KR101144866B1 - Hot pressed ZrB2-SiC using zirconium silicides as precursor and manufacturing method of the same - Google Patents

Abstract

The present invention relates to a method for producing a ZrB ₂ -SiC pressurized sintered composite material using the zirconium silicide group as a precursor, and to a composite material prepared from the method. More specifically, a mixture of a zirconium silicide group, boron, and carbon is mixed and mixed. Preparing a; Sintering the mixture; comprising a zirconium silicide group having a fine particle size and a uniform secondary phase distribution to obtain a densely sintered ZrB ₂ -SiC composite material through a pressure sintering method as a precursor. It provides a method for producing a ZrB ₂ -SiC pressure sintered composite material and a composite material prepared from the method.
According to the present invention, by using a zirconium silicide group (Zr _x Si _y , Zirconium silicides) in which Zr and Si are uniformly mixed at the molecular unit level as a starting material to prevent local concentration of the chemical composition uniform and fine microstructure The effect of producing a ZrB ₂ -SiC composition having a sintered ZrB ₂ -SiC sintered compact that is not densified by atmospheric sintering is expected to be compacted by using pressure sintering.

Description

Hot pressed ZrB2-SiC using zirconium silicides as precursor and manufacturing method of the same}

The present invention relates to a method for producing a ZrB ₂ -SiC pressurized sintered composite material using the zirconium silicide group as a precursor, and to a composite material prepared from the method. More specifically, a mixture of a zirconium silicide group, boron, and carbon is mixed and mixed. Preparing a; Sintering the mixture; comprising a zirconium silicide group having a fine particle size and a uniform secondary phase distribution to obtain a densely sintered ZrB ₂ -SiC composite material through a pressure sintering method as a precursor. It provides a method for producing a ZrB ₂ -SiC pressure sintered composite material and a composite material prepared from the method.

According to the present invention, by using a zirconium silicide group (Zr _x Si _y , Zirconium silicides) in which Zr and Si are uniformly mixed at the molecular unit level as a starting material to prevent local concentration of the chemical composition uniform and fine microstructure ZrB ₂ -SiC composition having a functional effect and ZrB ₂ -SiC sintered body prepared using a zirconium silicide group (Zr _x Si _y , Zirconium silicides) that is not densified by atmospheric sintering using pressure sintering By doing so, the effect that can be densified is expected.

ZrB ₂ has a very high melting point of about 3350 ℃, and has excellent mechanical properties such as excellent strength and hardness properties, so that its application is extensive in industrial fields, and many studies have been made for the application for military and aerospace applications. It's going on. However, there are many limitations in the application process by industry because of the high melting point material's sinterability and low oxidation resistance in the working temperature range of 1200 ~ 1500 ℃.

In order to overcome such sinterability, a method of applying an additive to ZrB ₂ has been applied. In particular, when 20 to 30% by weight of ZrB ₂ -SiC is added with SiC as an additive, sintering of ZrB ₂ is easier. It is known that not only greatly improve the oxidation resistance at 1200 ~ 1500 ℃ but also mechanical properties such as strength. However, SiC must be uniformly distributed in the ZrB ₂ matrix in order to exhibit the strength enhancing and antioxidant effects.

Therefore, in order to improve the sinterability of these ZrB ₂ powders and uniform mixing with SiC, commercially available ZrB ₂ powders have been converted into SiC and SiC using wet grinding methods using a high grinding device such as attrition mill and planetary mill and a liquid dispersion medium. Used by mixing. However, ZrB ₂ has a high modulus of elasticity, hardness and fracture toughness, so it is not easy to grind. Especially in the case of planetary mill, even if ZrB ₂ is continuously crushed for 72 hours at 200 rpm, the average particle size is less than 1㎛. It is not as easy to manufacture as possible. In addition, there is a problem that it is difficult to prevent a large amount of contaminants introduced from the grinding ball and the grinding container during the grinding. In addition, SiCs tend to re-aggregate in the process of mixing ZrB ₂ and SiC by a wet mixing method and drying them, which makes it difficult to manufacture a ZrB ₂ -SiC composite material in which SiC is uniformly distributed.

