JP2019065315A - Sintered component for internal chill and light-metal composite material - Google Patents

Abstract

To provide a sintered component for internal chill excellent in the strength of a sintered component and the adhesion and bond strength of a light-metal alloy.SOLUTION: A sintered component for internal chill 1 is used by being inserted in a light-metal alloy. The sintered component for internal chill 1 comprises a body part 10 and a bonding part 20. The body part 10 has a density ratio of 86% or higher and 91% or lower and the bonding part 20 has a density ratio of 80% or higher and 84% or lower.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cast-in-place sintered member that is cast and used in a light metal alloy, and more particularly to a cast-in-place sintered member and a light metal composite member that have excellent adhesion to the light metal alloy and bonding strength.

  In automobile parts, application of light metal alloys such as aluminum alloys has been promoted in order to reduce parts weight and improve fuel consumption. However, light metal alloys have low mechanical properties such as strength and rigidity, and low wear resistance and low sliding properties, so that their application is limited to some automotive structural parts. In such automobile structural parts, a part made of a light metal alloy such as an aluminum alloy and a part made of a conventional cast iron or the like may be used in combination with each other.

  With respect to aluminum alloy members as described above, methods have been proposed for casting dissimilar materials in order to improve mechanical properties and physical properties. However, when casting dissimilar materials in an aluminum alloy or the like using high-pressure die casting, it is difficult to stably secure the desired bonding strength at the interface, and in particular, it is possible to use porous sintered members as light metal alloys. In the case of casting and wrapping, the penetration state of the light metal alloy melt into the pores of the sintered member greatly affects the mechanical properties and physical properties of the casted aluminum alloy composite member. Sintered members have been proposed (see, for example, Patent Documents 1 and 2).

Patent Document 1 relates to a cast-in-place sintered member that is used by being cast and wrapped in a light metal alloy, and in the composition, copper (Cu): 3 to 5 mass% and carbon (C): 0.2 to 0.2 While exhibiting a metal structure containing 1.2% by mass and having a copper phase and pores distributed in the iron alloy matrix, the porosity of the pores is 11 to 22%, and the copper phase is on the surface and inside of the sintered member A sintered alloy is proposed in which the copper phase on the surface of the sintered member is distributed 2.0% or more in mass% more than the copper phase inside the sintered member.
Patent document 1 improves the strength of the sintered member itself while making it a low alloy iron-based sintered member with a small amount of addition of alloy elements, and adheres to the light metal alloy even when the casting pressure is a low pressure of about 30 to 50 MPa. A sintered member for cast-in, which has excellent properties and bonding strength, and a method for producing the same are described.

In Patent Document 2, it is cast-wrapped by an aluminum-based alloy base material having a concave surface continuously formed along the central axis center extension direction with a semicircular cross section, and the central axis core extension with a semicircular arc section along the concave surface Iron base material for forming a metal matrix composite having an inner circumferential surface continuous along the direction and a plurality of inner grooves formed on the inner circumferential surface at intervals along the circumferential direction while continuing along the extending direction of the central axis In the preform (sintered member), the inner groove is a flat portion whose base end is continuous to both end edges continuous with the inner circumferential surface and a groove bottom portion continuously formed between the back ends of both flat portions. The cross section of the flat portion opened from the base end to the back end is A, the groove width is B, and the cross section orthogonal to the central axis at the bottom of the groove. Radius of curvature of the shape C, relative to a straight reference line extending from the central axis to the groove width center Assuming that the inclination angle of the flat portion is E, and the distance between the groove width centers of adjacent inner grooves is F, 0.1 mm ≦ A ≦ 1.0 mm, 0.5 mm ≦ B ≦ 10.0 mm, C ≦ B, E A sintered member for forming a metal matrix composite, which is ≦ 5 ° and F / B ≦ 5, has been proposed.
According to Patent Document 2, each inner groove is formed in the circumferential direction with a large number of molten aluminum-based alloy molten metal poured in a thin-walled portion between the semicircular concave surface and the inner peripheral surface of the sintered member in the casting process. When a contraction stress is applied in the circumferential direction along the inner peripheral surface of the sintered member during solidification and contraction of the molten aluminum-based alloy molten metal poured into the thin-walled portion, the molten aluminum-based alloy melt It is described that contraction in the circumferential direction is equally received by the inner grooves formed in large numbers on the inner circumferential surface of the sintered member, and movement of the molten aluminum-based alloy in the circumferential direction is suppressed. Further, Patent Document 2 reduces the residual stress generated in the base material made of an aluminum-based alloy, in which the contraction stress generated at the time of solidification and contraction of the aluminum-based alloy molten metal is uniformly dispersed along the inner peripheral surface of the sintered member It is described that the residual stress between the concave surface and the inner circumferential surface of the sintered member can be alleviated by the equalization, and the cracking and the like of the portion can be prevented.

