KR20210073708A - Aluminum alloy for enamel coating and method for manufacturing die casted aluminum alloy frying pan - Google Patents

Abstract

Disclosed is a method for manufacturing aluminum alloy frying pan using an enamel-coating aluminum alloy and a die casting method. According to the present invention, an enamel-coating aluminum alloy contains, in weight percent (wt%), 1.2-3.4 wt% of iron and 0.8-3.8 wt% of silicon, with the remainder consisting of aluminum and inevitable impurities, and can maintain high-temperature strength at 550℃-570℃, which is a temperature range for enamel coating. In addition, according to another embodiment of the present invention, a method for manufacturing an enamel-coated frying pan using a die casting method comprises: a step for providing an aluminum alloy molten metal; a step for manufacturing a frying pan by die-casting the aluminum alloy molten metal, wherein a reactive gas reacting with the molten metal is injected into a die-casting mold before injecting the alloy molten metal into the die-casting mold, then the molten metal is injected to cause an exothermic reaction between the injected alloy molten metal and the reactive gas, and the alloy molten metal is then solidified in the mold to manufacture the frying pan; and a step for enamel-coating the frying pan in a temperature range of 550℃-570℃.

Description

An aluminum alloy for enamel coating and a method of manufacturing an aluminum alloy frying pan manufactured by a die casting method {ALUMINUM ALLOY FOR ENAMEL COATING AND METHOD FOR MANUFACTURING DIE CASTED ALUMINUM ALLOY FRYING PAN}

The present invention relates to an aluminum alloy for enamel coating, and more particularly, to an aluminum alloy for enamel coating that does not generate blisters during enamel coating at high temperatures, and a method for manufacturing an enamel coating frying pan manufactured by die-casting such an aluminum alloy it's about

The enamel-coated aluminum frying pan according to the prior art is manufactured by press forming, die casting and gravity casting or molten metal forging.

The manufacturing method by press molding of an aluminum sheet is a method of coating an aluminum sheet with a fluororesin on the inside and ceramic or enamel on the outside after press molding. Ceramic or enamel coating is possible because there is no shape change such as swelling (brist) on the surface of the frying pan.

On the other hand, in the aluminum plate press forming method, the thickness of the bottom and the side of the frying pan manufactured by press forming is constant, so that the cooked food is excessively localized overheating, and the degree of freedom in product design such as having to fix the handle with a piece has limited problems.

A method of manufacturing a frying pan by using an aluminum alloy die-casting method is a method of die-casting using an aluminum alloy with high silicon (Si) content, such as ADC 12 or ADC 10, and excellent fluidity.

Unlike the press molding method, the frying pan manufacturing method by the die casting method can give changes to the thickness of the bottom and side of the frying pan (generally, the thickness of the side is 2mm, the bottom is about 6-8mm), so the cooked food is excessively localized. There is no phenomenon of overheating due to this, and the degree of freedom in product design is high, such as being able to diversify the coupling method of the handle part.

However, in the frying pan manufacturing method by the die-casting method, when the frying pan is heated to 400°C or higher, a change in the surface shape (brist) occurs, making enamel coating impossible, and only low-temperature coatings below 400°C, such as fluororesin or ceramic coating. Can not.

The frying pan manufacturing method by gravity casting or molten metal forging does not cause change in surface shape (brist) even when the die-casting product is heated to 570℃ or higher in the painting process as in the die-casting method, so ceramic or enamel coating is possible. have.

However, in gravity casting or molten metal forging, when heating to about 570℃ for product coating, bubbles or casting defects do not occur inside the cast product, but it is difficult to cast to a thickness of about 2mm. Since the thickness must be adjusted, there is a problem in that the manufacturing process is complicated.

The prior literature (Utility Model Registration No. 20-0301176) discloses the contents of increasing abrasion resistance and sintering property by coating the inner and outer surfaces of a metal frying pan with enamel, then sandblasting the inner surface and then Teflon coating to increase the abrasion resistance and sinterability. Problems related to (enamel) coating are not disclosed.

