Rhenium in liquid state. Metal rhenium

Atomic number - 75, Re. The name takes from the Rhine - rivers in Germany. Metal opened in 1925. Obtaining the first batch of rhenium occurred in 1928. The last of open elements with a known stable isotope.

Rhenium - Metal With a white tint. Powder Rhenium He has opposite the black color. It is very solid and dense metal structure. Melting - 3186º C, boiling - 5596º C. has paramagnetic properties.

Natural mineral rhenium photos below:

At temperature mode, over 300º C, the metal begins intensively oxidically, depending on the temperature rise. Rhenium reactions are more resistant to oxide than for example, in tungsten. Reactions with hydrogen and nitrogen almost does not occur, only adsorption with hydrogen.

During heating, interaction with chlorine, fluorine and bromine begins to occur. Not dissolved in acids, except nitric acid. In the interaction of rhenium, Amalgam is formed.

Interacting with hydrogen peroxide (or rather by its aqueous solution), forms reneeed acid. The only element representing refractory metals that does not form carbides.

It is known that rhenium is not involved in biochemistry. There is a rather small number of facts about its possible impact on its possible exposure, but it is reliable toxicity, so in any case he is poisonous for living beings.

Mining and origin of rhenium

This is extremely rare metal. In natural departments, most often found combination of tungsten - rhenium - Molybdenum. The admixture of this element is also contained in the minerals of its neighbors. Basic mining Rhenium Going out of deposits where it is extracted alongside.

Also, rhenium is extracted from the rarest natural mineral called Jazcazganit - by the name of the Kazakh city, near which he was found. Also, the rhenium is contained in Columbate (Niobium), Cherchedean, Zircon and some rare-earth minerals.

Rhenium is dispersed worldwide, in insignificant concentrations. Only one serious deposit of this metal - ITUURUP, a small island on Kurilla, Russia, is reliably known. Opened in 1992 rhenium there is represented by the mineral rhenium RES2, which has a structure similar to molybdenite.

The field is a small platform on the top of the sleeping volcano where thermal sources actively act. This says that the deposit continues its height, and according to preliminary estimates, it annually misses about 37 tons of this metal into the atmosphere.

The second or less suitable for industrial development of the source of rhenium, can be considered a mine in Finland deposit. Tag Rhenium is contained in the mineral Tarka.

How to get rhenium? Production This metal is due to the processing of primary raw materials with a rather low metal percentage. Mostly use copper and molybdenum sulphides.

The steps of the pyrometallurgical process used when working with ore-containing ores include the melting procedure, conversion and oxidative firing.

At huge melting temperatures, the highest RE2O7 oxide is first obtained, which is delayed by special catchers. Often, part of rhenium remains in the sage after the firing, from which it can be obtained by hydrogen. Next, the resulting powder is interpreted in rhenium.

When melting out of ore, most of the rhenium is derived, the residue is settled in the matte. In the process of converting the matte, contained in it is highlighted by gas.

The concentration of rhenium is produced by sulfuric acid, after which the rhenium acid is obtained. Using certain purification methods, rhenium is released from an acid solution.

Based on the rather low productivity of this method, the output may be no more than 65% of the metal contained in ore, scientific research is constantly carried out for the identification of more productive alternative methods of metal production.

Modern technologies already imply the use of aqueous solution, instead of acidic. This will capture much more metal when cleaning.

Application Rhenium

The main benefits of rhenium, for which it is so appreciated throughout the world, are considered to be refilled, low corrosion when exposed to various chemicals, etc. In view of the high on this metal, it is trying to use it only in extreme and exceptional cases.

Not so long ago, the main area of \u200b\u200bits use was heat-resistant rhenium alloys With different metals used in rocket industry and aircraft manufacturing.

In particular, alloys went to the production of spare parts for supersonic fighters. Such alloys include in their composition at least 6% of metals.

This aspect quickly made jet engines with a major source of consumption of world stocks. In addition, due to this, he began to be considered a military-strategic reserve.

Special thermocouples containing rhenium allow measurement of huge temperatures. Rhenium allows platinum metals to extend their service life. Also, springs are made from rhenium for accurate equipment and incandescent threads for spectrometers and pressure gauges.

More precisely, it is used with a renewed coating. Due to its resistance to chemical impacts, rhenium is used to create protective coatings against the acidic and alkaline medium.

