JPH09324235A - Hyper-eutectic aluminum-silicon alloy, hyper-eutectic aluminum-silicon alloy die-cast casting, its production and method for using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hyper-eutectic Al-Si alloy for die casting in which the cost of working to the surface of a cast skin is reduced or, even in a state of nonworking in which working is not executed to the surface of the cast skin, capable of stably obtaining sufficiently good wear resistance and to obtain a hyper-eutectic Al-Si alloy die-cast casting. SOLUTION: The hyper-eutectic Al-Si alloy for die casting is the one having a compsn. contg., by weight, 12.0 to 25.0% Si, 0.5 to 5.0% Cu, 0.1 to 2.0% Mg, <=1.5% Fe, 0.001 to 0.02% P, one or two kinds of 0.1 to 0.5% Cr and 0.2 to 1.0% Mn, and the balance Al and the other required alloy elements, and the hyper-eutectic Al-Si alloy die-cast casting is the one composed of the casting obtd. by subjecting the above hyper-eutectic Al-Si alloy to die casting, and in which the generation of regions in which primary crystal Si is not crystallized out in the vicinity of the cast skin face is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hypereutectic Al-Si alloy for die casting, a hypereutectic Al-Si alloy die casting, a method for producing the same and a method for using the same, and more specifically, hypereutectic Al-Si. When one or two kinds of Cr and Mn are added when die-casting an alloy, a region in which primary crystal Si is not crystallized which occurs near the surface of the casting surface during die-casting is suppressed. In addition, a hypereutectic Al-Si alloy for die casting, which has a small machining allowance, improves the material yield, and can stably ensure wear resistance even when the sliding portion remains unprocessed, and such a The present invention relates to a hypereutectic Al-Si alloy die cast casting using an alloy, a method for producing the same, and a method for using the same.

[0002]

2. Description of the Related Art With the increasing demand for weight reduction of castings, replacement of conventional iron parts with aluminum has been studied. One of the properties that poses a problem in this case is the wear resistance of the aluminum alloy. A hypereutectic Al—Si-based alloy is widely known as an aluminum alloy applied to a portion where such wear resistance is required (for example, JIS H 5202 AC9A, AC9).
B, JIS H 5302 ADC14, etc.).

Further, in recent years, further cost reduction or high productivity has been demanded for aluminum alloy castings, and the productivity of these hypereutectic Al--Si alloy parts is also improved. In many cases, it is manufactured by an excellent die casting method.

[0004]

However, when the hypereutectic Al--Si alloy is die-cast, the results shown in FIG.
It is widely accepted that a region in which primary crystal Si is not crystallized is generated in the vicinity of the casting surface, as shown in FIG.

This region is inferior in wear resistance because the primary crystal Si is not crystallized, which is also the reason why the hypereutectic Al--Si alloy exhibits high wear resistance. Therefore, conventionally, this region is removed by working. The region where primary crystal Si is crystallized is used as a wear-resistant member by making it a casting surface.

Further, the region where the primary crystal Si is not crystallized may reach about 1 mm from the surface of the casting surface, so that the machining cost is large and the yield of the material is poor, or the machining cost is insufficient and the stability is stable. There was a problem that abrasion resistance could not be secured.

Furthermore, it has been widely known that when a hypereutectic Al--Si alloy is die-cast, a region in which the primary crystal Si is not crystallized is produced, but as a countermeasure, casting conditions and casting plan are used. The main changes were
There was also a tradeoff with suppression of casting defects, so it could not be a decisive measure.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and is a hypereutectic Al-Si.
When die casting the alloy, by adding one or two of Cr and Mn to the hypereutectic Al-Si alloy, primary crystal Si crystallizes when the hypereutectic Al-Si alloy is die cast. Hypereutectic Al- that can suppress the generation of non-working areas, improve the material yield by reducing the machining allowance, and ensure stable wear resistance even when the sliding part remains unprocessed. It is intended to provide a Si alloy die casting product.

[0009]

In order to solve the above-mentioned problems, the present invention has the following constitution.