In order to improve the problem of uniformity and the mixing of impurities through the long grinding and mixing process, ZrB ₂ -SiC composites were prepared using Zr, Si, B ₄ C and C as the starting materials. Examples have been reported. However, in these studies, due to the local concentration of chemical composition, the formed ZrB ₂ and SiC grow to a size similar to that of the starting materials Zr and Si, so that the composites produced by these methods are relatively coarse in grain size. There was a problem.

In addition, Zr powder, which is a starting material, has a high reactivity with air, which may cause an explosion when exposed to air in a powder state, and all experiments have a problem in that industrialization is difficult because it must be performed in an expensive inert atmosphere.

The present invention has been made to solve the problems described above, the present invention is a zirconium silicide group (Zr _{x x} Zr and Si is uniformly mixed at the molecular unit level as a starting material in the production of ZrB ₂ -SiC composite material The purpose of the present invention is to provide a ZrB ₂ -SiC composite material having a finer grain size and uniformly distributed SiC by preventing local concentration of chemical composition by using Si _y and Zirconium silicides).

In addition, the present invention is a source of boron (boron carbide (B ₄ C), boron oxide (B ₂ O ₃ ) or boric acid (H ₃ BO ₃ )) and a source of carbon (graphite, It is another object to obtain a high-purity ZrB ₂ -SiC composite material having a fine grain size and a uniform microstructure in spite of heat treatment at low temperature by mixing with carbon black, activated carbon, phenol resin, and pitch). .

In addition, the present invention by using the pressure sintering method instead of atmospheric sintering to prevent the coarsening of the particles generated at high temperatures, and to ensure that the sintering process using the low temperature deformation of the zirconium silicide group can be faithfully performed, thereby ZrB _2- It is another object of the present invention to manufacture a ZrB ₂ -SiC composite material that minimizes grain growth and maximizes densification, since the formation process of the SiC composite material is completed at an extremely low temperature compared with the existing results.

In order to achieve the above object, the present invention comprises the steps of preparing a mixture by mixing a zirconium silicide group, boron and carbon; Sintering the mixture; ZrB ₂ -SiC pressurized sintering with zirconium silicide group as a precursor to obtain a finely sintered high purity ZrB ₂ -SiC composite material with fine particle size and uniform secondary phase distribution through pressure sintering It provides a method for producing a composite material.

The pressing force of the pressure sintering is preferably to be carried out in the range of 30 ~ 120MPa.

The sintering is preferably to be carried out in 30 ~ 120MPa pressure range and 1300 ~ 1800 ℃ sintering temperature range.

Preference is given to adding at least one of ZrB ₂ or SiC to the mixture.

As a starting material of the composition, boron is preferably at least one selected from boron carbide, boron oxide and boric acid.

As a starting material of the composition, carbons are preferably at least one selected from graphite, carbon black, activated carbon, phenol resin, and pitch.

In addition, the present invention, in order to achieve the object as described above, ZrB ₂ -SiC pressure sintering composite having a nano-size as a precursor to the zirconium silicide group showing a relatively high degree of densification at the same grain size compared to the case of atmospheric pressure sintering Provide the material.

As described above, the present invention is a zirconium silicide group in which Zr and Si are uniformly mixed at the molecular unit level as a starting material in preparing a high purity ZrB ₂ -SiC composite material having fine grains and a uniform microstructure ( By using Zr _x Si _y and Zirconium silicides), it is expected to produce a ZrB ₂ -SiC composite material having a uniform and fine microstructure by preventing local concentration of chemical composition.

In addition, the present invention by using the pressure sintering method instead of atmospheric sintering to prevent the coarsening of the particles generated at high temperatures, and to ensure that the sintering process using the low temperature deformation of the zirconium silicide group can be faithfully performed, thereby ZrB _2- Since the formation process of the SiC composite material is completed at an extremely low temperature compared with the existing results, the effect of producing the ZrB ₂ -SiC composite material which minimizes grain growth and maximizes densification is expected.

1 is an XRD diffraction pattern according to a change in heat treatment temperature of a mixed powder of ZrSi ₂ , B ₄ C, C in a vacuum atmosphere to prepare a ZrB ₂ -SiC composition according to an embodiment of the present invention. (a) Specs mill mixing, 900 ° C., 10 minutes (b) Ultrasonic mixing, 1270 ° C., 10 minutes, (c) Ultrasonic mixing, 1300 ° C. 10 minutes. ●: ZrSi ₂ , ■: ZrB ₂ , ▼: SiC, □: ZrO ₂ , ↓: unidentified
2 is a 120 MPa pressing force of a powder in which 70 wt% ZrB ₂ powder and 30 wt% stoichiometric composition ZrSi ₂ + B ₄ C + C are mixed with respect to the total weight of the composite composition according to an embodiment of the present invention. Sintering shrinkage behavior with temperature change. (a) 1400 degreeC, 60 minutes, (b) 1450 degreeC, 60 minutes, (c) 1500 degreeC, 30 minutes, (d) 1650 degreeC, 5 minutes.
3 is a temperature under 120MPa pressing force of a powder in which 60% by weight ZrB ₂ powder and 40% by weight of the stoichiometric composition ZrSi ₂ + B ₄ C + C are mixed with respect to the total weight of the composite composition according to an embodiment of the present invention. Sintered shrinkage behavior with change. (a) 1400 degreeC, 60 minutes, (b) 1450 degreeC, 60 minutes, (c) 1500 degreeC, 30 minutes, (d) 1550 degreeC, 30 minutes, (e) 1650 degreeC, 5 minutes.
4 is a temperature under 120MPa pressure of a powder in which 50% by weight ZrB ₂ powder and 50% by weight of the stoichiometric composition ZrSi ₂ + B ₄ C + C are mixed with respect to the total weight of the composite composition according to one embodiment of the present invention. Sintered shrinkage behavior with change. (a) 1550 degreeC, 30 minutes, (b) 1650 degreeC, 5 minutes.
5 is a pressure of 120 MPa of a mixture of 50 wt% ZrB ₂ powder and 30 to 50 wt% stoichiometric composition ZrSi ₂ + B ₄ C + C mixed with respect to the total weight of the composite composition according to one embodiment of the present invention Shrinkage behavior when sintered at 1650 ° C. for 5 minutes. (a) 30, (b) 40, (c) 50% by weight.
Figure 6 is a microstructure obtained after sintering under a vacuum atmosphere, a pressing pressure of 120MPa to prepare a ZrB ₂ -SiC composition according to an embodiment of the present invention. (a) nano-SiC blend with spec mill, (b) ZrSi ₂ -B ₄ CC blend with spec mill.
7 is a ZrB ₂ under a vacuum atmosphere to produce the ZrB ₂ -SiC composition according to one embodiment of the present invention (a) and 40 (b) 50% by weight of ZrSi ₂ + B ₄ C + C a powder mixture of After sintering for 5 minutes at a pressing pressure of 120MPa and a sintering temperature of 1650 ℃, the microstructures are shown respectively.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Zirconium silicide groups (Zr _x Si _y , Zirconium silicide) include ZrSi ₂ , ZrSi, Zr ₅ Si ₄ , Zr ₅ Si ₃ , Zr ₃ Si ₂ , Zr ₂ Si and Zr ₃ Si depending on the ratio of Zr and Si. Their melting point exists over a wide range, from 1620 to 2500 ° C. Since these silicides are uniformly mixed at the molecular level, Zr and Si simultaneously form nanoscale ZrB ₂ and SiC when reacted with a boron source and a carbon source. The mixing ratio of ZrB ₂ and SiC can be controlled by selecting and using silicides of a desired composition or by mixing them in an appropriate range. In contrast, when Zr and Si raw powders are used, ZrB ₂ and SiC formed by the concentration of local Si and Zr composition grow similarly to the raw powders Zr and Si, and as a result, there is a problem of coarse particles. This is as described above.

