JP2007118036A - Composite member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite member in which an aluminum member is reinforced by a simple/inexpensive means. <P>SOLUTION: The composite member includes: a reinforcing member obtained by stacking planar members 1, 1' each composed of ferrous metal and having many through holes passing through the surface and back faces in two or more folds in such a manner that the oriented directions of these through holes close each other are shifted; and a matrix part with the planar members buried therein and composed of nonferrous metal. When the planar members (expand metal) having many through holes passing through the surface and back faces are adopted as the reinforcing material, the material composing the matrix part is inserted into the through hole parts, and thus the firm joining between the matrix part and the planar members is achieved. The strength of the formed composite member is therefore made high. In this case, when the through holes formed at the planar members are regularly arranged (oriented), anisotropy in accordance with the orientation is produced on the strength of the composite member in which the planar members are buried. Consequently, by stacking the plurality of planar members in such a manner that the orientation of the through holes is shifted, desired strength can be obtained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a composite member having a reinforced nonferrous metal as a matrix.

  In recent years, light metals and light alloys such as aluminum and magnesium have been adopted for the purpose of weight reduction. Here, as a technique for improving the strength with respect to a light metal or the like, there is MMC using ceramic fibers as a reinforcing material. As the reinforcing material dispersed in the metal matrix, a nitride material of alumina fiber or silica fiber can be cited (Patent Document 1), and further improvement in strength is desired.

  A silicon carbide whisker is an example of a reinforcing material that can realize further improvement in strength. However, while silicon carbide whiskers are attractive as reinforcing materials, they are expensive and difficult to process, and it is desirable to provide a technique that can realize improved strength at low cost.

Further, as a conventional technique, a cylinder block in which a net member having a through hole is overlaid is disclosed, but the orientation direction of the through hole between the superposed net members is not considered (Patent Document 2). ).
Japanese Patent Laid-Open No. 9-279267 Japanese Patent Laid-Open No. 10-318038 (FIG. 5)

  The present invention has been made in view of the above circumstances, and an object to be solved is to provide a composite member in which a member such as aluminum is reinforced by a simple and inexpensive method.

  As a result of intensive studies aimed at solving the above problems, the present inventors have adopted a plate-like member having a large number of through holes penetrating the front and back surfaces, such as expanded metal, as a reinforcing material. By inserting into the through-hole portion, it has been conceived that the matrix portion and the plate-like member can be firmly adhered and bonded, and the strength of the formed composite member can be increased.

  Here, if the arrangement of the through holes formed in the plate-like member is regular (orientated), anisotropy corresponding to the orientation occurs in the strength of the composite member in which the plate-like member is embedded. . Usually, the arrangement of the through holes is often oriented. For example, when an expanded metal or a net-like member is adopted as the plate-like member, the arrangement of the through holes is oriented in a certain direction because of the manufacturing method, and it is desired to control the influence of the orientation.

  Also, regularity often appears even when punching metal is employed. Since the amount (number, size, area, etc.) of the through holes is limited by the required strength, mass, and the like, a certain degree of orientation (that is, strength anisotropy) occurs in the arrangement of the through holes. Further, the strength required in the composite member to be formed is often different depending on the direction. In that case, in order to achieve a desired strength with a limited amount of through holes, the arrangement of the through holes is positively oriented. It is possible to make it.

  As described above, the composite member finally obtained is required to have the required strength even if a plate-like body with through holes oriented is used. For this purpose, it is required to optimize the arrangement of a large number of through holes formed in the plate member.

  However, providing a plate-like member according to the required performance is not preferable from the viewpoint of cost and the like. Furthermore, as will be described later, when the plate-like member is subjected to carburizing / nitriding treatment, etc. For reasons such as the thinner thickness of the member is desirable, the inventors have conceived that the plurality of plate-like members are laminated so that the orientations of the through holes are shifted, and the following invention has been completed.

That is, the composite member of the present invention that solves the above problems is a reinforcing member formed by laminating double or more plate-like members made of an iron-based metal and having many through holes penetrating the front and back surfaces,
Embedded with the reinforcing member, and having a matrix portion made of non-ferrous metal,
The reinforcing member is characterized in that a direction in which the through-holes that are close to each other are stacked is shifted between the stacked plate-shaped members.

  For example, the anisotropy of the strength can be reduced by adjusting the orientation direction of the through-hole for the plate-like member in which the through-hole is oriented in a certain direction (when the orientation direction is shifted: 90 ° It is considered that the anisotropy is most relaxed), can be strengthened (alignment direction is aligned: the anisotropy is considered to be strengthened most at 0 °), or can be adjusted in the middle.

