 5853821, EP 0747334, EP 0677499 and EP 0606851.

However, the effectiveness of such compositions is limited to a certain upper threshold temperature of approximately 1000°C, at which the active components of the composition are decomposed.

In order to improve the ability of resisting the ü higher temperatures, you can combine protection against oxidation phosphate-based metal diffusion barriers against access of oxygen to the composite material at high temperatures, such as reducing the vitreous phase or sealed outer layers. As an example, the outer layers of silicon carbide (SiC), obtained by chemical deposition from the gas phase (chemical vapor deposition, CVD), or by applying a liquid composition containing the silicon carbide in the form of a suspension, or containing a precursor of silicon carbide (such as resin polycarbosilane (PCS) type, which, when heat treatment is converted to silicon carbide). However, the process of forming complete protection against oxidation becomes much more complicated, because this protection consists of two layers, superimposed on each other, with the application of each of these layers is in a special way.

The INVENTION

The objective of the invention is to create a method that provides protection against oxidation products made of composite materials containing carbon, which could be easily implemented and provided protection, which is effective even in the presence of oxidation catalysts, in humid environments and at high temperatures, reviewsi 1000°C.

This problem is solved by a process comprising applying a sealing composition containing at least one metal phosphate in the form of a solution, and in the method in accordance with the invention applied composition also contains titanium diboride.

It is known that titanium diboride TiB2behaves as a source for the gradual formation of oxides, such as TiO2In2O3. These oxides are able to give protection against oxidation barrier properties against diffusion of oxygen from the environment, thus ensuring the sustainability of this protection at high temperatures, i.e. temperatures above 1000°C, and in the typical case of 1400°C or even higher.

First of all, when linking with the element phosphorus (P)present in the composition, and the metal (Me)or coming together with your predecessor phosphate, or formed during the interaction with a catalyst for oxidation of carbon coming from the external environment, TiB2able to form complex oxides of the type Ti-O-P-Me. Accordingly, the formation of such oxides provides the ability to capture oxidation catalyst coming from the external environment, and hold it in vitreous form, i.e. at temperatures above 1000°C. the Glass formed in this way also contributes to the effect of the barrier on which Fushi oxygen, at least up to a temperature of 1400°C, as it is insoluble in water. Thus, this glass provides stable protection in wet environments.

The titanium diboride preferably present in the impregnating composition in the form of a powder having a particle size ranging from 0.1 μm to 200 μm.

Impregnating composition may contain a solid heat-resistant fillers, other than the titanium diboride, preferably fillers other than the borides, such as silicon oxide, aluminum oxide, clay, in particular kaolin, or filler of talc is preferably in powder form.

The phosphate(s) of the metals contained in the impregnating composition can be selected from phosphates of aluminum, zinc and magnesium.

Typical impregnating composition may include:

from 20 wt.% up to 70 wt.% phosphate (phosphate) metals;

from 5 wt.% up to 50 wt.% of titanium diboride;

from 20 wt.% up to 50 wt.% water, and

from 0 wt.% up to 40 wt.% solid fillers other than titanium diboride.

Preferably impregnating composition is applied like a paint, for example, using a brush or by spraying.

A preliminary step can be implemented by processing the products from composite material by soaking it in an aqueous solution of the wetting agent with subsequent drying of an aqueous solution so as to give a composite material wettability, which in the presence of the wetting agent increases.

In accordance with another embodiment of the invention, the method may include the step of applying a solution of at least one metal phosphate without particulate filler prior to the step of applying a composition containing at least a metal phosphate in solution together with titanium diboride, and possibly other solid fillers. Because of the lower viscosity solution, which contains no particulate filler, in particular, does not contain titanium diboride, can penetrate more deeply into the remaining open internal pores of the composite material. As a result, protection against oxidation includes one or more phosphate metal, anchored deep in the pores of the composite material, and phosphate(s) of metal bound(s) with titanium diboride, and possibly other solid fillers that are closer to the surface of the composite material.

Another object of the invention is to create products made of composite material containing carbon and protected from oxidation.

This task is solved by the fact that the product provides protection against oxidation, comprising at least a metal phosphate and titanium diboride.

Protection from oxidation may further include heat-resistant solid fillers, other than the titanium diboride.

ACC is accordance with one embodiments of the invention, protection against oxidation provides a higher content of titanium diboride in part, located close to the surface than in a portion located deeper under the surface. Thus, protection against oxidation may not include titanium diboride in the most distant from the surface of its parts.

BRIEF DESCRIPTION of DRAWINGS

Other characteristics and advantages of the invention will be clear from the following description, given for purposes of illustration and not limiting of the scope of the invention, with reference to the accompanying drawings.

Figure 1 is a block diagram showing the implementation of the method according to the invention.

Figure 2 represents a variant of the method, shown in figure 1.

Fig. 3 through 12 are graphs showing the weight loss of the samples carbon-carbon composite material (C/C composite material)with and nesyrjevogo protection from oxidation in accordance with the invention and tested for oxidation under various conditions.

