JP2508145B2 - Fiber Reinforced Metals for Manufacturing Composite Materials - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fiber-reinforced metal composite material, and more particularly to a reinforcing fiber for producing a fiber-reinforced metal composite material having excellent wear resistance.

As a means for improving the wear resistance of a metal material, for example, Japanese Patent Application Laid-Open No. 58-93837, Japanese Patent Application Laid-Open No. 61-6242, which is filed by the same applicant as the present applicant, is disclosed. 61-108
No. 493, JP-A-61-99655, JP-A-62-192557, alumina short fibers, silicon carbide whiskers, silicon nitride whiskers, alumina-silica short fibers, mineral fibers, It has been conventionally known that it is effective to composite-reinforce a metal with a reinforcing fiber such as potassium titanate whisker to obtain a fiber-reinforced metal composite material.

Further, these reinforcing fibers are not used as they are, but are disclosed in, for example, JP-A-49-102519 and JP-A-50-10.
9903, JP-A-53-38791, JP-A-56-16636, JP-A-56-16638, JP-A-57-169038, JP-A-57-16903.
As described in JP-A No. 9 and JP-A-57-169040, it has been attempted to increase the abrasion resistance improving effect by coating the reinforcing fiber with various metals or hard materials. Is being considered more.

Problems to be Solved by the Invention When the reinforcing fibers are alumina short fibers, silicon carbide whiskers, silicon nitride whiskers, etc., a composite material having excellent wear resistance can be obtained, but these reinforcing fibers are very Since it is very expensive, the resulting composite material is also very expensive. Amorphous alumina-silica fibers, mineral fibers, potassium titanate whiskers, and glass fibers are much cheaper than the above high-performance fibers,
Since the effect of improving the wear resistance of these reinforcing fibers is not always sufficient, there is a problem that the wear resistance of the obtained composite material is low as compared with the case where high-performance reinforcing fibers are used.

Further, in the method of coating the reinforcing fiber with a metal or a hard material, it is possible to improve the wear resistance but not to reduce the cost, or to improve the wear resistance sufficiently. Often unable to

In view of the above-mentioned problems in conventional reinforcing fibers for producing a fiber-reinforced metal composite material, the present invention provides a reinforcing fiber which has the same performance as an expensive high-performance reinforcing fiber and is inexpensive. Is intended.

According to the present invention, a precursor fiber selected from the group consisting of alumina-silica fiber, mineral fiber, glass fiber, potassium titanate whiskers, and mixtures thereof is provided. By a reinforcing fiber for fiber-reinforced metal composite material production, which is covered with an oxide layer, and a composite oxide is formed by the precursor fiber and the oxide layer at the interface between the precursor fiber and the oxide layer. To be achieved.

According to the present invention, alumina-silica fiber, mineral fiber,
Glass fibers, precursor fibers of potassium titanate whiskers are covered with an oxide layer, and a composite oxide is formed by the precursor fibers and the oxide layer at the interface between the precursor fibers and the oxide layer. The layer is maintained in strong contact with the precursor fiber by the composite oxide. Therefore, for example, compared with the case where the precursor fiber is directly coated with the oxide layer without interposing the composite oxide, the wear resistance of the composite material is favorably improved by the hard oxide layer, and Since the reaction with the precursor fiber is surely avoided and the wettability of the reinforcing fiber to the molten metal of the matrix metal is improved satisfactorily, it will be described in detail in relation to the result of the experimental research conducted later by the inventors of the present application. As will be described, although the precursor fiber itself is not so high-performance fiber, it is possible to obtain a reinforcing fiber having an abrasion resistance improving effect equal to or higher than that of a high-performance reinforcing fiber such as alumina fiber.

Further, according to the present invention, a fiber which is much cheaper than alumina fiber or the like is used as the precursor fiber, and the precursor fiber coated with an oxide can be easily and easily heat-treated in the atmosphere, for example. Since it is possible to form complex oxides at low cost, it has performance equivalent to or better than that of alumina fibers, etc.
It is possible to obtain a very inexpensive reinforcing fiber of about 1/10 to 1/100.