Rhenium found use in the manufacture of special contacts that are self-cleaning after short-term short circuit. Oxide remains on ordinary contacts, which sometimes does not miss the current. On Rhenia, he also remains, but will soon disappear. Therefore, contacts from rhenium have a very long service life.

But a particularly important aspect of its application has become use of rhenium In special catalysts, with which certain components produce. Participation in the process of refining petroleum products, increased demand for rhenium several times. The world market has not been interested in this rare-earth metal.

Price rhenium

The global stock of this metal is about 13 thousand tons for the most part in molybdenum and copper deposits. They are its main sources in the metallurgical industry.

In principle, this is not surprising, more than 2/3 of all rhenium on the planet is contained in them. And the remaining third is a secondary material.

For some counts of these reserves, there are enough for more years on three hundred no less. And in this report, the secondary use was not taken into account. And such projects were developed for a long time, and some projects in practice have proven their consistency.

Prices for any product are established based on the availability of goods. How to become clear rhenium, buy which is not for his pocket, by no means affordable metal. In addition, there is an active demand for rhenium. Price He has naturally relevant.

According to the data for 2011 in order to acquire rhenium, the price per gram was about $ 4.5. Significant trends have not been observed. By that price depends on the degree of metal purification, therefore rhenium can cost both 1000 $ per kilogram, and ten times more expensive.

Application of rhenium as a alloying element in alloys and metal materials

A positive impact on the growth of production in the 1970-1980s, its wide and large-scale pile use in heat-resistant nickel alloys and in platinoreny catalysts of various purposes was provided. At the same time, the need for new materials of traditional areas of rhenium - electronics and special metallurgy is in interest in this metal from the side of industrial and science. According to the technical classification of rhenium, a typical refractory metal, but for a number of properties it is significantly different from other refractory metals, such as molybdenum or tungsten. According to the characteristics of rhenium, to some extent approaches the noble metals of the platinum type, osmium, iridium. It can be conventionally assumed that rhenium occupies an intermediate position between refractory metals, from one hundred-rubles, and platinum group metals on the other. For example, in contrast to tungsten, rhenium does not enter into the so-called water cycle - a negative phenomenon that causes damage to the filament of vacuum lamps. That is why a vacuum lamp made with reneeing thread is almost the "eternal" (its service life - up to 100 years).

By analogy with platinum metals, it has a high corrosion resistance in a humid atmosphere and in aggress-silic media. It almost does not interact at ordinary temperature rates with salt and sulfuric acids. Like tungsten and molyb den, paramagneuinence, but its specific electrical resistance is ~ 3.5 times more than these metals.

Particularly different mechanical properties of rhenium. It is characterized by high plasticity at room temperature and by the magnitude of the normal elastic module ranks third after Osmia and Iridia. This is due to the metal structure: re-own - the only element among the refractory metals of the fifth and sixth groups of the periodic system D.I. Mendeleeva (Van-Diy, Niobium, Tantalum, Chrome, Tungsten, Molybdenum), having a hex-gonnerable swept-packed lattice (GPU), similar to the re-coating of noble metals, such as Osmia or Ruthenium. The other refractory metals (tungsten, molybdenum) are characterized by a different structural type on the basis of a centrified cubic lattice (BCC).

The properties of rhenium at elevated temperatures are also beneficial and differ from the properties of other refractory metals. So, how to increase the temperature of the hardness of rhenium, as at tungsten and molybdenum, decreases, but the softening is not so much so far and at a temperature of 1000 ° C of rhenium has a hardness of ~ 2 times greater than tungsten in such conditions. In addition, at high temperatures, rhenium is characterized by increased long strength compared to tungsten and especially molybdenum and niobium. According to abrasion, rhenium is in second place after Osmia.

These unique properties of rhenium, as well as a number of others discussed in detail in the works. They determine the effectiveness of daving various metals and alloys in order to increase their plasticity, wear resistance and other pa-rameters.

The scientific and technical literature describes a large number of double and multicomponent alloys of rhenium with various metal lamen. These are widely known alloys of the type of nickel-re-riot, tungsten-rhenium, molybdenum, rhenium, nickel-molybdenia, nickel-tantaline rhenium, nickel-tungsten rhenium and a number of others.