Patent No. 5525995 Patent No. 4498255

  Although the sintered member for cast-in of the cited reference 2 improves adhesion with a light metal alloy and joint strength by increasing the surface area, the increase of the surface area is in a macroscopic range, and adhesion with the light metal And the bonding strength was low. On the other hand, the cast-in-place sintered member of Patent Document 1 makes it easy to infiltrate the molten metal of the aluminum alloy into the pores of the sintered member, and the adhesion with the aluminum alloy and the bonding strength are high. However, further improvement in adhesion and bonding strength is desired. In addition, in the case of an aluminum alloy composite member in which a sintered member is cast and wrapped, the strength of the sintered member ensures the strength of the aluminum alloy composite member, so that the sintered member is further improved to further improve the strength of the aluminum alloy composite member. It is desired to increase the strength of

  The object of the present invention is made in view of the above-mentioned circumstances, and is to provide a cast-in-place sintered member and a light metal composite member which are excellent in the strength of the sintered member and the adhesion and bonding strength of the light metal alloy.

In order to solve the above-mentioned problems, according to the inventors of the present invention, the sintered member to be cast in a light metal alloy is divided into a portion having high strength and a portion where penetration of the light metal alloy molten metal is easy. Therefore, it is possible to achieve both improvement in the strength of the sintered member and the adhesion and bonding strength of the light metal alloy, and a high strength region can be formed by increasing the density of the sintered member, and penetration of the light metal alloy melt is easy. It has been found that these sites can be formed by lowering the density of the sintered member. The present invention based on this finding relates to the following.
[1] A sintered member for cast-in, which is used by being cast-wrapped in a light metal alloy, wherein the cast-in sintered member comprises a main portion and a joint portion, and the density ratio of the main portion is A sintered member for cast-in, which is 86% or more and 91% or less, and the density ratio of the bonding portion is 80% or more and 84% or less.
[2] The sintered member for cast-in of [1], wherein the bonding portion has pores communicating with the outside, and the porosity of the pores in the bonding portion is 11% or more and 22% or less.
[3] The cast-sintered member according to [1] or [2], wherein the bonding portion is provided with a convex portion on the surface.
[4] The cast-sintered member according to [3], wherein the convex portion has a reverse tapered shape with a thick tip.
[5] The cast-in-part sintered member of [3] or [4], wherein at least two or more of the convex portions are present.
[6] A light metal composite member in which the cast-in-placement sintered member according to any one of [1] to [5] is cast in a light metal alloy.

  According to the present invention, it is possible to provide a cast-in-place sintered member and a light metal composite member which are excellent in the strength of the sintered member, the adhesion of the light metal alloy, and the bonding strength.

They are a front view, a bottom view, and a perspective view for explaining a sintered member for cast-in according to an embodiment of the present invention. It is a schematic diagram for demonstrating the surface shape of the coupling | bond part which concerns on embodiment of this invention. It is a schematic diagram for demonstrating the convex part provided in the surface of the coupling part which concerns on embodiment of invention. It is a cross-sectional process drawing for shape | molding the sintered member for casting according to the embodiment of the present invention. It is a front view for demonstrating the light metal composite member which concerns on embodiment of this invention. It is a process schematic diagram for producing the test piece of an Example. It is a schematic diagram which shows the tension test with respect to the test piece of an Example. It is a process schematic diagram for producing the test piece of a comparative example. It is a schematic diagram which shows the tension test with respect to the test piece of a comparative example.

