JPH07818B2 - Method for producing metal matrix-fiber composite material - Google Patents

Description

The present invention relates to a method for producing a metal matrix-fiber composite material. Metal matrix manufactured according to the present invention
The fiber composite material is used, for example, to adjust the coefficient of thermal expansion between the members, and is mounted and bonded between the ceramics and the semiconductor substrate which is a bonded body of the metal, and during the brazing or cooling / heating cycle, the heat dissipation plate metal and the insulating plate It is possible to prevent the ceramics from peeling off from the metal due to the difference in thermal expansion from the ceramics, or to prevent the ceramics from warping or cracking.

[Conventional technology]

A metal matrix-fiber composite material (hereinafter referred to as “FRM”) in which a metal is used as a matrix and fibers of the metal or ceramics are embedded in the matrix has both properties of the fiber and the matrix, and the orientation of the fiber is unidirectional. , It is used as a structural or functional member of various devices because the characteristics can be adjusted according to the direction by making a mesh shape, a spiral shape, or making it non-directional. One of such FRMs is carbon [C] fiber and copper [Cu] FRM.
Carbon fiber is also called graphite fiber or carbon fiber, but in the following, these are collectively referred to as carbon fiber. This C
The fiber and Cu FRM have an expansion coefficient intermediate between the negative thermal expansion coefficient of carbon and the positive expansion coefficient of Cu, and can adjust the thermal expansion coefficient between members.

There are an impregnation method and a hot press method in these FRM manufacturing methods. The impregnation method uses a metal for forming a matrix as a molten metal,
This is impregnated into fibers to form a composite. The hot press method is a method in which fibers are coated with a target matrix-forming metal in advance, and this is pressed at a high temperature to form a composite. The coating of the matrix in this hot press method is by electroplating, chemical vapor deposition, ion plating, thermal spraying, or the like. In addition, there are various manufacturing methods, and the manufacturing method is appropriately selected depending on the type of the target metal matrix fiber. For example, a Cu-C fiber composite material in which C fibers are embedded in a Cu matrix is manufactured by a hot press method, and the impregnation method is not applied. This is C
And Cu are not wet at all and impregnation is essentially impossible.
On the other hand, Cu-W fiber composite material in which W fiber is embedded in Cu can be composited by the hot pressing method, but Cu and W are excellent in wettability and do not form a compound, so generally impregnated. Method is used.

As described above, an arbitrary manufacturing method suitable for the composite system is selected, and particularly in the composite system in which the fiber and the matrix do not have wettability or a compound is formed between the fiber and the matrix, the matrix is treated as a solid phase. Used in the hot press method. This hot press method has preferable points such that the fiber and the matrix can be reliably combined.

The difference in the FRM manufacturing method is also reflected in the difference in heat resistance.
For example, a Cu-C fiber composite material having no wettability between Cu and C fibers has a sufficient heat resistance such that the Cu matrix is softened when heated and the C fiber and Cu matrix are separated to cause a swelling phenomenon in the composite material itself. Not. Therefore, in order to improve the heat resistance of the Cu-C fiber composite material, Cu matrix is added with Ti, Z
There are Cu-C fiber composites with added r, Cr, Nb, etc.
The heat resistance of the Cu-C fiber FRM is improved by adding Ti or the like to Cu because the intermetallic compound is formed between C and Ti, and the solid solution is formed between Cu and Ti. Formed Cu
This is because the C interface is strengthened.

As a conventional example of producing such an FRM with an enhanced interface, as described in Japanese Patent Publication No. 52-53720, powders of additive elements (such as Ti) are added, and methylcellulose is added to the powder to prepare a slurry. A method is known in which a medium is made between fibers and hot pressed. This conventional example has an advantage that any element can be added since the reaction can be controlled by the temperature and the time regardless of the wettability to the C fiber.