INFORMATION CONFIRMING the POSSIBILITY of carrying out the INVENTION

The invention is applicable to products manufactured from carbon composite materials, for example, the products formed from fiber reinforcement, densified by a matrix in which the reinforcing fibers and/or matrix is composed at least partially of carbon. Usually products are the products of the C/C composite material, or products made from composite material having reinforcing carbon fiber and the matrix representing a ceramic matrix, or a combination of carbon ceramic matrix. Examples of such products include brake discs, including discs for aircraft brakes.

The fabrication of the composite material of this type involves the formation of a fiber reinforced structure and the consolidation of its matrix. The seal can be made liquid by the method, i.e. by impregnation of reinforcing fibers with a liquid composition containing a precursor for the matrix, for example, the composition containing the resin, and the subsequent conversion of the precursor by heat treatment. The seal can also be carried out by the gas method, i.e. by chemical infiltration of the gas phase (chemical vapor infiltration, CVI).

Whatever the method of manufacture is used, the obtained composite material contains residual internal open pores, i.e. a lot of pores, which are in communication with each other in the thickness of the material.

Thus, the formation of the protection of the product against oxidation by soaking liquid composition is education available n the arts composite coating material, extending inward to a certain depth under the surface on which the composition is applied.

In the example embodiment of the invention shown in figure 1, the first stage of the method consists in the implementation of deep processing products with an aqueous solution containing a wetting agent or surfactant, which penetrates into the open pores of the material (step 10). After drying (step 20) wetting agent remains on the surface of the pores inside the material, giving them enhanced wettability.

This preliminary stage of deep processing of the products described in the above-mentioned document US 5853821.

Preferred is the use of a wetting agent, soluble in water and which is non-ionic, such as oksietilenovym fatty acid, oxyethylene fatty alcohol, oxyethylene alkyl phenol or higher ester of a polyol. Wetting agent added to water in concentrations of component preferably from 0.05 to 5 wt.% with respect to water, to ensure the fluidity of the aqueous solution, allowing it to easily penetrate into the inner part of the material.

Pre-treatment products can also be carried out in order to clean composite material. For this purpose, the product may be immersed, for example, in an ultrasonic vessel containing a wetting agent in water is the solution.

After pre-treatment can be carried out the first stage impregnation (step 30) of the product of composite material using an aqueous solution of at least one metal phosphate without adding any solid filler, in particular without the addition of titanium diboride. Can be used one or more phosphates, preferably selected from phosphates of aluminum, zinc and magnesium. The mass content of phosphate (phosphate) in the solution preferably ranges from 20% to 70%.

The next stage 40, which may be performed before or after drying of an aqueous solution of metal phosphate, consists in the impregnation of the product, but using a composition containing at least one metal phosphate in the aqueous solution together with titanium diboride TiB2in powder form. Used at least one metal phosphate selected from the group consisting of phosphates of aluminum, zinc and magnesium.

Except TiB2to impregnating composition can be optionally added solid heat-resistant fillers. In particular, these fillers contribute to the filling of pores of the composite material. Preferably, the additional heat-resistant fillers do not contain borides. They can be selected from, for example, powders of silicon oxide, aluminum oxide, kaolin, clay and that is ICA.

Preferably impregnating composition comprises (in mass percent): from 20% to 70% of phosphate (phosphate) metals, from 5% to 50% TiB2from 20% to 50% of water and from 0% to 40% more particulate fillers.

In order to maintain the ability to penetrate deep into the composite material, the average particle size of the powder TiB2should preferably be in the range from 0.1 μm to 200 μm. The same applies to the size of the powder particles (powders), forming a more solid fillers.

Aqueous solution at stage 30, and then impregnating composition on the stage 40 can be applied on the surface of the composite material at atmospheric pressure, for example, by coating with a brush, like painting, or by spraying. In the proposed method there is no need to resort to high pressure or vacuum, to ensure deeper penetration of the impregnating composition under the influence of pressure difference. In addition, the impregnating composition can be easily applied only on certain portions of the product. As for the brake discs, it is possible to avoid causing oxidation protection on the friction surface, as the application protection to these surfaces may damage the tribological properties.

Stage 30, as well as the stage 40, can the t can be consistently repeated several times.

After step 40 carry out the step of drying, for example, air in a drying oven at temperatures up to approximately 350°C. (step 50).

After drying, the product is subjected to heat treatment in a drying oven in an atmosphere of inert gas, such as nitrogen atmosphere (step 60), providing in this way the formation of the active compounds protect against the catalytic oxidation of carbon. The heat treatment is carried out by increasing the temperature to a value of from about 700°C. to 900°C.

It should be noted that the stages of pre-processing (steps 10 and 20), and the stage 30 are optional. However, a preliminary step may provide a deeper soaking material. The stage 30 is used to provide protection against oxidation on the basis of phosphate(phosphate) in the depth of the material, where the impregnating composition used in step 40, penetrates with great difficulty due to the fact that this impregnating composition has a higher viscosity. Item received thus protected from oxidation protection, with a higher content of titanium diboride in a part located closer to the surface than in the portion located farther from the surface of the part. Protection from oxidation caused in this way may not contain titanium diboride or other solid fillers in the part of the aircraft is Oia, which is further from the surface of the product.

In the embodiment of the invention shown in figure 2, after pre-processing (steps 10 and 20) is saturated (step 30') using a composition containing at least one metal phosphate in an aqueous solution together with titanium diboride.

However, the contents of the TiB2in the impregnating composition preferably is so low that it was possible the penetration of the composition into the depth of the material. Typical impregnating composition comprises, in percent by weight, from 20% to 70% of phosphate (phosphate) metals and from 5% to 30% TiB2and the rest is water. For the same reason, choose powder TiB2having a small average particle size, for example, less than 100 microns.

Next, the method includes the steps of impregnation, drying and heat processing (steps 40, 50 and 60, respectively), similar to the stages of the method shown in figure 1.

The following examples show that the presence of TiB2leads to the obvious benefits to the behavior in the oxidizing environment of the products protected by the method according to the invention, compared with products that is protected by methods known from the prior art, in particular described in document US 5853821, when exposed to high temperatures (1000°C or higher, in the presence of moisture and catalysts for oxidation of carbon.

During use of a product protected by the method according to the invention, the oxidation leads to the formation of oxides In2O3and TiO2. In addition, as was found by the authors of the invention, in combination with the element phosphorus (P) and the metal (Me)coming phosphate (phosphate), or the oxidation catalyst, which may be present in the environment, the presence of TiB2provides the possibility of formation of complex oxides Ti-P-O-Me, which is capable at temperatures above 1000°C to maintain the protective function of phosphate (phosphate) metals even in a humid environment, primarily by capturing the oxidation catalyst and the second - by contributing to the effect of the barrier to diffusion of oxygen provided by the action of simple oxides In2O3and TiO2.

Also, the inventors found that such properties are not observed when using other borides than TiB2. Therefore, the application of the method according to the invention or added as a solid heat-resistant fillers other borides than TiB2is very undesirable.

DESCRIPTION of embodiments of the INVENTION

Example 1

Samples of the composite material C/C were produced as follows. Sheets (x is lsti) unidirectional fibers of the precursor of carbon fibers (pre-oxidized polyacrylonitrile) were superimposed on each other in different directions and are connected by perforations ( called "igloprobivnye") as they are overlaying each other. The obtained fibrous billet was subjected to a heat treatment to convert the precursor to carbon by pyrolysis, and then sealed with a pyrolytic carbon matrix by chemical infiltration of the gas phase. This method is well known. As an example, a reference to the document US 4790052. Blocks of C/C material obtained in this way, samples were cut in the form of rectangular blocks having dimensions of 20 mm × 25 mm × 8 mm

Several samples were shielded from oxidation method containing the following steps:

a) pretreatment of samples by soaking in an ultrasonic vessel containing an aqueous solution of the wetting agent on the basis of polyethoxyl of isononylphenol, supplied by the German company Huls under the name "Marlophen NP9", in which the wetting agent is present in solution at a concentration of 5 wt.%. After impregnation, the samples were dried in a drying oven, after which the pores of the composite material remained covered with a wetting agent;

b) applying to the sample surface by means of a brush of an aqueous solution containing 50 wt.% the dihydrophosphate aluminum Al(N2PO4)3and the rest is water. The applied solution is sold in the of France, in particular, the firm Europhos called "Phosphate aluminique" (also applicable to aqueous solutions of Al(H2PO4)3from other suppliers, for example from the manufacturer from Germany Chemishe Fabrik Budenheim KG);

C) after a few minutes, and before the drying of a solution of Al(H2PO4)3on the front surface of the sample brush was applied an aqueous solution containing 35 wt.% Al(N2PO4)3and 44 wt.% powder TiB2having the average particle size of approximately 10 μm, the rest is water.

g) air drying in a drying oven at a temperature slowly rising to 350°C (at a rate of about 1°C/min), with intervals of 5 hours at 90°C, 3 hours at about 150°C, 1 hour at 220°C and 1 hour at 350°C; and

d) heat treatment in a drying oven in a nitrogen atmosphere, carried out according to the following cycle:

- temperatures up to 300°C at a rate of approximately 5°C/min;

- increasing the temperature from 300°C to 700°C at a rate of approximately 2°C/min;

break 5 hours at a temperature of 700°C.

Samples protected in accordance with the method according to the invention were respectively subjected to the following tests for oxidation, each of which was conducted on three samples:

1) oxidative cycle, including the effects of air at a temperature of 650°C for 5 hours, return to the temperature surrounding the it environment and pollution" by immersing in an aqueous solution, containing 5 wt.% potassium acetate, and the rest water; and four oxidation cycle sequential exposure to air at a temperature of 650°C for 5 hours with an intermediate stage of the return to ambient temperature (where the potassium acetate is a catalyst for the oxidation of carbon and a common component used in de-icing compositions for the runway);

2) test similar to the test (1), but in which oxidative cycle includes the impact of air at a temperature of 850°C for 30 minutes;

3) oxidation cycle by exposure to air at a temperature of 650°C for 5 hours exposure to air at 1000°C for 1 hour, pollution by immersing in an aqueous solution of potassium acetate (at a concentration of 5 wt.%) and two sequential oxidative cycle impact air at a temperature of 650°C for 5 hours;

4) oxidation cycle by exposure to air at a temperature of 650°C for 5 hours exposure to air at 1200°C for 20 minutes, pollution by immersing in an aqueous solution of potassium acetate (at a concentration of 5 wt.%) and two sequential oxidative cycle impact air at a temperature of 650°C for 5 hours;

5) test similar to the test (4), but without pollution potassium acetate;

6) test similar to the test (4), but without pollution AC is tatom potassium and with exposure to air at a temperature of 1400°C for 10 minutes (instead of 1200°C for 20 minutes) after the first oxidation cycle;

7) test, a similar test (4), but with the replacement phase contamination potassium acetate phase immersion in tap water at ambient temperature for 24 hours;

8) test similar to the test (4), but with the replacement phase contamination potassium acetate phase immersion in boiling water for 1 hour.

For comparison, each test was also carried out on three samples from the same C/C composite material, but is protected by a method known from the prior art, in particular described in document US 5853821, i.e. the method including the following steps as the above steps (a), (b) (repeated once), (d) and (e), i.e. excluding stage impregnation composition containing TiB2.

In Table 1 below and in Fig. 3 through 10 display the values of the mass loss measured after each test, in percent relative to the original mass, the samples protected by the method according to the invention and control samples, a secure manner known from the prior art.

26%
Table 1
Relative weight loss
Samples protected by the method according to the invention in accordance with the am 1 Control samples protected in a known manner
(1)
1×5 h 650°C
Pollution acetate5,5%6,9%7,3%6,7%7%8%
4×5 h 650°C
(2)
1×30 min - 850°C
Pollution acetate5,2%5,5%7%4,4%6,9%7,3%
4×30 min - 850°C
(3)
1×5 h 650°C
1×1 h - 1000°C9%9,5%14%17,5%18%23%
Pollution acetate
2×5 h 650°C
(4)
1×5 h 650°C
1×20 min - 1200°C11%12%22%35%39%56%
Pollution acetate
2×5 h 650°C
1×5 h 650°C
1×20 min - 1200°C2,6%2,6%3,4%9,2%13%13%
2×5 h 650°C
(6)
1×5 h 650°C
1×10 min to 1400°C2% 3%3,5%11,5%27%43,5%
2×5 h 650°C
(7)
1×5 h 650°C
1×20 min - 1200°C
24 h immersion in water6,5%7,5%8%29%31%37%
at temperatures
environment
2×5 h 650°C
(8)
1×5 h 650°C
1×20 min - 1200°C
1 hour immersion in7,5%8%9%15,5%31%
boiling water
2×5 h 650°C

The test results showed that, compared with this protection, known from the prior art, the protection against oxidation is performed by using a method in accordance with the present invention, has the following characteristics:

- similar effectiveness in the presence of an oxidation catalyst at temperatures in the range from 650°C to 850°C;

efficiency increases significantly in the presence of an oxidation catalyst after exposure to temperatures up to 1000°C (on average, about 11% weight loss, compared with 20%) and up to 1200°C (average 14% weight loss, compared with 43%);

- the efficiency is significantly improved in the absence of an oxidation catalyst after exposure to temperatures up to 1200°C (on average, about 3% weight loss compared with 12%) and 1400°C (on average approximately 3% loss of mass is compared with 24% and a large scatter in the results); and

- the efficiency is significantly better in a humid environment (on average, about 7% weight loss compared to 32% after immersion in water at ambient temperature for 24 hours, and an average of approximately 8% weight loss, compared with 24% and a large variation in results after immersion in boiling water for 1 hour).

Example 2

Implemented a procedure similar to that described in Example 1, but at the stage (C) used the impregnating composition comprising, in mass%: 32% Al(N2PO4)3and 56% ZrB2and the rest is water.

Several samples protected using the method according to Example 2, was tested for oxidation, identical to the test (5)described above.

Table 2 below illustrates the relative values of the mass loss measured on different samples after the implementation of the investigated test (in percent relative to the original weight). For comparison, Table 2 shows data on the mass loss observed in the same test for oxidation, for samples that are protected in accordance with Example 1, and for the control samples, in a secure manner known from the prior art.

Table 2
Samples Weight loss
Protected in accordance with Example 12,6%
2,6%
3,4%
Protected in accordance with Example 210,1%
11,4%
12,5%
Control9,2%
13%
13%

The obtained results show that the use of ZrB2as a replacement TiB2in the impregnating composition leads to a significant loss of efficiency of protection against oxidation, leading to results similar to the results observed in the samples in a secure manner known from the prior art.

Example 3

The used samples were made of C/C composite material of the same type as in Example 1, and they were protected from oxidation by the way, which, compared to the one described in Example 1 was changed as follows:

- on the stage (b) was used impregnating composition comprising (in mass percent): 44% Al(N2PO4)3and 14% TiB2in the form of a powder having an average particle size of approx the tion 10 μm, the rest is water; and

- on stage (in) used for impregnating composition comprising (in mass percent): 34% Al(N2PO4)3and 39% TiB2in the form of a powder having an average particle size of approximately 10 μm, the rest is water.

Example 4

The procedure corresponded to that described for Example 3, however, in process stage (b) was used a composition comprising (in mass percent): 39% Al(N2PO4)3and 28% TiB2in the form of a powder having an average particle size of approximately 10 μm, the rest is water; and the step (C) was used a composition comprising (in mass percent): 35% Al(N2PO4)3and 44% TiB2in the form of a powder having an average particle size of approximately 10 microns.

Two samples of E3and E4protected using the methods described in Example 3 and Example 4, respectively, were subjected to the oxidation test, identical to the test (4)described above.

In Table 3, below, and figure 11 displays the relative mass loss measured in percent in relation to the initial weight) after implementation of the test for oxidation for these samples, and the repeatability of results obtained for samples E1E'1and E1protected in accordance with Example 1, and control is protected samples ERE'Rand ER

Table 3
Sample E3protected in accordance with Example 3Sample E4protected in accordance with Example 4Samples of E1E'1and E1protected in accordance with Example 1Control samples ERE'Rand ER
10%9,5%11%12%22%35%39%56%

You may notice that the introduction of TiB2in the first impregnating composition comprising the phosphate makes it possible to obtain effective protection. However, it makes more difficult the penetration protection deep into the material.

The above examples show the obvious advantages provided by the use of TiB2as a source for the formation of oxides, which can function as a protective barrier against oxygen from the environment, and can interact with phosphorus and metal (regardless of whether they act from being used is of phosphate (phosphate), or catalyst for the oxidation of carbon) with the formation of glass and resists humidity and exciting oxidation catalyst coming from the outside.

Example 5

The procedure corresponded described in Example 1 except that in stage (b) was used a composition comprising (in mass%): 23% Al(N2PO4)3, 37% powder TiB29% of the powder of kaolin and 30% water.

Example 6

The procedure corresponded described in Example 1 except that in stage (b) was used a composition comprising (in mass percent): 24% Al(N2PO4)3, 39% powder TiB25% of powder of kaolin, 5% aluminum oxide and 27% water.

Example 7

The procedure corresponded described in Example 1 except that in stage (b) was used a composition comprising (in mass percent): 25% Al(N2PO4)340% of powder TiB210% aluminum hydroxide Al(OH)6and 25% water.

Example 8

The procedure corresponded described in Example 1 except that in stage (b) was used a composition comprising (in mass percent): 25% Al(N2PO4)340% of powder TiB210% phosphate zinc Zn3(PO4)2and 25% water.

Example 9

The procedure corresponded described in Example 1 except that in stage (b) was used in the composition is, containing (in mass percent): 25% Al(N2PO4)340% of powder TiB210% metaphosphate aluminum Al(RHO3)3and 25% water.

Samples of E5and E'5protected in accordance with Example 5, samples of E6E'6and E6protected in accordance with Example 6, examples of E7and E'7protected in accordance with Example 7, samples of E8and E'8protected in accordance with Example 8, and samples of E9and E'9protected in accordance with Example 9 was tested for oxidation, the same as described above the test (5).

On Fig displayed values of relative mass loss measured in percent in relation to the initial mass) for these different samples, and for samples E1E'1and E1protected in accordance with Example 1, and control is protected samples ERand E'R.

You may notice that the samples are protected in accordance with Examples 5 and 9, show a superior ability to resist oxidation compared to the control samples, even though their defense is less good than the samples protected in accordance with Example 1. This proves that in the framework of the present invention may use solid fillers (kaolin, aluminum oxide), ensuring that the value of the collateral is Deposit protection at a low level, as well as reactive fillers (aluminum hydroxide), phosphates, other than Al(N2PO4)3having anticatholicism properties (such as zinc phosphate), or even a phosphate of aluminium, other than Al(H2PO4)3.

The mass contents of one or more of these components, other than TiB2, Al(N2PO4)3and H2Oh, in the composition used for the deposition of the second protective layer (step (C)) is preferably chosen in the range from 0% to 40%.

1. The way to protect against oxidation products made of carbon-containing composite material and having a residual open internal pores, comprising at least one stage of impregnation of the composite material in the depth of the impregnating composition comprising at least one metal phosphate in solution, characterized in that the impregnating composition also contains titanium diboride in the form of a powder having an average particle size in the range from 0.1 to 200 microns.