(1) In a hypereutectic Al-Si alloy, Cr: 0.1 to 0.5% and Mn: 0.2 to 1.0 in weight%.
%, One or two of the above are included, and a hypereutectic Al-Si alloy for die casting.

(2) In weight%, Si: 12.0 to 2
5.0%, Cu: 0.5 to 5.0%, Mg: 0.1
2.0%, Fe: 1.5% or less, P: 0.001 to 0.
02%, Cr: 0.1-0.5%, Mn: 0.2
A hypereutectic Al-Si alloy for die casting, containing one or two of 1.0 to 1.0% and the balance Al and other necessary alloy elements.

(3) In weight%, Si: 12.0 to 2
5.0%, Cu: 0.5 to 5.0%, Mg: 0.1
2.0%, Fe: 1.5% or less, P: 0.001 to 0.
02%, Cr: 0.1-0.5%, Mn: 0.2
To 1.0% of one or two kinds, and a die cast casting of a hypereutectic Al-Si alloy containing the balance Al and other necessary alloy elements, and primary crystal Si near the casting surface is crystallized. A hypereutectic Al-Si alloy die-cast casting characterized by suppressing the formation of a non-existing region.

(4) By weight, Si: 16.0 to 1
8.0%, Cu: 4.0 to 5.0%, Mg: 0.45
0.65%, Fe: 1.5% or less, P: 0.001-
0.02%, Cr: 0.1-0.5%, Mn:
It is composed of a die-cast casting of a hypereutectic Al-Si alloy containing one or two of 0.2 to 1.0% and the balance Al and impurities, and primary crystal Si near the casting surface is crystallized. Hypereutectic A characterized by suppressing the formation of non-existing regions
l-Si alloy die casting.

(5) Si: 18.0-2 by weight%
0.0%, Cu: 0.5 to 1.5%, Mg: 0.5 to
1.5%, Fe: 1.5% or less, P: 0.001 to 0.
02%, Cr: 0.1-0.5%, Mn: 0.2
Of 1.0 to 1.0% of a die-cast casting of a hypereutectic Al-Si alloy containing the balance Al and impurities, and the primary crystal Si near the casting surface is not crystallized. Hypereutectic Al-S characterized by suppressing generation
i alloy die cast casting.

(6) Si: 22.0 to 2 by weight%
4.0%, Cu: 0.5 to 1.5%, Mg: 0.5 to
1.5%, Fe: 1.5% or less, P: 0.001 to 0.
02%, Cr: 0.1-0.5%, Mn: 0.2
Of 1.0 to 1.0% of a die-cast casting of a hypereutectic Al-Si alloy containing the balance Al and impurities, and the primary crystal Si near the casting surface is not crystallized. Hypereutectic Al-S characterized by suppressing generation
i alloy die cast casting.

(7) One or two of Cr and Mn
When die-casting a hypereutectic Al-Si alloy containing no seeds, Cr: 0.1-0.5%, Mn:
Hypereutectic Al characterized by suppressing the formation of a region where primary crystal Si is not crystallized in the vicinity of the casting surface by adding one or two of 0.2 to 1.0% -A method for producing a Si alloy die cast casting.

(8) The hypereutectic Al-Si according to any one of claims 3 to 6, wherein when used as a wear-resistant sliding member, the sliding portion is used without being processed.
How to use alloy die castings.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hypereutectic Al-for die casting according to the present invention
In a Si alloy and a hypereutectic Al-Si alloy die casting using the same, Si: 12.0 to 25.
0%, Cu: 0.5 to 5.0%, Mg: 0.1 to 2.0
%, Fe: 1.5% or less, P: 0.001 to 0.02%
In a hypereutectic Al-Si alloy containing Cr: 0.1 to 0.
5%, Mn: 0.2 to 1.0%, one or two
By containing the seed and other necessary alloying elements, the non-crystallized region of the primary crystal Si generated near the casting surface when the hypereutectic Al-Si alloy is die-cast is suppressed to be narrow, so that the die casting is performed. The machining allowance of the surface of the casting rough material is small, the material yield is improved, and the wear resistance is stably secured even if the surface of the die casting rough material remains unprocessed.

