JPH03193623A - Production of conjugated boride powder in as mo2feb2-base - Google Patents

Abstract

PURPOSE:To improve heat resistance, high temp. strength, oxidation resistance and corrosion resistance of conjugated boride powder by producing Mo2FeB2 type conjugated boride by bringing the powders of Fe, Mo, B and C to a solid phase reaction, then cooling and pulverizing the obtd. boride. CONSTITUTION:Two or more kinds of powders selected from simple powders of Fe, Mo, and B, borides and alloy powders incorporating two or more elements among above-mentioned powders, Fe, Mo, and B simple powders containing C, borides and alloys thereof, and carbon powder are compounded by the compounding ratio of 7.2-8.8wt.% of B, 64-78wt.% of Mo, and the balance of Fe and inevitable impurities. Then the compounded material is mixed and pulverized into 0.1-50mum mean particle size, heated in a nonoxidative atmosphere at 0.5-100 deg.C/min heating rate to 750-1500 deg.C and thermally treated for one minute to 5 hours at this temp. to bring it to a reduction reaction by C and the solid phase reaction to produce Mo2FeB2-based conjugated boride. This boride is then cooled, pulverized and a Mo2FeB2-based conjugated boride powder that has 0.1-50mum mean particle size and contains >=90wt.% Mo2FeB2-based boride, 0.005-1wt.% residual C and 0.001-0.5wt.% residual O is obtd.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a M O2F e B type 2 complex boride, (M
o + Fe * Cr) 3B type 2 complex boride,
and (Mo, Fe, Cr, X)3B2 (hereinafter, X is Ti).

Zr, Hf, V, Nb, Ta, W
, Co, Re.

A method for producing a powder of complex boride (hereinafter, these three types of complex boride are collectively referred to as Mo2FeB2 complex boride) representing one or more elements selected from the group consisting of Ni. Pause.

[Prior art] Mo2FeB2-based complex borides have excellent properties such as heat resistance, high temperature strength, high hardness, oxidation resistance, and corrosion resistance.
Regarding cermets or ceramics using FeB2 complex boride, for example, published in Japanese Patent Publication No. 55-5006
21, there is a hard sintered alloy shown in Japanese Patent Publication No. 60-57499. These are ferroboron powder as raw material powder,
MoB powder, Mo powder, Fe powder, Cr powder, Ni powder, etc. are used, and after mixing these at a predetermined weight ratio, the mixture is compressed to form a compact, and the compact is compressed in the presence of a liquid phase. , produced by sintering at a temperature and time sufficient for reaction and densification to form a MoaFeBt-based complex boride, and then cooling, the Mo2FeBt-based complex boride is made into a hard phase, and this is used as an alloy of Cr, Ni, etc. A boride-based cermet bonded with an iron-based bonding phase containing elements. According to these manufacturing methods using liquid phase sintering, a block sample of boride-based cermet, which is a composite of a densified Mo2FeBz-based complex boride and an iron-based bonding phase, can be obtained;
It is not possible to create powders of complex borides. Also, M
Since an industrial manufacturing method for O2FeB2-based complex boride powder has not been established, M02FeB2-based complex boride powder has never been used as a raw material powder for these boride-based cermets.

In addition, among other boride-based ultrahard materials, M O2FeB
There are products that use z-based complex boride as a raw material powder.
JP-A-59-45971, JP-A-60-103080,
JP-A-60-103148, JP-A-60-131867
is proposed. These are boride-based ultra-hard materials with TiB2 as a hard phase, and it has been revealed that various properties are significantly improved by adding Mo2FeB2-based complex boride powder. However, an industrial manufacturing method for Mo2FeB2-based complex boride powder used as a raw material powder has not yet been established, and at present, a mixed powder blended with an MO2FeB2-based complex boride composition is used for Mo or W electrodes in an inert atmosphere. 200% by arc melting method using
A small amount of Mo2Fe obtained by melting at a temperature of 0°C or higher
A method is used in which a block sample of Mo2FeB2-based complex boride is prepared by cooling a melt having a B2-based complex boride composition, and this is mechanically crushed and sieved using a stamp mill or the like to obtain a Mo2FeB2-based complex boride powder. However, the amount that can be processed at a time is extremely small, there are many impurities mixed in, and it takes a long time to grind.