  Below, the composite member of this invention is demonstrated based on embodiment. The composite member of the present embodiment has a matrix portion and a reinforcing member.

  The matrix portion is made of a non-ferrous metal. The type of non-ferrous metal is not particularly limited as long as it does not erode more than the reinforcing member can be tolerated in manufacturing, using, and storing the composite member. For example, a metal having a melting point lower than that of an iron-based metal constituting the reinforcing member can be easily manufactured by casting. In particular, the non-ferrous metal is preferably a light metal. If the non-ferrous metal is a light metal, it is a lightweight and high-strength composite member.

  Specifically, non-ferrous metals include pure aluminum, aluminum-based metals such as aluminum alloys containing Mg, Cu, Zn, Si, Mn, etc., pure magnesium, Zn, Al, Zr, Mn, Th, rare earth elements, etc. In addition to magnesium-based metals such as magnesium alloys, titanium-based metals and lithium-based metals are listed.

  The reinforcing member is a member that reinforces the matrix portion by being embedded in the matrix portion. The reinforcing member is composed of a plate member. The plate member is not particularly limited as long as it is made of an iron-based metal containing iron as a main component, but it is preferable to use various rolled steel plates (SPCC, SPHC, etc.) excellent in workability.

The plate-like member has a large number of through holes penetrating the front and back surfaces. By having the through-hole, when the plate-like member is embedded in the matrix portion, it is possible to ensure the adhesion between them. Furthermore, if the aperture ratio of the plate-like member is less than 28%, more preferably 18% or less, the strength of the composite member can be improved satisfactorily. At this time, the area of one through hole is preferably 300 μm ² or more. By setting the area of one through hole in the above range, the adhesion between the plate-like member and the matrix portion can be further improved.

  The plate-like member is formed by inserting a large number of slits in a plate and expanding the slits by pulling in the direction in which the plate extends to form through holes, and by forming a large number of through holes in the plate. Punching metal or the like is preferable. These members can be easily produced, are easily available, and have excellent workability. Under the present circumstances, it is preferable that the thickness of an iron-type member is 0.5-2 mm. When the thickness of the iron-based member is within the above range, the strength of the metal composite can be improved satisfactorily. Moreover, it is also possible to employ a rolled net made of a plurality of wires.

  Further, as these plate-like members, those having a roughened surface are desirable from the viewpoint of improving adhesion. The surface roughening should just be given to the interface of the iron-type member which contacts a nonferrous metal at least. The rough surface may be formed by a physical method using blasting such as shot blasting or shot peening, or a chemical method using chemicals.

  Moreover, it is desirable that the plate-like member has been subjected to carburizing treatment. The carburizing treatment is a treatment method in which only the surface portion is hardened by increasing the amount of carbon in the surface portion by allowing carbon to penetrate from the surface of the carbon steel. A steel plate used for an expanded metal or the like used as a plate-like member is relatively soft and excellent in workability. Therefore, it is desirable that the steel plate be hardened by performing a carburizing process or the like.

  And as above-mentioned, in the composite member of this embodiment, since the plate | board thickness of a plate-shaped member becomes like this. Preferably it is 0.5-2 mm, When a carburizing process is performed to such a plate-shaped member, thickness direction In all of the above, a member in which carbon penetrates and is hardened is obtained. The carburizing process may use any carburizing method among solid carburizing process, liquid carburizing process, gas carburizing process, and vacuum carburizing process, but the plate-like member is made of carbon and carbon in all parts in the thickness direction by carbonitriding process. Nitrogen infiltrated is desirable.

  Here, the “plate-like member” is generally a continuous member having a planar extension and a member in which a through hole is formed in the member, or a net-like body made of a plurality of wires such as a wire mesh. It may be a member that fits in a plane.

  The reinforcing member is a member obtained by laminating these plate-like members more than double. The distance between two or more plate-like members to be laminated is not particularly limited, but it is desirable that the distances are generally in close contact from the viewpoint of improving the strength. The case where the plate members are generally in close contact with each other will be described in detail. In addition to the case where all the stacked plate members are in close contact, the plate members are substantially parallel and between the plate members. It also includes a state in which is touching at one or more points. The lamination of the plate-like members is set so as to shift the direction in which the through holes adjacent to each other are oriented by the lamination. In addition to stacking plate members, which are separate members, when stacking two or more layers, it is also possible to stack by rounding or bending continuous members.

  Here, the “orientation” of the through holes means that the shape of the through holes is not circular but is arranged in a predetermined rule (for example, all in the same direction, alternately in opposite directions, etc.) This is the case when the circles are circular but the arrangement is regular. In that case, the direction in which portions other than the through-holes are largely continuous is defined as the orientation direction. Specifically, the direction with the highest strength in a single plate member is defined as the “orienting direction”. For example, expanded metal is prepared by pulling a plate material with a predetermined cut in a direction perpendicular to the cut, and as shown in FIG. 1, the strength is large in the direction LW in which the cut is made and the direction SW in which the cut is made. The direction in which the through-holes are oriented is the direction LW, which is different (it may be several times different depending on the manufacturing conditions).

  The position of the reinforcing member is not particularly limited as long as it is embedded in the matrix portion. For example, the reinforcing member is disposed in a portion where the strength is required in the composite member in a direction where the strength is required (a direction in which the plate-shaped member spreads in that direction). When a direction requiring strength is curved, it is desirable to curve the reinforcing member according to the curved surface. Furthermore, you may arrange | position so that a part of reinforcement member may be exposed to the surface.

  The composite member is desirably manufactured by casting. As a casting method, a general method (a so-called insert molding method) in which a reinforcing member is disposed at an arbitrary position in a mold and then a molten non-ferrous metal constituting a matrix portion is injected into the mold. . As the casting method, any method such as a gravity casting method, a low pressure casting method, a molten metal forging method, or a die casting method can be adopted. Furthermore, a higher strength composite member can be obtained by performing heat treatment as necessary after casting to perform a tempering treatment that adjusts the mechanical properties of the nonferrous metal constituting the matrix portion.

  The composite member having the above-described configuration can be suitably used for a pressure-resistant component such as an engine block, a hydraulic pump, or a compressor because it can have high strength and can be lightweight depending on the nonferrous metal constituting the matrix portion.

[Preparation of test sample]
An expanded metal (SPCC, thickness: 1000 μm, area of one through hole: about 300 μm ² ) having a plurality of through holes penetrating in the thickness direction in a plate shape was prepared. As shown in FIG. 1, the expanded metal 1 is a plate-like body in which a large number of through holes 12 are regularly formed. In order to evaluate the strength change depending on the direction of the expanded metal 1, four types of directions are defined: a direction LW parallel to the orientation of the through-hole 12, a direction MW deviated by 45 ° or 135 °, and a direction SW deviated by 90 °. did. Three types of aperture ratios of 8%, 18%, and 28% were prepared. The thing which carbonitrided the expanded metal of each aperture ratio was prepared. The carbonitriding process was performed by heating to 650-900 ° C. with a carburizing gas containing NH ₃ , reacting C and N simultaneously with the steel material to form a diffusion layer, and then quenching with oil. After carbonitriding, tempering was performed at 550 ° C. for 60 minutes, and shot blasting was performed for 2 minutes.

  A test sample (composite member) was produced using the expanded metal described above. For the production of the test sample, a mold apparatus composed of a lower mold having a recess having a predetermined shape and an upper mold having a shape that is fitted in sliding contact with the wall surface of the recess was used.

  When preparing the sample, the mold temperature of the mold apparatus is set to 200 to 350 ° C., and the expanded metal is placed on the bottom surface of the concave portion of the lower mold and preheated to 300 ° C., and in that state, aluminum is placed in the concave portion. Molten alloy (ADC12, molten metal temperature 650 to 800 ° C.) was poured. Thereafter, the upper mold was inserted into the lower mold and pressed (70 to 100 MPa) for casting.

  In the test sample of the example, as shown in FIGS. 2 (a) to 2 (c), two expanded metals 1 and 1 ′ having an aperture ratio of 18% are overlapped and inserted into the mold in a state shifted by 90 °. did. That is, the direction LW and the direction SW of the expanded metal 1 respectively overlap with the direction SW and the direction LW of the expanded metal 1 ′, and the direction MW (45 ° and 135 °) of the expanded metal 1 respectively corresponds to the direction MW ( The test samples overlapped at 135 ° and 45 °). Test examples 1 and 2 and, as a comparative example, a test sample using only one expanded metal 1 having an opening ratio of 8%, 28%, and 18% were also made into composite materials by the method described above.

  Further, each of the expanded metals having an opening ratio of 8%, 18% and 28% was subjected to a tensile test as it was before and after the carbonitriding treatment (Test Examples 3 to 8).

[Evaluation]
The strength of the test sample of each example, each comparative example, and each test example was evaluated by a tensile test.