The oxide constituting the oxide layer in the reinforcing fiber of the present invention is one that forms a complex oxide at the interface with the precursor fiber, preferably any oxide that is harder than the precursor fiber It may be an oxide, but is preferably aluminum oxide, chromium oxide, zirconium oxide, or a mixture thereof.

The thicknesses of the oxide layer and the composite oxide layer in the reinforcing fiber of the present invention are preferably 0.01 to 15 μm and 100 to 15000Å, respectively.

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

Example 1 First, an alumina-silica fiber (Isolite Babcock Refractory Co., Ltd. "Kauwool", average fiber diameter 2.8 μm, average fiber length 3 mm) was prepared as a precursor fiber, and 11.1 g of A was used.
l ₂ (SO ₄ ) ₃ · 18H ₂ O (manufactured by Nippon Kagaku Co., Ltd.) was dissolved in 100 g of water to form an aluminum sulfate aqueous solution. Then, as shown in FIG. 1, 16.6 g of alumina-silica fiber 12 was mixed with this aqueous solution 10 and stirred, and the solution in which the fibers were dispersed was put into the atmosphere by a heater (not shown). By heating at 500 ° C. for 1 hour, water was removed and aluminum oxide (Al ₂ O ₃ ) was formed around the alumina-silica fiber with a fine crystal structure.

Then, the alumina-silica fiber thus coated with aluminum oxide is heat-treated in the atmosphere at 1100 ° C. for 1 hour, so that mullite (3Al ₂ O ₃ ·. 2SiO ₂ ) was formed. FIG. 2 is a schematic view showing a cross section of the reinforcing fiber 14 thus formed, and in the figure, 16 and 18 respectively show a layer of aluminum oxide and a layer of mullite as a complex oxide, and their thicknesses. It was about 0.3 μm and about 500Å.

Then, as shown in FIG.
A fiber molding 20 having dimensions of × 80 × 20 mm was formed. The volume ratio of the reinforcing fibers is 5%, and the individual reinforcing fibers are 80 ×.
Randomly oriented in a plane parallel to the 80 mm plane, they were oriented in a stacked state in a direction perpendicular to this plane.

Then, after preheating the fiber molded body 20 to 500 ° C., the fiber molded body is placed in the mold cavity 24 of the mold 22 as shown in FIG.
1200 kg of aluminum alloy (JIS standard AC8A) molten metal 26 is poured by a plunger 28 that fits the molten metal into a mold
It was pressurized to a pressure of / cm ² and the pressurized state was maintained until the molten metal was completely solidified. Heat treatment T ₇ is applied to the solidified body 30 thus obtained, the composite material 14 ′ is cut out from the solidified body, and a plane perpendicular to the 80 × 80 mm plane of the original fiber molded body from the composite material is used as a test surface. A block test piece A ₁ for wear test was prepared by machining.

For the purpose of comparison, the reinforcing fibers 14 each have an alumina-silica fiber that does not have a coating layer of aluminum oxide, an alumina-silica fiber that is coated with aluminum oxide but has no mullite, and an alumina fiber (made by ICI). "Safir RG", average fiber diameter 3μm, average fiber length 1m
m), silicon carbide whiskers (manufactured by Tokai Carbon Co., Ltd.,
Block test pieces A _{2 to} A ₅ were prepared under the same procedures and conditions as the case of the block test piece A ₁ except that the fiber diameter was replaced with 0.1 to 1.0 μm and the fiber length was 50 to 200 μm.

Next, set each block test piece in the friction and wear tester one after another, and make contact with the outer surface of the cylindrical test piece of nitrided stainless steel (JIS standard SUS420J2, Hv = 800) that is the mating member, and the contact portion of those test pieces While supplying room temperature lubricating oil (Castle motor oil 5W-30), contact surface pressure 20kg / m
A wear test was carried out by rotating the cylindrical test piece for 1 hour at m ² and a sliding speed of 0.3 mm / sec.