Currently, nickel-rhenium alloys, tungsten reins and molybdenias obtained the largest spread on the scale of production, and according to some properties of rhenium alloys with tungsten and molybdenum, the properties of the individual dual metals are superior. Such alloys have high mechanical characteristics at room and elevated temperatures, form reduction and vibration, are not embrittable after crystallization, they are well welded, forming a carnate plastic seam. They are distinguished by high corrosion-bone in aggressive environments.

Rhenium alloys are used as a structural material in various operating conditions at high temperatures (\u003e 1800 ° C) and voltage, as responsible parts of electrovacuum devices, the material of electrocontacts, elastic elements of various devices and mechanisms, etc. The properties of rhenium alloys with refractory metals and nickel are described above (see Table 9), and in Table. 88 summarized some fi-zico-mechanical properties of tungsten alloys and molyb den rhenium.

Nickel-rhenium alloys are used in aviation, used as cores oxide cathodes, characterized by increased reliability and durability. Nickeli doping leads to an improvement in its strength characteristics when storing plasticity. These alloys also have high heat resistance, vibraroles and forms.

In recent years, Russian scientists have developed new supera-pillary rhenium-containing nickel alloys with uni-salted properties for workers vanes and disks of aviation and energy gas turbines. These are three groups of nickel-rhenium alloys.

1. Heat resistant nickel alloys containing 9-12%Re. , for the manufacture of workers of turbine blades, working at the peracters to 1100 ° C.

2. Intermetallic nickel alloys (1-2%Re. ) based on the connectionNi 3 al for the manufacture of turbine blades, working at temperatures up to 1250 ° C.

3. Heat resistant nickel alloys (1-2%Re. ) For the manufacture of discs of turbines operating at temperatures of 850-950 ° C.

Table 88.

Some physico-mechanical properties of rhenium alloys with tungsten and molybdenum

The use of which will be used below, is an element of a chemical periodic table under the atomic index 75 (re). The name of the substance occurred from the Rhine River in Germany. The year of discovery of this metal is considered to be 1925. The first significant batch of material was obtained in 1928. This element refers to the last analogue with a stable isotope. The rhenium itself is a metal with a white tint, and its powder mass is black. Melting and boiling temperatures are from +3186 to +5596 degrees Celsius. It has paramagnetic characteristics.

Features

The use of rhenium is not as broadly due to its exceptional parameters and high cost. At +300 ° C, the metal begins to be actively subjected to oxidation, the process of which depends on the further increase in temperature. This element is stable than tungsten, with hydrogen and nitrogen practically does not interact, providing only adsorption.

When heated, a reaction with chlorine, bromine and fluorine is noted. Rhenium is not dissolved only in nitric acid, and amalgam is formed when interacting with mercury. The reaction with the aqueous composition of hydrogen peroxide causes the formation of rhenium acid. This element is the only one among refractory metals that does not form carbides. The use of rhenium does not participate in biochemistry. There is little information about its possible impacts. Among reliable facts - toxicity and poisonousness for living organisms.

Prey

Rhenium - metal, which is extremely rare. In nature, it is most often found in combination with tungsten and molybdenum. In addition, impurities are available in the mineral sediments of its neighbors on the table. Mostly mining is carried out from molybdenum deposits by associated extraction.

In addition, the element in question is extracted from the Jescanite is a very rare natural mineral, which is so named after the Kazakh settlement near the deposit. Another rhenium can be distinguished from the cchedan, zirconium, columbit.

Metal is dispersed worldwide in a negligible concentration. Among the famous mining sites, where it is in significant quantities, Kurilsky is considered in Russia. Open deposit in 1992. Here, the metal is represented as similar to the molybdenum of the structure (RES 2).

Mining is carried out on a small platform hosted on the top of the sleeping volcano. There are actively thermal sources, which indicates the expansion of the field, which is preliminary estimated by the order of 37 tons of this metal per year.

The second production is considered a field of rhenium, suitable for industrial element extraction. It is located in Finland and is called khitachi. There, the metal is extracted from another mineral - Tarkianite.

Obtaining

Rhenium is obtained by treating primary raw materials, which initially has a low percentage of the content of this material. Most often extracted element from copper and molybdenum sulfides. Rhenium alloys are subjected to pyrometallurgical effects, which is used when working with melting ores, conversion and burning.

Excessive melting points make it possible to obtain RE-207, which is delayed by special capturing devices. It happens that part of the element settles in the sage after firing. From this substance, pure material can be obtained by hydrogen. Then the resulting powder substance is interposed directly to the ingots of rhenium. The use of ore for the extraction of the element under consideration is accompanied by the appearance of a precipitate in matte. Further conversion of this composition allows you to separate the rhenium by exposure to certain gases.

