JP3140025B2 - Method for producing particle-dispersed aluminum alloy using high energy density heat source - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aluminum alloy in which an intermetallic compound or ceramic particles are dispersed in order to obtain desired properties, in particular, a high energy density heat source such as an arc heat source. The present invention relates to a method for producing a particle-dispersed aluminum alloy used.

Conventional technology With the diversification of uses of Al materials, for example, high hardness, heat resistance, abrasion resistance, neutron absorption and other properties are selected according to the application.
It is required to be added to Al material.

Conventionally, to impart specific properties to the Al material as described above, ion plating, thermal spraying, forming a surface modification layer by overlay welding, etc. on the surface of the Al material, or partially modifying the surface,
In a conventional melting and casting method, various elements are added to the molten aluminum and the type and amount of the added elements are changed.

Problems to be Solved by the Invention However, in the surface modification method, since the surface properties of the Al material serving as the base material have a remarkable influence upon the formation of the surface modified layer, if the surface properties of the Al material are not good, good quality is obtained. There is a drawback that formation of a modified layer becomes difficult. In addition, since it is not easy to form a thick surface-modified layer, there is also a problem that the life of the product is shortened in severe cases such as abrasion with time. On the other hand, the melting / casting method has the advantage that the desired properties can be imparted to the entire Al material, but is limited by the type and amount of the added elements due to the limitation of the casting temperature, and the degree of freedom of reforming is limited. There was a problem that lacked.

The present invention has been made in view of such a technical background, and an object of the present invention is to provide a high-performance aluminum alloy capable of imparting various properties to the entire aluminum material and having a high degree of freedom in modification.

Means for Solving the ProblemsIn order to achieve the above object, the present invention provides a bottom plate of a mold as one electrode, disposing the other electrode above the mold, and using Al as an electrode wire, Using an arc generated between both electrodes, the electrode wire Al and one or more ceramics supplied into the arc are continuously melted, and the droplets are dropped to form the mold. A method for producing a particle-dispersed aluminum alloy using a high-energy-density heat source is characterized in that the molten metal is collected by forming a molten metal, and the molten metal is further electromagnetically stirred, and then cooled.

The high energy density heat source used in the present invention means a heat source having a relatively high input density. In the present invention, since it is necessary to dissolve Al and ceramics, the energy density of the heat source is desirably about 15 kW / cm ² or more. As a high energy density heat source, this invention uses MIG
Using a consumable electrode such as arc welding, Al and ceramics as a modifier are melted. The melting of the ceramic may be performed by supplying the ceramic into an arc generated between the positive and negative electrodes. Al serving as an alloy matrix is used as an electrode wire. This is because by forming the electrode wire with Al, the melting of the wire becomes a molten metal of Al, so that the efficiency is high, and when the electrode is formed of something other than Al, it is possible to avoid mixing of the electrode formed product into the molten metal. For reasons such as. The atmosphere is not particularly limited, and may be performed in the air, in a vacuum, or the like.

Al serving as a matrix may be pure Al or an Al alloy. In addition, ceramics as a modifier are dispersed in an Al matrix and alloyed to impart desired properties to an aluminum alloy. Such ceramics include TiC, SiC, WC, ZrC, NbC, and TiC, which have good wettability with aluminum.
B ₂ , TiN, TiSi ₂ , TiO, Al ₂ O _{3 and} other ceramics
What is necessary is just to use suitably according to the relationship with the property which should be provided to an aluminum alloy. For example, when it is desired to impart high hardness to an aluminum alloy, TiC, ZrC, WC, TiN, CrB ₂ , ZrB ₂ or the like may be used, and when it is desired to impart heat resistance, TiC, SiC,
ZrN, AlN, or the like may be used, and B, C, or the like may be used to impart neutron absorption and electrical resistance. As described above, the properties and properties of the ceramics can be imparted to the aluminum alloy according to the type of the ceramics dispersed in the Al matrix.