The results of these abrasion tests are shown in FIG. From FIG. 6, the wear amount of the block test piece A ₁ is much smaller than that of the block test pieces A ₂ and A ₃ of the comparative example, and the wear of the cylindrical test piece when the block test piece is A _1. It can be seen that the amount is considerably smaller than when the block test pieces are A ₄ and A ₅ of the comparative examples.

Thus, the composite material in which the reinforcing fiber is the reinforcing fiber of the example has better wear resistance than the precursor fiber and the precursor fiber coated only with the oxide layer, and when expensive expensive high performance reinforcing fiber is used. It has the same wear resistance as the above, and the amount of wear of the mating material is smaller than that when a high performance reinforcing material is used, and therefore it is superior in friction and wear characteristics to any of the comparative examples. I understand.

Example 2 First, potassium titanate whiskers (Otsuka Chemical Co., Ltd., average fiber diameter 0.2 μm, average fiber length 30 μ) were used as precursor fibers.
m) was prepared, and 33.8 g of Al I ₃ (manufactured by Yanagijima Pharmaceutical Co., Ltd.) was dissolved in 100 g of water to form an aluminum iodide aqueous solution. Next, 84.5 g of potassium titanate whiskers are mixed with this aqueous solution and stirred, and thus the solution in which the whiskers are dispersed is heated to 500 ° C. for 1 hour in the atmosphere to remove water and to surround the potassium titanate whiskers. Aluminum oxide was formed with a fine crystal structure.

Then, the potassium titanate whiskers thus coated with aluminum oxide are heat-treated in the air at 100 ° C. for 3 hours, whereby aluminum titanate (Al ₂ O 3) is formed at the interface between the potassium titanate whiskers and aluminum oxide. ₃ · TiO ₂ ) was formed. The thickness of aluminum oxide and aluminum titanate is about 0.1 μm,
It was about 200Å.

Then, in the same manner as in Example 1, 80 × 80 × 20 mm
To form a fiber molding having the following dimensions and in which the individual reinforcing fibers were oriented in a substantially three-dimensional random manner. The volume ratio of the reinforcing fibers was 20%.

Then, the matrix metal was replaced with an aluminum alloy (JIS standard AC7A), the temperature of the molten metal was set to 700 ° C., and the heat treatment was replaced with T ₄ , and the same procedures and conditions as in the case of the above-described Example 1 were used. Manufactures composite materials at
A block test piece B ₁ was prepared from the composite material.

Further, for the purpose of comparison, a comparison of Example 1 with potassium titanate whiskers in which the reinforcing fibers do not have a coating layer of aluminum oxide, potassium titanate whiskers coated with aluminum oxide but not formed with aluminum titanate, respectively. Block test piece B _{2 under the} same procedure and conditions as for block test piece B ₁ except that the same alumina fiber and silicon carbide whisker as those used in the example were replaced with alumina fiber and silicon carbide whisker. Created ~ B ₅ .

Next, the other material is spheroidal graphite cast iron (JIS standard FCD70, Hv = 25
Example 1 except that it was replaced with a cylindrical test piece manufactured by
A wear test was conducted under the same procedure and conditions as in the above.

The results of these abrasion tests are shown in FIG. From FIG. 7, the wear amount of the block test piece B ₁ is much smaller than the wear amount of the block test pieces B ₂ and B ₃ of the comparative example, and the wear of the cylindrical test piece when the block test piece is B _1. It can be seen that the amount is considerably smaller than when the block test pieces are B ₄ and B ₅ of the comparative examples.

Thus, even when the precursor fiber is potassium titanate whiskers and the counterpart material is spheroidal graphite cast iron, the composite material in which the reinforcing fiber is the reinforcing fiber of the example is a precursor fiber coated with only the precursor fiber and the oxide layer. The wear resistance of the mating material is higher than that of the high-performance reinforcing fiber, which is the same as when the expensive high-performance reinforcing fiber is used. Therefore, it is understood that the friction and wear characteristics are superior to any of the comparative examples.