[Problems to be solved by the invention]

However, in the above-mentioned conventional example, a high level technique is required to uniformly disperse the additional element due to factors such as the particle size of the powder, the fluidity of the methylcellulose and the additional element powder, since the powder is used. Especially, it is difficult to homogenize trace elements,
If the powder particle size is large, there is a risk that a homogeneous matrix will not be obtained. The presence of the non-uniform distribution of the additive element may cause the FRM to have a portion having poor heat resistance, and as a result, a swelling phenomenon due to an increase in heat may occur.

In addition, as in the above-mentioned conventional example, the additive element is changed to Cu by the slurry.
If it is attempted to disperse it uniformly in the matrix, a large amount of additional element is required. As a result, the thermal conductivity and conductivity of the FRM are significantly reduced.

Therefore, hot pressing can be considered by coating an alloy of Cu with an additive element such as Ti on the fiber, but in the case of an alloy, the components that can be coated are limited, and the content of the additive element can be controlled. It has manufacturing difficulties.

In order to solve such problems, it is an object of the present invention to provide an FRM having excellent heat resistance by strengthening the interface between the fiber and the metal matrix without lowering the electrical conductivity and thermal conductivity.

[Means for solving problems]

The present invention is a fiber bundle obtained by bundling a number of fibers coated with a matrix-forming metal, is a solid solution in the matrix-forming metal, and winds a thin metal wire containing an additive element that reacts with the fiber, This is a method for producing a metal matrix-fiber composite material, which comprises forming a composite of a metal for forming a matrix and a fiber by applying high temperature and high pressure.

[Action]

In the above-mentioned constitution of the present invention, the additional element is capable of forming a solid solution in the matrix-forming metal and reacting with the fiber to form an intermetallic compound. Therefore, the interface between the matrix-forming metal and the fiber is strengthened, and the heat resistance is improved. The amount of the additive element that forms a solid solution in the matrix metal is small because the additive element is obtained from the thin metal wire, and the additive element is homogeneously diffused in the matrix metal. Therefore, it is possible to prevent deterioration of thermal conductivity and conductivity.

〔Example〕

Next, an example of a method for producing a metal matrix-fiber composite material according to the present invention will be described.

First, as shown in FIG. 1, the fiber 1 is coated beforehand with a metal for matrix by electric plating or the like to form a coating layer 2. On the other hand, in consideration of the amount of the matrix-constituting metal coated on the fiber, a thin metal wire containing an additional element which is solid-soluble in the matrix-constituting metal and which reacts with the fiber is manufactured separately. The thin metal wire is an alloy of an additive element and a metal for forming a matrix or a thin metal wire containing only the additive element as necessary. The thin metal wire is thinned by hot or cold.

As shown in FIG. 2, the thin metal wire 3 is wound around the fiber bundle coated with the matrix-forming metal. The number of fiber bundles around which the metal thin wire 3 is wound is selected in consideration of the element content of the thin wire and the mechanical properties of the thin wire, and is typically 500 to 6000 in the case of a Cu-C fiber composite. The thin wire of alloy is
About 0.1 mm is preferable for easy wire drawing, and the winding density is preferably 15 to 20 turns / m from the viewpoint of workability.

The fiber bundle around which the fine metal wires are wound is woven in a predetermined fiber orientation. For example, it may be formed in a net shape, or may be formed in a stacked shape in which layers are alternately laminated. These are placed under high temperature and high pressure (hot press). The additive element contained in the thin metal wire diffuses into the main component metal coated on the fiber at a high temperature during hot pressing, and forms a solid solution with the main component metal. It also reacts with the fibers to form intermetallic compounds between the added metal and the fibers. As a result, the interface between the fiber and the metal matrix is strengthened, and a composite body as shown in FIG. 3 is formed. In FIG. 3, 3 indicates a metal thin wire and 4 indicates a fiber. The fibers around which the fine metal wires are wound are woven in a net shape. In the composite as shown in FIG. 3, the amount of the additional element dissolved from the thin metal wire is very small,
In addition, since it uniformly and sufficiently diffuses into the matrix-forming metal, it is possible to prevent deterioration of thermal conductivity and conductivity of the composite.

