JPH059009A - Production of intermetallic compound and ceramics - Google Patents

Abstract

PURPOSE:To inexpensively and rapidly obtain the intermetallic compd. and ceramics by adding a specific diluent to a mixture composed of (non)metallic oxides and (non)metallic elements to effect reaction. CONSTITUTION:The intermetallic compd. or ceramic powder is added as the diluent to the mixture composed of the (non)metallic oxides and the (non)metallic elements and while the reaction temp. is controlled under 0.1 to 30atm, the mixture is brought into reaction in accordance with formula {(a) to (f) are positive integers; [MaOb] is the (non)metallic oxide; E, R are the (non)metallic elements; [McEd] is the intermetallic compd., nonoxide ceramics; [ReOf] is the oxide ceramics; M is >=1 among Mn, Fe, Co, Ni, Cu, Zn, Tc, Ru, Rh, Pb, Ag, Re, Os, Ir, Pt, and Au; E is at least one among B, C, N, Al, Si, P, S, Sc, Ti, V, Cr, Y, Zr, Nb, etc.; R is at least one among B, Mg, Al, Si, Ca, lanthanoid element, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an intermetallic compound and ceramics.

[0002]

2. Description of the Related Art Conventionally, for the synthesis of intermetallic compounds and ceramics, it has been necessary to use a furnace at a temperature of 1000 ° C. to 2000 ° C. and perform external heating while controlling the atmosphere.

Therefore, the production of intermetallic compounds and ceramics requires enormous energy and a large heating mechanism, which is one of the causes of increasing the production cost.

Therefore, according to the present invention, an intermetallic compound or a ceramic can be produced inexpensively and in a short time without performing external heating or only by preheating at a temperature much lower than a usual synthesis temperature. Is to provide.

[0005]

In order to solve the above problems, the present invention is designed to synthesize an intermetallic compound and a ceramic by the following reaction formula.

[MaOb] + (ad / c) [E] + (be / f) [R] ⇒ (a / c) [McEd] + (b / f) [ReOf] where a, b, c , D, e, and f are positive integers, respectively, in the chemical formula, [MaOb] is a metal oxide and a nonmetal oxide, [E] and [R] are a metal element and a nonmetal element, and [McEd]. Are intermetallic compounds and non-oxide ceramics, [ReOf] is oxide ceramics, and the symbol M in the above chemical formula is Mn, Fe, Co, N.
i, Cu, Zn, Tc, Ru, Rh, Pd, Ag, R
At least one of e, Os, Ir, Pt, and Au elements, the symbol O in the chemical formula is an O element, and the symbol E in the chemical formula is B, C, N, Al, Si, P, S, Sc, Ti, V, C
At least one of r, Y, Zr, Nb, Mo, Hf, Ta, W, and a lanthanoid element, and the symbol R in the chemical formula is B, Mg, Al, Si, Ca, Sc, Ti, Y, Z.
It is at least one of r, Hf, and a lanthanoid element.

[0007]

According to the above reaction formula, a very high heat of reaction can be obtained and this heat of reaction can be utilized as energy required for the synthesis of intermetallic compounds and ceramics. It can be carried out in a short time without external heating or only by preheating at a temperature much lower than the usual synthesis temperature.

For example, the reaction heat in the reaction formula as shown in the formula (1) is utilized for the synthesis. In this reaction formula, the combustion temperature is 263 with the help of the oxidation reaction heat of Al.
The temperature can be raised to 3 ° C., and as a result, an ingot of NiTi, which is one of the intermetallic compounds, can be manufactured without external heating. In this example, Al ₂ O ₃ is also synthesized, but NiTi and Al ₂ O ₃ are obtained separately because of differences in wettability, specific gravity, viscosity, melting point and thermodynamic stability.

3NiO + 3Ti + 2Al ⇒ 3NiTi + Al ₂ O ₃ +289.05 KJ / mol (1) Formula

[0010]

EXAMPLES More specific examples of the present invention will be described below.

Example 1 NiO powder (purity 99.95%, average particle size 5 μm), Al
Powder (purity 99.99%, average particle size 2 μm), Al ₂ O ₃
Powders (purity 99.995%, average particle size 1 μm) were mixed in a molar ratio shown in the reaction formula (2). A part of the mixed powder was molded into a cylindrical shape having a diameter of 25 mm and a height of 20 mm using a die press.

21NiO + 35Al + 3Al ₂ O ₃ ⇒ 21NiAl + 1OAl ₂ O ₃ (2) Formula After placing this molded body on a carbon plate and storing it in a high-pressure reaction vessel, the upper end surface of the molded body was carbonized under an argon atmosphere of 30 atm. The oxidative combustion reaction of Al was induced by heating and igniting with a heater, and the reduced Ni reacted with excessively added Al to synthesize NiAl, while the combustion reaction proceeded in a chain to the lower end. From powder X-ray diffraction, the main generated phases were NiAl and Al ₂ O ₃ .

The combustion temperature is about 2800K, and N
Since both the melting point of iAl (1912K) and the melting point of Al ₂ O ₃ (2327K) were exceeded, both were melted. The electricity to the carbon heater was cut off immediately after the combustion reaction started. The obtained product was completely separated into two phases and had a shape in which Al ₂ O ₃ was attached around the button-shaped ingot of NiAl.

Example 2 NiO powder (purity 99.95%, average particle size 5 μm), Al
Powders (purity 99.9%, average particle size 5 μm) were mixed in a molar ratio shown in the reaction formula (3).

2NiO + 3Ti⇒2NiTi + TiO ₂ (3) A part of the mixed powder of the formula (3) was molded into a cylindrical shape having a diameter of 25 mm and a height of 20 mm by using a die press. This compact was placed on a carbon plate and housed in a reaction vessel. Then, the upper end surface of the compact was heated by an arc discharge under normal pressure of argon to ignite, thereby inducing an oxidation combustion reaction of Ti and reducing Ni. While reacting with Ti added in excess to synthesize NiTi, the combustion reaction proceeded in a chain to the lower end. The combustion temperature at this time was 2322K, and the product NiTi and T
Both of iO ₂ were melted. The obtained product was separated into two phases, and a TiO ₂ coating was formed around the button-like ingot of NiTi.

Example 3 NiO powder (purity 99.95%, average particle size 5 μm), Ti
Powders (purity 99.9%, average particle size 5 μm) were mixed in a molar ratio shown in the reaction formula of the above formula (3).

A part of the mixed powder was molded into a cylindrical shape having a diameter of 25 mm and a height of 20 mm using a die press. After placing this molded body on a carbon plate and storing it in a high-pressure reaction container, the oxidation combustion reaction of Ti is induced by heating and igniting the upper edge of the molded body with a carbon heater under vacuum,
The reduced Ni reacts with Ti added excessively to form NiT.
While synthesizing i, the combustion reaction proceeded in a chain to the lower end. The combustion temperature at this time was 2322K, and the product N
Both iTi and TiO ₂ were melted. Argon gas was introduced into the reaction vessel while the product was in a molten state, and 3
As a result of the isotropic pressurization of the product by increasing the pressure to 10 atm per second, a product without cavities reaching the theoretical density was obtained.

Example 4 NiO powder (purity 99.95%, average particle size 5 μm), Ni
Powder (purity 99.99%, particle size 1 μm or less), B powder (purity 99%, particle size 1 μm or less), Al powder (purity 99.99)
%, And an average particle size of 2 μm) were dry-mixed using a vibration mill at a molar ratio shown in the reaction formula (4).

3NiO + Ni + 4B + 2Al⇒4NiB + Al ₂ O ₃ (4) A part of the mixed powder of formula (4) was molded into a cylindrical shape having a diameter of 15 mm and a height of 30 mm using a die press. By placing this molded body on a carbon plate and heating the upper end surface of the molded body in the atmosphere by arc discharge to ignite, an oxidation combustion reaction of Al is induced, and Ni reduced in addition to Ni in the raw material While reacting with B to synthesize NiB, the combustion reaction proceeded in a chain to the lower end.

From powder X-ray diffraction, the main production phases are NiB and A.
It was 1 ₂ O ₃ . The combustion temperature was 2557 K, and both the products NiB and Al ₂ O ₃ were molten. The obtained product was separated into two phases, and a button-shaped ingot of NiB was covered with Al ₂ O ₃ .

Example 5 Fe ₂ O ₃ powder (purity 99.9%, average particle size 1 μm), A
1 powder (purity 99.9%, average particle size 2 μm) and Si powder (purity 99.9%, particle size 2 to 3 μm) were mixed at the molar ratio shown in the reaction formula (5).

Fe ₂ O ₃ + 4Si + 2Al⇒2FeSi ₂ + Al ₂ O ₃ (5) A part of the mixed powder of formula (5) was molded into a column shape having a diameter of 15 mm and a height of 30 mm by using a die press. By placing the compact on a carbon plate and heating the upper end surface of the compact in an argon arc to ignite it, the oxidation combustion reaction of Al is induced, and the reduced Fe reacts with the added Si. Fe
While synthesizing Si ₂ , the combustion reaction proceeded in a chain to the lower end. The traveling speed of the combustion wave front was 10 mm / sec. The combustion temperature is about 2500K, FeSi ₂ and Al
Both were above the melting point of ₂ O ₃ , and both were melting during the combustion reaction. As a result of powder X-ray diffraction, the produced phase was slightly FeS.
Although it contained i, it was mainly composed of FeSi ₂ and Al ₂ O ₃ . The obtained product was separated into two phases, and each was in the form of a ram.

Example 6 NiO powder (purity 99.95%, average particle size 5 μm), Ni
Powder (purity 99.99%, particle size 1 μm or less) and Al powder (purity 99.99%, average particle size 2 μm) were dry-mixed using a vibrating mill at a molar ratio shown in the reaction formula (6). .

3NiO + 4Ni + 9Al⇒7NiAl + Al ₂ O ₃ (6) A part of the mixed powder of formula (6) is filled in a porous carbon crucible having an inner diameter of 26 mm and a height of 60 mm, and a hole having a diameter of 10 mm is formed at the bottom to carry out a high pressure reaction. After being stored in a container, the upper end is heated by a carbon heater and ignited under an argon atmosphere of 80 atm to induce an oxidation combustion reaction of Al, and Ni reduced in addition to Ni in the raw material becomes Al. React to Ni
While synthesizing Al, the combustion reaction proceeded in a chain to the lower end. The combustion temperature was 2507 K, and both phases were melted, and only NiAl having a large specific gravity flowed out of the hole at the bottom and could flow into the graphite mold arranged below for casting. The molten Al ₂ O ₃ solidified on the wall surface of the carbon crucible. Cast Ni
Al was densified and no nest was observed.

[0025]

As described above, according to the present invention, the heat of reaction is
According to the present invention, since it is used as energy necessary for synthesizing metal oxides and ceramics, a container for controlling the atmosphere and an ignition device for initiating a combustion reaction can be used without external heating, or Since the synthesis can be performed at a temperature much lower than the normal synthesis temperature in a short time, the synthesis apparatus itself can be simplified and the manufacturing cost can be remarkably reduced.

Further, in the present invention, a part of the metal element or the non-metal element of the raw material is replaced with the metal oxide or the non-metal oxide, so that the production can be performed at a lower cost and the resource is stable. The effect is that supply is possible.

Claims (6)

[Claims] 1. A method for producing an intermetallic compound and a ceramic according to the following reaction formula. [MaOb] + (ad / c) [E] + (be / f) [R] ⇒ (a / c) [McEd] + (b / f) [ReOf] where a, b, c, d, e and f are positive integers, respectively, in the chemical formula, [MaOb] is a metal oxide and a non-metal oxide, [E] and [R] are a metal element and a non-metal element, and [McEd] is an intermetallic Compounds and non-oxide ceramics, [ReOf] represents oxide ceramics, and the symbol M in the above chemical formula is Mn, Fe, Co, Ni, Cu, Zn, T.
c, Ru, Rh, Pd, Ag, Re, Os, Ir, P
At least one of t and Au elements, the symbol O in the chemical formula is an O element, and the symbol E in the chemical formula is B, C, N, Al, S
i, P, S, Sc, Ti, V, Cr, Y, Zr, Nb,
At least one of Mo, Hf, Ta, W, and a lanthanoid element, wherein the symbol R in the chemical formula is B, Mg, Al,
It is at least one of Si, Ca, Sc, Ti, Y, Zr, Hf, and a lanthanoid element. 2. A mixture of a metal oxide and a non-metal oxide according to the reaction formula of claim 1 and a metal element and a non-metal element, which is the same as or different from the intermetallic compound and ceramics to be synthesized. The method for producing an intermetallic compound and ceramics according to claim 1, characterized in that the intermetallic compound and the ceramics are synthesized by adding a ceramic powder and a ceramic powder as a diluent for the synthetic reaction while controlling the reaction rate. 3. A mixture of a metal oxide and a non-metal oxide according to the reaction formula according to claim 1 and a metal element and a non-metal element is added by an appropriate amount of a mixture of a metal element and a non-metal element according to the following formula: The method for producing an intermetallic compound and ceramics according to claim 1, wherein the synthesis is performed while controlling the reaction temperature. c [M] + d [E] ⇒ [McEd] 4. After molding a mixture of metal oxides and non-metal oxides and metal elements and non-metal elements, a part of the molded body is heated to initiate the chemical reaction according to claim 1, 2. The intermetallic compound according to claim 1, wherein the reaction product generated at some time induces a synthetic reaction in an adjacent portion, and a chain combustion synthetic reaction proceeds to form the entire compact into an intermetallic compound and a ceramic. Methods for producing compounds and ceramics. 5. Utilizing the fact that a part or whole of the synthesized intermetallic compound and ceramics is melted by high reaction heat and the intermetallic compound and ceramics or two or more kinds of ceramics are separated or dispersed. 2. The method for producing an intermetallic compound and ceramics according to claim 1, wherein the intermetallic compound and ceramics are cast or hot-worked to obtain a desired shape. 6. The atmosphere during the chemical reaction according to claim 4, wherein the atmosphere is vacuum or air having a pressure of 0.1 to 3000 atm, nitrogen,
Oxygen, helium, neon, and argon, and a method for producing an intermetallic compound and ceramics.