[Problems to be Solved by the Invention] The reason why Mo2FeB2-based complex borides, which have excellent heat resistance, high-temperature strength, high hardness, oxidation resistance, and corrosion resistance, are not widely used as raw material powder for boride-based cermets, for example, is because Estimation 2
This is because an industrial manufacturing method for Mo2FeBz complex boride powder with a high melting point of 000° C. or higher has not yet been established.

For example, iron borides such as FeB and Fe2B, which are mainly composed of Fe, have a low melting point and can be easily produced industrially by an atomization method, but the melting point of Mo2FeB2-based complex borides is estimated to be 2000°C or higher. It is extremely difficult to obtain a melt of a MO2FeB2 complex boride composition by a method such as high-frequency induction heating, and then pulverize it into powder by water or gas atomization. This is because, in general, in order to perform the spraying operation smoothly and obtain good fine powder, the temperature of the melt is usually 100 to 100° higher than its melting point.
It is preferable that the Mo2FeB2 complex boride powder is 300°C higher. Therefore, when trying to obtain Mo2FeB2 complex boride powder by the atomization method, a high temperature of 2100 to 2400°C is required, which is not industrially practical. No examples have been manufactured.

In addition, with the method of producing a Mo2FeB2 complex boride block sample using an arc melting method and mechanically crushing and sieving it using a stamp mill or the like to obtain Mo2FeB2 complex boride powder, the amount that can be processed at one time is extremely small. Since the amount is small, it takes a long time to grind due to the contamination of impurities, and it is also less economical.

The present invention was made to solve these problems, and
The purpose is to use Mo2, which has a high melting point of over 2000℃.
The object of the present invention is to provide a method for industrially and economically producing FeB2-based complex boride powder at a lower processing temperature, in large quantities, and in a simple manner.

[Means for Solving the Problems] In the case of M O2F e B type 2 complex boride, the present invention includes simple powders of Fe, Mo, and B, boride and alloy powders containing two or more of the above elements, and Two or more of the above-mentioned simple substance containing C, boride and alloy powder, and C powder, B is 7.2 to 8.8% by weight and Mo is 64 to 78% by weight.
, the balance being Fe and unavoidable impurities, (Mo, Fe.

In the case of Cr)3B2 type complex boride, Fe, Mo,
B is 7.2. ~10.2% by weight, Mo 45.5~78Mtl
k%, Cr is 0.1 to 35% by weight, and the balance is Fe and unavoidable impurities (Mo, Fe,
Cr, X) In the case of 3B2 type complex boride, Fe, Mo, B
, Cr, Ti, Zr.

Hf, V, Nb, Ta, W, Co, Re,
Ni elemental powder, boride and alloy powder containing two or more of the above elements, and two or more of the elemental element, boride and alloy powder containing C, and C powder, when B is 7
．． 2 to 10.2i amount%, Mo 45.5 to 78% by weight,
Cr: 0.1 to 35% by weight, and Ti, jr, Hf
, V, Nb, Ta, W, Co+R
The total content of one or more elements selected from the group consisting of e, Ni is 0.1 to 20% by weight, and the balance is Fe and unavoidable impurities, and the average particle size is 0.
．． After pulverization and mixing to a size in the range of 1 to 60 μm, heat treatment is performed in a non-oxidizing atmosphere at a heating rate of 1 to bb for a duration of 1 minute to 5 hours to perform a reduction reaction with C and solid-phase reaction to form Mo2FeB2 complex boride. After forming, by cooling and crushing,
Contains at least 90% by weight of Mo2FeB2 complex boride with a high melting point estimated at 2000°C or higher, and has a residual C content of 0.0
Powder having a residual O content of 0.05 to 1% by weight, a residual O content of 0.0.01 to 1% by weight, and an average particle size of 0.1 to 5071 m is industrially processed in large quantities at a low processing temperature of 1500°C or less. Target,
It is possible to manufacture economically.

In addition, Mo2FeB2 is M o 2B-a Fe +
+b B 2±.