The present invention is to provide an aluminum alloy for manufacturing a frying pan that solves the problem of enamel coating by the above-described die-casting method, and a method for manufacturing a die-casting frying pan using the same.

The present invention is to solve various problems including the above problems, and to provide an aluminum alloy capable of enamel coating that does not cause blisters because local dissolution does not occur in the temperature range where the enamel coating is performed. do.

In addition, the present invention improves the fluidity of the molten metal by injecting the reactive gas into the mold before injection of the molten metal and then injecting the molten metal into a frying pan by the die-casting method of molten aluminum alloy with a low silicon content, thereby reducing defects such as pores. An object of the present invention is to provide a method for manufacturing a die-casting frying pan.

The aluminum alloy for enamel coating according to the first embodiment of the present invention contains 1.2 to 3.4% of iron (Fe) in weight percent (wt%), 0.8 to 3.8% of silicon (Si), and the balance is aluminum (Al) and unavoidable impurities. It is characterized in that it maintains high-temperature strength in the enamel coating temperature range of 550°C-570°C.

In addition, the aluminum alloy for enamel coating according to the second embodiment of the present invention by weight percent (wt%) iron (Fe) 1.2 to 3.4%, silicon (Si) 0.8 to 3.8%, nickel (Ni) 0.2 to 1.0% And the remainder contains aluminum (Al) and unavoidable impurities, characterized in that it maintains high-temperature strength in the enamel coating temperature range of 550°C-570°C.

In addition, the aluminum alloy for enamel coating according to the third embodiment of the present invention by weight percent (wt%) iron (Fe) 1.2 to 3.4%, silicon (Si) 0.8 to 3.8%, manganese (Mn) 0.4 to 1.8% And the remainder contains aluminum (Al) and unavoidable impurities, characterized in that it maintains high-temperature strength in the enamel coating temperature range of 550°C-570°C.

In addition, the aluminum alloy for enamel coating according to the fourth embodiment of the present invention is iron (Fe) 1.2 to 3.4%, silicon (Si) 0.8 to 3.8%, titanium (Ti) 0.1 to 0.5% by weight percent (wt%) And the remainder contains aluminum (Al) and unavoidable impurities, characterized in that it maintains high-temperature strength in the enamel coating temperature range of 550°C-570°C.

In addition, the aluminum alloy for enamel coating according to the fifth embodiment of the present invention is iron (Fe) 1.2 to 3.4%, silicon (Si) 0.8 to 3.8%, nickel by weight percent (wt%) by weight percent (wt%) (Ni) 0.2 to 1.0%, manganese (Mn) 0.3 to 0.8%, and the balance contains aluminum (Al) and inevitable impurities, characterized in that it maintains high temperature strength at 550 ° C.-570 ° C., which is the enamel coating temperature range .

The method for manufacturing an enamel-coated frying pan according to another embodiment of the present invention comprises the steps of providing a molten aluminum alloy, die-casting the aluminum alloy molten metal, and reacting with the molten metal in the die-casting mold before injecting the molten alloy into the die-casting mold By injecting gas and then pouring molten metal, the injected molten alloy and the reaction gas are exothermically reacted, and then the molten alloy is solidified in the mold to prepare a frying pan, and enamel the frying pan at a temperature range of 550°C-570°C. It includes the step of coating.

In the manufacturing method of the enamel-coated frying pan, the reactive gas is oxygen (O2).

Enamel-coated frying pan according to another embodiment of the present invention is characterized in that fine oxide particles (Al2O3) of less than 1 micron (㎛) are distributed inside the frying pan.

The aluminum alloy for enamel coating according to the present invention does not cause blistering because local dissolution does not occur in the 550°C-570°C temperature range where the enamel coating is performed.

In addition, the aluminum alloy for enamel coating according to the present invention is characterized in that the process temperature is high so that local melting does not occur even when heated to high temperature (590 ° C. or higher), and deformation does not occur when the alloy is taken out from the mold after die casting It has a high degree of strength and is characterized by high adhesive strength when coated with enamel.

