JP2016069697A - Aluminum alloy member for heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum alloy member for heating cooker capable of achieving high heat generation property by electromagnetic induction heating.SOLUTION: There is provided an aluminum alloy member for heating cooker containing a first phase consisting of an intermetallic compound of a first element and a second element and a second phase consisting of the first element and the second element other than the intermetallic compound, the first element is aluminum, the second element is one or more selected from a group consisting of manganese, iron, silicon, magnesium, chromium and copper and the content of the second element in the aluminum alloy member for heating cooker is 18 mass% to 25 mass%.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an aluminum alloy member for a cooking device.

  A member using aluminum (Al) and another material is known as a member for a cooking device used in an electromagnetic heating cooker.

  For example, JP 2004-249367 A (Patent Document 1) discloses an austenitic stainless steel plate material, an iron or iron alloy member coated with aluminum (Al) on its surface, an aluminum or aluminum alloy member, and an austenitic stainless steel plate material. The board | plate material laminated | stacked in this order is described. Japanese Unexamined Patent Application Publication No. 2007-144132 (Patent Document 2) describes a composite material in which a nonmagnetic substrate made of Al, a magnetic material layer, and a metal material layer are laminated in this order.

  However, since the plate material described in Patent Document 1 and the composite material described in Patent Document 2 have a structure in which a plurality of layers of different materials are stacked, deterioration due to peeling of the layers is likely to occur. In contrast, for example, Japanese Patent Application Laid-Open No. 2007-270351 (Patent Document 3) describes an aluminum foil made of an aluminum alloy containing Al as a main component and containing Mg, Cr, Mn, Ti, Cu, Si, and Fe. ing. According to this aluminum foil, the above problem of peeling can be solved.

JP 2004-249367 A JP 2007-144132 A JP 2007-270351 A

  However, the specific resistance value of the aluminum foil described in Patent Document 3 is 5 to 10 μΩcm, and there is a problem that the amount of power consumed by electromagnetic induction heating is less than 100 W and the heat generation amount is low. For this reason, development of the member for heating cooking utensils which can exhibit the high calorific value by electromagnetic induction heating is calculated | required.

  This invention is made | formed in view of the above present conditions, The place made into the objective is to provide the aluminum alloy member for heating cooking appliances which can exhibit the high emitted-heat amount by electromagnetic induction heating.

  The aluminum alloy member for a cooking device according to the present invention is a first phase composed of an intermetallic compound of a first element and a second element, and a second phase composed of a first element and a second element, which is different from the intermetallic compound. An aluminum alloy member for a cooking device including a phase, wherein the first element is aluminum and the second element is one or more selected from the group consisting of manganese, iron, silicon, magnesium, chromium and copper Yes, the content of the second element in the aluminum alloy member for a cooking device is 18% by mass or more and 25% by mass or less.

  In the above-mentioned aluminum alloy member for cooking utensils, the area of the first phase occupying one surface having a size of 174 μm × 134 μm and the other surface perpendicular to one surface and having a size of 174 μm × 134 μm It is preferable that the area of the 1st phase to occupy is 60% or more and 90% or less.

  In the aluminum alloy member for cooking utensils, the number of second phases included in one surface having a size of 174 μm × 134 μm and the other one perpendicular to one surface and having a size of 174 μm × 134 μm The number of second phases contained in the surface is preferably 200 or more and 1000 or less, respectively.

  It is preferable that the aluminum alloy member for a cooking device is a plate having a thickness of 500 μm or more and 5000 μm or less.

  According to the aluminum alloy member for a cooking device of the present invention, there is an effect that a high calorific value due to electromagnetic induction heating is exhibited.

  In addition, the surface in the aluminum alloy member for heat cooking appliances as used in the field of this invention means the area | region which can be confirmed with an optical microscope. Strictly speaking, an oxide film is formed on the surface of the aluminum alloy member for cooking utensils, but the surface in the aluminum alloy member for cooking utensils referred to in the present invention means a surface excluding this oxide film.

The aluminum alloy member for cooking utensils of the present embodiment is imaged with an optical microscope, the obtained image is a binarized image, and in the sample obtained from the aluminum alloy member for cooking utensils of Example 2 It is an image after binarization processing of an area of 174 μm × 134 μm. It is the image after the binarization process of the area | region of 174 micrometers x 134 micrometers in the sample obtained from the aluminum alloy member for heating utensils of the comparative example 5.