2. The method according to claim 1, characterized in that the impregnating composition also contains an additional heat-resistant solid filler in powder form with an average particle size in the range from 0.1 to 200 microns.

3. The method according to claim 2, characterized in that the additional heat resisting particulate filler selected from silica, kiselina, clay, kaolin and talc.

4. The method according to any one of claims 1 to 3, characterized in that the impregnating composition contains at least one metal phosphate selected from phosphates of aluminum, zinc and magnesium.

5. The method according to any one of claims 1 to 3, characterized in that the impregnating composition contains, wt%: 20-70 phosphate (phosphate) metal; 5-50 titanium diboride; 20-50 water and 0-40 heat-resistant solid filler other than titanium diboride.

6. The method according to any one of claims 1 to 3, characterized in that it includes a preliminary stage of processing of products made of composite material by soaking it with a solution containing a wetting agent, and drying, to give a composite material wettability, which increases in the presence of the wetting agent.

7. The method according to any one of claims 1 to 3, characterized in that before applying the impregnating composition containing at least a metal phosphate in solution and the titanium diboride perform at least one step of applying a solution of at least one metal phosphate without a solid filler.

8. The product is made of composite material containing carbon, is shielded from oxidation depth, including at least one metal phosphate, characterized in that the protection from oxidation within the volume of products made of composite material also includes di is arid titanium in powder form, having an average particle size in the range from 0.1 to 200 μm, and a complex oxide of the type Ti-O-P-Me, where Me is a metal originating from the specified phosphate or catalyst for the oxidation of carbon.

9. Product of claim 8, characterized in that the protection from oxidation further includes a heat-resistant solid filler in powder form with an average particle size in the range from 0.1 to 200 microns.

10. Product of claim 8 or 9, characterized in that the protection from oxidation contains more titanium diboride in part located nearer to the surface than in the part located further down from the surface of the product.



 

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FIELD: mechanics.

SUBSTANCE: invention relates to friction elements containing a polymer composite layer to be operated in various friction assemblies in contact with a metal counter body. The proposed friction product comprises a friction element made in a polymer binder, dispersed fillers, fibrous reinforcing and metal-containing fillers. The friction element comprises additionally not over 2.5 % of a material made from powder high-molecular polyethylene as filler.

EFFECT: higher friction-wear properties due to higher friction and mechanical-effect.

FIELD: engineering industry.

SUBSTANCE: invention refers to engineering industry, and namely to manufacturing methods of friction items with firm inserts, which are meant for various transport types. Method is realised by hot moulding of shoe from polymer compound in a moulding tool under pressure at simultaneous alignment thereof with metal frame and firm inserts. Hot moulding is carried out in moulding tool with grooves located in a punch that forms the shoe working surface in firm insert location areas. Process projections are formed from polymer friction material on shoe working surface in those zones; then, shoe working surface is machined and process projections are removed, thus providing arrangement of working surfaces of firm inserts and polymer friction material in one plane. Moulding tool used for shoe manufacturing consists of a matrix and upper and lower punches. Punch forming the shoe working surface is equipped with grooves meant for each of the inserts arranged in location areas of firm insert working surfaces. Each groove is bigger than the appropriate insert.

EFFECT: providing the possibility of manufacturing railroad transport means brake shoe and locating working surfaces of firm inserts and working surface of friction material of shoe friction element in one and the same plane, providing efficient operation from the very beginning of brake shoe operation, and minimising the number of expensive friction material waste appearing during machining of shoe working surface.

2 cl, 3 dwg, 4 ex

FIELD: transport.

SUBSTANCE: braking block comprises metal carcass, composite material friction element and two solid inserts arranged symmetrically relative to the block horizontal axis and overlapping its friction part over the width. The said metal carcass represents a wire carcass representing two closed frames press-fitted into the block rear part friction material and perforated tin press-fitted into the block rear part composite friction material. Inner parts of the said frames are partially interoverlapped and bent outwards from the block rear part to form an ear designed to pass the cotter. Rear nonoperating part of every cotter has consoles arranged on each side of the aforesaid inserts all along their length. One of the said consoles is bent towards the block rear surface and arranged in the central boss, the other one being located between the central and auxiliary bosses. Each of the inserts is fitted into one of the wire carcass frames and jammed therein. The inserts, along with the carcass, are pressed in the composite friction material so that the insert console rear surfaces are located in one plate with the perforated tin of the block rear side.

EFFECT: higher durability and safety, longer service life, sable braking capacity and wheel surface recovery in braking.

3 cl, 3 dwg

Gasket // 2341702

FIELD: machine building.

SUBSTANCE: invention relates to machine building, particularly, to components used for separation of stacked porous plates in production process. Proposed circular gasket has opposed first and second surfaces with multiple holes. The said gasket is made of metal wire screen and partially form multiple radial gas-passages, each passing between the gasket inner and outer radial sides to inter-joint them. Method of preparing circular carbon fiber blanks for chemical filtration in vapor phase consists in stacking the aforesaid carbon fiber blanks. Between every two circular blanks, a circular metal screen cushion is laid so as to make stacked circular blanks and circular gaskets form interfaces of internal space inside a stack. Every circular gasket has first and second opposed surfaces and is made so as to form multiple radial gas passages communicating the stack inner space with outside space.