(where a, b, and c are constants), it is said to be a non-stoichiometric compound with a wide composition range. Therefore, the Mo2FeB2 type amide referred to in this patent refers not only to Mo2FeB2 complex boride having a stoichiometric composition, but also to B2± from M O2± and Fe+ having a non-stoichiometric composition. Contains complex borides. In addition, when elements such as Cr and X are substituted and dissolved in M O2F eB2 complex boride, the crystal structure is affected
The lattice constant changes depending on the amount of the elements Cr and X substituted into solid solution. Here, complex borides with stoichiometric and non-stoichiometric compositions in which elements such as Cr and X) It is called 3B2 type complex boride.

[Operations] Mo2FeB2-based complex boride powder is produced by blending raw material powder into a predetermined composition, mixing and pulverizing the blended powder, and converting the mixed and pulverized powder into a liquid phase at a predetermined temperature and time in a non-oxidizing atmosphere. It is produced by a step of heat-treating the powder while it is in a solid state without forming it, and a step of cooling the heat-treated powder and then pulverizing it if necessary. The reasons for limiting the manufacturing conditions for each process will be described below.

The raw material powder used in the production of Mo2FeB2 complex boride powder is M 02 F e B 2 type complex boride powder.
elemental powders of e, Mo, and B, boride and alloy powders containing two or more of the above elements, and elemental, boride and alloy powders containing C, and C powder, (M
o, Fe, Cr) In the case of 3B2 type complex boride, Fe, Mo, Bs Cr simple powder, boride and alloy powder containing two or more of the above elements, and the simple substance containing C, boride and alloy powders, and C powders (Mo, Fe.

In the case of CrIX) 3B2 type complex boride, p'e and Mo.

B, Cr, Ti, Zr+ Hf, V
, Nb, Ta.

These are elemental powders of W, Co, Re, and Ni, boride and alloy powders containing two or more of the above elements, and elemental, boride and alloy powders containing C, and C powder. These two or more types of powder are mixed in a predetermined ratio, and through the reaction during heat treatment, Mo2Fe that does not exist in the raw material powder is removed.
A B2-based complex boride is formed by solid phase reaction. By using a solid phase reaction instead of a liquid phase reaction as the reaction during this heat treatment, grain growth of the Mo2FeB2 complex boride powder produced by the reaction can be suppressed and fine powder can be produced.

M O2F e B 2-type complex boride, (Mo + F
e, Cr) 3B2 type complex boride and (Mo, F
e, Cr, X) 3B2 type complex boride content to 90
The reason why the compound boride powder produced according to the present invention is limited to more than % by weight is that it has excellent wear resistance, heat resistance, high temperature strength, high hardness,
M02, material for parts that require oxidation resistance, corrosion resistance, etc.
When mixed with raw material powder for cermets or ceramics using FeB2-based complex boride, or powder for thermal spraying, etc., it is desirable that the purity of the Mo2FeB2-based complex boride powder is as high as possible, but at least 90% by weight or more. This is because the purity required for a material using MO2FeB2 complex boride powder is satisfied.

Therefore, the Mo2FeB2 complex boride contained in the M O2FeB2 complex boride powder, (M o + Fe
t Cr ) 3 B type 2 complex boride and (No, F
e, CrIX) 3B2 type complex boride content is 90% by weight
The content is preferably 95% by weight or more.

Next, the reasons for limiting the blending composition (wt%) will be described.

In order to form Mo2FeB2 with stoichiometric composition, B
Content is 8.0% by weight, Mo content is 71% by weight, Fe
The content is required to be 21% by weight. Therefore, the B content is 7
．． In the case of a composition in which the Mo content is less than 2% by weight and the remainder is Fe and unavoidable impurities, the Mo content is less than 644% by weight.
and Mo2Fe, which occupies the powder due to lack of Mo.
The proportion of B2 type complex boride is less than 90% by weight, and the balance is Fe.
and unavoidable impurities. On the other hand, B
The content exceeds 8.8% by weight, and the Mo content is 78% by weight.
In the case of a composition in which the remainder consists of Fe and unavoidable impurities, the amount of Mo in the powder decreases due to the lack of Fe.
A powder is produced in which the proportion of 2FeB2-type complex boride is less than 90% by weight, with the remainder consisting of B-, Mo, and inevitable impurities. Therefore, B is 7.2 to 8.8% by weight and Mo is 64 to 8.8% by weight.
By blending 78% by weight, the balance being Fe and unavoidable impurities, it is possible to produce a powder containing 90% by weight or more of Mo2FeB, a + type complex boride.