In addition, in the manufacturing method of the enamel-coated frying pan according to the present invention, the reactive gas is injected before the molten metal is injected in the mold when the frying pan is manufactured by die-casting the aluminum alloy molten metal with low silicon (Si) content and low fluidity of the molten metal. By doing so, it is possible to manufacture a die-casting frying pan with no or very reduced pores by maintaining good fluidity of the molten metal due to the exothermic reaction between the reactive gas and the molten metal.

In addition, in the enamel-coated frying pan according to the present invention, the fine oxide formed by the reaction between the reactive gas and the molten metal is uniformly distributed, so that the tensile properties are improved.

According to the present invention, a frying pan capable of enamel coating can be manufactured by a die-casting process, and thereby, the productivity is excellent, and the manufacturing time is shortened, thereby maximizing productivity.

1 is a view showing a frying pan before enamel coating.
Figure 2 is a view showing an enamel-coated frying pan at 570 ℃ as manufactured according to an embodiment of the present invention.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and are common in the art to which the present invention pertains. It is provided to fully inform those with knowledge of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, an aluminum alloy for enamel coating and a method of manufacturing an enamel coating frying pan according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings. For reference, in describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

1 is a view showing an aluminum alloy die-casting frying pan manufactured by the method according to the present invention.

The aluminum alloy for enamel coating according to the first embodiment of the present invention contains 1.2 to 3.4% of iron (Fe) in weight percent (wt%), 0.8 to 3.8% of silicon (Si), and the balance is aluminum (Al) and unavoidable impurities. It is characterized in that it maintains high-temperature strength in the enamel coating temperature range of 550°C-570°C.

Low-temperature enamel coating of aluminum alloy products is generally carried out in the range of 550°C-570°C, which is the melting temperature of enamel. When die casting of an aluminum alloy at a temperature at which the enamel melts, it is preferable that the die-casting product (eg, frying pan) is not thermally deformed by the solidification residual stress.

In addition, high-temperature strength sufficient to suppress the volume expansion of microbubbles remaining in the product and local dissolution in the product during die casting is required.

In the aluminum alloy (P590) according to the first embodiment of the present invention, the content of iron (Fe) is 1.2 to 3.4. In the die casting method, which injects molten aluminum into the mold at high speed and high pressure, when the iron (Fe) content is less than 0.8%, the product is burned on the surface of the mold, and when it exceeds 1.2%, iron in a process with a fast cooling rate such as die casting A very fine intermetallic compound of (Fe)-aluminum (Al)-silicon (Si) system is generated, and the high temperature strength is improved in the temperature range (550~570℃) where enamel coating is performed.

In particular, the iron-aluminum-silicon-based intermetallic compound does not lower the eutectic melting point of the product, and serves to strengthen the bonding strength with the enamel layer. If the content of iron (Fe) exceeds 3.4, it is very fragile and cracks occur in the product during die casting.

Silicon (Si) improves the adhesion with the enamel coating layer, and together with iron (Fe), it makes a very fine intermetallic compound that improves the high-temperature strength of the product to prevent deformation of the product even in the enamel coating temperature range. When the silicon (Si) content is less than 0.8%, this effect is insignificant and the fluidity of the molten metal is lowered, making product molding difficult.

In addition, when the silicon (Si) content exceeds 3.8%, a large amount of Al-Si eutectic tissue that dissolves at 550°C is generated, and when enamel is coated (at 570°C), blisters are generated on the surface, and the adhesive strength of the enamel coating layer may be lowered.

The aluminum alloy for enamel coating according to the second embodiment of the present invention is iron (Fe) 1.2 to 3.4%, silicon (Si) 0.8 to 3.8%, nickel (Ni) 0.2 to 1.0%, and glass by weight percent (wt%) Wealth contains aluminum (Al) and unavoidable impurities, and enamel coating is possible at a temperature of 550°C-570°C.

Nickel (Ni) is additionally added to the aluminum alloy according to the second embodiment of the present invention in order to improve adhesion to the enamel coating layer in the aluminum alloy (AP590) according to the first embodiment of the present invention.