EFFECT: updating production process.

20 cl, 11 dwg

Gasket // 2341701

FIELD: machine building.

SUBSTANCE: invention relates to machine building, particularly, to components used for separation of stacked porous plates in production process. Circular gasket is made of carbon material whereon an adhesive coat layer is applied and incorporates opposed first and second surfaces. Note that at least one of the said surfaces has multiple radial channels each passing between the gasket inner and outer radial sides to inter-joint them. Method of preparing circular carbon fiber blanks for chemical filtration in vapor phase consists in stacking the aforesaid carbon fiber blanks. Between every two circular blanks, a circular metal screen cushion is laid so as to make stacked circular blanks and circular gaskets form interfaces of internal space inside a stack. Every aforesaid circular gasket comprises adhesive coat layer applied thereon to prevent sticking of circular carbon blanks. Method of producing one-piece circular carbon-material gasket consists in forming one-piece circular carbon-material gasket with opposed first and second surfaces and radial channel and applying adhesive coat layer on the said circular gasket.

EFFECT: updating production process.

22 cl, 11 dwg

FIELD: transport.

SUBSTANCE: invention refers to railway transport, namely to brake blocks of railway vehicles. Brake block contains composite friction element, metal frame made of steel strip and solid insert welded to it, wire frame, central boss with orifice for splint and two side bosses. Metal frame of steel strip is less in width than wire frame, it is radiussed over brake block rear surface and pressed in brake block rear surface from both sides of solid insert between side bosses and central boss. Wire framework is essentially two closed up frames around block periphery pressed into composite friction element in the rear part of brake block. Inner parts of two closed up frames overlap each other are folded outside rear part of brake block forming an eye for a splint. Side bosses are made of composite friction material. Solid insert has slot open from the side of its rear surface is enclosed in wire frame and pressed in central boss so that its rear surface is in same plane with central boss rear surface. Enhancement of strength of brake block construction and tool-life gain are reached, as well as spoilage reduction in their manufacturing.

EFFECT: enhancement of strength of brake block construction and tool-life gain are reached, as well as spoilage reduction in their manufacturing.

2 dwg

FIELD: transport.

SUBSTANCE: invention refers to railway transport, namely to brake blocks of railway vehicles. Brake block contains composite friction element, wire framework, solid insert located in central part of block and pressed into composite friction element. Wire framework is essentially two closed up frames around block periphery pressed into composite friction element in the rear part of brake block. Inner parts of two closed up frames overlap each other are folded outside rear part of brake block forming an eye for a splint. The block contains in its rear part wire-mesh or perforated metal sheet pressed into composite friction element. Insert has slot in its upper idle part pressed by composite friction element with orifice for splint and cantilevers symmetrically located over insert length from each side. Upper idle part of insert is put in wire frame and jammed in it. Enhancement of strength, reliability of brake block construction, tool-life gain are reached.

EFFECT: enhancement of strength, reliability of brake block construction, tool-life gain are reached.

4 cl, 3 dwg

Friction plate // 2335670

FIELD: mechanics.

SUBSTANCE: friction plate has two holes and is made in a polymer anti-friction composite material reinforced by a thread or threads. The said polymer anti-friction composite material contains a smaller number of reinforcing threads compared to the other parts of the friction plate.

EFFECT: improved strength and operating properties allowed by reducing fracturing nearby holes.

Friction pad // 2324849

FIELD: mechanic.

SUBSTANCE: the invention relates to the area of mechanical engineering, in particular, to friction pads intended for operation in lubricated assemblies. The friction pad is designed as part of a cylindrical shell, on the internal surface of which rectangular grooves are made. The grooves located longitudinally to the pad length have the same width and depth. The grooves transversal to the pad length, have width increasing with the groove depth. This provides stability of friction characteristics of the pad and decreases friction pair wear due to providing of more favourable conditions for penetration of the lubricating oil to the friction contact area, more efficient cooling of the friction elements, and better cleaning of the friction contact area from the wear products.

EFFECT: increased stability of friction characteristics of pad and decreased friction pair wear.

3 dwg

FIELD: railway transport; brake shoes.

SUBSTANCE: proposed brake shoe contains metal skeleton, polymeric composite friction member, one or several abrasive friction inserts and support layer placed between polymeric composite friction member and metal skeleton. Support layer is placed also between polymeric composite friction member and abrasive friction insert (inserts), or between polymeric composite friction member and part of surface of abrasive friction insert (inserts). Invention is aimed at improving operating characteristics of shoe owing to increased strength of connection of insert (inserts) and polymeric composite friction member by additional locking and reduced possibility of burning out of polymeric composite friction member in zone of insert (inserts) owing to provision of heat insulation of member relative to insert.