Example 3 First, as precursor fiber, mineral fiber (“Microfiber” manufactured by Nitto Boseki Co., Ltd., 40 wt% SiO ₂ , 38 wt% CaO, 15 wt)
% Al ₂ O ₃ , 6 wt% MgO, average fiber diameter 4.9 μm, average fiber length 1 m
m) was prepared and stirred in a chromium oxide (Cr ₂ O ₃ ) binder (Nissan Chemical Co., Ltd.) to coat the mineral fibers with chromium oxide. Then, the mineral fibers thus coated with chromium oxide are heat-treated in the air at 800 ° C. for 6 hours, whereby calcium chromate (CaO · Cr ₂ O ₃ ) is added between the mineral fibers and the layer of chromium oxide. Was formed. The thicknesses of aluminum oxide and calcium chromate were about 2.5 μm and about 800 Å, respectively.

Then, in the same manner and conditions as in Example 1, 80 ×
A fiber molding having dimensions of 80 × 20 mm and in which the individual reinforcing fibers were oriented in a substantially two-dimensional random manner was formed. The volume ratio of the reinforcing fibers was 5%.

Then, the matrix metal was replaced with an aluminum alloy (JIS standard AC1A), the temperature of the molten metal was set to 720 ° C., and the heat treatment was replaced with T ₆ , and the same procedures and conditions as in the case of Example 1 described above were used. Manufactures composite materials at
A block test piece C ₁ was prepared from the composite material.

Further, for the purpose of comparison, in the comparative example of Example 1, mineral fibers in which the reinforcing fibers each do not have a coating layer of chromium oxide, mineral fibers coated with chromium oxide but calcium chromate is not formed, Block test piece except that the same alumina fibers and silicon carbide whiskers as those used were replaced with alumina fibers and silicon carbide whiskers.
Block test piece C ₂ ~ under the same procedure and conditions as for C ₁
Created C ₅ .

Next is mating material chrome steel (JIS standard SCr20, Hv = 720)
A wear test was conducted under the same conditions and conditions as in Example 1 except that the cylindrical test piece was replaced with a cylindrical test piece.

The results of these abrasion tests are shown in FIG. From FIG. 8, the wear amount of the block test piece C ₁ is much smaller than the wear amount of the block test pieces C ₂ and C ₃ of the comparative example, and the wear of the cylindrical test piece when the block test piece is C _1. It can be seen that the amount is considerably smaller than when the block test pieces are C ₄ and C ₅ of the comparative examples.

Thus, even when the precursor fiber is a mineral fiber and the counterpart material is chrome steel, the composite material in which the reinforcing fiber is the reinforcing fiber of the example has a higher resistance than the precursor fiber and the precursor fiber coated only with the oxide layer. It has excellent wear resistance and has the same wear resistance as when expensive high-performance reinforcing fiber is used, and the wear amount of the mating material is higher than that when high-performance reinforcing material is used. Therefore, it is understood that the friction and wear characteristics are superior to those of the comparative examples.

Example 4 First, glass fibers chopped as precursor fibers (manufactured by Asahi Glass Fiber Co., Ltd., 52 to 56 wt% SiO ₂ , 16
_{~25wt% CaO, 12~16wt% Al 2} O 3, 8~13wt% B 2 O 3, an average fiber diameter of 10 [mu] m, to prepare an average fiber length of 3 mm), also 9.3g of Z
rCl ₄ (manufactured by Shin Nippon Metal Co., Ltd.) was dissolved in 100 g of water to form a zirconium chloride aqueous solution. Then in this aqueous solution
49 g of glass fibers are mixed and stirred, and the solution in which the fibers are dispersed is heat-treated at 500 ° C. for 1 hour in the air, and zirconium oxide (ZrO ₂ ) is formed in fine crystal fibers around the glass fibers. And zirconium silicate (ZrO ₂ · SiO ₂ ) was formed at the interface between the glass fiber and zirconium oxide. The thicknesses of zirconium oxide and zirconium silicate are about 5 μm and about 200, respectively.
Was Å.

