JP2000144281A - Production of metal matrix composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the method for producing a metal matrix composite material with high productivity in such a manner that, at the time of impregnating a compacted body with molten metal and thereafter executing heating to produce compd. grains for dispersion strengthening, heating at a high temp. for a long time is not needed, and, also, the size of the applicable compacted body is expanded. SOLUTION: In this method for producing a metal matrix composite material in which compd. grains consisting of 1st and 2nd componential elements are dispersed into a metallic matrix, the compact consisting of the powder of the 1st componential elements, each powder of the 2nd componential elements or the compd. thereof and metal powder is impregnated with the molten metal of the metal, and then the whole of the compact is rapidly heated in an inert atmosphere to bring into chemical reaction of the 1st components and the metal as exothermic reaction in the compact, and the temp. of the compact is automatically, rapidly raised by the heat generation in the chemical reaction, then the producing reaction of the compd. grains is generated in the compact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a metal-based composite material containing a large amount of compound particles, and further relates to a method for producing a metal-based composite material using the above-mentioned composite material as a base material (compound for adding compound particles). About.

[0002]

2. Description of the Related Art As a method for producing a dispersion-strengthened metal matrix composite material, for example, Ti powder particles, C (graphite) powder particles, Al or Al A metal-based composite material in which a large amount of TiC particles are dispersed in a metal matrix composed of Al or an Al alloy by heating a compact formed of alloy powder particles in an inert atmosphere is used as a base material (dispersion particle addition medium). There is known a method of manufacturing, dissolving this base material in a molten metal of Al or Al alloy, and then solidifying it. According to this method, the content of the TiC particles (dispersion-strengthened particles) in the final composite material can be controlled to a desired value by the amount of the base material dissolved in the molten metal.

[0003] However, the present applicant has proposed that
When a C particle dispersion strengthened Al-based composite material was actually manufactured, it was found that the above method had the following problems. (1) Since the base material is porous and has a low specific gravity, it floats on the surface of the molten metal and is difficult to completely dissolve in the molten metal. (2) Since the base material is porous and has poor heat conduction, it takes a long time for the entire base material to reach the melting temperature and melt. (3) It is difficult for the molten metal to penetrate into the porous base material due to surface tension and viscosity. (4) Ti in the compact
Particles and C particles are likely to come into direct contact, and TiC particles are likely to grow excessively and become coarse. (5) Oxygen or nitrogen remaining in the molded body reacts with Al when the molded body is heated, and Al ₂ O ₃ or AlN is generated on the surface of the Al particles, thereby preventing dissolution of the base material in the molten metal.

[0004] In order to solve the above-mentioned problem, the present applicant has formed a compact formed of Ti powder or Zr powder, C powder, Al powder or Al alloy powder as disclosed in Japanese Patent No. 2734891. Then, the molded body is impregnated with a molten metal of Al or an Al alloy, and the molded body is heated to 1000 to 1800 ° C. in an inert atmosphere to generate TiC particles or ZrC particles in the molded body. Later, a method for dissolving the compact in a molten Al or Al alloy was developed.

[0005] According to this method, when impregnating the molten metal into the powder compact, Ti or Zr acts as a getter for adsorbing oxygen and nitrogen remaining in the voids and lowers the internal pressure of the voids. Is sucked into the gap, so that the impregnation can be performed well without requiring any special pressurization. The getter function further prevents the formation of Al ₂ O ₃ and AlN, so that the formation of Al ₂ O ₃ and AlN does not lower the solubility.

[0006] The molded body thus obtained is in a solid state in which the voids are filled with Al or an Al alloy.
Or, since it is equivalent to the molten aluminum alloy and has high thermal conductivity, it does not float on the surface of the molten metal and the entire molded body reaches the molten metal temperature in a short time and is easily dissolved in the molten metal. The Japanese Patent No. 2734 thus developed by the present applicant.
The method of No. 891 can solve the above-mentioned problems inevitably in the method of JP-A-63-83239, and obtains a molded article having extremely high solubility (dispersibility) in a molten metal. This is an excellent method that can easily and efficiently produce a composite material in which fine TiC particles are uniformly dispersed in an Al or Al alloy matrix.

[0007] However, the above method is performed at 1000 to 1800 ° C.
It usually requires heating for 3 hours or more,
The size of the molded body that can be applied is necessarily limited due to the necessity of preventing gravity segregation and the like, and the limit is about 20 to 30 g. Therefore, further improvement has been desired from the viewpoint of productivity.

[0008]

DISCLOSURE OF THE INVENTION The present invention has improved a method of forming a compound particle in a compact by heating after impregnating a powder compact with a molten metal. It is an object of the present invention to provide a method for producing a metal-based composite material with high productivity by increasing the size of an applicable molded body.

[0009]

In order to achieve the above object, a method for producing a metal-based composite material according to the first aspect of the present invention comprises a method of manufacturing a metal matrix comprising a metal or an alloy of metals. In the method for producing a metal-based composite material in which compound particles of the above are dispersed, the following steps: a powder of the first element, a powder of the second element or a compound of the second element, Forming a compact comprising an alloy powder; impregnating the compact with a melt of the metal or metal alloy; and rapidly heating the entire impregnated compact in an inert atmosphere. As a result, a compounding reaction between the first element and the metal, which is an exothermic reaction, occurs in the molded body, and the molded body is automatically heated rapidly by the heat generated by the compounding reaction, so that the above-mentioned metal is formed in the molded body. A process for generating a compound particle formation reaction The heating rate of the rapid heating is determined by the residual heat obtained by subtracting the heat loss due to the heat generated by the chemical reaction between the first element and the metal to the outside and the heat loss due to the possible endothermic reaction. The heating rate is such that the compounding reaction between the first element and the metal proceeds in a sufficiently short time so that the whole can be automatically heated to a temperature at which the formation reaction of the compound particles occurs. A step in which the attained temperature is in a range from a lower limit temperature at which a compounding reaction between the first element and the metal can occur to an upper limit temperature at which a formation reaction of the compound particles can occur.

Since the metal matrix composite material produced by the method of the first invention can be obtained in a form containing a very large amount of compound particles in a metal matrix, it is needless to say that a special material such as a wear-resistant sliding member is used. It can be used directly as the final particle-dispersed metal matrix composite in the application, or to produce the final particle-dispersed metal matrix composite,
A particle additive (typically a dispersion-strengthened particle introduction medium) for smoothly introducing compound particles (typically, dispersion-strengthened particles) into a molten metal or alloy constituting the matrix.
Can also be used.

That is, according to the second invention, the metal-based composite material containing the compound particles produced by the method of the first invention is introduced into a metal or metal alloy melt as a particle additive, and the metal-based composite material is introduced. A method for producing a metal-based composite material is provided, comprising dissolving a metal matrix of a material in the molten metal, dispersing the compound particles in the molten metal, and solidifying the molten metal.

A typical metal-based composite material manufactured according to the first or second invention is a particle-dispersed metal-based composite material applicable to various uses. It is a composite material. Generally, when the metal-based composite material according to the first invention is introduced into the molten metal in the second invention as a particle additive, the molten metal is a molten metal of the same kind of metal or alloy as that impregnated in the molded body in the first invention. . However, the particle additive may be introduced into a molten metal of a metal or alloy different from the impregnated metal or alloy. In this case, the composition in which the component of the impregnated metal or the impregnated alloy is added as an alloy component to the composition of the molten metal becomes the final composition of the metal matrix of the metal-based composite material.