The amount of the additive element in the metal thin wire is determined as follows. That is, since the additive element in the thin metal wire is a solid solution that is a solid solution with the matrix-forming metal, that is, the main component metal, the amount of the additional element should be such that the maximum solid solution limit for the main component metal is the upper limit. preferable. This is because when the amount of the additive element exceeding the maximum solid solution limit is solid-solved in the main component metal, the crystallized phase is precipitated in the matrix and the matrix is essentially inhomogeneous. If the amount of the additional element is within the maximum solid solubility limit, the additional element easily diffuses into the component metal coated on the fiber depending on the temperature and time during hot pressing to form a composite of the fiber and the metal matrix. However, when the partially precipitated phase in the matrix, which occurs when the additive element is contained in the metal wire beyond the maximum solid solubility limit, does not significantly deteriorate the properties of the composite even if it intervenes in the composite. Does not pose a special problem even if the content of additive element exceeds the maximum solid solubility limit. Alternatively, other properties may be exhibited by the interposition of a partial crystallization phase. The dispersion of the crystallized phase that is substantially generated is
It can be adjusted by the fiber bundle and the diameter of the thin wire.

The number of fiber bundles around which the thin metal wires are wound is preferably as small as possible in order to prevent partial precipitation of the crystallized phase or in order to make the additive element uniform in the matrix. In addition, the smaller the diameter of the metal fine wire, the easier the winding around the fiber bundle and the more uniform dispersion of the additive element of the metal fine wire in the matrix are preferable.

Next, specific examples will be described.

(Example 1) In order to improve the heat resistance of a reticulated Cu-C fiber composite material, a reticulated Cu-Cr-C fiber composite material in which Cr is an additive element was produced.

As shown in FIG. 1, a C fiber 1 having a diameter of 7 μ and a thickness of 1.7
The Cu2 of μ was coated by electric plating.

On the other hand, Cu-0.7wt% Cr alloy is melted by high frequency heating,
An ingot having a diameter of 30 mm was produced. This was subjected to hot and cold rolling to obtain a thin metal wire having a diameter of 0.1 mm.

As shown in FIG. 2, the above-mentioned C-fibers and alloy fine wires coated with Cu are treated with one alloy fine wire 3 per 1 Cu fiber bundle consisting of 3000 fibers 15 times per 1 m C-fiber bundle. Wrapped around at a frequency. Then weave density (1
A value of 10 pieces per inch) was hand woven and woven to form a woven cloth. Two pieces of this woven fabric were stacked and charged into a graphite mold, and hot pressed at a temperature of 1000 ° C. and a pressure of 250 kgf / cm ² for 1 hour. As a result, as shown in FIG. 3, Cu
The matrix contains approximately 0.16% by weight of Cr and has a C fiber content of 35.
A volume% reticulated Cu-Cr-C composite could be prepared.

(Example 2) A heat resistance test was performed by comparing the FRM produced in Example 1 above with a Cu-C fiber FRM containing no Cr. The results are shown in FIG. Heat resistance test is FR containing about 0.16 wt% Cr
This was done by heating FRM containing no M and Cr to 800 ° C and observing the swelling state of the FRM surface. Example 1 above
In FRM (1) containing Cr, the surface swelling did not occur even when heated to 800 ° C. On the other hand, it is 6 in the conventional FRM that does not contain Cr.
Swelling of the surface of the material to be mixed was observed at 00 ° C.

In addition, the FRM containing Cr of Example 1 has a conductivity of 48% and RT-
The average coefficient of thermal expansion at 200 ° C was 8.8 × 10 ^-6 / ° C, showing high conductivity and low thermal expansion characteristics.

Further, according to the result of examination by EPMA, it was revealed that Cr was uniformly diffused in the Cu plating and that it was a solid solution Cu matrix in which Cr was solid-dissolved in Cu. A peak of Cr concentration was observed at the interface between the Cu matrix and the C fiber, suggesting the formation of a reaction layer of Cr and C fiber on the surface of the C fiber. Therefore,
According to the above-mentioned Example 1, by interposing the alloy fine wire containing Cr in the C fiber bundle, Cr can be uniformly diffused in Cu, and
The interface between the metal and the fiber is strengthened due to the formation of an intermetallic compound between the metal and the fiber, and the heat resistance is improved.
At this time, since the amount of Cr, which is an additional element, is very small, there is no fear that the conductivity and thermal conductivity given to the FRM will decrease.