In addition, ZrSi ₂ is relatively stable in air and can be easily handled, whereas Zr powder is explosive in air, so the process using Zr powder as a raw material has problems in industrialization.

ZrSi ₂ zirconium silicide of these group has been reported to be possible to densify the ZrB ₂ eseo 1650 ℃ by pressureless sintering the addition of 40% by weight of the total composition, based on the weight of the composite material the ZrSi _2, because a melting point of as low as 1620 ℃. However, only the ZrSi ₂ is expected to be a high-temperature physical properties of the ZrB ₂ sintered body made by the melting of the ZrSi ₂ at a high temperature greatly reduced when it is used as a sintering aid has been indeed reported that the intensity values greatly reduced from 1400 ℃. If line by adding a stoichiometric B ₄ C and C in order to solve this problem, ZrSi _2, by reacting both the reduction in the high temperature properties due to changes in, and SiC as ZrB _2, but can be suppressed, a reaction of ZrSi ₂ Since it is completed before the liquidus formation temperature of 1620 ℃, ZrB ₂ cannot be completely densified by atmospheric sintering.

Therefore, the pressure sintering method may be more preferably applied. In general, in the temperature range of about 2/3 of the melting temperature, the material is known to start to deform due to pressure. In the case of ZrSi ₂ , this temperature range is around 1100 ° C. In addition, at 1400 ° C., deformation due to the pressure of ZrSi ₂ occurs greatly. Therefore, ZrSi, so the deformation of the ZrSi _2, the reaction was even a region of relatively low temperature that does not complete due to the pressure of the _two may be caused, and the densification of the ZrB ₂ can further be promoted through which, in the subsequent higher temperature, residual ZrSi ₂ in the heat treatment process, Since it disappears, it is possible to suppress the decrease in high temperature properties of the produced ZrB ₂ .

Preferred examples of the starting material for preparing the ZrB ₂ -SiC composition of the present invention include zirconium silicides as precursors of Zr and Si, boron which is at least one selected from boron carbide, boron oxide and boric acid; At least one carbon selected from graphite, carbon black, activated carbon, phenol resin, pitch, and poly acrylonitrile (PAN) was used. When expressed according to B ₄ C), boron oxide (B ₂ O ₃ ), boric acid (H ₃ BO ₃ ) are as follows.

Zirconium silicides + B ₄ C + C → ZrB ₂ + SiC (Equation 1)

Zirconium silicides + B ₂ O ₃ + C → ZrB ₂ + SiC + CO (Equation 2)

Zirconium silicides + H ₃ BO ₃ + C → ZrB ₂ + SiC + CO + H ₂ O (Equation 3)

If necessary, ZrB ₂ or SiC may be added to these mixtures, thereby improving properties such as cost reduction and sintering.

In the case of SiC as it has difficulty desired SiC content of only zirconium silicide group and can give an auxiliary added, with the same purpose as above for ZrB ₂ can be obtained an effect of reducing the overall sintering temperature by a pre-treatment of ZrB ₂ powder.

When mixing the raw material powder (silicides), boron source (boron source) and carbon source (carbon source), two methods were used as a mixing method. The following two methods may be preferred embodiments, but of course, it is obvious that the mixing method is not limited to the following methods.

The first method adopts a method of dispersing raw materials mixed in anhydrous benzene for 5 minutes using ultrasonic waves without mixing them with mechanical shock and contamination. In the second method, a 1 hour dry process is performed using a spex mill. Stronger mechanical mixing was added by mixing. Such methods can be adopted to prevent the incorporation of impurities caused in the manufacturing process of the composite material which has been pointed out as a problem in the prior art. When ZrB ₂ powder was added, the raw powders were dry mixed for 6 hours using a spex mill in order to promote grinding, uniform mixing, and sintering of the ZrB ₂ powder.

The sintering temperature was preferably in the temperature range of 1400 ~ 1650 ℃, the atmosphere was a vacuum and argon (Ar) atmosphere, the reaction was carried out by maintaining for 5 to 60 minutes using a spark plasma sintering method. .