According to the first aspect of the first invention, Al or
TiC particles dispersed in metal matrix composed of Al alloy
A method is provided for producing a metal-based composite material. sand
That is, production of the metal matrix composite material according to the first aspect of the first invention.
The method is performed in a metal matrix composed of Al or an Al alloy.
For producing metal matrix composite material having TiC particles dispersed therein
In the following steps: Ti powder and C powder (graphite powder)
To form a compact comprising aluminum and Al or Al alloy powder
Step, impregnating the molten body of Al or Al alloy in the compact
And the whole of the impregnated molded body is kept in an inert atmosphere.
By rapid heating in the air, the Al
Or TiAl occurring near the melting point of Al alloy_Three Generation reaction
The TiAl_Three Due to the heat generated by the formation reaction,
Automatically raises the temperature automatically to form TiC particles in the compact
A step of causing a reaction, the heating rate of said rapid heating
Is the TiAl_Three Release from heat generated in the formation reaction to the outside
Residue minus heat loss due to heat dissipation and possible endothermic reactions
Excess heat causes the entire compact to generate the TiC particle formation reaction.
Short enough to automatically raise the temperature
And the TiAl_Three Is the heating rate at which the formation reaction proceeds,
The ultimate temperature of heating by the rapid heating is TiAl _Three Generation reaction
From the lower limit temperature at which the TiC particle formation reaction may occur.
A process within a range up to an upper limit temperature.
And

In the first aspect of the first invention, the heating rate of the rapid heating is generally desirably 20 ° C./min or more. Further, the heating ultimate temperature of the rapid heating is typically TiAl ₃ due to the combination of solid Al and solid Ti.
From the lower limit temperature of 617 ° C. where the formation reaction can occur, the solid TiA
This is a temperature within a range up to an upper limit temperature of 992 ° C. at which a reaction of forming solid TiC particles by a reaction between l ₃ and solid C can occur.
Such rapid heating can be easily realized by induction heating.

In the first aspect of the first invention, SiC powder can be used in place of C powder to form a molded body. Furthermore, the second, third, fourth,
According to the fifth aspect, ZrC particles, Hf particles, NbC particles, Ti
Method for producing a metal matrix composite material in which any of B ₂ particles are dispersed is provided.

According to a second aspect of the present invention, there is provided a method of manufacturing a metal-based composite material, wherein the compound particles of ZrC are dispersed in the metal matrix of Al or an alloy of Al. Wherein the first element is Zr and the second element is C, and in the step of forming the compact, a compact comprising Zr powder, C powder and Al or Al alloy powder is formed. And

According to a third aspect of the present invention, there is provided a method of manufacturing a metal-based composite material, wherein the compound particles of HfC are dispersed in the metal matrix of Al or an alloy of Al. Wherein the first element is Hf and the second element is C, and wherein in the step of forming the compact, a compact comprising Hf powder, C powder and Al or Al alloy powder is formed. And

According to a fourth aspect of the present invention, there is provided a method of manufacturing a metal-based composite material, wherein the compound particles of NbC are dispersed in the metal matrix of Al or an alloy of Al. Wherein the first element is Nb and the second element is C, and wherein in the step of forming the compact, a compact comprising Nb powder, C powder and Al or Al alloy powder is formed. And

The metal matrix composite according to the fifth aspect of the first invention
The method for producing the metal comprises:
TiB in matrix_TwoWherein said compound particles comprising
A method for producing a metal matrix composite material, comprising:
The element is Ti and the second element is B, and the compact is formed.
In the forming process, Ti powder and AlB_TwoOr AlB ₁₂
Forming a compact consisting of powder and Al or Al alloy powder
It is characterized by doing.

In the second, third, fourth and fifth aspects of the first invention, the heating rate of the rapid heating is generally 20 ° C. /
Minutes or more. Such rapid heating can be easily realized by induction heating. According to the first, second, third, fourth and fifth aspects of the second invention, TiC particles produced by the methods of the first, second, third, fourth and fifth aspects of the first invention, respectively. , ZrC particles, HfC particles, NbC particles, TiB ₂ particles, Al, Al alloy, M
g or Mg alloy, the metal matrix of the compact is dissolved in the molten metal, and the T
Production of a particle-dispersion-strengthened metal matrix composite material comprising dispersing iC particles, the ZrC particles, the HfC particles, the NbC particles, and the TiB ₂ particles in the melt, and then solidifying the melt. A method is provided. When a molten metal of Mg or Mg alloy is used, Al or Al alloy impregnated in the compact forms a part of the alloy component of the Mg-based metal matrix of the metal-based composite material manufactured according to the second invention.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The principle of producing compound particles according to the present invention will be described below by taking as an example a case where TiC particles are produced in an Al-based matrix. Forming a compact consisting of Ti powder, graphite powder and Al or Al alloy powder,
The molded body is impregnated with a molten metal of Al or an Al alloy.

Next, when the compact is heated, the following chemical reactions (1) to (5) occur between Ti, Al, and C in the course of raising the temperature. Ti (s) + 3Al (s ) → TiAl 3 (s) 890K (617 ℃) (1) Al (s) → Al (l) 930K (657 ℃) (2) Ti (s) + 3Al (l) → TiAl 3 (s) 940K (667 ° C) (3) 3TiAl ₃ (s) + Al ₄ C ₃ (s) → 3TiC (s) + 13Al (l) 1150K (877 ° C) (4) TiAl ₃ (s) + C (s) → TiC (s) + 3Al (l) 1155K-1265K (5) (882-992 ° C) Figure 1 shows the above reactions as DTA (differential thermal).
analysis: Differential thermal analysis). The figure shows 5 ° C /
This is the result of observation at a slow heating rate of about min.

Two large upward heat generation peaks and one large downward heat absorption peak sandwiched between the two heat generation peaks are generated on the left side (low temperature side) in the drawing. These peaks are, in order from the low temperature side, (1) an exothermic peak (61) of a reaction in which solid Ti and solid Al are combined to form solid TiAl _3.
(2) Endothermic peak at which Al melts (657).
C.) and (3) an exothermic peak (starting at 667 ° C. and ending at 747 ° C.) of the reaction in which liquid Al and solid Ti combine to form solid TiAl ₃ .

Further, as the temperature rises, the reaction of (4) and (5)
Solid TiAl_Three And solid Al _Four C_Three Or solid C
Exothermic peak and intermediate produced by the formation of solid TiC
Exothermic and endothermic peaks due to formation and decomposition of the product
It is observed in the temperature range of from 9C to 992C. In the present invention
Is obtained by rapidly heating the compact in an inert atmosphere.
The melting point of Al or Al alloy in the compact (reaction (2))
TiAl that occurs most recently_Three Formation reaction (Reaction (1), Reaction (3)
 ), And the TiAl_Three Generation reaction (1) (3)
The temperature of the compact is automatically raised rapidly by heat, and T
iC particle formation reaction (reaction (4), reaction (5))
You.