Preferably, the contents of B and Mo are each 7.6 to 8.
By setting the content to 4% by weight and 66.5 to 75.5% by weight, it is possible to produce powder with good purity containing 95% by weight or more of Mo2FeB2 type complex boride.

(Mo, Fe, Cr)3B2 type complex boride is M O2F
This is a boride whose corrosion resistance is further improved by substituting Cr into eB2 as a solid solution. If the amount of C and r added is less than 0.1% by weight, no improvement in corrosion resistance is observed, and even if the amount added exceeds 35% by weight, no improvement in corrosion resistance is observed. e+Cr) 3
Formation of B2 type complex boride becomes difficult. Therefore, (Mo
, Fe, Cr) 3B2 type complex boride powder contains C
When containing r, the content is 0.1 to 35% by weight.

When the Cr content is the lowest 0.1% by weight, the B and Mo contents in the blended composition of the raw material powder are each 7.2%, the same as in the case of Mo2FeB2 complex boride powder that does not contain Cr.
~8.8% by weight, 64-78% by weight, (Mo
, Fe, Cr) A powder containing 90% by weight or more of 3B2 type complex boride can be produced.

The added Cr forms a solid solution by substitution with Mo and Fe in the Mo2FeB2 type complex boride, but as a result of various experiments, the method of substitution is determined by the formula (MO2-YIF e I-YICr
2v) It is inferred that B2 (0<Y<1) is followed.

According to this formula, 35% by weight of Cr was substituted as a solid solution (Mo
, Fe, Cr) The content of each alloying element in the powder containing 100% by weight of 3B2 type complex boride is as follows: B is 9.3%;
% by weight, Mo is 50% by weight, and Cr is 35% by weight.

Therefore, when the Cr content is the highest, 35%, B
In the case of a composition in which the content is less than 8.4% by weight, the Mo content is less than 45.5% by weight, and the balance is Fe and unavoidable impurities, B and Mo are insufficient, and the ( A powder containing less than 90% by weight of 3B2 type complex boride (Mo , Fe +Cr ) is produced. On the other hand, in the case of a composition in which the B content exceeds 10.2% by weight, the Mo content exceeds 54.5% by weight, and the balance consists of Fe and unavoidable impurities, Fe and Cr are insufficient. A powder is produced in which the proportion of (Mo 2 , Fe , Cr ) 3B2-type complex complexes in the powder is less than 90%. Therefore, when the Cr content is the highest, 35% by weight, the B and Mo contents in the blended composition of the raw material powder are each 8.4 to 8.4%.
If it is 10.2% by weight, 45.5 to 54.5% by weight,
(Mo, Fe, Cr) 90% by weight of 3B2 type complex boride
Powder containing the above can be manufactured.

Therefore, B is 7.2 to 10.2% by weight, M.

is 45.5 to 78% by weight, Cr is 0.1 to 35% by weight,
By blending so that the balance consists of Fe and unavoidable impurities, it is possible to produce a powder containing 90% by weight or more of (Mo + Fe, Cr) 3B2 type complex boride. Preferably, by blending so that B is 7.6 to 9.8% by weight, Mo is 47.5 to 76% by weight, Cr is 1 to 30% by weight, and the balance is Fe and unavoidable impurities, ( M.

, Fe, Cr) 3B2 type complex boride in an amount of 95% by weight or more, it is possible to produce a powder with good purity.

(Mo, Fe, Cr,

Hf, V, Nb, Ta, W, Co, Re,
Including elements such as Ni not only increases the hardness of the cermet or ceramic, but also makes it possible to suppress coarsening of crystal grains. These elements are dissolved in solid solution in (Mo, Fe, Cr)3B2 boride, and exhibit an effect when added in small amounts, but no effect appears when added in amounts less than 0.1% by weight. On the other hand, even when added in an amount exceeding 20% by weight, not only is no improvement in any of the properties observed, but these elements are generally expensive, leading to an increase in cost.