The reason why the region where the primary crystal Si is not crystallized is narrowed by adding one or two of Cr and Mn is that Cr crystallized prior to the crystallization of the primary crystal Si. That the crystallization product of the system, the crystallization product of the Mn system, or the crystallization product of the (Cr, Mn) system becomes a heterogeneous nucleus of the crystallization of the primary crystal Si to promote the crystallization of the primary crystal Si, and Cr, Mn
It is conceivable that the addition of Al changes the state of supercooling of the molten metal, which affects the formation of regions in which primary Si is not crystallized.

Therefore, it is considered that elements such as Cu and Mg that do not crystallize a crystallized substance that becomes a heterogeneous nucleus are not effective in suppressing the region where primary crystal Si is not crystallized.

Below, the action of each element constituting the hypereutectic Al-Si alloy for die casting and the hypereutectic Al-Si alloy die casting according to the present invention and the reasons for limiting the composition range (% by weight) will be shown.

Si: Si is an element that contributes to the improvement of wear resistance. Primary crystal Si, which contributes to the improvement of wear resistance, does not crystallize if the Si content is less than 12.0%, so 12.0% was made the lower limit. However, if the content exceeds 25.0%, the liquidus temperature of the alloy rises, the melting and casting properties deteriorate, and the machinability also deteriorates significantly, so the content was made 25.0% or less.

Cu: Cu is an element that contributes to the improvement of room temperature and high temperature strength by solid solution strengthening and age hardening. However, if less than 0.5%, the effect is small.
If the content is more than 0%, the toughness decreases and the number of shrinkage cavities increases, so the content was made 0.5 to 5.0%.

Mg: Mg is an element that contributes to the improvement of strength by age hardening when coexisting with Si. However,
If the content is less than 0.1%, the effect is small, and if the content exceeds 2.0%, the toughness decreases, so the content was made 0.1 to 2.0%.

Fe: Fe is an element effective in preventing the molten metal from sticking to the mold during die casting.
However, if the content exceeds 1.5%, the mechanical properties of the casting deteriorate due to the crystallization of the Fe-based intermetallic compound, so the content was made 1.5% or less.

P: P is an element having the effect of refining the primary crystal Si and uniformly dispersing it. However, 0.00
If it is less than 1%, its effect is small, and if it exceeds 0.02%, the castability such as molten metal flow is deteriorated.
The range was up to 0.02%.

Mn: Mn is an element that contributes to reduce the area where primary crystal Si is not crystallized, which is generated near the surface of the casting surface when the hypereutectic Al-Si alloy is die-cast. However, if less than 0.2%, the effect is small, 1.0%
If it is contained in excess of 1.0, the castability and mechanical properties will be deteriorated, so the content was made 0.2 to 1.0%.

Cr: Cr is also an element which contributes to reduce the area where primary crystal Si is not crystallized, which occurs in the vicinity of the casting surface when the hypereutectic Al-Si alloy is die cast. However, if less than 0.1%, the effect is small and 0.5
%, The castability is deteriorated and the Al—Cr-based crystallized product is coarsened, resulting in deterioration of mechanical properties.
The range was 0.1 to 0.5%.

Hypereutectic Al-for die casting according to the present invention
The Si alloy and the hypereutectic Al-Si alloy die casting have the chemical composition as described above in claims 1 to 3, but in an embodiment thereof,
A hypereutectic Al-Si alloy for die casting or a hypereutectic Al-Si alloy die-cast casting as described below can be used.

That is, as described in claim 4, in correspondence with JIS ADC14 alloy, in weight%, Si: 16.0 to 18.0%, Cu: 4.0 to
5.0%, Mg: 0.45 to 0.65%, Fe: 1.5
% Or less, P: 0.001 to 0.02%, and Cr:
0.1-0.5%, Mn: 0.2-1.0% of 1
Type or two types, the hypereutectic Al-Si alloy for die casting consisting of the balance Al and impurities, and the primary crystal Si near the casting surface by die casting the molten metal of the hypereutectic Al-Si alloy for die casting A hypereutectic Al-Si alloy die-casting product in which the generation of uncrystallized regions is suppressed can be obtained.