  Each test sample was processed into a predetermined shape to prepare a JIS flat plate test piece. At this time, processing was performed so that the tensile direction of the tensile test was the direction LW with respect to the expanded metal 1. Moreover, about the test sample (opening ratio 18%) of the Example and comparative example which performed the carbonitriding process, the test piece processed so that direction SW and direction MW (45 degrees) of the expanded metal 1 may become a tensile direction, respectively. Created.

  The tensile test was performed by a 5t autograph (manufactured by Shimadzu Corporation, AG-5000A) at a tensile speed of 0.5 mm / min. The test piece used was processed so that the direction LW of the expanded metal 1 was the tensile direction. A tensile test was performed (Test 1). In addition, a test piece prepared from a test sample having an aperture ratio of 18% is held at 500 ° C. for 10 hours, held at 180 ° C. for 4 hours, and then at 180 ° C., the expanded metal 1 has a MW (45 °) direction. In addition, further tests were performed (Test 2).

  Table 1 and FIG. 3 (Test 1) and Table 2 and FIG. 4 (Test 2) show the test results (breaking stress) of the tensile test performed on each test sample, respectively. For Test 1 (FIG. 3), the predicted values obtained by calculation (maximum: serial addition, minimum: parallel addition) are also shown.

  Test 1: As is apparent from Table 1 and FIG. 3, the tensile strength of the test piece prepared from the test sample having an aperture ratio of 28% is lower than that of the test specimen prepared from the test sample having an aperture ratio of 18%, and It was found that the strength increase due to the composite material was small, and the aperture ratio was preferably less than 28% (more preferably 18% or less).

  A test piece prepared from a test sample having an open area ratio of 8% had higher tensile strength than a test piece prepared from a test sample having an open area ratio of 18%. From the test results of the comparative example, it was found that when the aperture ratios were 8% and 18%, the strength increase due to carbonitriding was larger than when the aperture ratio was 28%, and the strength could be increased. However, when the anchor effect by the through-hole portion provided in the plate-like member is taken into consideration, there is a possibility that the strength is higher when the aperture ratio is 18% than 8%.

  Test 2: As is clear from Table 2 and FIG. 4, in the case where the tensile direction is the direction SW and the direction MW (45 °) of the expanded metal 1, the example in which two sheets are laminated rather than one comparative example is better. It showed higher tensile stress. In either case, the tensile strength was lower than that in the case of one expanded metal and the tensile direction was the direction LW, but the change in strength due to the tensile direction could be kept small.

It is a top view which shows an expanded metal typically. It is the top view (c) which shows typically the reinforcement | strengthening member embed | buried in the composite member of this invention in an Example in the top view (a), (b) which shows an expanded metal. It is a graph which shows the result of the tension test of the test piece created from the test sample of an Example and a comparative example. It is a graph which shows the result of the tension test of the test piece created from the test sample of an Example and a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1 '... Expanded metal 12, 12' ... Through-hole LW ... Direction parallel to the direction where a through-hole is orientated SW ... Direction orthogonal to the direction where a through-hole is orientated MW ... 45 degree with respect to the direction where a through-hole is orientated Direction shifted by 135 °

Claims (11)

A reinforcing member formed by laminating a plate-like member composed of an iron-based metal and having many through holes penetrating the front and back surfaces; and
Embedded with the reinforcing member, and having a matrix portion made of non-ferrous metal,
The reinforcing member is a composite member characterized by shifting a direction in which the through holes that are close to each other by lamination between the laminated plate-like members are oriented.   2. The composite member according to claim 1, wherein the plate-like member has a plurality of through holes oriented in a predetermined direction, and has anisotropy in strength depending on a direction of an extension direction of the plate-like member.   The composite member according to claim 1 or 2, wherein in two of the laminated plate-like members, directions in which the plurality of adjacent through holes are oriented are substantially orthogonal to each other.   The composite member according to claim 1, wherein an aperture ratio of the plate-shaped member is less than 28%.   The composite member according to claim 4, wherein the plate member has an aperture ratio of 18% or less.   The composite member according to claim 1, wherein the plate-like members constituting the reinforcing member are in close contact with each other.   The composite member according to claim 1, wherein the plate-like member is a punching metal or an expanded metal.   The composite member according to any one of claims 1 to 6, wherein the plate-like member is a rolled mesh body made of a plurality of wires.   The composite member according to claim 1, wherein a surface of the plate member is a rough surface.   The composite member according to claim 1, wherein the plate-like member has a thickness of 0.5 mm or more and 2 mm or less.   The composite member according to claim 1, wherein the plate-like member is carbonitrided.

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