Then, in the same manner and conditions as in Example 1, 80 ×
A fiber molding having dimensions of 80 × 20 mm and in which the individual reinforcing fibers were oriented in a substantially two-dimensional random manner was formed. The volume ratio of the reinforcing fibers was 15%.

Then, the matrix metal was replaced with an aluminum alloy (JIS standard MDC1-A), the temperature of the molten metal was set at 690 ° C., and the heat treatment was not performed. Manufactures composite materials at
A block test piece D ₁ was prepared from the composite material.

Further, for the purpose of comparison, a glass fiber in which each reinforcing fiber does not have a coating layer of zirconium oxide, a glass fiber coated with zirconium oxide but not formed with zirconium silicate, in Comparative Example 1 Except that the alumina fiber and silicon carbide whiskers used were the same as the alumina fibers and silicon carbide whiskers used,
The block test pieces D _{2 to} D ₅ were prepared under the same procedure and conditions as the case of the block test piece D ₁ , and the block test piece D ₀ made of only the magnesium alloy as the matrix metal was prepared.

Next is mating material chrome steel (JIS standard SCr20, Hv = 7200)
A wear test was conducted under the same conditions and conditions as in Example 1 except that the cylindrical test piece was replaced with a cylindrical test piece.

The results of these abrasion tests are shown in Table 1. In Table 1, the wear amount ratio (%) of the block test pieces means the wear amount of the block test pieces D _{1 to} D ₅ (wear depth μm with respect to the wear amount of the block test piece D _{0 made} of only matrix metal). ) Is meant (the same applies to Tables 2 to 5 below).

From Table 1, the amount of wear of the block test piece D ₁ is much smaller than the amount of wear of the block test pieces D ₂ and D ₃ of the comparative example, and the amount of wear of the cylindrical test piece when the block test piece is D _1. It can be seen that is a much smaller value than when the block test pieces are D ₄ and D ₅ of the comparative examples.

Thus, even when the precursor fiber is a glass fiber, the matrix metal is a magnesium alloy, and the counterpart material is chrome steel, the composite material in which the reinforcing fiber is the reinforcing fiber of the example has only the precursor fiber and the oxide layer. It has better wear resistance than the coated precursor fiber, and has the same wear resistance as when expensive expensive high-performance reinforcing fibers are used. It can be seen that the frictional wear characteristics are superior to those of any of the comparative examples, as compared with the case of being used.

Example 5 The volume ratio of the reinforcing fibers formed in Example 1 above is
40%, the matrix metal was replaced with a zinc alloy (JIS standard ZDC1), and the temperature of the molten metal was set to 500 ° C., except that the composite material was prepared in the same procedure and conditions as in Example 1. Manufactured and manufactured from its composite material Block specimen E ₁
Was formed.

Further, for the purpose of comparison, except that the reinforcing fibers are each replaced with an alumina-silica fiber having no coating layer of aluminum oxide, an alumina-silica fiber coated with aluminum oxide but not having mullite formed,
The block test pieces E ₂ and E ₃ were prepared under the same procedure and conditions as the case of the block test piece E ₁ , and the block test piece E ₀ made of only the zinc alloy as the matrix metal was prepared.

Then, an abrasion test was performed on these block test pieces under the same procedure and conditions as in the case of the above-mentioned Example 3. The results of these abrasion tests are shown in Table 2.

From Table 2, the amount of wear of the block test piece E ₁ is much smaller than the amount of wear of the block test pieces E ₂ and E ₃ of the comparative example, and the amount of wear of the cylindrical test piece is also E _{2 of the} block test piece of the comparative example. as well as
It can be seen that the value is as small as when E ₃ .