These elements can not only be added individually, but also two or more elements can be added in combination. Therefore, B is 7.2 to 10.2% by weight, Mo is 45.5 to 78% by weight.
The element X was solid-dissolved in a 3B2 type complex boride (Mo9Fe, Cr) consisting of 0.1 to 35 wt% Cr and the balance Fe and unavoidable impurities (Mo, Fe, Cr,
X) The amount of element X added in the 3B2 type complex boride is Ti
, Zr, Hf, V.

The total of one or more elements selected from the group consisting of Nb, Ta, W, Co, Re, and Ni is 0.1 to
20% by weight, (Mo, Fe, Cr.

X) Produce a powder containing 90% by weight or more of 3B2 type complex boride. Preferably, B is 7.6 to 9.8% by weight, Mo is 47.5 to 76% by weight, Cr is 1 to 30% by weight, Ti,
Zr2. Hf, V, Nb, Ta,
W.

(Mo, Fe , Cr,

Among the other elements contained in the Mo2FeBz-based hard alloy powder system, C and O have a large influence on the properties. This is because the pulverized and mixed powder before heat treatment is quite oxidized, and the oxide film on the powder surface is M O2F e B2.
In order to inhibit the solid phase reaction that forms complex borides, and to ensure that the solid phase reaction occurs sufficiently during heat treatment, oxygen on the powder surface is removed by a Boudoir reaction (C+1/ 202→C○) is preferable.

However, if the added C exceeds 1tJ1%, M O2Fe
If Cff1 remains in the Bz-based complex boride powder, a large amount of carbides will be observed, and the adverse effect on the properties will be significant, so the residual Cff1 is set to 0.005 to 1% by weight. Preferably, it is 0.005 to 1% by weight. If more than 1% by weight of 0 remains, a large amount of oxides will be observed, and the adverse effect on the properties will be greater.
Weight%. Preferably 0.001 to 0.3% by weight
shall be.

The main unavoidable impurity elements contained in the MozFeBz-based hard alloy powder are Si, AI, and Mn.

Mg, P, S, and N, and the content of these impurity elements is to be kept as low as possible, but if the total of these impurity elements is 2% by weight or less, the powder is treated with cermet or ceramics, etc. When used as a raw material powder, the effect on properties is relatively small. Therefore, the content of these impurity elements is 2% by weight or less, preferably 1% by weight or less.

The Mo2FeB2-based complex boride powder is prepared by blending raw material powders into a predetermined composition and then pulverizing and mixing the powder to have an average particle size in the range of 0.1 to 50 μm. There are various methods of pulverizing and mixing, but in a dry method or in a wet method using an organic solvent,
After pulverization and mixing, drying and granulation are carried out using the ball mill method, rod mill method, attritor method, stamp mill method, cutter mill method, eraday mill method, microteaser method, etc., by mechanical alloying method or mechanical pulverization mixing method. If the average particle size is adjusted to a range of 0.1 to 50 μm, Mo2
This is preferable because the reaction occurs quickly during the heat treatment to form the FeB2-based complex boride, and the Mo2FeB2-based complex boride is formed in a short time. In addition, even if finely pulverized into non-grooved particles with an average particle size of 0.1 μm, not only is the effect of significantly speeding up the Mo2FeB2 complex boride formation reaction not only, but also a lot of time and energy is spent to finely pulverize. It turns out. In addition, 501Lm was added to the pulverized and mixed powder.
If coarse powder exceeding 10% remains, the solid phase reaction to form the Mo2FeB2 complex boride will not take place and unreacted materials will remain. Therefore, the average particle size after pulverization and mixing is 0.1 to 50 μm, preferably 0.1 to 25 μm.

The powder after pulverization and mixing is placed in an alumina magnetic container or a graphite case coated with BN as a powder, and the powder is placed in a non-oxidizing atmosphere of vacuum, H2 gas, Ar gas, He gas, or N2 gas. So, the heating rate is 1 to 100
C./min at a heating temperature of 750 to 1500.degree. C. for a holding time of 1 minute to 5 hours to carry out a reduction reaction with C and form a Mo2FeB2 complex boride by solid phase reaction.