Technological moments

It is possible to achieve the desired concentration during production due to the properties of the rhenium and the use of sulfuric acid. After the passage of special cleaning methods, it is possible to highlight a clean element from ore.

This method is not very productive, the output of the clean product is no more than 65%. This indicator varies depending on the metal content in ore. In this soil, scientific research is regularly carried out to identify more advanced and alternative production methods.

Modern technologies make it possible to optimize the properties of the rhenium obtained artificially. Such a solution allows the use of aqueous solution instead of acidic. This makes it possible to catch significantly more pure metal during cleaning.

Application

First consider the main characteristics of the element under consideration, for which it is especially valued:

• Infusibility.
• Minimum corrosion exposure.
• Lack of deformation when exposed to chemicals and acids.

Since the price of this metal is extremely high, it is used mainly in rare cases. The main area of \u200b\u200bapplication of this element is the production of heat-resistant alloys with various metals, which are used in the structure of missiles and aviation industry. As a rule, rhenium are used for the release of spare parts for supersonic fighters. Such formulations include at least 6% of the metal.

Such source quickly turned into a basic means for creating reactive power units. At the same time, the material began to be considered a military-strategic reserve. Specially provided thermal pairs allow measurement of temperatures in huge ranges. The element in question makes it possible to extend the majority of the aggregated metals their service life. From rhenium, the use of which is discussed above, springs are also made for accurate equipment, platinum metals, spectrometers, pressure gauges.

More precisely, there is a tungsten with a rhenium coating. Due to its chemical resistance, this metal is included in the protective coatings against the acidic and alkaline medium.

Rhenium is also used for the manufacture of special contacts. They have the property of self-cleaning in the case of short-term closure. On ordinary metals, it remains oxidized, which does not allow current. Through the renewed alloys also passes the current, but no traces after herself leaves. In this regard, contacts from this metal have a long service life.

The most important aspect of the use of rhenium was the possibility of its use to create catalysts that help to produce certain components of gasoline fuel. The possibility of using a chemical element in the oil industry has led to an increase in its demand at the relevant market several times. In the world, seriously became interested in this unique material.

Stocks

It is worth noting that the global stock of rhenium is at least 13 thousand tons only in molybdenum and copper deposits. They are the main sources of this component in the metallurgical industry. More than 2/3 of all rhenium on the planet is contained in such configurations. The remaining third is secondary remnants. If you reduce all stocks of reserves to a single denominator, they should be enough for at least three hundred years. In the calculation of scientists, secondary use was not taken into account. Similar projects were developed for a long time, some of them have proven their worth.

Cost

Prices for the product of most categories are formed by the availability and demand of goods. Such a component, like rhenium, refers to one of the most expensive metals in the world, so it is not for each manufacturer by pocket, although it has unique properties that allow you to level the costs of expensive use. At the same time, rhenium possesses such parameters, which no other metal is posted. To create space and aviation structures, its characteristics are suitable. It is not surprising that the price is high, although it corresponds to all indicators characteristic of this unique material.

Already in 2011, the average cost of Rhenium was about 4.5 US dollars per gram. Subsequently, any tendencies for lower prices were observed. Often the final cost depends on the degree of metal purification. The price of the material can reach thousands of dollars and above.

History opening

This element was opened by German chemists - ID and Walter Noddakov in 1925. They conducted research using colombural analysis in the Laboratory of the Siemens and Shake Group. After this event, an appropriate report was held at the meeting of German chemistry specialists in Nuremberg. After a year, the team of scientists allocated the first two milligrams of rhenium from Molybdenum.

In a relatively pure form, the element was obtained only in 1928. To obtain one milligram of the substance, it was necessary to recycle over 600 kilograms of Norwegian molybdenum. Industrial production of this metal started also in Germany (1930). The capacity of processing plants allowed to obtain about 120 kg of metal annually. At that time, it fully satisfied the need for rhenium on the whole world market. In America, the first industrial 4.5 kg of unique metal was obtained in 1943 by processing concentrated molybdenum. It was this element that became the last open metal with a stable isotope. All other analogues, previously opened, including artificially, did not have such properties.