On the other hand, this may be carried out by a pressure sintering process, the pressurization range during sintering may be carried out in the range of 30 ~ 120MPa, where the pressurization pressure is less than 30MPa, the densification effect due to the pressure deformation of the zirconium silicides at low temperature is clearly seen If it exceeds 120Mpa, it is difficult to manufacture industrially due to the limitation of the equipment, and the above pressurization range has its critical meaning at the upper and lower limits. In addition, the sintering temperature range can be extended to more than 1300 ~ 1800 ℃ by expanding more than the sintering temperature of the above embodiment, when the sintering temperature is less than 1300 ℃, the deformation due to the pressurization of zirconium silicide does not occur actively, densification is suppressed, 1800 If the temperature is exceeded, densification is possible, but the grain growth of the formed silicon carbide is large, and thus a composite material having a fine grain size, which is the object of the present invention, cannot be manufactured, and thus the temperature range has critical significance at its upper and lower limits.

On the other hand, when using a zirconium silicide as a starting material, ZrSi ₂ when a melting point of addition of the ZrSi ₂ to 40% by weight of the total weight of preparation because it is the composite material near 1650 ℃ the liquid formed in 1650 ℃, therefore normal pressure sintering of the ZrB ₂ This was possible. However, when the mixing here B ₄ C and C temperature increase during and the ZrSi ₂ is not the end of the liquid by the ZrSi ₂ formed since the ZrB ₂ + SiC to ZrSi ₂ reacts with these prior to reaching the melting point Therefore, the problem that the densification is insufficient may arise. On the other hand, the pressure sintering is advantageous because it can promote densification, so it is more preferable to adopt the pressure sintering method.

Figure 1 shows the phase formation behavior with increasing temperature of the ZrSi ₂ + B ₄ C + C powder mixed with the spec mill and ultrasonic. As shown, the powder mixed using the spec mill was maintained for 10 minutes at the phase forming temperature of 900 ℃ pure ZrB ₂ and SiC was formed, but remained after maintaining for 10 minutes at 1270 ℃ when mixed by ultrasonic ZrSi ₂ was present and ZrSi ₂ was completely consumed only after holding at 1300 ° C. for 10 minutes. From these results, it can be seen that when mixed with the spec mill, the reactivity between the raw materials is more activated.

Table 1 shows the relative densities measured after pressure sintering at 120 MPa of ZrSi ₂ + B ₄ C + C mixed powder for ZrB ₂ + SiC formation according to Equation 1.

Raw material powder mixing and sintering conditions
(Sintering temperature, sintering time) Relative Density (%) Ultrasonic mixing, 1650 ℃ -5min 96.8 Specs Mill Mix, 1650 ℃ -5min 102.3

After sintering at 1650 ° C. for 5 minutes, it showed a high relative density regardless of the mixing method of the raw powders, and it was found that the densification was mostly performed under these conditions. In particular, the powder mixed by using a spex mill showed a relative density about 5% higher than the powder mixed by using an ultrasonic wave, and densification was almost completed. This is considered to be because finer powder is formed by grinding the raw powders during milling, and the mixing between the raw powders is more uniform due to the strong mechanical mixing. As a result, it is thought that densification is promoted because the reactivity and sinterability between the raw material powders are improved when mixed in a spec mill like the XRD results.

In contrast, the ZrB ₂ -SiC mixture without sintering aid required pressurization and sintering at 1850 ° C. In the case of reactive hot pressing in which Zr powder and Si, B ₄ C, and C were mixed, at 1650 ° C without using sintering aid Densification is possible, but the risks of Zr powder and the disadvantages of difficult microstructure control are as described above.

2 to 4 show the sintering behavior of the mixed powder in which ZrSi ₂ + B ₄ C + C was added to ZrB ₂ , respectively, of 30, 40 and 50 wt% of the total weight of the composite composition. In all cases, shrinkage occurred during 1 hour sintering at 1400 ° C and 1450 ° C under pressure of 120 MPa, but more pronounced sintering shrinkage behavior occurred above 1500 ° C. It was found that densification was completed at 1650 ° C. or lower.