Thereafter, M02FeB2-based complex boride powder having an average particle size of 0.1 to 50 μm is produced by cooling and optionally pulverizing.

Among the heat treatment conditions, there is a relationship between the heating rate, heating temperature, and holding time; if the heating rate is slowed, Mo2FeB2 complex boride is formed by an in-phase reaction even if the holding time at the heating temperature is shortened. Is possible. Conversely, if the heating rate is increased, it is necessary to increase the holding time at the heating temperature. Furthermore, it is possible to shorten the holding time by increasing the heating temperature, and it is necessary to lengthen the holding time by decreasing the heating temperature.

If the heating rate is slower than 1° C./min, it will take a long time to reach the predetermined heating temperature, and the heat treatment will take too much time.

Moreover, if the speed is too high than 100° C./min, the temperature of the heat treatment furnace cannot be controlled.

Therefore, the heating rate is 1 to 100° C./min, preferably 1 to b. If it is less than 750° C., Mo2FeB2 type complex boride will not be formed by solid phase reaction. On the other hand, when the temperature exceeds 1500℃, M
Although the o2FeB2-based complex boride is sufficiently formed, it remains in a powder state due to the formation of a liquid phase, making it impossible to obtain the Mo2FeB2-based complex boride. Moreover, the cost increases because energy required for heating is consumed more than necessary. Therefore, the heating temperature is 750-1500°C, preferably 90°C.
The temperature shall be 0 to 1350°C. If the holding time is shorter than 1 minute, it will not end in 1 minute. In addition, even if the length of time exceeds 5 hours, the Mo2
The solid-phase reaction to form the FeB2-based complex boride was sufficiently completed, and no effect was observed as the time was increased. Therefore, the holding time is from 1 minute to 5 hours, preferably from 5 minutes to
It will be 3 hours.

During the heat treatment, in order to sufficiently carry out the Mo2FeB2-based complex boride formation reaction and the solid phase reaction that forms the complex boride, the oxide film on the surface of the pulverized and mixed powder before heat treatment was subjected to a Boudoir reaction (C). C+ 1/202→C
It is preferable to sufficiently reduce and remove with O>. Therefore, the atmosphere during the heat treatment is preferably a non-oxidizing atmosphere such as vacuum, N2 gas, Ar gas, He gas, or N2 gas, which is a highly reducing atmosphere such as vacuum or N2 gas.

Mo2FeB2-based complex boride powder can be obtained by cooling after heat treatment, but if heat treatment is performed under appropriate conditions in the solid phase without forming a liquid phase, the pulverized and mixed 0,1-
Mo2FeB2-based complex boride powder with a size of 0.1 to 50 μm can be obtained without grain growth while keeping the size of the raw material powder of 50 μm. The amount of C remaining in this Mo2FeB2 complex boride powder is 0.005 to 1% by weight, and the amount of O is 0.005 to 1% by weight.
001 to 1% by weight, but if the raw material powder before heat treatment is oxidized and the oxygen content is high, (C+1/
According to the Boudoir reaction represented by 202→Co), enough C is added to reduce the oxide film, and the amount of residual C and O is adjusted to the above amount. When the amount of added C is large, contact coalescence of the neck portions occurs, which is thought to be due to the formation of a liquid phase containing C at the neck portions where the raw material powders are in contact with each other, resulting in the formation of particles larger than 50 μm. Skeletons (originally meaning skeleton or skeleton; powder particles are bonded at contact points and aggregated together with sufficient gaps to form porous powder aggregates) may form, but they are light By pulverization, it can be easily made into a size of 0.1 to 50 μm.

Mo2FeB2 complex boride powder with an average particle size of 0.1 to 50 μm is not only difficult to handle if the average particle size is less than 0.1 μm, but it is also expensive because it consumes a lot of time and energy for pulverization. becomes higher. Also, 50μ
Coarse powders with a particle size of m or more often require further finer grinding when used as raw material powders for cermets, ceramics, etc., and are not suitable. Therefore, the average particle size of the produced Mo2FeB2 complex boride powder is 0.1 to 50 μm, preferably 0.1 to 25 μm.
shall be.