(Example 3) Next, the Cu-Cr-C fiber FRM produced in Example 1 and the FR obtained by the conventional methylcellulose + Cr powder slurry method
The differences in electrical conductivity and thermal conductivity between M and M were investigated.

Methylcellulose + Cr powder Cr powder in the slurry method is 200
I used the one from Messyu. Thus, the Cr content in the FRM formed by the methylcellulose + Cr powder slurry method is 25% by weight with respect to the Cu matrix. On the other hand, the Cr content in the Cu-Cr-C fiber FRM produced in Example 1 is 0.16% by weight. The difference in conductivity between the two is shown in Table 1 below.

As can be seen from Table 1 above, the conductivity of the FRM produced according to Example 1 is 48% when compared with the conventional methylcellulose + Cr.
It can be seen that the conductivity of FRM manufactured by the powder slurry method is 27%, which is quite good. this is,
If Cr is made to diffuse in Cu by an alloy thin wire, Cr
Is a small amount and diffuses sufficiently in the Cu matrix. The thermal conductivity is Cr in the matrix.
It is related to the amount of (additional element), and the thermal conductivity also deteriorates as the amount of Cr (the amount of additional element) increases like the conductivity. In this example, the heat resistance standard for both FRMs was set to 800 ° C, and Cu
The ratio of the amount of C fiber with respect to C was 35% by volume.

(Example 4) Similar to the above-mentioned Example 1, a Cu wire and a fine wire of Cu-Cr alloy were prepared, and a reticulated Cu-Cr-containing C fiber amount of 45% by volume was used.
A C fiber composite material was produced and its heat resistance was examined. As a result, the heat resistance was 800 ° C, that is, no swelling of the surface was observed even when heated to 800 ° C, and the conductivity was 36%.
The coefficient of thermal expansion was 6.2 × 10 ^-6 / ° C, and a structure in which Cr was dissolved in Cu matrix was observed. According to this example, even when the C fiber content is large relative to the Cu matrix, the heat resistance can be improved without lowering the electrical conductivity and the thermal conductivity as in Example 1.

〔The invention's effect〕

As described above, according to the method for producing a metal matrix-fiber composite material of the present invention, a small amount of additional element that is solid-dissolved in the matrix-forming metal and that reacts with the fiber is uniformly dissolved in the matrix-forming metal. can do. Therefore, the interface between the matrix-forming metal and the fiber is reinforced, and the heat resistance can be improved without lowering the electrical conductivity and thermal conductivity.

In addition, the additive element is wound as a thin metal wire around a fiber bundle formed by bundling a large number of fibers coated with a matrix-forming metal, and the winding pitch is changed to easily finely adjust the added amount to add the additive element. It can be dissolved in matrix.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a fiber coated with a metal for forming a matrix, and FIG. 2 is a side view showing a state in which a thin metal wire containing an additive element is wrapped around a fiber coated with a metal for forming a matrix. FIG. 3 is a block diagram of the composite material showing a state in which fibers are woven in a net shape, and FIG. 4 is a graph showing the relationship between the heating temperature and the plate pressure increase rate of the composite material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshimi Sasaki 2-832, Horiguchi, Katsuta City, Ibaraki Prefecture Hitachi Ltd. Katsuta Factory (56) References JP-A-60-169534 (JP, A) JP-A-58 -93834 (JP, A) JP-A-49-53119 (JP, A)

Claims (1)

[Claims] 1. A thin metal wire comprising an additive element which is solid-solved in the matrix-forming metal and which reacts with the fiber is wound around a fiber bundle in which a large number of fibers coated with the matrix-forming metal are bundled. A method for producing a metal matrix-fiber composite material, which comprises forming a composite of a metal for forming a matrix and a fiber by subjecting this to high temperature and high pressure.