Natural reserves

To date, according to the natural reserves of the metal under consideration, the list of fields can be positioned in the following order:

• Chilean copy.
• United States of America.
• The island of ITUURUP, the deposits on which is estimated up to 20 tons per year (in the form of volcanic gas eruptions).

In the Russian Federation, semi-element fields of hydrogenic type are estimated as sections that have the maximum potential of copper-porphy and copper-molybdenum ores. In total, judging by the forecasts of specialists, the field of Rhenium in Russia is 2900 tons (76% of the state's resource). The lion's share of these deposits is in (82%). The following deposit in stocks - Briquette-jaratuahin pool in the Ryazan region.

Outcome

Rhenium is a chemical element that refers to a group of rare metals with unique characteristics. The above describes its properties, places of production, scope of application.

The effect of dopping on the deformation behavior and mechanical properties of heterophase monocrystals of alloyed heat-resistant alloy based on No. 3A1

G.P. Grabowetskaya, Yu.R. Kolobov, V.P. Buntushkin1, E.V. Kozlov2.

1 Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, 634021, Russia 2 All-Russian Institute of Aviation Materials, Moscow, 107005, Russia 3 Tomsk State Architectural and Construction University, Tomsk, 634003, Russia

Structure and phase composition of single crystals were studied by methods of raster electron microscopy<001 > Alloy type VKNA. The effect of doping on the deformation behavior and temperature dependence of the mechanical properties of single crystals in the temperature range 293-1373 K is studied in the temperature range of 293-1373 K.. Possible physical reasons for changing the nature of the deformation behavior by the rationing of single crystals<001 > Alloys of the VKNA type in the temperature range 2931 073 K.

The Effect Of Re Alloying On Deformation Behavior and Mechanical Properties of Heterophase Single Crystals of Doped High Temperature Ni3al-Based Alloy

G.P. Grabovetskaya, Yu.r. Kolobov, v.p. Buntushkin, and E.V Kozlov

The Structure and Phase Composition Of Single Crystals<001> Of VKha-Type Alloy Have Been Investigated by Scanning Electron Microscopy. The Effect Of Re Alloying On Dependence Of Mechanical Properties of Above-Mentioned Single Crystals In The Temperature Range of 293-1 373 K Has Been Examined. Consideration Are Given to Possible Physical Reasons of Changing Deformation Behavior Characteristics Of Reas Alloying Of Single Crystals<001> Of VKha-Type Alloy In The Temperature Range of 293-1 073 K.

1. Introduction

Perspective materials for turbine blades

currently, poly- and single crystals of heat-resistant (y + y ") nickel alloys with a large

volume fraction of phase (intermetallic №3A1) with super-

l12 structure. Such alloys have high heatproof and can function for a long time at high temperatures. Polycrystalline alloys based on No. 3A1 quite well investigated

In particular, it was found that in such materials, the processes of deformation and destruction during high-temperature creep are localized at the borders of the grains. This leads to the emergence and diffusion-controlled growth of grain boundary wedge-shaped cracks

With the simultaneous development of slipping on grain boundaries. The absence of grain boundaries in single crystals of these alloys eliminates the negative effects of grain boundary processes and allows

implement the performance of the alloys under consideration.

In the work, it is shown that in the process of deformation of single crystals (y + y /) - alloys when tangent stresses achieved in the current system of sliding critical magnitude, the incident of slip takes place on the interfacial boundaries of U / y. "Slide develops first in the phase, and then occurs Sluorrow of high-strength particles in "phase dislocations. In the future, with an increase in the deformation, the sliding is also developing in "-Fase. At the same time, it is mostly localized in a less durable y-phase. Hence, the less in the volume of the y-phase, the greater the sliding in the phase and the higher the resistance to the deformation of the single crystal ( + U ") - alloy. Another way to increase the strength of single crystals (y + y ") - alloys - doping with elements that increase the strength characteristics of the u and y7-phases.

© Grabovetskaya G.P., Kolobov Yu.R, Buntushkin V.P., Kozlov E.V., 2004

In this paper, a study was conducted by the effect of doping on the deformation behavior and the temperature dependence of the mechanical properties of complexized alloy single crystals based on Ni3al.

2. Material and Test Methods

Materials used single crystals<001 > Ni3al-based alloy containing elements Cr, Ti, W, Mo, HF, C, the total number of which did not exceed 14 weight. % (Alloy type VKNA).