Therefore, the heating rate of the rapid heating is Ti
Al ₃ formation reaction (1) The heat generated in (3) dissipates to the outside and the residual heat obtained by subtracting the heat loss due to possible endothermic reaction (reaction (2), etc.) causes the entire molded body to react to form TiC particles. (4) In order to automatically raise the temperature to the temperature at which (5) occurs (882 ° C to 992 ° C), the TiO should be sufficiently short in a short time.
The heating rate at which the l ₃ generation reaction (1) (3) proceeds. In addition, the ultimate temperature of heating by rapid heating depends on the TiAl ₃ formation reaction.
(1) From the lower limit temperature at which (3) can occur (= lower limit temperature at which reaction (1) occurs 617 ° C.) to the upper limit temperature at which TiC particle formation reaction (4) (5) can occur (= upper limit temperature at which reaction (5) occurs) 992 ° C)
Within the range up to.

By performing rapid heating as described above,
Originally, they are independent reactions as shown in Fig. 1 (1) to (5)
The reaction (1) occurs continuously and apparently becomes one exothermic reaction, and the reaction (5) is completed in a very short time of about 1 to 2 minutes from the start of the reaction (1). FIG. 2 schematically shows the DTA behavior with respect to the time when rapid heating according to the present invention is performed, as compared with the behavior at the time of slow heating as shown in FIG. 1 (the horizontal axis is time). Rapid heating can be easily performed by induction heating. If the heating device is set at an ultimate temperature of 700 ° C. and the heating rate is 20 ° C./min, the reactions (1) to (5) automatically and continuously proceed. Is enough. In this case, the reaction starts immediately before reaching the set temperature of 700 ° C. (617 ° C.).
(1) causes heat generation, and the temperature of the molded body actually increases at a set temperature of 700 ° C. without continuing to rise,
It reaches about 1200 ° C. in about 1 to 2 minutes. Reaction (5)
When the formation of TiC is completed, the temperature of the compact rapidly decreases.

In order to induce the exothermic reaction by rapid heating to complete the generation of TiC particles in a short time as described above, impregnation is crucial in the following two points. (1) Miniaturization of Compound Particles Almost all voids in the compact are filled with Al by impregnation. Thereby, since impregnated Al is interposed between Ti powder particles, C powder particles, and compound particles with Al, each product particle, particularly final TiC particles, is aggregated during reaction by rapid heating. A metal matrix composite material in which coarsening is prevented and fine TiC particles are dispersed can be obtained. The fine dispersion of particles imparts excellent mechanical properties when the metal matrix composite is directly put into practical use, and when the metal matrix composite is introduced into a molten metal as a particle additive, the particles are not easily dispersed. It is easily finely dispersed in the molten metal and contributes to the improvement of the mechanical properties of the metal matrix composite obtained by solidification.

(2) Acceleration of Reaction During Rapid Heating During the impregnation, the Al molten metal and the Ti powder particles react to form fine TiAl ₃ particles around the Ti particles, and the final reaction during rapid heating, TiAl ₃ + C → TiC + 3Al is promoted. This lowers the apparent reaction initiation temperature,
The efficient generation of TiC particles by the rapid heating of the present invention is enabled.

Further, the voids in the molded body are almost completely A due to the impregnation.
Since it is filled with l, heat conduction is promoted throughout the molded body during rapid heating, and the reaction is promoted. As described above, according to the present invention, the generation reaction of the TiC particles can be completed in a very short time, for example, in minutes, without requiring high-temperature and long-time heating as in the related art. Furthermore, since problems such as gravitational segregation unlike the conventional case do not occur, the size of the molded body can be considerably increased.

That is, in the conventional high-temperature and long-time heating, one of the causes is that the matrix component Al or A
Since the alloy is maintained in a molten state for a long time, the gravitational segregation of the component elements and the generated compound particles from each powder is liable to occur. Another factor is that the temperature distribution increases when the size of the compact increases. Due to the non-uniformity, it is impossible to complete the reaction of forming TiC particles over the entire volume of a large-sized compact.

In the present invention, the above-mentioned conventional problems are solved by heating the entire molded body rapidly, that is, for a short time, to the heating reaction starting temperature and automatically proceeding each reaction leading to TiC formation. The restriction on the size of the file is greatly relaxed. Instead of the TiC particles of the first aspect, the ZrC particles, HfC particles, N
Even when bC particles and TiB ₂ particles are generated, each particle can be generated in a large compact in an extremely short time by the same principle.

[0032]

[Embodiment 1] According to the first embodiment of the first invention,
A metal-based composite material in which TiC particles were generated in pure aluminum was manufactured by the following procedure. C powder was used as a C source of TiC. [Production of molded article] Pure aluminum powder (-45 μm, 9
9.3%), pure titanium powder (-45 μm, 99.4%),
7 g each of pure graphite powder (-45 μm, 99.4%)
11.2 g, 2.8 g were weighed and mixed, and the molding pressure was 7 t / cm.
^{In step 2} , a cylindrical molded body having a diameter of 30 mm was produced. The porosity of the obtained molded body was about 10%.

[Impregnation of Molten Aluminum] The above compact was immersed in 730 ° C. pure aluminum (purity: 99.9%) for 30 seconds, then immediately taken out of the melt, and the pure aluminum melt was inserted into the voids of the compact. Was impregnated. By this impregnation, the weight of the molded body was reduced from 18.5 g before impregnation to about 3
Increased to 0 g.

The impregnated aluminum melt has the effect of increasing the adhesiveness and thermal conductivity inside the compact, and reacts with the titanium powder particles to form fine Al ₃ Ti particles around the Ti particles. The reaction up to the generation of TiC by rapid heating is efficiently advanced, and contributes to the miniaturization of the TiC particle size. FIG.
An example of the microstructure of the compact after impregnation is shown below. Many fine TiAl ₃ (gray) of about 1 μm are generated around Ti particles (white) dispersed in an Al matrix (black).

On the other hand, the formed compact without impregnation had a remarkably low heating efficiency in the subsequent high-frequency heating, and a sound Al-TiC pellet could not be obtained. The same comparative material was heated up to 1300 ° C. at a rate of 5 ° C./min to generate TiC. The generated TiC particles had a large average particle size of 3 μm. [Production of TiC Particles] Rapid heating for producing TiC particles was performed using a vacuum melting furnace equipped with a high-frequency motor generator having a frequency of 3600 Hz and an output of 20 kW.

Seven pieces of the impregnated compacts were stacked and charged in a furnace (total 210 g), the inside of the furnace was evacuated to 10 ⁻² Torr, and Ar gas was introduced to −20 cmHg. For rapid heating. The heating rate was controlled by setting the high frequency output. As shown in Table 1, the heating rate of the sample and the set ultimate temperature of the apparatus were respectively 30 ° C./min and 700 ° C. for Invention Example 1, and 50 ° C./min for Invention Example 2.
, 800 ° C, Invention Example 3: 100 ° C / min, 650 ° C.

Comparative Example 1 was an example in which the treatment was performed under the same conditions as in Invention Example 1 except that the heating set temperature was set at 600 ° C., which was lower than the range of the present invention (i.e., 617 ° C. or more, which is the lower limit temperature of the TiAl ₃ generation reaction). It is. In Comparative Examples 2 to 5, the heating rate was within the range of the present invention (after the TiAl ₃ generation reaction started, T
As an example that is slower than the heating rate at which the temperature can be automatically raised to the temperature at which the iC particle generation reaction occurs), heating was performed in a normal electric furnace as in the related art. The heating rate was 10 ° C./min, which is the maximum capacity of the furnace, and the heating set temperature was 800 in Comparative Example 2.
° C, and 1200 ° C in Comparative Examples 3, 4, and 5. Heating and holding were not performed, and cooling was performed in the furnace after reaching the set temperature.

