JPH05311261A - Filter for molten metal - Google Patents

Abstract

(57) [Summary] [Structure] A metal or ceramic filter material for filtering a melt of a metal selected from the group consisting of zinc, aluminum, copper, magnesium and alloys thereof, which is in contact with the melt. A filter for molten metal, wherein the surface of the filter is plated with zinc, aluminum or an alloy thereof, preferably an alloy of zinc and 0.1% by weight or more of aluminum. The filter material for molten metal of the present invention is excellent in the filterability (permeability) of the molten metal selected from the group consisting of zinc, aluminum, copper, magnesium and alloys thereof, and the inclusions (impurities) ) Is also excellent in removal rate, and is a metal or ceramic filter material suitable for filtering out inclusions (impurities) contained in the molten metal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter material for molten metal, and more specifically, inclusions contained in molten metal selected from the group consisting of zinc, aluminum, copper, magnesium and alloys thereof ( The present invention relates to a metal or ceramic filter material suitable for filtering out (impurities).

[0002]

2. Description of the Related Art When a molded product of a metal selected from the group consisting of zinc, aluminum, copper, magnesium and alloys thereof is manufactured by casting, when a new ingot is used as a starting material and a scrap material is used. There are cases where it is used and cases where it is used together with scrap metal. In each case, it is considered that the following inclusions (impurities) are present in each molten metal: a) Metal particles mainly composed of iron, metal compound particles and intermetallic compound particles; b) Metal oxides mainly composed of iron, zinc, aluminum, copper and magnesium; c) Other non-metal particles such as brick scraps. ..

It is considered that if these inclusions (impurities) in the molten metal are cast as they are without being removed, these inclusions are entrained in the casting and cause internal defects or surface defects in the casting. .. As a means for removing inclusions in the molten metal, it has been conventionally known to filter the molten aluminum alloy using a ceramic or metallic filter.

[0004]

However, in order to remove inclusions in the molten metal, it is selected from the group consisting of zinc, aluminum, copper, magnesium and alloys thereof using a ceramic or metal filter. When the molten metal is filtered, when the fineness of the filter is small, the molten metal adheres to the filter as the filtration of the molten metal progresses, clogging occurs, and the filtration speed gradually decreases, which is not practical. Also, if a coarse filter is used to improve the filtration rate, inclusions (impurities) cannot be sufficiently filtered out, which is not practical.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a molten metal containing a metal selected from the group consisting of zinc, aluminum, copper, magnesium and alloys thereof. It is an object of the present invention to provide a filter material made of metal or ceramic, which is suitable for filtering out inclusions (impurities) contained in (3) and which is unlikely to cause clogging due to adhesion of molten metal.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted various studies in order to solve the above-mentioned problems, and as a result, the surface of a metal or ceramic filter material which comes into contact with the molten metal is treated with each molten metal. With a metal that can easily form an alloy, more preferably by plating with a metal that can form a solid solution with a molten metal, it is found that clogging due to the adhesion of the molten metal is less likely to occur, The present invention has been reached.

That is, the molten metal filter medium of the present invention is a metal or ceramic filter medium for filtering molten metal selected from the group consisting of zinc, aluminum, copper, magnesium and alloys thereof. The surface of the filter material that comes into contact with the molten metal is plated with zinc, aluminum, or an alloy thereof.

The molten metal filter material of the present invention is prepared by first forming a filter material of metal or ceramic having heat resistance and mechanical strength, such as SUS, and then applying zinc to the surface of the filter material in contact with the molten metal. It can be obtained by forming a plating layer made of aluminum or an alloy thereof by an electrodeposition method, an electroless plating method, a hot dipping method or the like.