  As shown in FIG. 1, the cast-in-place sintered member 1 according to the embodiment of the present invention (simply referred to as "sintered member") is a cast-in type used by being cast and wrapped in a light metal alloy. It is a sintered member 1 for. The cast-in-place sintered member includes the main body portion 10 and the bonding portion 20, the density ratio of the main body portion 10 is 86% or more and 91% or less, and the density ratio of the bonding portion 20 is 80% or more and 84% It is below.

[Base of sintered members for casting]
The composition and metal structure of the cast-in sintered member are not particularly limited, but it is preferable to use the sintered member of Patent Document 1. Specifically, it is preferable that the cast-in-place sintered member 1 be inexpensive and have a high strength iron (Fe) -carbon (C) alloy as a basic base structure. Carbon combines with Fe in the matrix to form a perlite structure, which contributes to the improvement of strength. If the amount of carbon is less than 0.2% by mass, the amount of pearlite to be formed is scarce, and the ferrite having low strength is excessive, and the strength of the sintered member becomes low. Therefore, the amount of carbon needs to be 0.2% by mass or more. As the amount of carbon increases, the amount of pearlite formed increases, and in proportion to this, the amount of ferrite decreases, and the strength of the sintered member increases. When the amount of carbon is less than 0.8% by mass, the base structure is a mixed structure of pearlite and ferrite, but when the lower limit of the amount of carbon is 0.8% by mass or more, the single structure of pearlite is formed, and the strength of the sintered member is It is preferable because it is the largest.

  The cast-in-place sintered member 1 may be subjected to dimension correction processing (sizing processing) after sintering to obtain the required dimensional accuracy, and may be machined after sintering if the dimensional accuracy is strictly required. Excessive precipitation of cementite in the world makes it difficult to perform sizing and machining. Therefore, from the viewpoint of securing the strength of the sintered member without precipitation of hard and brittle cementite at grain boundaries, it is preferable to set the upper limit of the amount of carbon to 1.2% by mass.

  If an iron-carbon alloy powder obtained by adding carbon in the above content to iron is used as the raw material powder to make the base mentioned above, the powder becomes hard and the compressibility decreases. For this reason, all carbon of the above content is added in the form of graphite powder to soft iron powder having excellent compressibility, and the whole amount is diffused to the iron matrix at the time of sintering to obtain the above base structure. . Therefore, it is preferable that the addition amount of the graphite powder added to iron powder sets it as 0.2 mass% or more and 1.2 mass% or less.

  As described above, since it is necessary to diffuse the whole amount of carbon provided in the form of graphite powder to the matrix at the time of sintering, the sintering temperature is set to 910 ° C. or more. Further, as the graphite powder, it is preferable to use many fine powders so as to be easily diffused in the iron matrix. On the other hand, since too fine powder tends to cause segregation of the raw material powder, it is preferable to use a graphite powder having an average particle diameter of about 2 μm to 22 μm. In addition, as an iron powder, the thing of about 50 micrometers-300 micrometers of average particle diameters used by normal powder metallurgy can be used.

[Density ratio of sintered members for casting]
In the sintered component 1 for castables of the present invention, the density ratio of the main body portion 10 is 86% or more and 91% or less. The density ratio of the main body portion 10 is preferably 87% or more and 91% or less, more preferably 88% or more and 91% or less, and more preferably 89% or more and 91% because mechanical properties increase as the value increases. It is more preferable that it is the following.
Here, the density ratio is a value obtained by dividing the density of the sintered member by the true density of the steel material. Specifically, when the volume of the sintered member and the steel material is the same 50 cm ³ , if the weight of the sintered member is 340 g, the density of the sintered member is 6.80 g / cm ³ and the weight of the steel material is Since the density of steel materials is 7.86 g / cm ^{3 if} it is 393 g, the density ratio is 86.5% (= 6.80 / 7.86).