However, when using Mo2FeB2 complex boride powder mixed with powder for thermal spraying, or when putting it into a precision mold and compressing it with a press machine to pressure mold it into the desired shape and size, the powder Since it is necessary to fill the powder quickly and a coarse powder is more suitable, it may be used unpulverized.

[Example] Examples 1 to 14 of the present invention will be explained with reference to Tables 1 to 5.

Example 1 As raw material powders, acupuncture metal powders shown in Table 1 and
Among the borides and alloy powders shown in the table, Fe powder, M
o powder, Fe-B boride powder, M.

-B boride powder, each 5.9% as shown in Table 3.
% by weight, 26.3% by weight, 17.8% by weight, and 50.0% by weight. As shown in Table 4, the chemical composition in this case is 7.97% by weight of B, 71.01% by weight of Mo, and 7.97% by weight of B.
e is 20.76% by weight, and the remainder that is not 100% by weight is the weight of C, O, and unavoidable impurity elements. The thus blended powder was pulverized and mixed in acetone for 28 hours using a vibrating ball mill, then dried and sized to give an average particle size of 1.5 μm as shown in Table 5. These ball-milled powders were put into an alumina magnetic container as they were without being press-molded, and the amount of powder inserted into the furnace at one time was 5 kg, and the heating rate was 10°C in vacuum as shown in Table 5. The heat treatment was performed at a heating temperature of 1300°C and a holding time of 20 minutes.

1 and 2 show the Mo2Fe produced in Example 1.
A scanning electron micrograph showing the structure of B2-based complex boride powder and an X-ray diffraction pattern using Cu-Kα rays were published by JCPD.
As shown with the data of S-No. 180839, the average particle size is 2.0 μm, and as shown in Table 4, C
M in which f1L is 0.02% by weight and On is 0.1% by weight
o2FeB2-based complex boride powder could be produced.

Examples 2 to 14 As in Example 1, pure metal powders shown in Table 1 with purity and average particle size of pure metal powders shown in Table 1 and boride and alloy powders shown in Table 2 were used as raw material powders, The formulations were as shown in Table 3.

The chemical composition in this case is shown in Table 4. ball mill time,
The working conditions, such as heating rate, furnace atmosphere, heating temperature, and holding time, are as shown in Table 5. In addition to confirming whether the shape after heat treatment is powder, the Mo2FeB2 complex was determined by X-ray diffraction measurement. When we investigated whether borides were formed, we found that the average particle size was 1.5 as shown in Table 5.
~10. .

/I III, and as shown in Table 4, the amount of C is 0. O
1 to 0.10% by weight, O amount 0.05 to 0.30% by weight
A Mo2FeB2 complex boride powder was produced.

Comparative Example 20g of powder blended with the same composition as Example 1 was completely melted at a high temperature of 2100 ° C by arc melting method.
The obtained melt was cooled to make a block sample, which was mechanically crushed and sieved using a stamp mill to obtain Mo2FeB.
Although a two-system complex boride was produced, the amount that could be processed at one time was small, the cost was high, and it took a long time.

[Effects of the invention] The present invention has excellent heat resistance, high temperature strength, toughness, hardness, oxidation resistance,
Mo2FeB2 type complex boride powder with excellent corrosion resistance (M
o +F e +Cr ) 3B2 type complex boride powder, and (M OT F e e Cr + X) 3
This is a new industrial manufacturing method that uses B2 type complex boride powder in large quantities at low temperatures.