As the ceramic that melts together with Al, only one type may be used, or two types of ceramics of different types may be used.
It may be used in combination of more than one kind. The ceramic to be supplied to the arc is preferably in the form of a fine wire or powder in order to promote its melting. Also, it is needless to say that Al as a consumable electrode such as MIG arc welding needs to be formed into a wire shape.

The amount of ceramics that fuses with Al should be set so that the amount of ceramics in the entire aluminum alloy after casting is 1 to 75 wt%. If the content is less than 1 wt%, the amount of the ceramic dispersed in the Al matrix is too small, and the desired modifying effect may not be obtained. On the other hand, if it exceeds 75% by weight, the wettability with Al is deteriorated, and there is a possibility that defects such as a decrease in strength may be caused. Also,
Processing such as extrusion, rolling, and cutting may be difficult.

After melting Al and ceramics as described above, the molten metal is then collected in a mold to produce a molten metal. In order to uniformly disperse the ceramic in the Al matrix, it is desirable to stir the molten metal with an electromagnetic force or the like. The molten metal thus produced is cooled by natural cooling or, if necessary, by using a forced cooling device such as a water cooling device, to obtain an aluminum alloy ingot. The continuous casting may be performed by continuously manufacturing the molten metal and continuously cooling the molten metal from the bottom thereof.

The aluminum alloy ingot produced as described above has a structure state in which ceramic particles are uniformly dispersed in an aluminum matrix, and has desired properties due to these dispersed particles.

The aluminum alloy thus manufactured is subjected to secondary processing such as rolling, extrusion, cutting, and the like, if necessary, and is supplied to actual products.

FIG. 1 illustrates an apparatus embodying the present invention. In the figure, (1) is a MIG welding machine, and a power source (1
1), a metal plate electrode (12), an electrode wire (13), and an electrode wire supply device (14). In this embodiment, the electrode wire (13) is formed of Al which is an alloy matrix. (2) is a ceramic supply device. The ceramic supply device (2) includes an arc (3) generated between an electrode wire (13) and a metal plate electrode (12) of a MIG welding machine (1). The ceramic (4) is continuously supplied in the form of powder, wire, or a mixture thereof, if necessary, by carrying the carrier gas or the like.

Reference numeral (5) denotes a mold for collecting the molten and dropped Al and ceramic droplets, and the bottom plate of the mold (5) is also used by the metal plate electrode (12) of the MIG welding machine (1). The entire mold (5) is movable up and down to enable continuous casting.

(6) is an electromagnetic coil, and the electromagnetic coil (6) plays a role of electromagnetically stirring the molten metal in the mold (5) to uniformly disperse the ceramics in the Al matrix. The electromagnetic coil (6) is driven by a low-frequency AC power supply.

In order to manufacture an aluminum alloy using the illustrated manufacturing apparatus, first, the MIG welding machine (1) is operated to operate the electrode wire (1).
An arc (3) is generated between 3) and the metal plate electrode (12) to melt Al forming the electrode wire (13), and the droplets are dropped on the mold (5). At the same time, the ceramics (4) are supplied into the arc (3) from the ceramics supply device (2) and melted by the energy. The molten ceramic droplets drop into the mold (4) separately or integrally with the Al droplets. By continuously performing this operation, a molten metal (7) composed of a collection of droplets is generated in the mold (4). This molten metal (7) is electromagnetically stirred by the electromagnetic coil (6), and the ceramics are uniformly dispersed in the Al molten metal. As the amount of molten metal generated increases, the mold (5) is lowered and the molten metal is sequentially cooled by a cooling device (not shown) arranged around the mold to continuously cast the desired aluminum alloy ingot (8). .

Example An aluminum alloy was continuously cast using the same apparatus as shown in FIG. 1 under the following conditions.

[Example] A MIG welding power supply 500A was used, and SiC powder was used as ceramics, and the SiC powder was supplied into an arc (3) from a supply device (2) while being carried in an Ar gas flow as a carrier gas. The amount of the SiC in the alloy was set to 35 wt%. Other test conditions were as follows.