  In the cast-in-place sintered member 1 of the present invention, the density ratio of the bonding portion 20 is 80% or more and 84% or less. The density ratio of the bonding portion 20 is preferably 80% or more and 83% or less, and is 80% or more and 82% or less from the viewpoint of facilitating penetration of the light metal alloy molten metal into the pores and improving adhesion with the light metal alloy. Is more preferable, and 80% or more and 81% or less is more preferable.

[Pore of sintered member for casting]
In the cast-in-place sintered member 1 of the present invention, the bonding portion 20 has pores communicating with the outside, and the porosity of the pores in the bonding portion 20 is preferably 11% to 22%. . Here, the porosity refers to the ratio of pores communicating with the outside of the sintered member, and refers to the open porosity.
The pores are those in which the gaps between the powders in the compact remain after sintering, and are distributed in the bonding portion 20 and partially open on the surface of the bonding portion 20. Such pores contribute to the bonding between the joint portion 20 and the light metal alloy member. That is, the light metal alloy molten metal such as aluminum alloy intrudes into the pores in the sintered member from the pores opened on the surface of the bonding portion 20, and performs strong bonding after casting. When the pores are scarce, the light metal alloy molten metal hardly penetrates into the pores, and the amount of the light metal alloy molten metal infiltrating into the pores becomes scarce, and the bonding strength between the joint portion 20 and the light metal alloy member becomes poor. Therefore, the porosity of the pores is preferably 11% or more. On the other hand, when the pores increase, the light metal alloy molten metal easily intrudes into the pores, and the amount of the light metal alloy molten metal invading into the pores increases to increase the bonding strength between the joint portion 20 and the light metal alloy member. As the strength of the bonding portion 20 decreases as the temperature is increased, the upper limit of the porosity of the pores is preferably set to 22%. The porosity of the pores in the bonding portion 20 is preferably 12% or more and 21% or less, more preferably 13% or more and 20% or less, and still more preferably 14% or more and 19% or less.

  The porosity of the pores is controlled by the gap between the powder at the time of molding, that is, the applied pressure at the time of molding. In order to make the amount of pores of the bonding portion 20 after sintering to be in the above-mentioned range, the compacting may be carried out with a pressing force of at least 210 MPa and at most 561 MPa.

The shape and size of the pores are not particularly limited, but if the pores are too fine, it is difficult for the light metal alloy molten metal to penetrate even if reaction occurs and the solidification point is lowered. The total pore volume is preferably 10% by volume or less.
Further, if the iron powder used as the main raw material powder is fine, the gaps between the powders in the compact become small, and the pores formed after sintering become fine. Therefore, as the iron powder used as the main raw material powder, It is preferable to use one having an average particle size of 40 μm or more. It should be noted that if iron powder is sieved to remove fine powder or only coarse powder is used, the cost will increase, and such operation is not performed, and among commercially available iron powders, the average particle diameter is 40 μm or more What is necessary is just to use 100 micrometers or less.

  In the cast-in-place sintered member 1 according to the present invention, since the main body 10 does not require the penetration of the light metal alloy molten metal, the pores distributed in the matrix may or may not exist. . The porosity of the pores in the main body portion 10 is not particularly limited, and is preferably 0% or more and 10% or less, more preferably 2% or more and 8% or less, and 4% or more and 6% or less More preferable.

  In order to make the amount of pores of the main body portion 10 after sintering to be in the above-mentioned range, the compacting may be performed with a pressing force of 570 MPa or more at the time of molding.

[Shape of joint]
It is preferable that the convex part 21 is provided in the surface, as the connection part 20 is shown in FIG. By providing the projections 21 in the joint portion 20, the surface area of the joint portion 20 can be increased, and the surface area in contact with the light metal alloy in casting is increased, and the adhesion to the light metal alloy and the joint strength Can be improved.