Further, as described in claim 5, in weight%, Si: 18.0 to 20.0%, Cu: 0.5 to
1.5%, Mg: 0.5 to 1.5%, Fe: 1.5% or less, P: 0.001 to 0.02%, and Cr: 0.1
˜0.5%, Mn: 0.2 to 1.0%, one or two kinds, and a hypereutectic Al-Si alloy for die casting, which comprises the balance Al and impurities, and a hypereutectic for die casting. By die-casting the molten Al-Si alloy, it is possible to obtain a hypereutectic Al-Si alloy die-cast casting in which the formation of a region where primary crystal Si is not crystallized near the casting surface is suppressed.

Further, as described in claim 6,
% By weight, Si: 22.0 to 24.0%, Cu: 0.5
~ 1.5%, Mg: 0.5-1.5%, Fe: 1.5%
Hereinafter, P: 0.001 to 0.02% and Cr: 0.
1 to 0.5%, Mn: 0.2 to 1.0% of one or two, and a hypereutectic Al-Si alloy for die casting, which comprises the balance Al and impurities, and a hypereutectic alloy for die casting. A hypereutectic Al-Si alloy die-cast casting in which the formation of a region in which primary crystal Si is not crystallized near the casting surface is suppressed can be obtained by die-casting the molten Al-Si alloy melt.

Furthermore, the hypereutectic Al-- according to the present invention
In the method for producing a Si alloy die cast casting, as described in claim 7, one or two of Cr and Mn are not included, for example, any one of claims 2 to 3 or 4 to 6. When die-casting a hypereutectic Al-Si alloy having a composition, in weight%, Cr: 0.1 to 0.5%,
By adding one or two of Mn: 0.2 to 1.0%, it is possible to suppress the formation of a region near the casting surface where the primary crystal Si is not crystallized.

Furthermore, the hypereutectic Al-- according to the present invention
In the method of using the Si alloy die-cast casting, as described in claim 8, when used as a wear-resistant sliding member, the sliding portion can be used without being processed.

[0035]

As described above, the hypereutectic Al-Si alloy for die casting according to the present invention contains Cr: 0.1 to 0.5% by weight in the hypereutectic Al-Si alloy. Mn:
Since it contains one or two of 0.2 to 1.0%, it is the first time compared with a die-cast casting using a conventional hypereutectic Al-Si alloy containing no Cr or Mn. The area where crystal Si is not crystallized is controlled to be narrow, the machining allowance of the die-cast rough material is reduced and the material yield is improved, and it can be used as a wear-resistant sliding member even when it is not machined. It is possible, and a remarkably excellent effect such as a good abrasion resistance can be stably obtained is brought about.

Then, as described in claim 2,
% By weight, Si: 12.0 to 25.0%, Cu: 0.5
~ 5.0%, Mg: 0.1-2.0%, Fe: 1.5%
Hereinafter, P: 0.001 to 0.02% and Cr: 0.
1-0.5%, Mn: 0.2-1.0% of 1 type or 2 types, and by making it the hypereutectic Al-Si alloy for die castings which consists of the balance Al and other required alloy elements. , Which is remarkably excellent in that it is possible to exhibit sufficient wear resistance by reducing the machining allowance of the surface or leaving it unprocessed as compared with the conventional die-cast casting using a hypereutectic Al-Si alloy. The effect is brought.

Then, as described in claim 3,
% By weight, Si: 12.0 to 25.0%, Cu: 0.5
~ 5.0%, Mg: 0.1-2.0%, Fe: 1.5%
Hereinafter, P: 0.001 to 0.02% and Cr: 0.
1 to 0.5%, Mn: 0.2 to 1.0% of one or two, consisting of a die cast casting of a hypereutectic Al-Si alloy consisting of the balance Al and other necessary alloy elements, A hypereutectic Al-Si alloy die-cast casting that suppresses the formation of a region where primary crystal Si is not crystallized near the casting surface,
Of these, the Si content is 1 as described in claim 4.
6.0 to 18.0%, 18.0 to 20.0% as described in claim 5, or 22.0 to 24.0% as described in claim 6. By adjusting the Cu content and the Mg content as appropriate,
It has castability, mechanical properties, and corrosion resistance corresponding to each, and it can stably obtain good wear resistance even if the machining allowance of the surface of the die cast casting is reduced or it remains unprocessed. The remarkable effect that it is possible to provide a hypereutectic Al-Si alloy die casting is brought about.

Furthermore, when the hypereutectic Al-Si alloy containing no one or two of Cr and Mn is die-casted, the weight% is
And Cr: 0.1-0.5%, Mn: 0.2-1.0%
One or two of these are added to suppress the formation of regions in which primary crystal Si near the casting surface is not crystallized, thereby reducing the machining allowance of the surface or unprocessing. As a result, it is possible to produce a hypereutectic Al-Si alloy die-cast casting that can stably obtain good wear resistance, which is a remarkably excellent effect.

And, as described in claim 8,
When the die-cast casting is used as a wear-resistant sliding member, the sliding portion is used as it is without being machined, so that the surface treatment is not required when the die-cast casting is used.

[0040]

EXAMPLES Examples of the present invention will be specifically described below together with comparative examples.

In the examples and the comparative examples, the thickness of the region in which the primary crystal Si was not crystallized in the vicinity of the casting surface was measured and the wear resistance was evaluated by the following method.

(Melting and Casting Method) Various materials having the chemical composition shown in Table 1 were melted in a metal resistance crucible furnace and then die-cast under the conditions shown in Table 2 using a 350-ton die casting machine. 180 x 150 x 6 mm
A hypereutectic Al-Si alloy die-casting product made of the plate-shaped test piece was obtained.

[0043]

[Table 1]

[0044]

[Table 2]

(Measurement method of the area where primary crystal Si is not crystallized) After the die-cast casting obtained by the above (melting and casting method) is cut, emery paper polishing and buff polishing are performed to obtain a microstructure photograph of the casting cross section. I took a picture of. The magnification of the photograph at this time was 50 times.

For each of the microstructure photographs thus obtained, as shown in FIG. 10, n = 6 locations (L ₁ to
L ₆₎ for casting the primary crystal Si from the skin makes a depth measurement of up area begins to crystallize, this value is the primary crystal Si and a thickness of in the region not crystallized.

(Abrasion resistance evaluation method) Of the die castings obtained by the above (melting and casting method), those shown in Table 3 were subjected to a friction and wear test using a ring-plate type friction and wear tester. It was

At this time, as the ring, the ring 1 made of bearing steel having the shape shown in FIG. 1 was used. That is, this ring 1 has an outer diameter D ₀ = 25.6 (+0.1, −0.1) m.
m, inner diameter D _I = 20.0 (+ 0.05, -0) mm, length L = 17 (+ 0.1, -0.1) mm, and width W _L = 6.0 (+0). .1, -0) mm and a depth C _L = 3.0 (+0.1, -0.1) mm, which is slightly larger, and a width W _S = 4.0 (+0.1, -0.1). ) M
The cutout 1b has a depth C m of 2.5 mm and a depth C _{S of} 2.5 (+0.1, −0.1) mm.

As the plate, the plate 2 having the shape shown in FIG. 2 cut out from the die-cast casting shown in Table 3 was used. That is, this plate 2 has a side length L
_{A = 35 (+ 0, -0.1} ) mm, the other side length _L B = 3
A rectangle of 5 (+0, -0.1) mm is formed and a thickness T =
3.0 (+0.1, -0.1) mm, with D in the center
= 4 mm round hole 2a is formed.

The friction and wear test conditions were as follows: surface pressure: 18
MPa, sliding speed: 0.1 m / s, sliding distance: 36
The oil temperature was 0 m and the oil temperature was room temperature.

After the above friction and wear test was completed, roughness was measured in the direction of the friction surface 3 of the test piece to measure the amount of step wear.

[0052]

[Table 3]

Thickness measurement of uncrystallized region of primary Si
Results (Comparative Examples 1, 2 and Examples 1, 2, 3) Hypereutectic A having the compositions shown in Comparative Examples 1, 2 and Examples 1, 2, 3 shown in Table 1
A molten metal of the 1-Si alloy was cast under the conditions shown in Table 2 and the thickness of the region where the primary crystal Si was not crystallized was measured. The result is shown in FIG.

As shown in FIG. 3, in the hypereutectic Al-Si alloy die castings of Examples 1 to 3 containing one or both of Mn and Cr, Comparative Example 1 containing no Mn and Cr was used. It can be seen that the thickness of the region where the primary crystal Si is not crystallized is narrower than that of the No. 2 sample.

(Comparative Examples 3, 4 and Examples 4, 5, 6) Table 1
The hypereutectic Al—Si alloy melts having the compositions shown in Comparative Examples 3 and 4 and Examples 4, 5 and 6 shown in FIG. The thickness was measured. FIG. 4 shows the results.

As shown in FIG. 4, hypereutectic Al--S of Examples 4, 5 and 6 containing one or both of Mn and Cr.
In the i-alloy die-cast casting, it can be seen that the thickness of the region where primary crystal Si is not crystallized is narrower than that of Comparative Examples 3 and 4 which do not contain Mn and Cr.

(Comparative Examples 5, 6 and Examples 7, 8, 9) Table 1
The melts of the hypereutectic Al-Si alloys having the compositions shown in Comparative Examples 5 and 6 and Examples 7, 8 and 9 shown in Table 1 were cast under the conditions shown in Table 2, and The thickness was measured. The result is shown in FIG.

As shown in FIG. 5, hypereutectic Al--S of Examples 7, 8 and 9 containing one or both of Mn and Cr.
It can be seen that in the i alloy die cast casting, the thickness of the region in which the primary crystal Si is not crystallized is narrower than that in Comparative Examples 5 and 6 which do not contain Mn and Cr.

(Examples 1 to 9) As described above with reference to FIGS. 3 to 5, the thickness of the region where the primary crystal Si is not crystallized is Si.
It was recognized that the alloy with higher content tended to be thicker. It is considered that this is because, if the cooling rate is the same, the degree of supercooling at the time of solidification becomes larger when the amount of Si is larger.

Results of Evaluation of Wear Resistance (Comparative Examples 1 and 3) Friction and wear tests were conducted on die cast castings having the compositions of Comparative Example 1 and Example 3 shown in Table 1 with the casting surface as the sliding surface. It was The result is shown in FIG.
Shown in In Comparative Example 1, the result at the time when the test was interrupted at the slip distance of 60 m is shown.

As shown in FIG. 6, although the hardness of the casting surface is the same in Example 3 and Comparative Example 1, the amount of stepped wear may be significantly smaller in Example 3. Admitted. This is because in the casting of Example 3, primary crystal Si crystallizes from very near the casting surface, whereas in the casting of Comparative Example 1, primary Si crystallizes near the casting surface. It is thought that this is due to the absence.

Therefore, in the casting of Example 3,
By adding Mn and Cr, the primary crystal S from very near the casting surface
Since i is crystallized out, it can be used as a wear-resistant sliding member with the sliding surface left unprocessed.

(Comparative Examples 3 and 6) Friction and wear tests were conducted on the die-cast castings having the compositions of Comparative Example 3 and Example 6 shown in Table 1 with the casting surface as the sliding surface. The result is shown in FIG. In Comparative Example 3, the results at the time when the test was interrupted at a slip distance of 60 m are shown.

As shown in FIG. 7, although the hardness of the casting surface was the same in Example 6 and Comparative Example 3, the amount of stepped wear was significantly smaller in Example 6. Admitted. This is because, in the casting of Example 6, primary crystal Si crystallizes from very near the casting surface, whereas in the casting of Comparative Example 3, primary Si crystallizes near the casting surface. It is thought that this is due to the absence.

Therefore, in the casting of Example 6,
By adding Mn and Cr, the primary crystal S from very near the casting surface
Since i is crystallized out, it can be used as a wear-resistant sliding member with the sliding surface left unprocessed.

Comparative Examples 5 and 9 For the die-cast castings having the compositions of Comparative Example 5 and Example 9 shown in Table 1, a friction wear test was conducted with the casting surface as the sliding surface. The result is shown in FIG. In Comparative Example 5, the results at the time when the test was interrupted at a slip distance of 60 m are shown.

As shown in FIG. 8, although the hardness of the casting surface is the same in Example 9 and Comparative Example 5, the amount of stepped wear may be significantly smaller in Example 9. Admitted. This is because, in the casting of Example 9, primary crystal Si crystallizes from very near the casting surface, whereas in the casting of Comparative Example 5, primary Si crystallizes near the casting surface. It is thought that this is due to the absence.

Therefore, in the casting of Example 9,
By adding Mn and Cr, the primary crystal S from very near the casting surface
Since i is crystallized out, it can be used as a wear-resistant sliding member with the sliding surface left unprocessed.

[Brief description of drawings]

1 is a cross-sectional explanatory view ((A) of FIG. 1) and a front explanatory view (((1) of FIG. 1) showing a shape of a ring material used for carrying out a friction and wear test in Examples and Comparative Examples of the present invention. B)).

FIG. 2 is a front explanatory view (FIG. 2A) and a sectional explanatory view (B of FIG. 2) showing the shape of a plate material used for carrying out a friction and wear test in Examples and Comparative Examples of the present invention. )).

FIG. 3 is a comparative example 1 and 2 and examples 1, 2, and 3 of the present invention.
3 is a graph showing the result of measuring the thickness of a region in which primary crystal Si is not crystallized.

FIG. 4 is a comparative example 3, 4 of the present invention and examples 4, 5, 6;
3 is a graph showing the result of measuring the thickness of a region in which primary crystal Si is not crystallized.

FIG. 5: Comparative examples 5 and 6 of the present invention and Examples 7, 8 and 9
3 is a graph showing the result of measuring the thickness of a region in which primary crystal Si is not crystallized.

FIG. 6 is a graph showing the results of measuring the amount of step wear by conducting a friction wear test in Comparative Example 1 and Example 3 of the present invention.

FIG. 7 is a graph showing the results of measuring the amount of step wear by conducting a friction wear test in Comparative Example 3 and Example 6 of the present invention.

FIG. 8 is a graph showing the results of measuring the amount of step wear by conducting a friction wear test in Comparative Example 5 and Example 9 of the present invention.

FIG. 9 is an explanatory diagram showing a region where primary crystal Si is not crystallized in a hypereutectic Al—Si alloy die casting product.

FIG. 10 is an explanatory diagram illustrating a method for measuring the thickness of a region in which primary crystal Si is not crystallized in a hypereutectic Al—Si alloy die casting.

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] August 19, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Figure 9

[Correction method] Change

[Correction contents]

FIG. 9 is a metallographic micrograph showing a region where primary crystal Si is not crystallized in a hypereutectic Al—Si alloy die-cast casting.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masuyuki Kuramo 2-20, Higashi-Shinagawa, Shinagawa-ku, Tokyo Within Japan Light Metal Co., Ltd. (72) Inventor Akio Hashimoto 2-chome, Higashi-Shinagawa, Shinagawa-ku, Tokyo 2-20 No. 20 Japan Light Metal Co., Ltd. (72) Inventor Haruyasu Koto 2-2-20 Higashi-Shinagawa, Shinagawa-ku, Tokyo Within Japan Light Metal Co. Ltd. (72) Inventor Hiroshi Horikawa 2 Higashi-Shinagawa, Shinagawa-ku, Tokyo 2-20, Nihon Light Metal Co., Ltd. (72) Inventor Takaaki Ino, 2-22, Higashi-Shinagawa, Shinagawa-ku, Tokyo Kenji Tsushima (72) Inventor, Kenji Tsushima, Kanagawa Yokohama, Kanagawa 2 Takara-cho, ward Nissan Motor Co., Ltd. (72) Inventor Masahiko Shioda 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Inventor Taku Hiroshi Kanagawa Kanagawa-ku, Yokohama-shi Takaracho Address 2 Nissan Automobile Co., Ltd. in the (72) inventor sheath nurses protect Kanagawa Prefecture, Kanagawa-ku, Yokohama-shi Takaracho Address 2 Nissan-car Co., Ltd.

Claims (8)

[Claims] 1. A hypereutectic Al-Si alloy, in wt%,
A hypereutectic Al-Si alloy for die casting, comprising one or two of Cr: 0.1 to 0.5% and Mn: 0.2 to 1.0%. 2. Si by weight: 12.0 to 25.0
%, Cu: 0.5 to 5.0%, Mg: 0.1 to 2.0
%, Fe: 1.5% or less, P: 0.001 to 0.02
%, Cr: 0.1 to 0.5%, Mn: 0.2 to
A hypereutectic Al-Si alloy for die casting, comprising one or two of 1.0% and the balance Al and other necessary alloy elements. 3. Si by weight: 12.0 to 25.0
%, Cu: 0.5 to 5.0%, Mg: 0.1 to 2.0
%, Fe: 1.5% or less, P: 0.001 to 0.02
%, Cr: 0.1 to 0.5%, Mn: 0.2 to
It consists of a die-cast casting of a hypereutectic Al-Si alloy containing 1.0% of one or two kinds and the balance Al and other necessary alloy elements, and primary crystal Si near the casting surface is not crystallized. A hypereutectic Al-Si alloy die cast casting characterized by suppressing the formation of regions. 4. Si: 16.0 to 18.0 by weight%.
%, Cu: 4.0-5.0%, Mg: 0.45-0.6
5%, Fe: 1.5% or less, P: 0.001 to 0.02
%, Cr: 0.1 to 0.5%, Mn: 0.2 to
Formation of a region in which primary crystal Si near the casting surface is not crystallized, which is formed of a die-cast casting of a hypereutectic Al-Si alloy containing one or two of 1.0% and the balance Al and impurities Which suppresses the hypereutectic Al-Si
Alloy die casting casting. 5. Si: 18.0-20.0% by weight.
%, Cu: 0.5 to 1.5%, Mg: 0.5 to 1.5
%, Fe: 1.5% or less, P: 0.001 to 0.02
%, Cr: 0.1 to 0.5%, Mn: 0.2 to
Formation of a region in which primary crystal Si near the casting surface is not crystallized, which is formed of a die-cast casting of a hypereutectic Al-Si alloy containing one or two of 1.0% and the balance Al and impurities Which suppresses the hypereutectic Al-Si
Alloy die casting casting. 6. Si: 22.0 to 24.0 in weight%.
%, Cu: 0.5 to 1.5%, Mg: 0.5 to 1.5
%, Fe: 1.5% or less, P: 0.001 to 0.02
%, Cr: 0.1 to 0.5%, Mn: 0.2 to
Formation of a region in which primary crystal Si near the casting surface is not crystallized, which is formed of a die-cast casting of a hypereutectic Al-Si alloy containing one or two of 1.0% and the balance Al and impurities Which suppresses the hypereutectic Al-Si
Alloy die casting casting. 7. When die-casting a hypereutectic Al-Si alloy containing no one or two of Cr and Mn, Cr: 0.1-0.5%, Mn: 0. Two
Of 1.0 to 1.0% is added to suppress the formation of a region where primary crystal Si is not crystallized in the vicinity of the casting surface by adding one or two of them. Manufacturing method of die casting. 8. The hypereutectic Al-Si alloy die-casting according to claim 3, wherein when used as a wear-resistant sliding member, the sliding portion is used without being processed. How to use castings.