JPH09155497A - Mold coating material for metal mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold coating material for metal molds which suppresses the penetration of molten metal of an aluminum system, etc., and is advantageous for prolonging the life of a mold coating film. SOLUTION: This mold coating material for metal molds contains at least one kind among metals having electron orbits d<3> to d<10> among transition metals, the oxides of these metals and mixtures contg. these metals. For example, the material may contain at least one kind among chromium(Cr), molybdenum(Mo), tungsten(W), manganese(Mn), iron(Fe), cobalt(Co), nickel(Ni), platinum(Part), palladium(Pd), silver(Ag), gold(Au) and copper(Cu).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold coating agent which can be used for casting a molten metal of non-ferrous metal such as aluminum and a molten metal of ferrous metal such as cast iron and cast steel with a mold.

[0002]

2. Description of the Related Art Conventionally, mold coating agents for molds have been applied to the cavity mold surface of a mold to protect the cavity mold surface from molten metal and to ensure mold releasability of a cast product. . The mold coating agent is generally configured to include an aggregate, a binder, and the like. Sodium silicate and aluminum monophosphate are used as the binder, and oxides, nitrides, and carbides of metals having a high melting point are used as the aggregate. Further, the mold coating agent often contains a plasticizer and an additive. Clay-based materials are used as plasticizers, and foaming agents, dispersants, stabilizers, etc. are used as additives.

[0003]

The above-mentioned mold coating agent for mold has a very short life of the coating film. Therefore, it was necessary to correct the coatable film with the auxiliary coat. By the way, if casting is continuously continued without an auxiliary coat, which is a modification of the coating type, the following new problem that has not occurred in the conventional die coating agent occurs. This problem is a problem that molten metal such as aluminum alloy permeates into the mold coating film, and as a result, aluminum alloy adheres to the surface of the mold coating film in the form of dots or planes.

The above-mentioned problem is a problem that has not appeared in the conventional mold coating agent according to the prior art, which has a short life due to severe abrasion, and a new problem occurs in a mold coating film capable of extending the life. Is. The present invention has been made in view of the above situation, and an object of the present invention is to provide a mold coating agent for a mold, which suppresses the penetration of molten metal and is advantageous for extending the life of the coating film.

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventor has eagerly developed a mold-coating agent. And among the transition metal elements, electron orbits d ^{3 to} d ¹⁰
When at least one kind of a metal having a metal, an oxide of the metal, and a mixture containing the metal is contained in a mold coating agent for a mold, it is advantageous in suppressing penetration of molten metal, and The inventors have found that the life can be extended and confirmed by a test, and completed the mold coating agent according to the present invention.

That is, the mold coating agent according to claim 1 is at least one of transition metal elements having a metal having electron trajectories d ^{3 to} d ¹⁰ , an oxide of the metal, and a mixture containing the metal. It is characterized by containing a seed. According to a second aspect of the present invention, in the mold coating agent according to the first aspect, the metal in the metal, the oxide of the metal, or the mixture containing the metal is chromium (Cr), molybdenum (Mo), tungsten (W), At least one of manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), platinum (Pt), palladium (Pd), silver (Ag), gold (Au), and copper (Cu). It is characterized by that.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The mold coating agent for a mold preferably contains an aggregate and a binder as in the prior art. As the aggregate, known aggregates such as calcium carbonate and zircon can be adopted. As a binder, sodium silicate (kH ₂ O · mN)
a ₂ O ・ nSiO ₂ ), aluminum monophosphate (kH ₂ O ・
Well-known binders such as mAl ₂ O ₃ · P ₂ O ₅ ) can be adopted.

Further, as a binder, sodium silicoaluminate (kH ₂ O.hNa ₂ O.mSiO ₂ .nAl) is used.
₂ O ₃ ), sodium silicate zirconate ((kH ₂ O · hNa
₂ O · mSiO ₂ · nZrO ₂ ) can also be adopted. In this case, it is advantageous for improving the strength of the coating film. As a mode of containing the component of the transition metal according to the present invention in the mold coating agent, in order to suppress the penetration of molten metal such as an aluminum alloy, the size is smaller than that of the coarse form. It is considered preferable. If the particle size can be understood, the upper limit of the average particle size is 100 μm, 50 μm.
m, 30 μm, and the lower limit is in the atomic order, or 0.
It can be 1 μm, 0.5 μm, 1 μm. Further, in terms of improving the surface roughness of the coating film, finer one is preferable.