Protrusions 21, as shown in FIG. 3, it is preferred tip is thicker inversely tapered shape (thick shape tip width D ₁ is from the root width D _2). Since the convex portion 21 has an inverse tapered shape, after casting a light metal alloy, the side surface 21a constituting the convex portion 21 acts as a weir, and improves the tensile strength of the light metal alloy interface. From this, the bonding strength between the bonding portion 20 and the light metal alloy can be improved.

  As shown in FIG. 2 and FIG. 3, it is preferable that at least two or more protrusions 21 be present, more preferably 2 or more and 20 or less, and still more preferably 2 or more and 10 or less. . The surface area in contact with the light metal alloy is increased at the time of cast-in when the convex portion 21 is a plurality of two or more, and adhesion with the light metal alloy and bonding strength can be improved. Further, in the case where there are a plurality of two or more protrusions 21 having the reverse taper shape, after casting the light metal alloy, the light metal alloy formed between the protrusions 21 also has the reverse taper shape, The convex portion 21 and the light metal alloy are engaged to improve the tensile strength of the light metal alloy interface. From this, the bonding strength between the bonding portion 20 and the light metal alloy can be improved.

[Forming method of sintered member for casting]
The formation method of the sintered member 1 for cast-in of this invention is demonstrated, referring FIG.
First, as shown in FIG. 4A, the first lower punch 40 and the second lower punch 41 are disposed in the compression molding die 100. The first lower punch 40 and the second lower punch 41 are split punches capable of independently performing pressing operations.
Then, raw material powder containing iron powder or iron alloy powder as a main component is filled in the mold holes formed by the compression molding die 100, the first lower punch 40 and the second lower punch 41. As raw material powder, the thing of patent 5525995 can be used.

Next, as shown in FIG. 4B, the first upper punch 60 and the second upper punch 61 are disposed on the filled raw material powder. The first upper punch 60 and the second upper punch 61 are split punches capable of independently performing pressing operations.
The distance between the first lower punch 40 and the first upper punch 60 at this time is _{L 11,} and the second lower punch 41 is the distance between the second upper punch 61 is _{L 21.}

Next, as shown in FIG. 4C, the first lower punch 40, the first upper punch 60, the second lower punch 41, and the second upper punch 61 press and compact.
The distance between the first lower punch 40 and the first upper punch 60 when the compacting is L _12, and the second lower punch 41 is the distance between the second upper punch 61 is L _22. Adjustment is made such that the pressure by the first lower punch 40 and the first upper punch 60 for forming the main body portion 10 is larger than the pressure by the second lower punch 41 and the second upper punch 61 for forming the joint portion 20 Do. Therefore, it is necessary to satisfy L ₂₂ / L ₂₁ > L ₁₂ / L ₁₁ .
By adjusting the pressing by the second lower punch 41 and the second upper punch 61 and the pressing by the first lower punch 40 and the first upper punch 60, the density of each pressing position is the density of the main body 10 and the connecting portion 20. A shaped body can be obtained which is a ratio.

  Next, the obtained molded product is sintered at a temperature of not less than 950 ° C. and a melting point (1085 ° C.) of copper, preferably not less than 1000 ° C. and not more than 1080 ° C., as shown in FIG. The cast-in-place sintered member 1 is obtained.

[Light Metal Composite Member]
The light metal composite member according to the embodiment of the present invention is a cast-in-place sintered member 1 cast in a light metal alloy. The casting method of the light metal composite member which concerns on embodiment of this invention is shown below.

The cast-in-place sintered member 1 is placed in the mold without preheating or preheating.
By preheating the cast-in-place sintered member 1, it is possible to prevent the molten light metal alloy from being cooled and solidified at the same time as coming into contact with the cast-in-place sintered member 1. The atmosphere in the case of preheating is not particularly limited, and can be performed in an atmosphere of air, vacuum, inert gas atmosphere, reducing gas, and the like.