Thus, even when the matrix metal is a zinc alloy, the composite material in which the reinforcing fiber is the reinforcing fiber of the example is superior in wear resistance to the precursor fiber and the precursor fiber coated only with the oxide layer, and is expensive. Has the same wear resistance as when high performance reinforcing fiber is used, and the amount of wear of the mating material is smaller than when high performance reinforcing material is used. It is understood that the friction and wear characteristics are superior to those of the above.

Example 6 The reinforcing fibers formed in Example 2 above and the copper alloy (Cu-10 wt% Sn) powder were weighed and mixed so that the volume ratio of the reinforcing fibers was 3%, and the mixture was mixed. A small amount of ethanol was added and mixed with a stirrer for about 30 minutes. The mixture thus obtained is dried at 80 ° C. for 5 hours, then a predetermined amount of the mixture is filled in a mold, and the mixture is punched to 400 k.
A plate was formed by compressing at a pressure of g / cm ² .
Then, the plate-shaped body was sintered by heating it at 770 ° C for 30 minutes in a batch-type sintering furnace set in a decomposed ammonia gas (dew point -30 ° C) atmosphere, and gradually cooled in a cooling zone in the sintering furnace. A composite material was manufactured by cooling, and a block test piece F ₁ was prepared from the composite material.

For the purpose of comparison, the reinforcing fibers were replaced with potassium titanate whiskers not having a coating layer of aluminum oxide and potassium titanate whiskers coated with aluminum oxide but not having aluminum titanate formed. Except for the above, the block test pieces F ₂ and F ₃ were prepared under the same procedure and conditions as the case of the block test piece F ₁ , and the block test piece F ₀ made only of the copper alloy as the matrix metal was prepared.

Then, a wear test was performed on these block test pieces under the same procedure and conditions as in the case of the above-mentioned Example 3.
The results of these abrasion tests are shown in Table 3.

From Table 3, the amount of wear of the block test piece F ₁ is much smaller than the amount of wear of the block test pieces F ₂ and F ₃ of the comparative example, and the amount of wear of the cylindrical test piece of the block test piece is F _{2 of the} comparative example. as well as
It can be seen that the value is as small as F ₃ .

Thus, even if the matrix metal is a copper alloy,
The composite material in which the reinforcing fiber is the reinforcing fiber of the example has better wear resistance than the precursor fiber and the precursor fiber coated only with the oxide layer, and when expensive expensive high-performance reinforcing fiber is used, It has the same wear resistance, and the amount of wear of the mating material is smaller than when high performance reinforcement is used,
Therefore, it is understood that the friction and wear characteristics are superior to any of the comparative examples.

Example 7 The volume ratio of the reinforcing fibers formed in Example 3 above is
A composite material was prepared under the same conditions and conditions as in Example 1, except that the matrix metal was replaced with a zinc alloy (JIS standard WJ8) and the temperature of the molten metal was set to 410 ° C. A block test piece G ₁ was manufactured from the composite material.

For comparison purposes, the block test was carried out except that the reinforcing fibers were replaced with mineral fibers not having a coating layer of chromium oxide, and mineral fibers coated with chromium oxide but not having calcium chromate formed. The block test pieces G ₂ and G ₃ were prepared under the same procedure and conditions as the case of the piece G ₁ , and the block test piece G ₀ made only of the lead alloy as the matrix metal was prepared.

Then, an abrasion test was performed on these block test pieces under the same procedure and conditions as in the case of the above-mentioned Example 3. The results of these abrasion tests are shown in Table 4.

From Table 4, the amount of wear of the block test piece G ₁ is far smaller than the amount of wear of the block test pieces G ₂ and G ₃ of the comparative example, and the amount of wear of the cylindrical test piece is G _{2 of the} block test piece of the comparative example. as well as
It can be seen that the value is as small as when G ₃ .

Thus, even if the matrix metal is a lead alloy,
The composite material in which the reinforcing fiber is the reinforcing fiber of the example has better wear resistance than the precursor fiber and the precursor fiber coated only with the oxide layer, and when expensive expensive high-performance reinforcing fiber is used, It has the same wear resistance, and the amount of wear of the mating material is smaller than when high performance reinforcement is used,
Therefore, it is understood that the friction and wear characteristics are superior to any of the comparative examples.