When 0.2~1.0% of nickel (Ni) is added, a fine intermetallic compound of aluminum (Al)-iron (Fe)-nickel (Ni) is generated, and the aluminum structure is refined to further improve strength at high temperature. In addition, the intermetallic compound of aluminum (Al)-iron (Fe)-nickel (Ni) does not lower the melting temperature of the product, and improves the bonding strength with the enamel coating layer during enamel coating.

When the content of nickel is less than 0.2%, the effect of improving the high-temperature strength of the alloy is insignificant, and when it exceeds 1.0%, the fluidity of the aluminum alloy is lowered and cracks may occur during solidification after die casting.

The aluminum alloy for enamel coating according to a third embodiment of the present invention is iron (Fe) 1.2 to 3.4%, silicon (Si) 0.8 to 3.8%, manganese (Mn) 0.4 to 1.8%, and residue by weight percent (wt%) Wealth contains aluminum (Al) and unavoidable impurities, and enamel coating is possible at a temperature of 550°C-570°C.

In the aluminum alloy (AP605) according to the third embodiment of the present invention, manganese (Mn) is additionally added to improve high-temperature strength in the aluminum alloy according to the first embodiment of the present invention.

When manganese (Mn) is added by 0.4 to 1.8%, the shape of the aluminum (Al)-iron (Fe)-based intermetallic compound generated during solidification is improved to a spherical shape, so the effect of preventing cracks occurring during solidification is obtained. can

When the manganese (Mn) content is less than 0.4%, the effect of improving the shape of the iron (Fe)-aluminum (Al) based intermetallic compound is insignificant, and when the manganese (Mn) content exceeds 1.8%, the bonding strength with the enamel coating layer is reduced. can lower it

The aluminum alloy for enamel coating according to the fourth embodiment of the present invention is iron (Fe) 1.2 to 3.4%, silicon (Si) 0.8 to 3.8%, titanium (Ti) 0.1 to 0.5% and glass by weight percent (wt%) Wealth contains aluminum (Al) and unavoidable impurities, and enamel coating is possible at a temperature of 550°C-570°C.

In the aluminum alloy (AP606) according to the fourth embodiment of the present invention, titanium (Ti) is additionally added to improve the strength by selectively refining the structure of the aluminum alloy in the aluminum alloy (AP590) according to the first embodiment of the present invention. do.

When 0.1~0.5% of titanium (Ti) is added, the structure of the aluminum alloy and the shape of the aluminum (Al)-iron (Fe)-based intermetallic compound are refined without lowering the void temperature to prevent cracks occurring during solidification. effect can be obtained.

In addition, when titanium (Ti) is added, the bonding strength with the enamel coating layer can be improved. When the titanium (Ti) content is less than 0.1%, the effect of refining the structure of the aluminum alloy can be obtained, but the effect of improving the formation of the iron (Fe)-aluminum (Al)-based intermetallic compound is insufficient.

When the titanium (Ti) content exceeds 0.5%, fluidity may be lowered and cracks may occur during the solidification process.

The aluminum alloy for enamel coating according to the fifth embodiment of the present invention is iron (Fe) 1.2 to 3.4%, silicon (Si) 0.8 to 3.8%, nickel (Ni) 0.2 to 1.0%, manganese by weight percent (wt%) (Mn) 0.3 to 0.8% and the balance contains aluminum (Al) and unavoidable impurities, and enamel coating is possible at a temperature of 550°C-570°C.

The aluminum alloy (AP610) according to the fifth embodiment of the present invention is an iron (Fe)-aluminum (Al)-nickel (Ni)-based intermetallic compound produced from the aluminum alloy (AP600) according to the fourth embodiment of the present invention. Manganese (Mn) is added to improve the high-temperature strength by refining the shape of

Manganese (Mn) is added by 0.3~0.8%, and by this, the iron (Fe)-based intermetallic compound formed during solidification is refined and its shape is improved to a spherical shape, so it is possible to prevent cracks occurring during solidification during product molding. and can improve strength at high temperatures.

When the content of manganese (Mn) is less than 0.3%, the effect is insignificant, and when it exceeds 0.8%, the fluidity of aluminum may be lowered and the adhesive strength of the enamel coating layer may be lowered.