Next, the light metal alloy molten metal is introduced into the mold, and the cast-in-place sintered member 1 is cast while being cast in the form of the light-metal alloy, as shown in FIG. A light metal composite member in which at least the light metal alloy portion 30 is provided on the surface of 20 is obtained.
As the light metal alloy melt, one containing aluminum (Al) as a main component is preferable, but if silicon (Si) is contained at 5.0% by mass or more and 12.0% by mass or less, from a sintered member for casting Since the solidification point of the molten metal is further lowered due to the ternary eutectic of Al-Cu-Si between the diffused Cu and the molten Al and Si, the molten metal easily intrudes into the pores of the cast-in sintered member. Particularly preferred. In addition, when the light metal alloy molten metal contains in advance 1.5% by mass or more and 5.0% by mass or less of Cu, the action of the solidification point effect by the amount of Cu diffused from the sintered member for cast-in can be obtained faster. Therefore, this is also a preferred form. As such an Al-Si-Cu based aluminum alloy, eight kinds of ADCs, ten kinds of ADCs, and 12 kinds of ADCs specified in JIS H5302: 2006 correspond. Moreover, as such an aluminum alloy, magnesium (Mg): 0.3 mass% or less, zinc (Zn): 2.0 mass% or less, iron (Fe): 1.3 mass% or less, manganese (Mn) It may be at least one of 0.6 mass% or less, nickel (Ni): 0.5 mass% or less, and tin (Sn): 0.3 mass% or less.

  In the light metal composite member, the light metal alloy penetrates from the surface of the bonding portion of the cast-in-place sintered member into the pores inside. The penetration depth from the surface of the bonding portion of the light metal composite member is preferably 0.5 mm or more and 4.0 mm or less, from the viewpoint of improving the adhesion between the bonding portion and the light metal alloy and the bonding strength, 1.0 mm The diameter is more preferably 3.5 mm or less, and still more preferably 1.5 mm or more and 3.0 mm or less.

  EXAMPLES Hereinafter, the present invention will be more specifically described by way of examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

  The following evaluation was performed about the sintered member for cast-in obtained by the Example and the comparative example. The results are shown in Table 1.

<Measurement of density ratio>
In the examples, the density ratio of the main body portion and the bonding portion of the cast-in-place sintered member was measured. In the comparative example, the density ratio of the main body of the cast-in sintered member was measured.

<Measurement of infiltration of light alloy melt>
In the examples, the penetration of the light alloy melt into the main body and the joint of the cast-in-place sintered member was measured. In the comparative example, the infiltration of the light alloy melt in the main body of the cast-in-place sintered member was measured.
As a method of measuring the infiltration of the light metal melt, the cross section of the sample of the light metal composite member is mirror-polished, and the penetration depth of the light metal alloy from the surface of the joint of the sintered member for casting to the inside of the pores It was measured. The average value was calculated after measuring ten places.

<Measurement of strength>
In the examples, the strength (tensile strength) of the main body portion and the joint portion of the cast-in-place sintered member was measured. In the comparative example, the strength (tensile strength) of the main body of the cast-in sintered member was measured.