  The aluminum alloy member for a cooking device of the present embodiment (hereinafter also referred to as “Al alloy member”) is different from the first phase composed of the intermetallic compound of the first element and the second element, and the intermetallic compound, and A second phase composed of a first element and a second element, wherein the first element is aluminum (Al), and the second element is manganese (Mn), iron (Fe), silicon (Si), magnesium ( One or more selected from the group consisting of Mg), chromium (Cr) and copper (Cu), and the content of the second element in the Al alloy member is 18% by mass or more and 25% by mass or less. When a plurality of second elements are included, the total amount of the plurality of second elements is 18% by mass or more and 25% by mass or less.

Examples of intermetallic compounds constituting the first phase include binary intermetallic compounds such as Al-Mn and Al-Fe, and ternary metals such as Al-Mn-Fe and Al-Fe-Si. A compound can be mentioned. The composition of the intermetallic compound is not limited to one, For example, the Al-Mn intermetallic compound, and the like MnAl _6, MnAl ₄ or MnAl _3.

  The second phase is different from the above-described intermetallic compound and is a phase composed of a first element and a second element. In the second phase, the second element is dissolved in the first element (Al).

  Needless to say, the Al alloy member of this embodiment may contain unintentional impurities. Inevitable impurities include Fe, Si, Cu, Mn, Mg, Zn, Ti, Zr, Ga, Cr, V, and the like. The content of each element as an inevitable impurity is 0.05% by mass or less. Inevitable impurities can be included in both the first phase and the second phase.

  The Al alloy member of this embodiment can be produced using a known DC (Direct Casting) casting method.

  The Al alloy member of the present embodiment can have a high specific resistance value of 40 μΩcm or more, and thereby can exhibit a high power consumption of 100 W or more by electromagnetic induction heating, thereby exhibiting a high calorific value. can do.

  FIG. 1 is an image obtained by photographing the Al alloy member of the present embodiment with an optical microscope and binarizing the obtained image. Specifically, it is an image obtained by photographing the surface of an Al alloy member of Example 2 described later at a magnification of 500 times and binarizing the obtained image based on the contrast of light and shade.

  In FIG. 1, a white area | region is a 1st phase which consists of an Al-Mn type intermetallic compound, and the black area | region dotted in island shape so that it may be enclosed by a 1st phase is a 2nd phase. In addition, inevitable impurities may be contained in the first phase and the second phase. Since the second phase is a phase in which Mn is dissolved in Al, the first phase and the second phase are clearly distinguished from each other in FIG.

  As shown in FIG. 1, the periphery of the second phase is surrounded by the first phase, and the first phase exists so as to be continuous (continuous). With such a structure, since the movement of electrons between the second phases is suppressed by the first phase, it can have a remarkably higher specific resistance than previously considered, and thereby, a high calorific value can be obtained. It is presumed that this will be possible.

  On the other hand, in the Al alloy member of the present embodiment, when the content of the second element is less than 18% by mass, the high heat generation amount as described above cannot be exhibited. This is because when the content of the second element is less than 18% by mass, the proportion of the first phase in the Al alloy member is low, so that the connection between the second phases cannot be sufficiently eliminated by the first phase. As a result, it is assumed that the movement of electrons between the second phases cannot be sufficiently suppressed. When the content of the second element was more than 25% by mass, an Al alloy member could not be produced by the DC casting method.

  In the Al alloy member of the present embodiment, the content of the second element is preferably 22% by mass or more and 25% by mass or less. In this case, a high power consumption of 140 W or more can be exhibited by electromagnetic induction heating. .

  In addition, the Al alloy member of the present embodiment has an area of the first phase occupying one arbitrary surface having a size of 174 μm × 134 μm, a size perpendicular to the one surface, and a size of 174 μm × 134 μm. It is preferable that the area of the first phase occupying one surface is 60% or more and 90% or less. Also in this case, high power consumption of 100 W or more can be exhibited by electromagnetic induction heating. The area of the first phase included in the two surfaces perpendicular to each other is more preferably 70% or more and 90% or less.

The area of the first phase in each of the two mutually perpendicular surfaces of the Al alloy member is determined as follows. First, an image is obtained by imaging the surface of the Al alloy member at a magnification of 500 times. In the obtained image, an image corresponding to the surface region of 174 μm × 134 μm of the Al alloy member is binarized based on the contrast of light and shade. And the ratio of the area which the 1st phase occupies in the image after a binarization process is calculated, and let this be the area of the 1st phase which occupies one surface of an Al alloy member. In addition, the same processing is performed on the other surface perpendicular to the one surface, and the calculated value is calculated as the area of the first phase in the other surface perpendicular to the one surface of the Al alloy member. To do. The first phase with an area of 1 μm ² or less is excluded from the number of measurements.