MIG welding conditions Current: 300 A, Arc voltage: 32 V, Shielding gas (Ar); 25 L / min, Electrode wire: A1100WY-1.6φ, SiC powder supply conditions Supply amount: 10 g / min, Carrier gas: 3 L / min Electromagnetic Stirring conditions Frequency: 50Hz Mold Size: 50mm inner diameter x 100mm length, Cooling method: Water cooling, Observing the microstructure of the aluminum alloy ingot obtained above, the SiC particles were uniformly dispersed in the Al matrix. I was The hardness of this ingot at 300 ℃ is Hv
(100 gf) was 150.

[Comparative Example] The Vickers hardness (Hv100gf) of a single A1100 material manufactured by a melting and casting method according to a conventional method was 35 to 40.

As can be seen from the above results, the product of the present invention has significantly improved hardness and heat resistance of the aluminum alloy as compared to the base A1100 alloy, and modified the Al material in terms of hardness and heat resistance. I confirmed that

In addition, when similar experiments were performed using other ceramics, it was found that the effect of modifying hardness, heat resistance, etc., was remarkable.

According to the present invention, as described above, the bottom plate of the mold is used as one electrode, the other electrode is disposed above the mold, and Al is used as an electrode wire, and an arc generated between the two electrodes Utilizing the electrode wire
While continuously melting Al and one or more kinds of ceramics supplied into the arc, the molten metal is dropped and collected in the mold to form a molten metal, and the molten metal is further electromagnetically stirred. It cools down. Therefore, the produced aluminum alloy has a structure in which ceramic particles are uniformly dispersed in an Al matrix, and the ceramic particles can have desired properties such as high hardness, wear resistance, and heat resistance. Furthermore, unlike the conventional surface modification method, such ceramics can be applied to the entire aluminum alloy, and the danger that the surface modification layer disappears due to abrasion with time can be eliminated. A material capable of sustaining the imparted properties over a long period of time can be obtained, and a highly durable modified aluminum alloy can be provided. Furthermore, unlike the melting / casting method according to the standard method, the additive element is not added to the molten aluminum, but Al and ceramics are melted using a high-energy heat source, so that the casting temperature is not restricted.
Al and ceramics can be reliably melted, and the type and amount of the ceramics to be melted can be freely controlled to give properties corresponding to the aluminum alloy, greatly improving the freedom of reforming. Can. Therefore,
It becomes possible to manufacture and provide multifunctional aluminum alloys having various properties.

In addition, since the molten metal is magnetically stirred, the ceramics
It is possible to produce an aluminum alloy that can be more uniformly stirred in the matrix and can stably exhibit desired properties without variation.

In addition, since the bottom plate of the mold is used as one electrode and the other electrode is placed above the mold, an arc etc. is generated between the electrode above the mold and the surface of the mold or the molten metal accumulated in the mold. I do. For this reason, the molten Al and ceramic droplets exist in high-density energy such as an arc until they fall into the mold, and sufficient heat is applied during that time. Can be maintained over

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of an aluminum alloy manufacturing apparatus for implementing the present invention. (1) MIG welding machine, (2) Modifier supply device,
(3) ... arc, (4) ... modifier (ceramics), (5) ... mold, (6) ... electromagnetic coil, (7)
…… Aluminum alloy melt, (8) …… Aluminum alloy ingot.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-62832 (JP, A) JP-A-58-177426 (JP, A) JP-A-61-279663 (JP, A) JP-A 64-64 73066 (JP, A) JP-A-64-2293 (JP, A) JP-A-61-270376 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C22C 1/10 C22C 1 / 02 503 C22B 9/20 C04B 35/60

Claims (1)

(57) [Claims] 1. A method according to claim 1, wherein the bottom plate of the mold is used as one electrode.
The other electrode is disposed above the mold, and Al is used as the electrode wire, and the arc generated between the two electrodes is used to supply the electrode wire, Al, and one or two kinds supplied into the arc. A high-energy-density heat source characterized by continuously melting the above ceramics, dropping the droplets, collecting them in the mold to form a molten metal, further electromagnetically stirring the molten metal, and then cooling the molten metal. Method for producing the particle-dispersed aluminum alloy used.