Comparative Example 6 is an example in which high-frequency heating was performed under heating conditions within the range of the present invention without performing impregnation. The sample size was 30 g in Comparative Examples 2 and 3 (one molded body), and Comparative Example 4
Was changed to 60 g (two molded bodies) and Comparative Example 5 was changed to 90 g (three molded bodies). The sample size of Comparative Example 6 is 60 g.
(Two molded bodies).

Inventive Example 1 in which rapid heating was performed according to the present invention,
In 2 and 3, in the temperature rising process, a sharp rise in the sample temperature starts around a temperature exceeding 600 ° C., and reaches 1215 ° C., 1235 ° C., and 1320 ° C. in 20 seconds to 40 seconds, respectively, and thereafter, the temperature rapidly increases. Descended. This is the reaction (1)
This is because the temperature of the sample rises in a short time due to the self-heating due to the continuous occurrence of (5), and the temperature falls rapidly with the completion of the last reaction (5). As described above, since self-heating due to the reaction far exceeds artificial heating by the high-frequency device, if the set temperature is within the range of the present embodiment,
The time required for TiC generation is extremely short, almost the same.

For the samples treated according to Invention Examples 1 to 3 and Comparative Examples 1 to 6, phase identification by X-ray diffraction and SE
The particle size was measured by image processing of an M microstructure photograph.
Table 1 also shows the results of these investigations. Inventive Examples 1 to 3 in which rapid heating was performed according to the present invention had a structure in which TiC particles having an average particle size of 0.2 μm were uniformly dispersed in an Al matrix. No other phases were detected.

In Comparative Example 1, the heating rate was the same as in Invention Example 1.
However, the heating setting temperature of 600 ° C._Three 
Since the Ti formation reaction start temperature did not reach 617 ° C,
No self-heating occurred due to the reaction of
The temperature at which the material is reached is 600 ° C. of the heating set temperature, and T
It did not lead to the generation of iC. The treated sample is impregnated
Solidification phase, Al particles (undissolved during impregnation), Ti particles
Particles, C particles, TiAl _Three The structure was a mixture of particles.

In Comparative Example 2, although the heating set temperature was 800 ° C. and the reaction (1) and (3) generated heat due to the generation of TiAl ₃ , the heating rate was lower than the range of the present invention.
Reactions (4) and (5) did not occur continuously from (1) and (3), and no TiC was formed. The sample after the treatment had a structure in which Ti, C, and TiAl ₃ particles were mixed in the Al solidification phase.

Comparative Examples 3, 4, and 5 satisfy the conventional processing conditions according to Japanese Patent No. 27348891, which was developed by the present applicant. A structure in which 2 μm TiC particles were uniformly dispersed was obtained. However, in Comparative Example 3 in which the sample size was 30 g, only the Al phase and TiC particles were observed. In Comparative Examples 4 and 5 in which the sample size was increased to 60 g and 90 g,
The TiAl ₃ phase was mixed in addition to the phase and the TiC particles, and the amount increased as the sample size increased. Since there was a strong tendency for TiAl ₃ particles to be present in the lower part of the sample in the processing furnace, the reason for the existence is considered as follows.

That is, T
In the iC generation process, since the time required for completing all of the reactions (1) to (5) is long, the composition variation occurs due to gravitational segregation in the molten Al at 1200 ° C. Whether TiAl ₃ , which should be an intermediate product formed in reactions (1) and (3), remained without proceeding to reactions (4) and (5),
(B) Since the sample size is large, the temperature distribution is likely to be non-uniform, and whether the progress of the reaction has become incomplete locally, or whether both of them have been concurrently performed.

In Inventive Examples 1 to 3, the entire sample was rapidly heated to at least a temperature at which reaction (1) could take place.
(2) to (5) are automatically advanced continuously to complete the reaction up to the TiC generation reaction (5) in a short time. _No residue of ₃ occurs. Furthermore, even if the total weight of the molded articles according to Inventive Examples 1 to 3 increases, the average particle size of TiC is 0.2 μm. Although not shown in Table 1, TiC particles having a uniform particle size and 0.3 μm or more exist. do not do.

On the other hand, in Comparative Examples 3 to 5 in which conventional high-temperature heat treatment was performed, the average particle diameter of TiC was 0.2 μm, but a particle diameter distribution of 0.1 μm to 1.5 μm was observed.
Thus, the uniform TiC particle size was obtained by the present invention, in addition to the fact that TiC generation was completed in a very short time,
This is considered to be because a temperature difference hardly occurs in the molded body.

[0047]

[Table 1]

Example 2 According to the first aspect of the first invention, as an additive for TiC particles,
A metal-based composite material that produced C particles was produced by the following procedure. SiC powder was used as a C source of TiC. [Production of molded article] Pure aluminum powder (-45 μm, 9
9.3%), pure titanium powder (-45 μm, 99.4%),
SiC powders (13 μm and 50 μm) were mixed in the respective formulations shown in Table 2 to produce a cylindrical molded body having a molding pressure of 7 t / cm ² and a diameter of 30 mm. Inventive Examples 1 and 3 show that all of SiC is Ti
And the molar ratio that reacts with the SiC powder. In Invention Example 2, the amount of SiC was twice as much as the amount required for the reaction with Ti. The porosity of the obtained molded body was about 7%.

[0049]

[Table 2]

[Impregnation of molten aluminum] The above-mentioned molded body was immersed in pure aluminum molten metal (purity 99.9%) at 730 ° C for 30 seconds, then immediately taken out of the molten metal, and pure aluminum molten metal was filled in the voids of the molded body. Was impregnated. Due to this impregnation, the weight of the molded article in Inventive Example 1 was 2% before impregnation.
From 7.6 g to about 31 g, and in Invention Example 2, from 37 g to 42 g
g, and in Invention Example 3, from 27.6 g to 30 g. Al, Ti, Si are contained in the compact after impregnation.
C and Al ₃ Ti were present. Al ₃ Ti was generated as fine particles (about 1 μm in diameter) around the Ti particles.

[Production of TiC Particles] Rapid heating for producing TiC particles was performed using the same vacuum melting furnace as in Example 1. The molded body after the impregnation was charged into the furnace with the weight and number shown in Table 3, and the inside of the furnace was evacuated to 10 ^-2 Torr, and then Ar gas was introduced to -20 cmHg, Rapid heating was performed by heating.

The heating rate was controlled by setting the high frequency output. The heating speed of the sample and the set temperature of the apparatus were all 100 ° C./min and 700 ° C. In each case of invention examples 1 to 3, in the heating process, a sharp rise in the sample temperature starts at around 700 ° C. and reaches about 1300 ° C. in 20 to 40 seconds.
, And then the temperature dropped sharply. This rapid temperature increase is considered to be due to the following exothermic reaction.

Ti + 3Al → TiAl ₃ TiAl ₃ + SiC → 3Al + TiC + Si (*) Ti + SiC → TiC + Si (*) (*: When the compounding amount of the SiC powder is excessive with respect to the Ti powder,
That is, the temperature of the sample rises due to self-heating caused by the continuous occurrence of the above-mentioned exothermic reaction, and the generation reaction of TiC proceeds in an extremely short time.