In the aluminum alloy according to the first to fifth embodiments according to the present invention, magnesium (Mg), copper (Cu), and zinc (Zn) may be contained as impurities in addition to the main components, but Cu (copper), In the case of zinc (Zn), if the content of each exceeds 0.25% by weight, the process temperature is lowered, so a part that is locally dissolved at the enamel coating temperature may occur.

In particular, since magnesium (Mg) is highly oxidized at high temperature and significantly reduces the bonding strength of the enamel coating layer, it is preferable to regulate its content to 0.1% or less by weight percent.

Table 1 below shows the component range of the aluminum alloy capable of enamel coating according to the present invention by dividing it in more detail.

Alloy Example AP590 indicates an alloy having an aluminum alloy melting point near 590° C., and AP600 indicates an alloy having an aluminum alloy melting point near 600° C.

In addition, the alloy examples AP605, AP606, and AP610 show alloys in which the melting point of the aluminum alloy is around 605°C, 606°C and 610°C, respectively.

The aluminum alloy maintaining high-temperature strength in the temperature range where enamel coating according to the present invention is possible minimizes local dissolution by minimizing the amount of process tissue by controlling the Si content to 3.8% or less.

In addition, the aluminum alloy according to the present invention contains a certain amount of intermetallic compounds such as iron (Fe)-aluminum (Al), nickel (Ni)-aluminum (Al), and titanium (Ti)-aluminum (Al) with a fast cooling rate. When solidified by the die-casting method, since the intermetallic compound is finely dispersed, thermal deformation and blistering of the alloy do not occur even at high temperatures due to the dispersion strengthening effect.

<Ingredient range of examples of aluminum alloys capable of enamel coating according to the present invention> Alloy Examples Fe Si Ni Mn Ti remainder (Al and inevitable impurities) AP590 1.2~3.4 0.8~3.8 AP600 1.2~3.4 0.8~3.8 0.2~1.0 AP605 1.2~3.4 0.8~3.8 0.4~1.8 AP606 1.2~3.4 0.8~3.8 0.1~0.5 AP610 1.2~3.4 0.8~3.8 0.2~1.0 0.3~0.8

Unlike conventional die-casting alloys, the above five alloys can improve adhesion with the enamel coating layer, and are suitable for manufacturing die-casting frying pans and pots for enamel coating because they are composed of components and contents that do not lower the process temperature of aluminum. Do.

The manufacturing method of an enamel-coated frying pan according to another embodiment of the present invention includes the steps of providing a molten aluminum alloy according to the first to fifth embodiments, and die casting the aluminum alloy molten metal, but die casting the molten alloy After injecting the gas reacting with the molten metal into the die-casting mold before injection into the mold, and then injecting the molten alloy to exothermic the injected molten alloy and the reaction gas, and then solidifying the molten alloy in the mold to produce a frying pan; Including the step of enamel coating the frying pan in the temperature range of 550 ℃-570 ℃.

In the present invention, five types of aluminum alloys of AP590, AP600, AP605, AP606 and AP610 according to the above-described embodiment are used for manufacturing a die-casting frying pan for enamel coating. Since these alloys have melting temperatures of about 590℃, 600℃, 605℃, 606℃, and 610℃, respectively, blisters due to local melting do not occur at 550℃~570℃, which is a high temperature region where enamel coating is applied. It is possible to secure the adhesive strength of the coating layer.

However, when the alloy of the aluminum alloy is cast, the content of silicon (Si), which is advantageous for fluidity, is low, and the fluidity of the molten metal is lowered, so that casting defects may occur inside the die-casting product. Therefore, by injecting oxygen, which is a reactive gas, into the mold before high-speed injection of the molten aluminum alloy into the mold, the filling properties of the molten aluminum alloy in the mold can be improved.

If oxygen is injected into the mold before the molten aluminum alloy is injected into the die-casting mold and then the molten aluminum alloy is injected into the mold at high speed, the aluminum and oxygen react instantaneously to cause an exothermic reaction. As the fluidity of the alloy can be secured, it is possible to manufacture a frying pan without casting defects inside.