EFFECT: increased service life of shoe.

3 dwg

FIELD: corrosion protection.

SUBSTANCE: invention provides homogenous corrosion-inhibiting composition, which contains 20-30% water-soluble phosphate, 5-20% starch, and balancing amount of zeolite and/or schungite, said water-soluble phosphate being selected from alkali or alkali-earth metal phosphates, orthophosphates, and dihydrogenorthophosphates, in particular dipotassium phosphate. Composition may further contain sodium or potassium silicofluoride. Composition is of especial importance for use as corrosion inhibitor for solid antiicing agents based on inexpensive and accessible chlorides, particularly magnesium chloride.

EFFECT: increased efficiency and stability of protective properties and duration of effect, especially on building and road-building materials.

1 tbl

FIELD: manufacture of building materials.

SUBSTANCE: invention provides aqueous composition to coat consolidated gypsum material and method to treat consolidated gypsum-containing material, which composition contains at least one trimetaphosphate salt, at least one monobasic phosphate salt, and at least one acyclic polyphosphate salt containing at least three phosphate units. Consolidated gypsum material is treated by deposition of at least one compound thereon selected from at least two types of inorganic phosphate salts: monobasic phosphate salts, trimetaphosphate salts, and acyclic polyphosphate salts containing at least three phosphate units.

EFFECT: increased strength of consolidated gypsum containing materials, surface hardness, wear resistance and/or resistance against water-caused erosion.

36 cl, 4 tbl, 21 ex

The invention relates to the construction materials industry, namely the production of decorative mineral grains intended for finishing the surface of concrete products and roofing materials

The invention relates to the technology of construction materials intended for use as a protective and decorative coatings for metal, concrete, wood, wood boards, asbestos cement

The invention relates to the construction industry and is designed for protective and decorative finishing of building materials and metal structures

FIELD: manufacture of building materials.

SUBSTANCE: invention provides aqueous composition to coat consolidated gypsum material and method to treat consolidated gypsum-containing material, which composition contains at least one trimetaphosphate salt, at least one monobasic phosphate salt, and at least one acyclic polyphosphate salt containing at least three phosphate units. Consolidated gypsum material is treated by deposition of at least one compound thereon selected from at least two types of inorganic phosphate salts: monobasic phosphate salts, trimetaphosphate salts, and acyclic polyphosphate salts containing at least three phosphate units.

EFFECT: increased strength of consolidated gypsum containing materials, surface hardness, wear resistance and/or resistance against water-caused erosion.

36 cl, 4 tbl, 21 ex

FIELD: corrosion protection.

SUBSTANCE: invention provides homogenous corrosion-inhibiting composition, which contains 20-30% water-soluble phosphate, 5-20% starch, and balancing amount of zeolite and/or schungite, said water-soluble phosphate being selected from alkali or alkali-earth metal phosphates, orthophosphates, and dihydrogenorthophosphates, in particular dipotassium phosphate. Composition may further contain sodium or potassium silicofluoride. Composition is of especial importance for use as corrosion inhibitor for solid antiicing agents based on inexpensive and accessible chlorides, particularly magnesium chloride.

EFFECT: increased efficiency and stability of protective properties and duration of effect, especially on building and road-building materials.

1 tbl

FIELD: chemistry.

SUBSTANCE: invention refers to the method for oxidation defence of the article made from composite carbon-containing material and having the residual open inner pores. The said method includes at least one stage of composite material impregnating to depth with the impregnating composition containing at least one metal phosphate in the solution and titanium diboride in the form of the powder with particle size in the range from 0.1 mcm to 200 mcm. The invention refers also to the article obtained by the aforementioned method. Invention is developed in related items of invention formula.

EFFECT: invention provides the article oxidation defence at temperatures more than 1000°C, particularly in the presence of carbon oxidation catalyst and in wet conditions.

10 cl, 12 dwg, 9 ex, 3 tbl

Friction article // 2245467

FIELD: mechanical engineering.

SUBSTANCE: friction article is made of a polymeric friction composite reinforced with fibers. The diameter of openings for rivets is larger than that of the reinforcing fibers by a factor of 2-8.

EFFECT: enhanced reliability.

Friction article // 2246645

FIELD: mechanical engineering.

SUBSTANCE: friction article comprises indicator of wearing mounted on the side of the article and made of hollow and projection. The indicator comprises at least two surfaces one of which is a wall and the other one is a flat surface. The plane of the flat surface of the indicator is nonparallel to the plane of the side surface of the article.

EFFECT: improved visibility of wearing indicator.

4 cl, 7 dwg

Friction article // 2251035

FIELD: mechanical engineering.

SUBSTANCE: friction article comprises friction member and metallic structure whose surface is covered with a paint. The paint covering is hard and has relief surface which is defined by the alternating projections and hollows. The hollows receive metallic particles the hardness of which is less than that of the structure metal.

EFFECT: enhanced noise suppresion and simplified design.

2 dwg

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