The samples of Invention Examples 1 to 3 after the above treatment were subjected to phase identification by X-ray diffraction and particle size measurement by image processing of SEM microstructure photographs. Table 3 shows the results of these investigations.

[0055]

[Table 3]

In each of Invention Examples 1 to 3, the structure was such that TiC particles having an average particle size of 0.2 μm were uniformly dispersed in the Al matrix. In addition, Si as a reaction by-product
Although there is a phase (5 to 50 μm), Si has the effect of improving the strength, wear resistance and castability of the Al alloy. In Invention Example 2, the excessively added SiC particles remained, and an aluminum-based composite material having two types of dispersed particles (reinforced particles) of TiC particles and SiC particles was obtained.

In this embodiment, the use of SiC powder instead of graphite powder as the C source of TiC particles is advantageous in the following points. SiC powder is inexpensive, at a fraction of the price, compared to graphite powder. Si, which is a by-product of the reaction between SiC and Ti,
It is an element that enhances the fluidity and castability of Al melt, and the solubility of TiC particles (and SiC particles) in the melt when the compact is added to the Al melt as a TiC particle additive. Enhance the nature. As can be seen from the Al-Si system binary phase diagram, the melting point of 660 ° C. of pure Al is lowered to at least 577 ° C. by the addition of Si. can get.

As in Invention Example 2, SiC was intentionally replaced with Ti.
When SiC coexists in the compact after the TiC generation treatment, the amount of S
The advantage that the iC particles have higher dispersibility in the Al melt can be used as follows. The alloy composition of the molten metal to which the compact having generated the TiC particles is added is, for example, Al-
When Sn-Si or the like is used, the TiC particles tend to be discharged from the Al phase and segregated at the grain boundary, which is the final solidified portion, at the time of solidification after addition and dissolution of the molded body. TiC due to segregation
In some cases, the particles cannot sufficiently exhibit the original dispersing effect, and the desired strength characteristics cannot be obtained as a composite material. In particular, when segregation is remarkable, grain boundary embrittlement occurs due to the TiC particles segregated at the grain boundary, and there is a risk that the strength is rather lowered.

For an Al alloy having such a composition, T
When the iC particles and the SiC particles coexist, the dispersion strengthening can be performed by the SiC particles having higher dispersibility than the TiC particles, and at the same time, the Al matrix can be miniaturized and the wear resistance can be improved by the TiC particles. Example 3 According to the first aspect of the second invention, a metal-based composite material was produced by adding a TiC particle-containing compact to a molten Mg or Mg alloy by the following procedure.

Pure Mg and AZ91Mg alloy were each dissolved in an SF ₆ gas atmosphere. Mg or M obtained
The TiC particle-containing compacts prepared in Inventive Example 1 and Inventive Example 3 were added to the molten g alloy, and the mixture was mechanically stirred for 5 minutes, and then cast at 750 ° C. in a JIS No. 4 boat mold. The TiC content in the cast material was changed in the range of 0 to 5 vol% by changing the amount of the formed body in various ways.
The results of examining the hardness, tensile properties, and wear resistance of each cast material are shown in FIGS. Dispersion strengthening by TiC particles was obtained for both pure Mg and AZ91Mg alloy. The tensile strength characteristics and wear resistance characteristics were determined by tests under the following conditions.

<Tensile test conditions> Test specimen shape: parallel part, φ5 × 25 (mm) Peeling speed: 1 mm / min <Wear test conditions> Test specimen shape: 15.7 × 10.1 × 6.3 : Φ35 ring shape Material of mating material: SUJ-2 Rotation speed: 160 rpm Load: 196N Test time: 60 minutes Lubrication: 5W-30 base oil In addition, the crystal grain of the cast material was refined by adding TiC particles. FIG. 8 shows a casting structure of a pure Mg casting material. As compared to the cast material (A) without the addition of TiC particles,
The cast material (B) containing 1 vol% of C particles has a remarkably fine cast structure.

Conventionally, fine structure of cast structure of Mg and Mg alloy
Hexachloroethane (C_TwoCl₆) Etc.
Widely used as material
_FourC _ThreeHeterogeneous nucleation theory is generally taken. Book
According to the invention, at the same time as the improvement of the strength characteristics by dispersion strengthening,
Improvement of strength characteristics and corrosion resistance by refinement of casting structure
Will be possible.

Example 4 According to the second aspect of the first invention, a metal-based composite material in which ZrC particles were formed in pure aluminum was manufactured by the following procedure. [Production of molded article] Pure aluminum powder (-45 μm, 9
9.99%), pure zirconium powder (-147 μm, 9
9.9%) and pure graphite powder (−45 μm, 99%) were weighed and mixed in an amount of 7 g, 16.85 g and 2.22 g, respectively, to produce a columnar molded body of φ30 mm at a molding pressure of 7 t / cm ² .
The porosity of the obtained molded body was about 3%.

At this time, the mixing ratio of Zr powder and C powder is Z
It is desirable to correspond to the stoichiometric ratio (molar ratio) of rC. The mixing ratio of Zr powder or C powder to Al powder is not particularly limited. The mixing ratio of the powder is ZrC
It can be adjusted according to the target ZrC concentration of the particle-containing compact. [Impregnation of molten aluminum] After immersing the above-mentioned molded body in 730 ° C pure aluminum molten metal (purity: 99.99%) for 30 seconds, it is immediately taken out of the molten metal, and the voids of the molded body are impregnated with the pure aluminum molten metal. Was. With this impregnation,
The weight of the compact increased from 26.07 g before impregnation to about 50 g. For comparison, a sample without impregnation was also prepared.

[Production of ZrC Particles] Rapid heating for producing ZrC particles was performed by high-frequency induction heating using the same vacuum melting furnace as in Example 1. However, for comparison, heating with a normal electric furnace was also performed. The resulting particles were subjected to phase identification by X-ray diffraction and particle size measurement by image processing of SEM microstructure photographs. Table 4 shows heating conditions and formed phases.

[0066]

[Table 4]

[Addition to the Molten Metal] According to the second aspect of the second invention, the ZrC particle-containing compact produced according to Inventive Example 1 was kept at 800 ° C. using an Al—Si alloy (AC8A).
(Weight: 500 g) (addition amount: 40 g)
g) After stirring for 5 minutes, at a melt temperature of 750 ° C. and 80 ° C.
JIS No. 4 boat mold was preheated. For comparison,
Casting was performed in the same manner without the above addition. It was confirmed that the addition of the ZrC particles improved the hardness, wear resistance, and tensile strength.

By atomizing the molten alloy to which the ZrC particles are added, a ZrC particle-containing metal-based composite material powder can be produced. Since the ZrC particles do not dissolve in the molten Al alloy, a higher strength metal-based composite material can be obtained by increasing the amount of the ZrC particles added. Example 5 According to the third aspect of the first invention, a metal-based composite material in which HfC particles were formed in pure aluminum was manufactured by the following procedure.

[Preparation of molded article] Pure aluminum powder (-4
5 μm, 99.99%), pure hafnium powder (−45 μm)
m, 98%) and pure graphite powder (−45 μm, 99%) were weighed and mixed in 7 g, 31.73 g, and 2.14 g, respectively.
At a molding pressure of 7 t / cm ² , a cylindrical molded body having a diameter of 30 mm was produced. The porosity of the obtained molded body was about 6%.

At this time, the mixing ratio between the Hf powder and the C powder is H
It is desirable to correspond to the stoichiometric ratio (molar ratio) of fC. The mixing ratio of the Hf powder and the C powder to the Al powder is not particularly limited. The mixing ratio of the powder is HfC
It can be adjusted according to the target HfC concentration of the particle-containing compact. [Impregnation of molten aluminum] After immersing the above-mentioned molded body in 730 ° C pure aluminum molten metal (purity: 99.99%) for 30 seconds, it is immediately taken out of the molten metal, and the voids of the molded body are impregnated with the pure aluminum molten metal. Was. With this impregnation,
The weight of the compact increased from 40.87 g before impregnation to about 65 g.

[Production of HfC Particles] Rapid heating for producing HfC particles was performed by high-frequency induction heating using the same vacuum melting furnace as in Example 1. However, for comparison, heating with a normal electric furnace was also performed. The resulting particles were subjected to phase identification by X-ray diffraction and particle size measurement by SEM microstructure photograph image analysis. Table 5 shows heating conditions and formed phases.

[0072]

[Table 5]

The generation of HfC particles is caused by the following reactions occurring in the temperature range of about 650 ° C. or higher in order from the lower temperature side. Hf + 3Al → HfAl ₃ (1) HfAl ₃ + C → HfC + 3Al (2) When impregnating the powder compact with molten aluminum, Hf powder particles and A
(1) reacts with the molten metal to form fine HfAl ₃ particles around the Hf powder particles. When the next rapid heating is performed in this state, the reaction of (2) is accelerated.

For the production of HfC by the reaction (2), usually 1
It is necessary to heat to a high temperature range of 000 ° C. or higher. According to the present invention, if the mixture is heated to about 650 ° C. at which the reaction (1) occurs by rapid heating at a rate of temperature increase of 20 ° C./min or more, the temperature is automatically increased by the self-heating of the reaction (1), and the reaction (2) ) Occurs to generate HfC. The required heating time was 20 seconds to 2 minutes.

In this embodiment, an inert gas atmosphere is used as the heating atmosphere. However, even if heating is performed in the air, the rapid heating of the present invention only slightly oxidizes the surface of the molded body. No problem. [Addition to the Molten Metal] According to the third embodiment of the second invention, the HfC particle-containing compact produced according to Inventive Example 1 was treated with 800
JIS which was added to a molten metal (weight: 500 g) of an Al-Si alloy (AC8A) maintained at a temperature of 500 ° C. (addition amount: 45 g), stirred for 5 minutes, and then preheated to a temperature of 750 ° C. and a temperature of 80 ° C.
It was cast into a No. 4 boat mold. For comparison, the same casting was performed without the above addition. It was confirmed that the addition of the HfC particles improved the hardness, wear resistance, and tensile strength.

By atomizing the molten alloy to which the HfC particles have been added, a metal-based composite material powder containing HfC particles can be produced. Since the HfC particles do not dissolve in the Al alloy melt, a higher strength metal-based composite material can be obtained by increasing the amount of the HfC particles added. Example 6 According to the fourth aspect of the first invention, a metal-based composite material in which NbC particles were formed in pure aluminum was manufactured by the following procedure.

[Preparation of molded article] Pure aluminum powder (-4
5 μm, 99.99%), pure niobium powder (−150 μm,
99.9%) and 7 g, 19.49 g, and 2.52 g of pure graphite powder (−45 μm, 99%) were weighed and mixed, respectively.
At a molding pressure of 7 t / cm ² , a cylindrical molded body having a diameter of 30 mm was produced. The porosity of the obtained molded body was about 10%.

At this time, it is desirable that the mixing ratio of the Nb powder and the graphite powder correspond to the stoichiometric ratio (molar ratio) of NbC. The mixing ratio of Nb powder or graphite powder to Al powder is not particularly limited. The mixing ratio of the powder is
It can be adjusted according to the target NbC concentration of the bC particle-containing molded body. [Impregnation of molten aluminum] After immersing the above-mentioned molded body in 730 ° C pure aluminum molten metal (purity: 99.99%) for 30 seconds, it is immediately taken out of the molten metal, and the voids of the molded body are impregnated with the pure aluminum molten metal. Was. With this impregnation,
The weight of the compact increased from 29.01 g before impregnation to about 35 g.

[Production of NbC Particles] Rapid heating for producing NbC particles was performed by high-frequency induction heating using the same vacuum melting furnace as in Example 1. However, for comparison, heating with a normal electric furnace was also performed. The resulting particles were subjected to phase identification by X-ray diffraction and particle size measurement by SEM microstructure photograph image analysis. Table 6 shows heating conditions and formed phases.

[0080]

[Table 6]

The generation of NbC particles is based on the following reactions occurring in the temperature range of about 650 ° C. or higher in order from the lower temperature side. Nb + 3Al → NbAl ₃ (1) NbAl ₃ + C → NbC + 3Al (2) When impregnating a powder compact with molten Al, Nb powder particles and A
(1) reacts with the molten metal to produce fine NbAl ₃ particles around the Nb powder particles. When the next rapid heating is performed in this state, the reaction of (2) is accelerated.

For the production of NbC by the reaction (2), usually 1
It is necessary to heat to a high temperature range of 000 ° C. or higher. According to the present invention, if the mixture is heated to about 650 ° C. at which the reaction (1) occurs by rapid heating at a rate of temperature increase of 20 ° C./min or more, the temperature is automatically increased by the self-heating of the reaction (1), and the reaction (2) ) Occurs to generate NbC. The required heating time was 20 seconds to 2 minutes.

In this embodiment, an inert gas atmosphere is used as the heating atmosphere. However, even if heating is performed in the air, the rapid heating of the present invention only slightly oxidizes the surface of the molded body. No problem. [Addition to Molten Metal] According to the fourth aspect of the second aspect of the present invention, the NbC particle-containing molded body produced according to Inventive Example 1 was prepared by
JI which was added to a molten metal (weight: 500 g) of an Al-Si alloy (AC8A) held at 0 ° C. (addition amount: 35 g), stirred for 5 minutes, and then preheated to 80 ° C. at a molten metal temperature of 750 ° C.
It was cast into S4 boat mold. For comparison, the same casting was performed without the above addition. It was confirmed that the addition of NbC particles improved hardness, wear resistance, and tensile strength.

By atomizing the molten alloy to which the NbC particles are added, a metal-based composite material powder containing NbC particles can be produced. Since the NbC particles do not dissolve in the Al alloy melt, a higher strength metal-based composite material can be obtained by increasing the amount of the NbC particles added. Example 7 According to a fifth aspect of the first invention, a metal-based composite material in which TiB ₂ particles were formed in pure aluminum was manufactured by the following procedure.

[Preparation of molded article] Pure aluminum powder (-4
5 μm, 99.99%), pure titanium powder (−150 μm,
99.4%) and AlB ₂ powder (−45 μm, 99%) were mixed at a weight ratio of 5: 8: 8 to produce a columnar molded body of φ30 × 10 mm at a molding pressure of 7 t / cm ² . The porosity of the obtained molded body was about 10%.

At this time, it is desirable that the mixing ratio of the Ti powder and the AlB ₂ powder correspond to the stoichiometric ratio (molar ratio) of TiB ₂ . The mixing ratio of Ti powder or AlB ₂ powder to Al powder is not particularly limited. The mixing ratio of the powder can be adjusted according to the target TiB ₂ concentration of the TiB ₂ particle-containing compact to be finally produced. [Impregnation of molten aluminum] After immersing the above-mentioned molded body in 730 ° C pure aluminum molten metal (purity: 99.99%) for 30 seconds, it is immediately taken out of the molten metal, and the voids of the molded body are impregnated with the pure aluminum molten metal. Was. With this impregnation,
The weight of the compact increased from 24.87 g before impregnation to about 35 g.

[0087] The rapid heating for [TiB generation of ₂ Particles] TiB ₂ particles produced was carried out by high-frequency induction heating using the same vacuum melting furnace as in Example 1. However, for comparison, heating with a normal electric furnace was also performed. For the generated particles, X
Phase identification by X-ray diffraction and particle size measurement by image analysis of SEM microstructure photographs were performed. Table 7 shows heating conditions and formed phases.

[0088]

[Table 7]

The generation of TiB ₂ particles is based on the following reactions occurring in the temperature range of 617 ° C. or higher in order from the lower temperature side. Ti + 3Al → TiAl ₃ (1) TiAl ₃ + AlB ₂ → TiB ₂ + 3Al (2) AlB ₂ + T → Al + TiB ₂ (3) When impregnating a powder compact with molten aluminum, Ti powder particles and A
(1) reacts with the molten metal to form fine TiAl ₃ particles around the Ti powder particles. When the next rapid heating is performed in this state, the reaction of (2) is accelerated.

The production of TiB ₂ by the reactions (2) and (3) usually requires heating to a high temperature range of 1000 ° C. or higher. According to the present invention, by heating rapidly to a temperature of 617 ° C. at which the reaction (1) occurs by rapidly heating at a temperature rising rate of 20 ° C./min or more, the temperature automatically rises due to the self-heating of the reaction (1), and the reaction (2) And (3) occur to produce TiB ₂ . The heating time for formation was 20 seconds to 2 minutes.

In Table 7, Invention Example 1 was made of aluminum.
After impregnating the molten metal, it is heated up to 700 ° C at 20 ° C / min by high frequency heating.
After reaching 700 ° C, the above reaction
Automatic up to 1350 ° C due to self-heating by the chain of (1) to (3)
The temperature rose rapidly, and then dropped sharply. From 700 ° C
The time required to 1350 ° C. was about 20 seconds. After heating
The sample with the average particle size of 0.2 μm (the
Large particle size 3μm) TiB _TwoThe particles were uniformly dispersed.

In Comparative Example 1, heating was performed at a rate of 20 ° C./min to 600 ° C. by high-frequency heating after the impregnation of the molten aluminum. Since the temperature of the reaction (1) was not reached, self-heating did not occur. In the sample after heating, TiB ₂ was not generated, and Al, Ti, AlB _{2 of} the raw material powder and Al ₃ Ti generated during the impregnation were mixed. Comparative Example 2
Was heated in an electric furnace to 1100 ° C. at 10 ° C./min after impregnation with the molten aluminum. After reaching 1100 ° C., the output of the furnace was turned off and the furnace was cooled to room temperature. In the sample after heating, TiB ₂ particles having an average particle size of 0.5 μm (maximum particle size of 3 μm) were uniformly dispersed in the Al matrix, but unreacted AlB ₂ and Ti remained.

Comparative Example 3 was heated in an electric furnace in the same manner as Comparative Example 2 without impregnating the molten aluminum. However,
The heating atmosphere was in the air. The sample after heating had an average particle size of 3 μm (maximum particle size of 10 μm) in a porous Al matrix.
m) TiB ₂ particles were dispersed. Also, oxides such as Al ₂ O ₃ were formed on the sample surface. [Addition to the Molten Metal] According to the fifth aspect of the second invention, a TiB ₂ particle-containing molded product (TiB
₂ concentration: about 33 vol% (45 wt%)
Al-4.5Cu alloy and Al-Si held at 0 ° C
Was added to the molten metal (weight 500 g) of the alloy (AC8A) (TiB ₂ added amount: 0.05 to 5 vol%), after stirring for 5 min, at melt temperature of 750 ° C., it was preheated to 80 ° C. JIS
It was cast into a No. 4 boat mold. For comparison, the same casting was performed without the above addition.

It was confirmed that the macrostructure of the cast material was significantly reduced by the addition of TiB ₂ . This refining effect was equivalent for the addition amount in the above range. Al-4.
The average crystal grain size of the 5Cu alloy was about 3 mm in the non-added material, but it was refined to 30 μm in the TiB ₂ added material, and the shape of the crystal grains was all changed from a dendrite structure to an equiaxed crystal. Was. In the AC8A alloy, the dendrite structure remained, and the crystal grain size could not be quantitatively measured. However, as shown in FIG. 9, it can be seen that the crystal size was significantly reduced by the addition of TiB ₂ .

Table 8 shows the mechanical properties. Invention Examples 2 to 7 and Comparative Examples 4 and 5 are cast materials produced by the above-described casting. Inventive Examples 8 and 9 are powder metallurgy materials produced by hot extrusion from powders obtained by atomizing the melt after the addition of TiB _{2 under the} following conditions. The tensile strength characteristics and the wear resistance characteristics were evaluated by the same test as in Example 3. <Atomizing conditions> Molten metal temperature: 1100 ° C Spray pressure: 9.8 MPa (N ₂ gas) Spray nozzle diameter: φ2 mm <Hot extrusion conditions> 30 g of atomized powder is put into a φ30 mm copper can and pressed at a pressure of 3 ton / cm ^2. After a reform was produced and heated for 1 hour in a nitrogen gas atmosphere to be degassed, indirect extrusion was performed.

Temperature: 400 ° C. Extrusion ratio: 12 Ram speed: 0.2 mm / sec

[0097]

[Table 8]

From the results in Table 8, it was found that in all the cast materials,
It can be seen that the strength and ductility are significantly improved by the addition of TiB ₂ . As described above, according to the present invention, a remarkable effect that strength and ductility can be simultaneously improved by refining the structure and strengthening the dispersion is obtained. It can be seen that high strength and ductility can both be achieved for powder metallurgy. In this example, only the evaluation with the same composition as the cast material was performed. However, since the TiB ₂ particles do not dissolve in the molten Al alloy,
By increasing the amount of TiB ₂ particles added, a metal-based composite material having higher strength can be obtained.

In each of the above embodiments, the case where an Al-based composite material in which TiC, ZrC, HfC, NbC, or TiB ₂ particles are dispersed in an Al or Al alloy matrix is described, but the present invention is not limited to this. The present invention can of course be applied to any matrix composition and compound composition that can automatically and continuously proceed to the final compound particle generation reaction due to the self-heating of the compound generation reaction upon rapid heating without rapid heating. is there.

[0100]

As described above, according to the present invention,
Improve the method of producing the compound particles for dispersion strengthening by impregnating the molten powder into the powder and then heating it to form a compound particle for dispersion strengthening. It is possible to increase the size and manufacture the metal matrix composite with high productivity.