The alloy microstructure was examined using a raster (Philips SEM 515) microscope. The phase composition was determined by the methods of x-ray structural analysis at the installation of Dron-2.

Mechanical tensile tests were carried out on an upgraded PV-3012M installation in the temperature range 293-1373 K at a rate of 3.3 * 10-3 C1. Samples for mechanical testing in the form of a double blade with dimensions of the working part 10x2.5x1 mm were cut out with a electric cleaner. Before testing from surfaces, the samples were removed with a layer with a thickness of about 100 μm with mechanical grinding and electrolytic polishing.

3. The results of the experiment and their discussion

Studies Studies have shown that in the initial state (state 1) of single crystals<001 > Alloy

the type of VKNA contains two phases-y and u7. In the volume of the alloy, large allocations of incorrect form in "-Fases with dimensions of 30-100 μm and a fine mixture of plates U7 and U-phases, sizes of the order of several micrometers in length and ~ 1 μm in width (Fig. 1, a). Main volume It occupies the Y-phase (-90%) - a solid solution based on Ni3AL. In this case, the volume fraction of large sections of the Y-phase is -22%.

Introduction to the alloy of a small (less than 2 wt.%)

rye (condition 2) leads to the appearance in

the volume of single crystals of the third phase - A1 ^ e. However, its volumetric share does not exceed 0.5%. The main volume of the material still occupies the U7 phase (-75%). In this case, the volume fraction of large secretions of the U7 phase decreases to 10%, and their dimensions are up to 5-30 microns (Fig. 1, b).

In fig. 2, 3 presents typical flow curves and temperature dependence of mechanical properties when stretching monocrystals<001 > WP Alloy in state 1 in the temperature range 293-1 373 K. from fig. 2 It can be seen that on the flow curves of the specified single crystals at temperatures below 1073 K there is an extended stage of deformation hardening with a high deformation hardening coefficient, which is characteristic of multiple slip in octahedral planes of single crystals with superstructure L12. This character of sliding is confirmed by the presence on a pre-polished surface of single crystals<001 > The Alloy of the type of VKNA is 1 after testing in the temperature range 293-1 073 to thin and / or coarse tracks of sliding in two mutually perpendicular sliding systems that pass through both phases without interrupting.

On curves of monocrystals<001 > The alloy of the VKNA type is in state at temperatures 1 273 and 1373 K there is a platform or an acute tooth of yield strength, followed by an extended stage of deformation hardening with a low deformation hardening coefficient. This type of stretching curves is typical for single crystals with superstructure L12 in case the deformation is carried out by sliding offices in the plane of the cube. At a pre-polished surface of the samples after testing at temperatures above 1073, the tracks are not observed, which is characteristic of cubic slip in single crystals<001 > Intermetallide number 3A1. Near the destroyer, cracks appear. They are located on the borders of the section of large dand-rites of U7-phase and fine mixture (y + u7) -Fases. The density of cracks p is not high. For example, after the test

Fig. 1. Structure of SPNA alloy single crystals in states 1 (a) and 2 (b)

Deformation,%

Fig. 2. Monocrystal flow curves<001> AV alloy in state 1, calculated in the approximation of uniform elongation: 293 (1); 873 (2); 1073 (3); 1273 (4); 1373 K (5)

Temperature, K.

Fig. 4. The dependence of the size of the strength (1), the yield strength (2) and deformation to the destruction (3) on the temperature of the test of single crystals<001 > Alloy type VKNA in state 2

tania at 1373 to P is -10 mm-2. The length of cracks ranges from 20 to 150 microns.

Special flow curves for single crystals<001 > The Alloy of the VKNA type is observed at a temperature of 1,073 K. For this temperature, a very short stage of deformation hardening is characterized with a maximum deformation hardening coefficient, which is replaced by the stage of softening. On the surface of the samples after stretching at a temperature of 1073 K, both traces of sliding in two mutually perpendicular sliding systems and cracks are observed.

From fig. 3 It can be seen that for single crystals< 001 > The Alloy of the VKNA type is in state 1 is characterized by a monotonous increase in the yield strength A0 2 in the temperature range 293-1 073 K, and then after reaching the maximum at a temperature close to 1,073 K, its sharp drop. Plasticity monocrystals<001 > Alloy

the type of VKNA is in state 1 with increasing temperature decreases, reaches a minimum at a temperature of 1073 K, and then increases. The magnitude of the strength of AV monocrystals<001 > The Alloy of the VKNA type is in state 1 in the temperature range 293-873 to virtually unchanged. With an increase in the temperature of AB, it is increasingly increasing and, reaching a maximum at 1073 K, drops sharply.