This suppresses the generation of bubbles by maintaining the high-temperature fluidity of the molten metal by the exothermic reaction between the reactive gas and the aluminum molten metal, and forms a fine metal oxide (alumina, Al2O3) between the reactive gas and aluminum to form a fine metal oxide in the solidified structure of the alloy. By doing so, it is possible to improve the high-temperature strength.

In the method for manufacturing an enamel-coated frying pan by the die-casting method, the reactive gas is oxygen (O2).

In the present invention, the reactive gas injected into the die-casting mold before injecting the molten aluminum alloy includes oxygen, which can react with the molten metal within a short time, but is not limited thereto, and any gas that can react with the molten aluminum can be used. .

Enamel-coated frying pan according to another embodiment of the present invention is characterized in that fine oxide particles (Al2O3) of less than 1 micron (㎛) are distributed inside the frying pan.

Due to the rapid reaction between the reactive gas injected into the die-casting mold and the aluminum alloy, fine oxide particles (Al2O3) are distributed in the solidified structure of the alloy, thereby improving the tensile properties and fatigue properties of the final casting.

If oxygen is injected into the mold in advance and then the developed aluminum alloy molten metal is injected into the mold at high speed, a sudden exothermic reaction occurs between aluminum and oxygen, and the fluidity of the aluminum alloy molten metal is reduced by the exothermic reaction heat generated. It is possible to manufacture a frying pan without casting defects such as pores inside.

Although the present invention has been described with reference to the embodiments shown in the drawings, which are merely exemplary, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

Claims (8)

1.2 to 3.4% of iron (Fe) in weight percent (wt%), 0.8 to 3.8% of silicon (Si), and the balance contains aluminum (Al) and unavoidable impurities, and high temperature in the enamel coating temperature range of 550°C-570°C Aluminum alloy for enamel coating to maintain strength.
In weight percent (wt%), iron (Fe) 1.2 to 3.4%, silicon (Si) 0.8 to 3.8%, nickel (Ni) 0.2 to 1.0%, and the balance contains aluminum (Al) and unavoidable impurities, the enamel coating temperature Aluminum alloy for enamel coating that maintains high-temperature strength in the range of 550℃-570℃.
In weight percent (wt%), iron (Fe) 1.2 to 3.4%, silicon (Si) 0.8 to 3.8%, manganese (Mn) 0.4 to 1.8%, and the balance includes aluminum (Al) and unavoidable impurities, the enamel coating temperature Aluminum alloy for enamel coating that maintains high-temperature strength in the range of 550℃-570℃.
In weight percent (wt%), iron (Fe) 1.2 to 3.4%, silicon (Si) 0.8 to 3.8%, titanium (Ti) 0.1 to 0.5%, and the balance contains aluminum (Al) and unavoidable impurities, the enamel coating temperature Aluminum alloy for enamel coating that maintains high-temperature strength in the range of 550℃-570℃.

By weight percent (wt%), iron (Fe) 1.2 to 3.4%, silicon (Si) 0.8 to 3.8%, nickel (Ni) 0.2 to 1.0%, manganese (Mn) 0.3 to 0.8%, and the balance is aluminum (Al) and Aluminum alloy for enamel coating that contains unavoidable impurities and maintains high-temperature strength in the enamel coating temperature range of 550°C-570°C.
Providing a molten aluminum alloy according to claim 1 to 5;
The molten aluminum alloy is manufactured by die-casting, but before injecting the molten alloy into the die-casting mold, a gas reacting with the molten metal is injected into the die-casting mold, and then the molten metal is injected, thereby exothermicly reacting the injected molten alloy with the reaction gas and then the mold Preparing a frying pan by solidifying the molten alloy in the; and
Method for producing an enamel-coated frying pan by a die-casting method comprising the step of coating the frying pan with enamel in a temperature range of 550°C-570°C.
7. The method of claim 6,
The reactive gas is a method of manufacturing an enamel-coated frying pan by a die-casting method, characterized in that oxygen (O2).
As an enamel-coated frying pan manufactured by the manufacturing method according to claim 6,
Enamel coated frying pan, characterized in that fine oxide particles (Al2O3) of less than 1 micron (㎛) are distributed inside the frying pan.

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