[Brief explanation of drawings]

FIG. 1 is a scanning electron micrograph at a magnification of 3000 times, showing the structure of the Mo2FeB2-based complex boride powder of Example 1.
and FIG. 2 is a diagram showing an X-ray diffraction pattern of the M 02FeB2 type complex boride powder of Example 1. Figure Figure Figure 0 0 2θ 0 0 Procedural amendment (method) % formula % 1, Indication of case 1999 Patent Application No. 332588 2
, Title of the invention Method for producing Mo2FeB2-based complex boride powder 3, Relationship with the person making the amendment Patent applicant representative Kunobe 4, agent address Toyo Kohan Co., Ltd. 1-4-3 Kasumigaseki, Chiyoda-ku, Tokyo Company name

Claims (5)

[Claims] (1) Fe, Mo, and B elemental powders, boride and alloy powders containing two or more of the above elements, and two or more of the elemental elements, boride and alloy powders containing C, and C powder, B is 7.2-8.8% by weight, Mo is 64-78%
% by weight, the balance being Fe and unavoidable impurities, pulverized and mixed to have an average particle size in the range of 0.1 to 50 μm, and heated at a rate of 0.5 to 100° C./min in a non-oxidizing atmosphere. Heat treatment is performed at a heating temperature of 750 to 1500°C and a holding time of 1 minute to 5 hours to perform a reduction reaction with C and form a Mo_2FeB_2 type complex boride by solid phase reaction, followed by cooling and pulverization to form a Mo_2FeB_2 type complex. Contains 90% or more of boride by weight and has a residual C content of 0.00
5 to 1% by weight, residual O content is 0.001 to 0.5% by weight, and the average particle size of the powder is 0.1 to 50 μm. . (2) Single powders of Fe, Mo, B, and Cr, boride and alloy powders containing two or more of the above elements, and two or more of the single powders, borides and alloy powders containing C, and C powders. , B is 7.2 to 10.2 wt%, Mo is 4
5.5 to 78% by weight, 0.1 to 35% by weight of Cr, and the balance consisting of Fe and unavoidable impurities. After grinding and mixing to an average particle size of 0.1 to 50 μm, non-oxidizing Heating rate 0.5-100℃/min in atmosphere, heating temperature 7
Heat treated at 50 to 1500°C for a holding time of 1 minute to 5 hours,
A reduction reaction with C is carried out and a solid phase reaction (
After forming a type complex boride (Mo, Fe, Cr)_3B_2, it is cooled and pulverized to form (Mo, Fe, Cr)_3
Contains 90% by weight or more of B_2 type complex boride, with residual C
The amount is 0.005 to 1% by weight, and the amount of residual O is 0.001 to 0.
．． 5% by weight, and the average particle size of the powder is 0.1-50
(Mo, Fe, Cr)_3
Method for producing B_2 type complex boride powder. (3) Fe, Mo, B, Cr, Ti, Zr, Hf, V,
Single powders of Nb, Ta, W, Co, Re, and Ni, boride and alloy powders containing two or more of the above elements, and two types of single powders, borides and alloy powders containing C, and C powders. The above, B is 7.2 to 10.2% by weight, M
O is 45.5 to 78% by weight, Cr is 0.1 to 35% by weight
, and Ti, Zr, Hf, V, Nb, Ta, W, Co,
The total content of one or more elements selected from the group consisting of Re and Ni is 0.1 to 20% by weight, and the balance is Fe.
and unavoidable impurities, pulverized and mixed to have an average particle size in the range of 0.1 to 50 μm, and then heated in a non-oxidizing atmosphere at a heating rate of 0.5 to 100°C/min and a heating temperature of 750 to 750°C.
Heat treatment was carried out at 1500°C for a holding time of 1 minute to 5 hours to carry out a reduction reaction with C and to conduct a solid phase reaction (Mo,
Fe, Cr, X)_3B_2 (hereinafter, X is Ti, Zr,
After forming a )-type complex boride representing one or more elements selected from the group consisting of Hf, V, Nb, Ta, W, Co, Re, and Ni, cooling and pulverization are performed. Contains 90% by weight or more of Mo, Fe, Cr,
% by weight, the amount of residual O is 0.001 to 0.5% by weight,
A method for producing a (Mo, Fe, Cr, (4) Claims 1 and 2, characterized in that in the pulverization and mixing step, a mechanical alloying method or a mechanical pulverization and mixing method is used.
Or the method for producing complex boride powder according to 3. (5) The non-oxidizing atmosphere is vacuum, H_2 gas, Ar gas, He gas or N_2 gas,
A method for producing a complex boride powder according to claim 1, 2 or 3.