Thus, the temperature dependence of the deformation behavior, the strength and plastic characteristics of single crystals<001 > The Alloy of the VKNA type is in state 1 is similar to the anomalous dependence on intermetallic monocrystals No. 3A1.

Doping with rhenium leads to a significant increase in values \u200b\u200bof A 02 and and in single crystals<001 > Alloy type VKNA in the temperature range from room to 873 K (Fig. 4), which may be due to solid

Fig. 3. The dependence of the magnitude of the strength of (1), the flow limit. 5. Monocrystal flow curves<001> Alloy VKNA in

honor (2) and deformation before the destruction (3) on the temperature of the standing 2, calculated in the approximation of uniform elongation:

monocrystals<001> Alloy type VKNA in state 1 293 (1); 1073 (2); 1173 (3); 1273 (4); 1373 K (5)

mortar hardening. At the same time, in the indicated temperature range, the values \u200b\u200bof A0 2 and AB are almost constant. At temperatures above 873 to the values \u200b\u200bof A02 and A in single crystals<001 > The Alloy of the VKNA type is in state 2 sharply decrease to the values \u200b\u200bcorresponding to the state 1. The value of 8 single crystals<001 > The alloy of the VKNA type when doped with rhenium, on the contrary, is reduced compared to the corresponding values \u200b\u200b8 for state 1. However, in the entire temperature range, it monotonically increases with increasing temperatures from 16 to 33% (Fig. 4).

In fig. 5 presents typical flow curves when stretching monocrystals<001 > Alloy type VKNA is in a state 2 in the temperature range 2931373 K. from fig. 5 It can be seen that on the flow curve of the specified single crystals at room temperature, there is an extended stage of deformation hardening with a large deformation hardening coefficient than corresponding to state 1. With an increase in the test temperature, the length of the strain hardening of single crystals<001 > Alloy the type of VKNA is in a state of 2 monotonically increases, and the deformation hardening coefficient is reduced monotonically. While the deformation hardening coefficient for single crystals<001 > Alloy the type of VKNA is in state 1 with increasing temperature varies by a curve with a maximum (Fig. 2).

On a pre-polished surface of single crystals<001 > WP Alloy 2, as well as on the surface of single crystals<001 > The Alloy of the VKNA type is in state 1, after stretching in the temperature range 293-1073 K there are thin and / or coarse tracks of sliding in two mutually perpendicular slip systems, and after testing at temperatures above 1073, there are no tracks of sliding. In this case, the density and length of cracks on the surface near the destroyer in single crystals<001 > VKNNA alloy is 2 less than in state 1. So, after stretching at 1373 to the density of cracks on the surface of single crystals<001 > The VKNA alloy is in a state of 2 is -3 mm-2, and the length of cracks ranges from 15 to 30 microns.

Thus, the given data show that doping leads to a qualitative change in the deformation behavior of single crystals<001 > Alloys of the VKNA type in the temperature range 2931073 K.

Anomalous dependence of the deformation behavior and the strength characteristics of the intermetallide No. 3A1 on temperature, in accordance with, is associated with the formation of the L12 of thermoactivated dislocation barriers to Kira-Wilsdorf, which is reduced in the process of deformation in single crystals.

poly in a certain temperature range is practically not destroyed. Dislocation barriers like Kira-Wilsdorf are two split super-fat dislocations, associated with a strip of the anti-phase border in the cube plane. The activation energy of the formation and destruction of these barriers is largely determined by the energies of the antiphase boundary and the packaging defect. It is known that the values \u200b\u200bof the anti-phase boundary energy and the Ni3al intermetalline packaging defect are significantly dependent on the type and number of alloying elements. From here you can assume that the change in the nature of the temperature dependences of the values \u200b\u200bof St02, STTs and 8 single crystals<001 > Alloys of the type of VKNA with doping is associated with a change in the magnitudes of the anti-phase border and the packaging defect in the Y-phase.

4. Conclusion

Thus, doping leads to a change in the nature of the deformation behavior of single crystals<001 > Waste alloys in the temperature range 293-1073 K. There is an increase in the deformation hardening coefficients and the strength characteristics of the specified single crystals while maintaining satisfactory plasticity.

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