The transition metal component according to the present invention may be contained in the mold coating agent in the form of at least one of a metal, an oxide of the metal, and a mixture containing the metal. It can also be added in the form of a salt that dissolves in water to form ions. The oxide may be in the form of a complex oxide. Generally, in order to disperse the component of the transition metal according to the present invention in a finer form in the coating film,
Na salt, K salt, Li salt
It can be dispersed in the mold coating agent in the form of ammonium salt / carbonate / oxalate / sulfate / phosphate. In this case, the uniform dispersibility is improved, and it is considered that it is effective for the penetration of the molten metal into the coating film.

According to the mold coating agent of the present invention, when the mold coating agent is 100%, at least one of a transition metal, an oxide of the metal, and a mixture containing the metal is used. The weight ratio can be, for example, 10%, 5% for the upper limit and 0.05%, 0.01% for the lower limit. The mold coating agent according to the present invention includes not only the form before being applied to the mold but also the form applied as a mold coating film to the mold.

By the way, the molten metal that is poured into the cavity of the mold and becomes a cast product comes into contact with the mold coating film formed by the mold coating agent according to the present invention. As such a molten metal, a molten metal of a non-ferrous metal such as aluminum or a molten metal of a ferrous metal such as cast iron or cast steel can be adopted. As the molten metal, a molten material such as a waste material or an ingot melted by a heating means such as a burner combustion flame can be used.

[0012]

Embodiments of the present invention will be described below.
In each of the examples, the mold coating agent and the casting conditions were all the same as described below. Casting method: Low-pressure casting of aluminum alloy (JIS-AC4C) Casting product: Taking two wheels of vehicle Casting condition: Same as mass-produced product Mixing of base material of mold coating agent according to this example: In this specification,% means% by weight unless otherwise specified.

Calcium carbonate (aggregate) 30.0% Zircon (aggregate) 27.0% Kaolin clay (plastic material) 2.5% Sodium silicate aluminate (binder) 20.0% Sodium silicate zirconate (viscous) Binder) 20.0% Silicon polymer (also called silicone) 0.5
% The component of the transition metal according to each example was added to 100 g of the base material having this composition to prepare a mold coating agent. Then, the mold coating agent was diluted with water and applied to the cavity mold surface of the heated mold with a spray gun, and a mold coating film (thickness: about 50 to 100 μm) was laminated on the cavity mold surface.
The degree of dilution with water is a weight ratio of mold coating agent: water = 1: 4.
It is.

Example 1 Platinum metal powder particles (particle size 1 μm or less) were used as the transition metal component, and the addition amount was changed within the range of 0.1 to 5.0 g as shown in Table 1. It was added to the base material and tested. S shown in Table 1 is the number of shots.

[0015]

[Table 1] The casting quality according to Example 1 was at a level of non-defective product up to the number of castings. As described above, even if the addition amount is 0.1 g, the number of castings in which a good product is obtained can be considerably increased.

(Example 2) As a component of a transition metal element,
Tungsten oxide (main component: WO ₃ , particle size: 1 μm or less) is used, and the addition amount is 0.1 to 10.0 as shown in Table 2.
It changed in the range of g and added to the base material and tested.

[0017]

[Table 2] The casting quality according to Example 2 was at a level of non-defective product up to the number of castings. As described above, even if the addition amount is 0.1 g, the number of castings in which a good product is obtained can be considerably increased.

(Example 3) Sodium tungstate was used as the component of the transition metal, and the addition amount was set to 0.
The amount was changed in the range of 1 to 5.0 g and added to the base material for testing.

[0019]

[Table 3] The casting quality according to Example 3 was at a level of non-defective products up to the number of castings. As described above, even if the addition amount is 0.1 g, the number of castings in which a good product is obtained can be considerably increased.

Example 4 Iron oxide (main component: Fe ₂ O ₃ , particle size: 1 μm or less) was used as a component of the transition metal,
As shown in Table 4, the amount of addition was changed in the range of 0.1 to 5.0 g, and added to the base material for testing.

[0021]

[Table 4] The casting quality according to Example 4 was at a level of non-defective product up to the number of castings. As described above, even if the addition amount is 0.1 g, the number of castings in which a good product is obtained can be considerably increased.

Example 5 Cupric oxide (particle size: 1 μm or less) was used as a component of the transition metal, and the addition amount was changed in the range of 0.1 to 5.0 g as shown in Table 5. It was added to the base material and tested.

[0023]

[Table 5] The casting quality according to Example 5 was at a level of non-defective product up to the number of castings. As described above, even if the addition amount is 0.1 g, the number of castings in which a good product is obtained can be considerably increased.

Example 6 Potassium permanganate (particle size: 1 μm or less) was used as a component of the transition metal, and the addition amount was changed in the range of 0.1 to 5.0 g as shown in Table 5 to obtain a base material. It was added to wood and tested.

[0025]

[Table 6] The casting quality according to Example 6 was at a level of non-defective product up to the number of castings. As described above, even if the addition amount is 0.1 g, the number of castings in which a good product is obtained can be considerably increased.

Example 7 Molybdenum oxide (particle size: 1 μm or less) was used as the component of the transition metal, and the addition amount was changed in the range of 0.1 to 5.0 g as shown in Table 7 to obtain the base material. And tested.

[0027]

[Table 7] The casting quality according to Example 7 was at a level of good product up to the number of castings. As described above, even if the addition amount is 0.1 g, the number of castings in which a good product is obtained can be considerably increased.

Example 8 As a transition metal component, zinc oxide, that is, zinc oxide (ZnO, average particle size 5 μm) was used, and the addition amount was changed as shown in Table 8 to the base material. Tested.

[0029]

[Table 8] The casting quality according to Example 8 was at a level of non-defective products up to the number of castings. However, the number of castings in which a cast product can be a good product is slightly smaller than that in each of the above-described examples.

(Comparative Example 1) As Comparative Example 1, a base material (containing no transition metal component) of the coating agent having the above composition was used. In Comparative Example 1, the number of castings was 146 S, and impregnation had already occurred. Further, the number of castings was 164S, and the aluminum alloy was adhered to the die in a planar manner, and the appearance of the die coating film and the cast product was deteriorated.

(Test Example) A test was conducted by adding an oxide of a transition metal to a mold coating agent for a mold and examining the degree of penetration into the mold coating film. In this test, a plate-shaped test piece (size: 1
00mm × 100mm × 10mm, material: SKD61)
Was used to apply a mold coating agent to a plate-shaped test piece to form a mold coating film. The mold coating agent is 100 g of the base material described above.
On the other hand, 0.5 g of an oxide of a transition metal element is added.

Then, the plate-shaped test piece having the coating film was suspended in a wire and dipped in a molten metal (JIS-AC4C) of an aluminum alloy at a predetermined temperature for 10 minutes. The number of soak points in the coating film applied to the surface was counted. If the number of points soaked in is large, the aluminum alloy adheres to the surface and is difficult to count. The test results are shown in FIG.

Among the transition metals, among the transition metals, scandium (Sc), yttrium (Y), lanthanum (La), which has electron orbits of d ¹ and d ² ,
An oxide of actinium (Ac), titanium (Ti), zirconium (Zr), or hafnium (Hf) was used. Further, as the metal oxide according to the example, among the transition metals,
Chromium (C which is an element having an electron orbit of d ^{3 to} d ¹⁰
r), molybdenum (Mo), tungsten (W), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), platinum (Pt), palladium (Pd), silver (Ag), gold ( Au) and copper (Cu) oxide are used, and further zinc (Zn), osmium (Os), iridium (Ir), rhenium (Re), rhodium (Rh), ruthenium (Ru), technetium (Tc), An oxide of cadmium (Cd) was also used.

The dotted line IV shown in FIG. 1 has a score of 1
8 points are shown. When the number of permeation points was 18 or more, the permeation in the coating film became almost planar, and the number of adhesion points could not be substantially counted. This uncountable area is shown as area I in FIG. The above-mentioned comparative example was in the range of the region I shown in FIG. That is, Sc, Y, La, Ac, Ti, which have electron trajectories of d ¹ and d ² ,
In the case of Zr and Hf, even though the heat resistance of the oxide is high, when immersed in an aluminum alloy with a melting temperature of 650 ° C, many test pieces soaked into the aluminum alloy, and a large amount of the aluminum alloy spread in a plane. Has adhered to.