Example 1
Atomized iron powder as iron powder (average particle size: 72 μm), electrolytic copper powder as copper powder (aspect ratio: 1.6, average particle size: 46 μm) and stamp powder (aspect ratio: 16.0, average particle size: 45 μm) ), Natural graphite powder (average particle size: 10 μm) was prepared as graphite powder. Adding these powders in the proportions shown in Table 1, mixed, using a raw material powder obtained, the density of the coupling portion 20 is 6.4 mg / ^{m 3,} the density of the main body portion 10 and 7.0 mg / ^{m 3} The resultant was compacted into a plate-like compact having a width of 12.5 mm, a length of 32 mm and a thickness of 5 mm. The resulting compact was sintered at 1050 ° C. in ammonia decomposition gas (FIG. 6).
The obtained sintered body is preheated to 75 ° C. in the air atmosphere, mounted on a predetermined position of a simple mold, and then, a molten aluminum alloy (equivalent to JIS ADC12) by die casting under a casting pressure of 40 MPa. ) Was poured, and the sintered member 1 was cast while being cast, and a composite member sample 71 of the aluminum alloy composite member 70 was produced.
With respect to this composite member sample 71, its cross section was mirror-polished, and the infiltration depth of the aluminum alloy member 70 from the surface of the cast sintered member 1 into pores inside was measured.
Thereafter, as shown in FIG. 6, a test piece 72 was produced from the composite member sample 71 by machining. That is, the composite member sample 71 obtained as described above is cut in the width direction so that the cast-in-place sintered member 1 remains in the central portion on one side, and further cut in the orthogonal direction to bake the cast-in part. The portions of the connecting member 1 and the aluminum alloy member 70 are substantially square to form an adjacent rectangular shape, and the sintered member is subjected to a hole forming process to obtain a test piece 72.
About this test piece 72, as shown to FIG. 7 (a) and (b), while holding the part of the aluminum alloy member 70 with the chuck | zipper 80, inserting the pin 81 in the hole of the sintered member 1 for casting and pulling A test was conducted to determine the tensile strength. These results are shown together in Table 1.

Comparative Example 1
The raw material powder used in Example 1 was molded to have an overall density of 7.0 Mg / m ^3, and was pressed to a plate-like compact having a width of 12.5 mm, a length of 32 mm and a thickness of 5 mm. Powder molded. The resulting compact was sintered at 1050 ° C. in ammonia decomposition gas (FIG. 8).
The resulting sintered body is poured into a molten aluminum alloy (equivalent to JIS ADC12) by die casting in the same manner as in Example 1 to cast the sintered member 1a while casting, thereby forming an aluminum alloy composite member The 70a composite member sample 71a was prepared, and the infiltration depth was similarly measured.
Thereafter, as shown in FIG. 8, a test piece 72a was produced from the composite member sample 71a by machining. That is, the composite member sample 71a obtained as described above is cut in the width direction so that the sintered member 1a remains in the central portion on one side, and further cut in the orthogonal direction to cut the sintered member 1a and the aluminum alloy The portion of the member 70a has a substantially square shape to form an adjacent rectangular shape, and the sintered member is subjected to a drilling process to obtain a test piece 72a.
About this test piece 72a, as shown in FIG. 9 (a) and FIG.9 (b), the pin 81 is inserted in the hole of the sintered member 1a while holding the part of the aluminum alloy member 70a by the chuck 80, and a tensile test And the tensile strength was determined. These results are shown together in Table 1.

  The sintered member for castables according to the present invention is inexpensive and has excellent mechanical properties and is excellent in castability, and various light alloy composites obtained by cast-sintered sintered members such as parts for automobiles with light metal melt It is suitable for a member.

DESCRIPTION OF SYMBOLS 1 Sintered member 1 a Sintered member 1 a Sintered member 10 Body part 20 Bonding part 21 Convex part 30 Light metal alloy part 40 1st lower punch 41 2nd lower punch 60 1st upper punch 61 2nd upper punch 70, 70a aluminum alloy composite Member 71, 71a composite member sample 72, 72a test piece 80 chuck 81 pin 100 compression molding die

Claims (6)

A cast-in-place sintered member that is cast and used in a light metal alloy,
The cast-in-placement sintered member includes a main body portion and a joint portion,
The density ratio of the main body portion is 86% or more and 91% or less,
The sintered member for cast-in, wherein the density ratio of the joint portion is 80% or more and 84% or less. The connecting portion has pores communicating with the outside,
The sintered member for cast-in according to claim 1, wherein the porosity of the pores in the joint portion is 11% or more and 22% or less.   The sintered part for cast-in of Claim 1 or 2 in which the said connection part is provided with the convex part on the surface.   The sintered member for castable according to claim 3, wherein the convex portion has a reverse tapered shape with a thick tip.   5. The cast-in-place sintered member according to claim 3, wherein at least two or more convex portions are present.   The light metal composite member by which the sintering member for cast-in of any one of Claims 1-5 was casted by the light metal alloy.