[Brief description of the drawings]

FIG. 1 is a diagram showing a differential heat showing an exothermic peak and an endothermic peak generated in a process in which a compact formed of Ti powder, graphite powder, and Al powder is impregnated with Al in a process of slowly raising the temperature from room temperature. It is an analysis (DTA) chart. The horizontal axis represents temperature, and the vertical axis represents a temperature difference ΔT from a standard sample (a substance having neither exothermic reaction nor endothermic reaction in the measurement temperature range).

FIG. 2 is a graph schematically showing an exothermic peak in a case where a series of reactions seemingly and continuously proceeds by self-heating during rapid heating according to the present invention, in comparison with the DTA curve of FIG. 1; It is. However, the horizontal axis is time.

FIG. 3 is a metallographic photograph showing an example of a microstructure of a compact after impregnation. Many fine TiAl ₃ (gray) of about 1 μm are generated around Ti particles (white) dispersed in an Al matrix (black).

FIG. 4 shows hardness and T of pure Mg and AZ91 alloy.
It is a graph which shows the relationship of the addition amount of iC particle.

FIG. 5 is a graph showing the relationship between the wear depth of pure Mg and AZ91 alloy and the amount of TiC particles added.

FIG. 6 is a graph showing the relationship between the tensile strength of pure Mg and AZ91 alloy and the amount of TiC particles added.

FIG. 7 shows elongation and T of pure Mg and AZ91 alloy.
It is a graph which shows the relationship of the addition amount of iC particle.

FIG. 8 is a metallographic photograph showing the macrostructure of a pure Mg cast material with and without TiC particles added (A) and (B).

FIG. 9 is a metallographic photograph showing a macrostructure of an AC8C alloy cast material with and without TiB ₂ particle addition (A) and (B).

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C22C 49/11 C22C 1/09 T // C22C 32/00 32/00 Q (72) Inventor Hiroyuki Shamoto 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F term (reference) 4K018 AA13 AA14 AB02 AB04 AC04 BA03 BA07 BA08 BA11 BB04 BC12 CA11 FA08 FA35 JA10 JA16 KA01 4K020 AA22 AC01 AC02 BA02 BB27 BC02

Claims (13)

[Claims] 1. A method for producing a metal-based composite material in which compound particles of a first element and a second element are dispersed in a metal matrix made of a metal or an alloy of a metal, the method comprising: Forming a compact comprising a powder, a powder of the second element or the compound of the second element, and a powder of the metal or alloy of the metal; and forming a molten metal of the metal or alloy of the metal in the compact. A step of impregnating, and rapidly heating the whole of the impregnated molded body in an inert atmosphere to cause a compounding reaction between the first element and the metal which is an exothermic reaction in the molded body, A step of automatically raising the temperature of the molded body by the heat generated by the compounding reaction to cause a formation reaction of the compound particles in the molded body, wherein the heating rate of the rapid heating is the first element and the heating rate. From heat generated by chemical reaction with metal to the outside The first element is combined with the first element in a short enough time to allow the entire molded body to automatically rise to the temperature at which the reaction for forming the compound particles occurs by the residual heat after subtracting the heat loss due to heat dissipation due to heat dissipation and possible endothermic reaction. A heating rate at which a compounding reaction with the metal proceeds, and a temperature at which heating by rapid heating reaches a maximum temperature at which a compounding reaction between the first element and the metal can occur to a temperature at which the compounding particle forming reaction can occur. A process for producing a metal-based composite material, comprising the steps of: 2. A molded article containing the compound particles produced by the method according to claim 1 is introduced into a molten metal or metal alloy, and a metal matrix of the molded article is dissolved in the molten metal and the compound is melted. A method for producing a metal-based composite material, comprising: dispersing particles in the molten metal; and then solidifying the molten metal. 3. The method according to claim 1, wherein the compound particles made of TiC are dispersed in the metal matrix made of Al or an alloy of Al. Wherein the element is Ti and the second element is C, and wherein in the step of forming the compact, a compact comprising Ti powder, C powder and Al or Al alloy powder is formed. Production method. 4. The method according to claim 3, wherein a SiC powder is used in place of the C powder in the step of forming the molded body. 5. The method according to claim 1, wherein the compound particles made of ZrC are dispersed in the metal matrix made of Al or an Al alloy. Wherein the element is Zr and the second element is C, and wherein in the step of forming the compact, a compact comprising Zr powder, C powder and Al or Al alloy powder is formed. Production method. 6. The method according to claim 1, wherein said compound particles comprising HfC are dispersed in said metal matrix comprising Al or an Al alloy. The element is Hf, the second element is C, and a step of forming the compact forms a compact comprising Hf powder, C powder, and Al or Al alloy powder. Production method. 7. The method according to claim 1, wherein said compound particles comprising NbC are dispersed in said metal matrix comprising Al or an Al alloy. Wherein the element is Nb and the second element is C, and wherein in the step of forming the compact, a compact comprising Nb powder, C powder and Al or Al alloy powder is formed. Production method. 8. The method of claim 1, wherein TiB _{2 is} contained in said metal matrix comprising Al or an alloy of Al.
A method of producing a metal-based composite material in which the compound particles are dispersed, wherein the first element is Ti and the second element is B;
A method for producing a metal-based composite material, comprising forming a compact comprising powder, AlB ₂ or AlB ₁₂ powder, and Al or Al alloy powder. 9. A metal matrix made of Al or an Al alloy.
Of metal-based composite material in which TiC particles are dispersed
In the manufacturing method, the following steps: Ti powder, C powder and Al
Or a step of forming a compact comprising an Al alloy powder and a step of impregnating the compact with a molten metal of Al or an Al alloy.
And the whole of the impregnated molded body is placed in an inert atmosphere.
Al or A in the compact by rapid heating
TiAl occurring near the melting point of 1 alloy_Three Producing a reaction
The TiAl_Three The compact is automatically turned on by the heat generated by the formation reaction.
And rapidly raise the temperature to cause the TiC particle formation reaction in the compact.
Wherein the heating rate of the rapid heating is
TiAl_Three Dissipation of heat generated by the formation reaction to the outside
Residual heat less heat loss due to possible endothermic reactions
The temperature at which the TiC particle formation reaction takes place
The T for a short enough time to automatically raise the temperature to
iAl_Three The heating rate at which the formation reaction proceeds
The ultimate temperature of heating by heating is _Three Generation reaction occurs
From the lower limit temperature to the upper limit at which the TiC particle formation reaction can occur
A step within a range up to a temperature.
A method for producing a metal matrix composite material. 10. The heating ultimate temperature of the rapid heating is a solid
TiAl by combining Al and solid Ti_Three Production reaction
From the lower limit temperature of 617 ° C _Three And solid C
Upper limit at which the reaction to produce solid TiC particles by the reaction with
The temperature is within a range up to 992 ° C.
The method for producing a metal matrix composite material according to claim 9. 11. The method for producing a metal-based composite material according to claim 3, wherein a heating rate of the rapid heating is 20 ° C./min or more. 12. The method for producing a metal-based composite material according to claim 3, wherein the rapid heating is performed by induction heating. 13. TiC particles, ZrC particles, H produced by the method according to any one of claims 3 to 12.
fC particles, NbC particles, the molded body containing any of the TiB ₂ particles, Al, Al alloy, Mg, or introduced into a molten metal of Mg or Mg alloy, while melting the metal matrix of the molded body in the molten metal A method for producing a metal-based composite material, comprising: dispersing the particles in the molten metal; and then solidifying the molten metal.