Example 8 The volume ratio of the reinforcing fibers formed in Example 4 above is
10%, the matrix metal was replaced with a zinc alloy (JIS standard WJ2), and the temperature of the molten metal was set to 330 ° C. A block test piece H ₁ was formed from the composite material manufactured.

For the purpose of comparison, a block test was conducted except that the reinforcing fibers were replaced with glass fibers not having a coating layer of zirconium oxide and glass fibers coated with zirconium oxide but not having zirconium silicate formed. Block test piece under the same procedure and conditions as for piece H ₁
H ₂ and H ₃ were prepared, and a block test piece H ₀ composed only of a tin alloy which was a matrix metal was prepared.

Then, a wear test was performed on these block test pieces under the same procedure and conditions as in the case of the above-mentioned Example 3.
The results of these abrasion tests are shown in Table 5.

From Table 5, the amount of wear of the block test piece H ₁ is much smaller than that of the block test pieces H ₂ and H ₃ of the comparative example, and the amount of wear of the cylindrical test piece is H _{2 of the} comparative example. as well as
It can be seen that the value is as small as when H ₃ .

Thus, even when the matrix metal is a tin alloy, the composite material in which the reinforcing fiber is the reinforcing fiber of the example is superior in wear resistance to the precursor fiber and the precursor fiber coated only with the oxide layer, and is expensive. Has the same wear resistance as when high performance reinforcing fiber is used, and the amount of wear of the mating material is smaller than when high performance reinforcing material is used. It is understood that the friction and wear characteristics are superior to those of the above.

Incidentally, when the cross section of the composite material of each of the above-mentioned examples was observed by an optical microscope, the adhesion between the reinforcing fiber and the matrix metal was good in any of the examples, and the oxide layer around the reinforcing fiber was obtained. It was found that the composite oxide layer substantially maintained the state before the composite material was manufactured.

In the above, the present invention has been described in detail with respect to specific embodiments, but the present invention is not limited to these embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art.

[Brief description of drawings]

FIG. 1 is a schematic view showing a step of coating alumina-silica short fibers as precursor fibers with aluminum oxide, and FIG. 2 is a schematic sectional view showing one embodiment of a reinforcing fiber according to the present invention, FIG. FIG. 4 is a perspective view showing a fiber molded body formed of the reinforcing fibers shown in FIG. 2, and FIG. 4 is a high pressure casting for manufacturing a composite material performed using the fiber molded body shown in FIG. FIG. 5 is a perspective view showing a solidified body obtained by the casting process shown in FIG. 4, and FIGS. 6 to 8 are abrasions in Examples 1 to 3, respectively. It is a graph which shows the result of a test. 10 …… Solution, 12 …… Alumina-silica short fiber, 14 …… Reinforcing fiber, 16 …… Aluminum oxide, 18 …… Mullite, 20 ……
Fiber molding, 22 …… Mold, 24 …… Mold cavity, 26
...... Melted metal, 28 ...... Plunger, 30 ...... Coagulate

Claims (2)

(57) [Claims] 1. A precursor fiber selected from the group consisting of alumina-silica fiber, mineral fiber, glass fiber, potassium titanate whiskers, and a mixture thereof is coated with an oxide layer, and the precursor fiber and the oxide are included. A reinforcing fiber for producing a fiber-reinforced metal composite material, wherein a composite oxide is formed by the precursor fiber and the oxide layer at an interface between the layer and the layer. 2. The reinforcing fiber for producing a fiber-reinforced metal composite material according to claim 1, wherein the oxide constituting the oxide layer is aluminum oxide, chromium oxide, zirconium oxide, or a mixture thereof. A reinforcing fiber for producing a fiber-reinforced metal composite material, which is an oxide selected from the group consisting of: