JP2609107B2 - Intermetallic compound particle dispersion strengthened alloy and method for producing the same - Google Patents

Description

The present invention relates to an intermetallic compound particle dispersion strengthened alloy and a method for producing the same.

[Conventional technology]

The AlMn-based intermetallic compound powder is a powder of high hardness, has good wettability with the Al-Mn-Mg-based matrix of the same type, and has excellent stability. Incidentally, the intermetallic compound powder, Al
When directly added to a conventional aluminum alloy melt such as a Si-based alloy or the like, it melts in a short time, and thus, conventionally, the metal particle and the intermetallic compound particle dispersion strengthened alloy are manufactured by a sintering method.

In the conventional sintering method, a metal powder or an intermetallic compound powder is added to a fine mother alloy powder and mechanically stirred and mixed.
This is press-formed and heat-sintered to produce a metal particle or intermetallic compound particle dispersion-strengthened alloy, which is a method of manufacturing a target product by heat-sintering an extruder or a rolling mill. . However, in the conventional sintering method, the metal powder or the intermetallic compound powder and the master alloy powder are mechanically stirred and mixed.However, it is not possible to uniformly disperse and mix the metal powder or the intermetallic compound powder in the matrix mother alloy powder. It was difficult due to agglomeration and specific gravity difference between particles.

In addition, because of the participation in press molding and heat sintering, an antioxidant method and equipment are required in the process of heat sintering, and therefore products with high dimensional accuracy and limited strength are also expensive. In view of this, there is a considerable problem in that it is difficult to mass-produce a particle-dispersed alloy at low cost. For this reason, there has been a demand for an intermetallic compound particle dispersion strengthened alloy which is excellent in mechanical properties, particularly abrasion resistance or corrosion resistance, in which intermetallic compound particles are sufficiently and uniformly dispersed in a mother alloy by an easy method. A hypereutectic Al-Si alloy is generally known as a wear-resistant aluminum alloy for die casting, and 390 alloy is standardized to ASTM.

[Problems to be solved by the invention]

The present invention has been made to solve the above problems, and conventionally, it has been considered impossible to directly add the intermetallic compound powder to the melt in order to dissolve it when added to the master alloy melt, By using a die casting machine,
It can be added directly into the molten metal and disperse the intermetallic compound particles uniformly in the matrix without dissolving by short-time mechanical stirring, thereby having excellent mechanical properties without reducing ductility. It is another object of the present invention to provide an intermetallic compound particle dispersion strengthened alloy having excellent corrosion resistance by using a corrosion-resistant aluminum alloy for die-casting as a matrix, and a method for producing the same.

[Means for solving the problem]

The present invention provides a AlMn-Mg-based alloy as a matrix, AlMn in the _{matrix, Al 3 Mn, Al 4 Mn} , dispersing one or more intermetallic compound powder of Al ₆ Mn, also the
The above-mentioned problem is solved by directly adding the above-mentioned intermetallic compound powder into a molten metal of an Al-Mn-Mg alloy, stirring and mixing, and then dispersing the powder uniformly in a matrix by die casting. It was done.

[Specific configuration of the invention]

 Hereinafter, the present invention will be described in more detail.

The Al-Mn-Mg-based alloy used in the present invention is a matrix, and specifically, Al-0.5 to 4.0 wt% Mn-
4.0 to 8.0 wt% Mg alloy.

The reason for this is that a low-Mn Al-Mn-Mg alloy has excellent mechanical properties and corrosion resistance and is suitable as a matrix material in terms of cost. If the Mn content is 0.5 wt% or less, the corrosion resistance is insufficient, and if it is 4.0 wt% or more, the mechanical properties deteriorate. If the Mg content is 4.0 wt% or less, sufficient strength cannot be obtained, and if it is 8 wt% or more, Mg segregation becomes severe and mechanical properties deteriorate.

In the present invention, the particles to be mixed and dispersed in the matrix (hereinafter referred to as dispersed particles) are AlMn, Al ₃ Mn, Al ₄ Mn, Al
It is preferably at least one intermetallic compound powder selected from ₆ Mn.

The reason for this is that, as shown in the Al-Mn equilibrium state in FIG. 2, the wettability is good and the stability is excellent, since it is the same as the Al-Mn-Mg matrix material.

Further, Table 1 shows the hardness (Vickers hardness: Hv) of the Al-Mn-based intermetallic compound. Since each of them has a hardness of 500 (Hv) or more, these high-hardness particles were added to the mother alloy melt. By adding the same, an alloy having excellent wear resistance can be obtained.

The added amount of the dispersed particles is preferably 3 to 30% by weight, more preferably 5 to 20% by weight, and still more preferably.
It is 10 to 20% by weight. The reason is that if the addition amount is less than 3%, there is no effect of improving the wear resistance, and if it exceeds 30% by weight, the molten mother alloy rapidly solidifies in the stirring stage, so that it is difficult to produce by the production method of the present invention. Because there is.

The particle size of the dispersed particles is preferably 100 μm or less, more preferably 50 μm or less. The reason is that the particle diameter is 10
If it exceeds 0 μm, the dispersibility in the matrix is poor, and the mechanical properties deteriorate.

That is, since the dispersion of the dispersed particles in the matrix is uniform, the metal particles and the intermetallic compound particle dispersion strengthened alloy are excellent in mechanical properties such as abrasion resistance without losing ductility.

The intermetallic compound particle dispersion strengthened alloy according to the present invention is basically configured as described above, and the manufacturing method thereof will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a partial cross-sectional view of one configuration example of a stirring and mixing apparatus used in the method for producing an intermetallic compound particle dispersion strengthened alloy according to the present invention.

First, a predetermined amount of molten Al-Mn-Mg alloy (master alloy) serving as a matrix is poured into a stirring and mixing tank 2 of a stirring and mixing device, and then a predetermined amount of the dispersed particles is added to the molten metal and added to the stirring blade 3. Is rotated by a motor 4 and stirred and mixed for a short time to obtain a dispersed particle mixed alloy melt 1.

As shown in FIG. 2, the temperature of the molten Al-Mn-Mg alloy
The temperature is preferably 650 to 850 ° C, more preferably 730 to 800 ° C, and particularly preferably 750 to 780 ° C. The reason for this is that if the temperature is lower than 650 ° C., the molten Al—Mn—Mg alloy is immediately solidified, and if the temperature exceeds 850 ° C., casting problems such as seizure to a mold during casting occur.

The time required for stirring and mixing may be such that the aggregation of the dispersed particles does not occur and the mixing and stirring can be performed to such an extent that the dispersed particles can be uniformly dispersed in the matrix by a die casting machine described below, and is preferably 5 minutes or less. . More preferably, it is 3 to 60 seconds, particularly preferably 5 to 60 seconds.
~ 10 seconds. The reason for this is that if it exceeds 5 minutes, the dispersed particles are dissolved and become integrated with the matrix mother alloy, and no improvement in wear resistance is observed.

After the stirring and mixing, the melt 1 containing the dispersed particles is supplied to a die casting machine and formed into a desired shape. At this time, the dispersed particles are dispersed in the matrix even in the die casting machine, and are further homogenized.

In this way, an intermetallic compound particle dispersion strengthened alloy having excellent mechanical properties such as abrasion resistance and ductility in which the dispersed particles are uniformly dispersed in the matrix, and further having excellent corrosion resistance is produced. Therefore, unlike the conventional sintered powder metallurgy method, a costly surface treatment method, an antioxidant method and an apparatus are not required, and a product having a complicated shape can be easily and inexpensively manufactured.

〔Example〕

 Hereinafter, the present invention will be specifically described based on examples.

[Example 1] Al-2wt% Mn-5wt% Mg which is a matrix (master alloy)
AlMn, Al ₃ Mn, Al ₄ Mn, Al ₄
10 wt% of ₆ Mn intermetallic compound powder was added, and the mixture was stirred and mixed by a stirring and mixing device shown in FIG. Obtained. FIG. 3a shows a micrograph of the AlMn intermetallic compound powder before addition, and FIG. 3a shows an enlarged view of a test piece obtained at the tip of the mold and at the gate when the AlMn intermetallic compound was added. Micrographs at 50 × magnification are shown in FIGS. 3b and 3c, respectively. Further, as dispersed particles Al ₃ Mn, Al ₄ Mn,
The micrographs of the test pieces obtained at the gate of the mold when the Al ₆ Mn intermetallic compound powder was used were taken at a magnification of 50 times, and
This is shown in FIGS. 3d, 3e and 3f.

As apparent from FIGS. 3b to 3f, AlMn, Al ₃ M
It can be seen that n, Al ₄ Mn, and Al ₆ Mn intermetallic compound particles are uniformly dispersed in the master alloy.

Also, comparing FIG. 3a with FIG. 3b and FIG.
It can be seen that although the AlMn intermetallic compound powder is slightly dissolved in the molten master alloy, it remains uniformly and completely dispersed.

That is, AlMn, Al ₃ Mn, Al ₄ Mn, and Al ₆ Mn intermetallic compound powders all have extremely high hardness as shown in Table 1, and Al
It can be seen that the bonding force with the -Mn-Mg alloy matrix and the wettability are very excellent and stable, so that mixing is easy and uniform dispersion is possible.

As a result, it can be understood that excellent wear resistance can be obtained without losing excellent mechanical properties of the Al-Mn-Mg alloy as the master alloy.

[Example 2] The above-mentioned intermetallic compound powder was added to a molten master alloy, mixed with stirring, and then fed to a die-casting machine to provide a test piece for a tensile test and abrasion of the intermetallic compound particle dispersion strengthened alloy of the present invention. Test specimens were cast.

Here, in the example of the present invention, Al-2wt% Mn-5
A wt% Mg alloy was used, and AlMn intermetallic compound powder was used as dispersed particles, and the content was 3, 5, 10, 15, and 30 wt%.

As a comparative example, only the master alloy Al containing no dispersed particles was used.
With -2wt% Mn-5wt% Mg alloy and its mother molten alloy intermetallic particles dispersion strengthened alloys the AlMn intermetallic compound powder containing 2 wt% as the dispersed particles and 390 alloy and 10wt% Si ₃ N ₄ / ADC10 A tensile test piece and a wear test piece were cast by a die casting method.

Table 2 shows the chemical composition of the Al-based master alloy used in the present invention and the comparative examples.

Each of the obtained test pieces was subjected to the following tests.

The friction test was carried out using an Ogoshi type abrasion tester using FC25 standard rotating disk material as the mating material under a non-lubricated condition with a final load of 2.1 kg, a constant sliding distance of 100 m, and a sliding speed of 0.9.
The measurement was carried out by changing to four steps of 4, 1.96, 2.86, and 4.36 m / s, and the specific wear amount was measured from the wear scar width.

The test results are shown in Table 3, Table 4, Table 5, Table 6, and FIG. 4, FIG. 5, FIG. 6, and FIG.

FIG. 4 shows that the content of the dispersed particles in the AlMn intermetallic compound particle dispersion strengthened alloy using the Al-2wt% Mn-5wt% Mg alloy as the matrix which is the comparative example and the example of the present invention from Table-3 is 3,
It is the graph which plotted the horizontal axis | shaft as sliding speed and the vertical axis | shaft as specific wear amount about the case of 5, 10, 15, and 30 wt%.

According to Table 3 and FIG. 4, the 10, 15, and 30 wt% AlMn intermetallic compound particle dispersion strengthened alloys have almost the same wear resistance,
It can be seen that the abrasion resistance is superior to that of the Al-2wt% Mn-5wt% Mg alloy containing only the master alloy as a comparative example. 3.5wt% A
It can be seen that the 1Mn intermetallic compound particle dispersion strengthened alloy also exhibits higher wear resistance than the Al-2wt% Mn-5wt% Mg alloy, which is a comparative example. In addition, 2 wt% AlMn / Al-2 wt% Mn-5 wt% Mg also shows higher wear resistance than the Al-2 wt% Mn-5 wt% Mg alloy as a comparative example, but there is no remarkable improvement in wear resistance. You can see that.

Further, if more than 30 wt% of dispersed particles are added, the molten master alloy rapidly solidifies in the stirring stage, so that it is difficult to produce by the production method of the present invention.

FIG. 5 shows Al ₃ Mn / Al-2 wt% Mn as an example of the present invention in Table-4.
-5 wt% Mg content of dispersed particles 2, 3, 5, 10, 1
It is the graph which plotted the wear test result in the case of 5, 30 wt% as a sliding speed on the horizontal axis and a specific wear amount on the vertical axis.

From Table 4 and Fig. 5, 2, 3, 5, 10, 15, 30 wt% Al
Table 3 and No. 4 show the ₃ Mn intermetallic compound particle dispersion strengthened alloys.
It can be seen that the abrasion resistance is higher than that of the Al-2wt% Mn-5wt% Mg alloy containing only the master alloy shown in the figure. In the case of 2 wt%, the same high abrasion resistance as in the case of 3 wt% is exhibited, but the specific wear amount is larger.

FIG. 6 shows Al ₄ Mn / Al-2 wt% M which is an example of the present invention in Table-5.
The content of the dispersed particles for n-5 wt% Mg is 2, 3, 5, 10,
It is the graph which plotted the abrasion test result in the case of 15, 30 wt% as a sliding speed on the horizontal axis and a specific wear amount on the vertical axis.

From Table 5 and FIG. 6, 2, 3, 5, 10, 15, 30 wt% Al
Table 3 and Table 4 show the ₄ Mn intermetallic compound particle dispersion strengthened alloys.
It can be seen that the abrasion resistance is higher than that of the Al-2wt% Mn-5wt% Mg alloy containing only the master alloy shown in the figure. FIG. 7 is a wear test in the case of Al ₆ Mn / Al-2 wt% Mn-5 wt% Mg, which is an example of the present invention in Table 6, when the content of dispersed particles is 2, 3, 5, 10, 15, 30 wt%. It is the graph which plotted the result as a sliding speed on the horizontal axis and a specific wear amount on the vertical axis.

From Table 6 and Fig. 7, 2, 3, 5, 10, 15, 30 wt%
Al ₆ Mn intermetallic particles dispersion strengthened alloy it can be seen that the indicated master alloy only Al-2wt% Mn-5wt% Mg high wear resistance than the alloy in Table 3 and Figure 4.

Further, Table 7 shows four kinds of the present invention which are AlMn, Al ₃ Mn, Al ₄ Mn, and Al ₆ Mn alloys with dispersion strengthened intermetallic compound particles, and Comparative Example 3
Shows the mechanical properties of the species.

The ductility (elongation) of each of the examples of the present invention is extremely excellent at 3.9 to 4.3%, while the elongation of the same type of Si ₃ N ₄ or SiC particle dispersion strengthened alloy or the elongation of the 390 alloy is only 0.7 to 0.8%. You can see that it is.

Also shows AlMn, Al ₃ Mn, Al ₄ Mn, Comparative Example 3 kinds of corrosion promoting test results with the present invention Example 4 species is Al ₆ Mn intermetallic particles dispersion strengthened alloys in Table 8. The corrosion test is performed by continuous salt spray, and the corrosion state is rated by a rating number (ASTM
Standard).

Rating number from the results shown in Table 8 in 16 hours of salt spray tests ADC10,10wt% Si ₃ N ₄ / ADC10,39
While 0 is 2.0, all of the alloys of the present invention show 9.3 or more, indicating that the corrosion resistance is extremely excellent.

[Effect of the Invention] As described above, according to the intermetallic compound particle dispersion strengthened alloy according to the present invention, the Al-Mn-based intermetallic compound powder is uniformly dispersed in the master alloy, that is, the Al-Mn-Mg-based alloy matrix. By dispersing it in the metal, there is an effect of developing excellent mechanical properties and corrosion resistance without reducing ductility.

Further, according to the production method of the present invention, the Al-Mn-based intermetallic compound powder is added directly to the mother alloy melt, and after stirring and mixing, the mixture is uniformly dispersed in the matrix by die casting. Therefore, a particle dispersion-strengthened alloy having excellent mechanical properties and corrosion resistance can be uniformly dispersed in the matrix by short-time mechanical stirring without causing a problem such as dissolution, and the production method of the present invention is further improved. According to the use of the die casting method, unlike the conventional sintering and powder metallurgy methods, costly surface treatment methods and oxidation prevention methods and equipment are not required, so products with complicated shapes can be easily manufactured.
In addition, there is an effect that it can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a side view partially showing an example of a stirring and mixing apparatus used in the method for producing an intermetallic compound particle dispersion strengthened alloy according to the present invention, FIG. 2 is an Al-Mn equilibrium diagram, FIG. FIG. 3a is a micrograph of AlMn intermetallic compound powder before addition, FIG.
FIG. B shows the AlMn / A according to the invention obtained at the mold tip.
FIGS. 3c, 3d, 3e and 3f are micrographs of the l-2wt% Mn-5wt% Mg intermetallic compound particle dispersion-strengthened alloy, respectively. AlMn / Al according to
−2wt% Mn−5wt% Mg, Al ₃ Mn / Al−2wt% Mn−5wt% Mg, Al
_{4 Mn / Al-2wt% Mn} -5wt% Mg, Al 6 Mn / Al-2wt% Mn-5wt%
Each micrograph of Mg each intermetallic compound particle dispersion strengthened alloy,
FIG. 4, FIG. 5, FIG. 6, and FIG. 7 are graphs each showing the relationship between the sliding speed of each test piece with respect to the mating material and the specific wear amount.

Claims (2)

(57) [Claims] An Al-0.5 to 4.0 wt% Mn-4.0 to 8.0 wt% Mg alloy is used as a matrix, and AlMn, Al ₃ M
n, at least one intermetallic compound powder selected from Al ₄ Mn and Al ₆ Mn is dispersed as an additive powder, and the content of the additive powder is in a range of 3 to 30 wt%. Intermetallic compound particle dispersion strengthened alloy. 2. The method according to claim 1, wherein at least one metal selected from the group consisting of AlMn, Al ₃ Mn, Al ₄ Mn and Al ₆ Mn is contained in the molten Al-0.5 to 4.0 wt% Mn-4.0 to 8.0 wt% Mg alloy. A method for producing an intermetallic compound particle dispersion-strengthened alloy, wherein 3 to 30% by weight of a compound powder is directly added, the mixture is stirred and mixed, and then the above-mentioned intermetallic compound powder is uniformly dispersed in a matrix by die-casting.