In the area II shown in FIG. 1, zinc (Zn), rhodium (Rh) and ruthenium (R) according to the embodiment are used.
u), technetium (Tc), rhenium (Re), osmium (Os), iridium (Ir), cadmium (C
Each oxide of d) is included. As for zinc (Zn) oxide, aluminum alloys at 650 ° C., aluminum alloys at 750 ° C., and aluminum alloys at 800 ° C. were tested. Regarding oxides of osmium (Os) and iridium (Ir), aluminum alloys at 700 ° C and 750 ° C are also tested. As for cadmium (Cd) oxide, aluminum alloys at 700 ° C and 800 ° C are also tested.

According to the area II shown in FIG. 1, d ³ to d ¹⁰
With respect to the transition metal element having the electron orbit of No. 3, the number of soaked points was smaller than that in the region I, and there was an effect of suppressing soaking. That is, although the phenomenon that the aluminum alloy adheres to the coating film in spots remained, the aluminum alloy did not adhere to the surface of the test piece. Therefore, the effect of suppressing penetration is confirmed.

In the region III shown in FIG. 1, chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni) according to the embodiment. ), Platinum (Pt), palladium (Pd), silver (Ag), gold (Au), and copper (Cu). The triangles shown in FIG. 1 show some of these test results. With these transition metal oxides, even when immersed in an aluminum alloy having a melting temperature of 800 ° C., the penetration of the test piece in the mold coating film was less than 5 points. Further, when it was immersed in an aluminum alloy having a melting temperature of 750 ° C., 700 ° C., and 600 ° C., there was substantially no penetration (see Δ mark in FIG. 1). Therefore, a good effect of suppressing penetration is confirmed.

(Other Examples) The coating film is composed of a lower layer laminated on the mold and an upper layer laminated on the lower layer, and the upper layer contains the transition metal according to the present invention, its oxide, and its mixture. You can also In this case, as the composition of the lower layer, one having good adhesion to the mold can be adopted. (Supplementary Note) The following technical ideas can be understood from the above-described embodiments. A mold coating agent having a binder and containing a transition metal oxide and a mixture of transition metals.
In this case, the following advantages are obtained. That is, it partially reacts with the binder, and not only as particles, but also as a part of the binder, which facilitates fine dispersion.

[0039]

EFFECTS OF THE INVENTION According to the mold coating agent of the present invention, it is possible to prevent molten metal such as aluminum alloy from seeping into the coating film, and to suppress or avoid erosion of the surface of the mold cavity surface. To be done. According to the conventional technique, the casting surface of the cast product has a rough cast surface due to the deposition caused by the penetration of the molten metal such as an aluminum alloy into the mold coating film. According to this, since the penetration is suppressed or avoided, it is advantageous to finely and stabilize the casting surface of the cast product. It is also advantageous for reducing or avoiding a bad scraping.

According to such a mold coating agent for a mold according to the present invention, the auxiliary coat for modifying the mold coating film can be eliminated or simplified. Therefore, continuous casting with stable quality of cast products becomes possible.

[Brief description of the drawings]

FIG. 1 is a graph showing test results for examining the number of penetration points when a metal oxide is added to a mold coating agent.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takayuki Baba 1 Toyota-cho, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor Katsu Anfuku 1-cho, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. ( 72) Inventor Yuji Sengoku 57-1, Hashime-cho, Okazaki-shi, Aichi

Claims (2)

[Claims] 1. An electron orbit d ^{3 to} d ¹⁰ among transition metal elements.
A mold coating agent for a die, comprising at least one kind of a metal having a metal, an oxide of the metal, and a mixture containing the metal. 2. The metal according to claim 1, a metal oxide,
The metal in the mixture containing the metal is chromium (Cr), molybdenum (Mo), tungsten (W), manganese (M).
n), iron (Fe), cobalt (Co), nickel (N
i), platinum (Pt), palladium (Pd), silver (A
g), gold (Au), and at least one of copper (Cu).