In Table 2, ZrB ₂ was mixed with 30, 40, and 50% by weight of stoichiometrically mixed ZrSi ₂ + B ₄ C + C, respectively. Density is shown.

Sintering Condition
(Sintering Temperature-Holding Time) Relative density 30 wt% 40 wt% 50 wt% 1400 ℃ -60min 91.4 88.9 - 1450 ℃ -60min 92.5 99.5 - 1500 ℃ -30min 98.5 102 96.2 1550 ℃ -30min - 101.2 - 1650 ℃ -5min 98.3 100.3 98.5

When 30% by weight was added, the specimen sintered at a temperature of 1500 ° C. or higher was densely sintered as in FIG.

5 is a composite material composition total weight compared to 30 to the ZrSi mixed stoichiometrically and 50% by weight of ₂ + B ₄ C + the mixed powder added to the C 5 minutes at a pressing force and a sintering temperature of 1650 ℃ of 120MPa to ZrB ₂ After sintering under pressure, the sintering behavior of the powder is shown. In all cases densification was completed during the temperature rise.

In Table 3, when the pressure was sintered for 5 minutes at a pressing pressure of 120 MPa and a sintering temperature of 1650 ° C., the starting temperature and the ending temperature of the sintering shrinkage of each specimen were displayed. Overall, as the content of ZrSi ₂ + B ₄ C + C increased, the sintering start temperature and sintering completion temperature were lowered.

The decrease in densification temperature with increasing ZrSi ₂ + B ₄ C + C content in Table 2 and the results in Table 3 below showed that ZrSi ₂ + B ₄ C + C mixtures helped the densification of ZrB ₂ . It is considered to be because the deformation due to the pressure of the ZrSi ₂ as described.

ZrSi ₂ + B ₄ C + C content (% by weight) 30 40 50 Shrink Start Temperature (℃) 1310 1315 1290 Shrinkage Stop Temperature (℃) 1640 1610 1570

From these results, a suitable sintering temperature for producing the composite material according to the present invention can be determined in the temperature range of 1300 ℃ ~ 1800 ℃. When the temperature is less than 1300 ° C., the strength of the sintered compact is too weak due to the densification of a commercially available degree, and when the heat treatment exceeds 1800 ° C., the sintering is already completed, but since the particles are coarsened, the present invention seeks to realize a composition having fine grains. Since it deviates from the meaning of, it has the critical meaning in the above heat processing temperature range.

Table 4 shows the four-point bending strength values of ZrB ₂ -SiC composites obtained by sintering at various compositions, sintering temperatures and pressures of 120 MPa using the method proposed in the present invention.

Condition Strength (MPa) (ZrSi ₂ + B ₄ C + C) 30% by weight, 1500 ° C, 30 minutes sintered 516 (ZrSi ₂ + B ₄ C + C) 40 wt%, 1500 ° C., 30 minutes sintered 603 (ZrSi ₂ + B ₄ C + C) 50% by weight, 1650 ° C, 50 minutes sintered 501

As can be seen from the above table, although the sintering temperature is significantly lower than the existing results, it can be seen that the excellent four-point bending strength value of 500 ~ 600MPa.

6 is then perspex mill dry mixing the nano SiC in ZrB ₂ ZrB ₂ -SiC manufactured by a composite with a perspex ZrSi ₂ -B ₄ CC mixed powder mill proposed in the present invention after dry mixing the microstructure of a composite material prepared Show each one. After sintering, the nano-SiC was mixed by sintering due to the strong aggregation between SiCs, and SiCs of about 1 micrometers were significantly larger than 30 nm, the size of the original nano-SiC. The grown SiCs were found to be in the form of agglomeration. On the other hand, the microstructure obtained as a result of the present invention can be confirmed that such aggregation is suppressed and fine SiC of 100 to 300nm is uniformly distributed.