In the molten metal filter material of the present invention, the metal forming the plating layer is zinc, aluminum or an alloy thereof, and these metals are zinc, aluminum,
Since it can easily form an alloy with copper, magnesium and their alloys and can form a solid solution, it is composed of zinc, aluminum, copper, magnesium and their alloys for the molten metal filter material of the present invention. The wettability of the molten metal selected from the group is extremely good, and therefore, the molten metal hardly adheres to the filter to cause clogging as the filtration of the molten metal progresses.

In the molten metal filter material of the present invention, the metal forming the plating layer may be zinc, aluminum or an alloy thereof, but the plating layer contains zinc in an amount of 0.1% by weight or more, preferably 3 to. An alloy composed of 6% by weight of aluminum is preferable because the mechanical properties such as hardness of the plating layer and the corrosion resistance are improved as compared with the case of metal alone.

[0011]

EXAMPLES The following are preferred examples of the present invention: Example 1 Mesh sizes of 30, 50, 100 and 20 respectively
Six kinds of mesh structure SUS filters of 0, 300 and 400 were prepared. Zinc on their filter surface,
A filter layer of the present invention was obtained by forming a plated layer of aluminum or 95 wt% zinc-5 wt% aluminum alloy. Using the thus obtained filter of the present invention and the control filter having no plated layer, various metal melts shown in Table 1 were filtered, and the filterability of these filters was evaluated. The device shown in FIG. 1 was prepared to evaluate the filterability. The apparatus shown in FIG. 1 uses a heat-resistant heat insulating material having a thickness of about 10 mm and has an inner diameter of 100 mm × 100 mm × 120 mm.
Make two (height) containers, and put 5 in the center of the bottom of one container.
A hole of 0 mm × 50 mm was opened, they were stacked as shown in FIG. 1, and a filter was placed on the bottom of the upper container. 50 ℃ above the melting point of the test metal in the container above this equipment
A high temperature metal melt was poured to a height of 100 mm, and the amount (volume%) of the metal melt that passed through the filter was determined.
Incidentally, in the case of the molten magnesium and the molten magnesium alloy, it was carried out in an argon atmosphere. The results are shown in Table 1.
It was as shown in. Significances of symbols in Table 1 are as follows: ◯: Filterability (transmittance) 80% or more Δ: Filterability (transmittance) 40% or more and less than 80% ×: Filterability (transmittance) less than 40% -: Not evaluated

[0012]

[Table 1]

Example 2 The filterability of the filter material was evaluated in the same manner as in Example 1 except that a ceramic filter was used instead of the SUS filter. The results were the same as in Example 1.

Example 3 A mesh type SUS filter having a mesh size of 400 was prepared. 95% by weight zinc on the filter surface
A 5 wt% aluminum alloy plating layer was formed to obtain a filter material of the present invention. About 0.1% by weight of iron was added to the alloys shown in Table 2 to form a molten metal, and the molten metal was filtered with the above-described filter material of the present invention, and the filtration performance of the filter material was evaluated.
The iron content (% by weight) and the iron removal rate before and after filtration were as shown in Table 2.

[0015]

[Table 2]

[0016]

As described above, the molten metal filter material of the present invention having a surface contacting the molten metal plated with zinc, aluminum or an alloy thereof is a non-plated filter material of the same mesh size. Compared with, the filterability (transmittance) of the molten metal selected from the group consisting of zinc, aluminum, copper, magnesium and their alloys is excellent, and the removal rate of inclusions (impurities) is also excellent. Cage,
It is a metal filter material suitable for filtering out inclusions (impurities) contained in the molten metal.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of an apparatus used for evaluation of filterability.

Claims (2)

[Claims] 1. A metal or ceramic filter material for filtering a melt of a metal selected from the group consisting of zinc, aluminum, copper, magnesium and alloys thereof, the surface of the filter material being in contact with the melt. Is a metal, which is plated with zinc, aluminum, or an alloy thereof, and is a filter material for molten metal. 2. The filter material for molten metal according to claim 1, wherein the surface of the filter material is plated with an alloy of zinc and 0.1% by weight or more of aluminum.