Figure 7 is a 30 to 50% by weight, based on the weight of the entire mixture to the stoichiometric composition of the composite material of the ZrB ₂ ZrSi ₂ + B ₄ C + a mixed powder formed after the addition of C-pressing by the pressing force of 120MPa ZrB ₂ -SiC It shows the microstructure of the fracture surface of the composite material. As shown, it can be seen that the above fracture surface forms a fine structure with a grain size of 1 μm or less. From these results the _{ZrB 2 ZrSi 2 + B 4 C} + C mixture, and to the fine size of the ZrB ₂ and the SiC formed by a reaction between the mixture if added with sintering, ZrB having a fine particle diameter of less than 1㎛ therefrom + ₂ it can be seen that it is possible to manufacture a SiC composite material.

As described above, although ZrB ₂ -SiC composite materials are manufactured by mixing Zr, Si, B ₄ C, and C at low temperature, there is a big problem in commercialization due to the strong explosiveness of the raw material Zr powder. The composition was concentrated locally because it was unable to secure a uniform distribution of chemical composition. Therefore, it was difficult to realize a composite material in which the grain size was fine and the secondary phase SiC was uniformly distributed. When pulverizing and mixing the raw powders with force, it was not possible to prevent the incorporation of impurities from the balls and jars, which are mixed media, in a large amount.

Since the prior art as described above is already known, data related thereto will be omitted. On the contrary, the ZrB ₂ -SiC composite material according to the present invention is a zirconium silicide group, which is a raw material powder, is relatively stable in air, so it is easy to handle, and Zr and Si are uniformly mixed in molecular units therein. Therefore, ZrB ₂ and SiC grains formed after sintering have a size range of 1 μm or less even when mixing raw powders with strong mechanical force as well as ultrasonic mixing. This is a composite material including a secondary phase having a fine size. It can be seen as a preferred size range.

In addition, zirconium silicide group is relatively due to the low melting temperature if the sintering pressed at a temperature of at least 1300 ℃ and the high temperature deformation of the zirconium silicide group contributes to the densification, and the B ₄ C and a high temperature stability merchant ZrB _2, by reaction with C was added with subsequent Since it is changed to SiC, sintering can easily occur even at low temperatures, and it is expected that excellent high temperature properties can be satisfied at the same time.

Therefore, it should be noted that the significance of the present invention can be grasped by comparing the results of the present invention with the ease of operation, purity, uniform distribution of secondary phases, grain size, and sintering temperature of conventional composite materials.

Although the present invention has been described in more detail with reference to the examples, the present invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (7)

Preparing a mixture by mixing zirconium silicide group, boron and carbon;
Sintering the mixture;
Consists of including
Preparation of ZrB ₂ -SiC pressure sintered composite material using zirconium silicide group as a precursor, characterized by obtaining a high purity ZrB ₂ -SiC composite material with fine particle size and uniform secondary phase distribution by pressure sintering method Way. The method of claim 1,
The pressurization of the pressure sintering is a method of manufacturing a ZrB ₂ -SiC pressure sintered composite material using a zirconium silicide group as a precursor, characterized in that performed in the range of 30 ~ 120MPa. The method of claim 1,
The sintering temperature is a method for producing a ZrB ₂ -SiC pressure sintered composite material as a precursor to the zirconium silicide group, characterized in that performed in the range of 1300 ~ 1800 ℃. The method of claim 1,
A method for producing a ZrB ₂ -SiC pressure sintered composite material using as a precursor a zirconium silicide group, characterized in that at least one selected from ZrB ₂ or SiC is added to the mixture. The method of claim 1,
The boron is a method of producing a ZrB ₂ -SiC pressure sintered composite material as a precursor of the zirconium silicide group, characterized in that at least one selected from boron carbide, boron oxide and boric acid. The method of claim 1,
The carbon is a method of producing a ZrB ₂ -SiC pressure sintered composite material as a precursor of a zirconium silicide group, characterized in that at least one selected from graphite, carbon black, activated carbon, phenol resin, pitch. Prepared by the method of any one of claims 1 to 6,
ZrB ₂ -SiC pressure sintered composite material using the zirconium silicide group as a precursor, characterized in that it exhibits a relatively high degree of densification at the same grain size as compared with the case of atmospheric pressure sintering.

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