  In addition, the Al alloy member of the present embodiment has a number of second phases included in any one surface having a size of 174 μm × 134 μm, a size perpendicular to one surface, and a size of 174 μm × 134 μm. It is preferable that the number of the second phases included in one surface is 200 or more and 1000 or less, respectively. Also in this case, a high heat generation amount of 100 W or more can be exhibited by electromagnetic induction heating. More preferably, the number of second phases contained in the two surfaces perpendicular to each other is 200 or more and 800 or less, respectively.

The number of second phases in each of the two surfaces perpendicular to each other of the Al alloy member is the number of second phases scattered in the image after binarization obtained by the same method as the method for obtaining the area of the first phase. It is obtained by measuring the number of two phases. That is, the second phase surrounded by the first phase becomes one second phase. The second phase having an area of 1 μm ² or less is excluded from the number of measurements.

  Moreover, it is preferable that the Al alloy member of this embodiment is a plate-shaped object having a thickness of 500 μm or more and 5000 μm or less. When the thickness of the Al alloy member, which is a plate-like material, is less than 500 μm, the strength tends to be weak, and there is a risk of deformation when used as a cooking device such as a frying pan or a pan. When the thickness of the Al alloy member, which is a plate-like material, exceeds 5000 μm, the calorific value tends to decrease.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

Example 1
A molten aluminum was prepared, and Mn was added so that the Mn content in the Al alloy member was 18% by mass while heating the molten aluminum so that Mn could be dissolved. An aluminum alloy member having a length of 100 mm, a width of 120 mm and a thickness of 3.5 mm was produced by pouring the molten aluminum after Mn was poured into a copper mold and solidifying it. In addition, the total amount of inevitable impurities in the obtained Al alloy member was 0.01% by mass or less.

(Examples 2 to 4)
The Al alloy members of Examples 2 to 4 were the same as Example 1 except that Mn was added so that the Mn content in the Al alloy member was 20% by mass, 22% by mass, and 25% by mass, respectively. Was made. Also in Examples 2 to 4, the total amount of inevitable impurities in the obtained Al alloy member was 0.01% by mass or less.

(Comparative Examples 1-5)
As Comparative Example 1, an Al alloy member having a Mn content of 0.01% or less and a total amount of inevitable impurities of 0.01% or less was prepared. Further, a comparison was made in the same manner as in Example 1 except that Mn was added so that the content of Mn in the Al alloy member was 0.8% by mass, 10% by mass, 15% by mass, and 16% by mass, respectively. Al alloy members of Examples 2 to 5 were prepared. Also in Comparative Examples 2 to 5, the total amount of inevitable impurities in the obtained Al alloy member was 0.01% by mass or less.

(Tissue observation)
About each Al alloy member of Examples 1-4 and Comparative Examples 1-5, the ratio of each area of the 1st phase (Al-Mn intermetallic compound) in two mutually perpendicular | vertical surfaces according to the following method, and 2nd Each number of phases (Al material) was measured.

  Specifically, first, a part of the Al alloy member was cut out to prepare a rectangular parallelepiped sample. Next, using a light microscope (manufactured by Nikon Corporation, product name: “ECLIPSE L200”), one surface A of the sample was imaged at a magnification of 500 times to obtain an image A. Further, an image B was obtained in the same manner for another surface B perpendicular to one surface A of the sample. A region that appears bright with an optical microscope (black region in FIGS. 1 and 2) is the second phase, and a region that appears dark (white region in FIGS. 1 and 2) is the first phase.

  Next, the obtained images A and B (corresponding to a rectangular area of 174 μm × 134 μm on the surface in the Al alloy member) are read into a digital microscope VHX200 manufactured by Keyence Corporation, and the measurement tool of the digital microscope is used. Binarization processing was performed.

Then, the ratio of the area of the first phase in the binarized images A and B was calculated using the measurement tool of the digital microscope. The first phase having an area of 1 μm ² or less was excluded. Further, the number of second phases contained in the binarized images A and B was measured using a digital microscope measurement tool. The second phase having an area of 1 μm ² or less was excluded from the number of measurements. These results are shown in Table 1.

(Measurement of electrical characteristics)
About each Al alloy member of Examples 1-4 and Comparative Examples 1-5, the specific resistance value and the power consumption were measured with the following method.

  First, a part of the Al alloy member was cut out to prepare a sample having a length of 10 mm, a width of 75 mm, and a thickness of 3 mm. And the specific resistance value (microohm cm) of the sample was measured with the direct current | flow four-terminal method using the resistance meter (the Hioki Electric company make, model number 3541). Further, a part of the Al alloy member was cut out to prepare a sample of 75 mm length × 75 mm width. Then, a wattmeter (manufactured by SANWA) was attached to an IH water heater (manufactured by Tiger Thermos Co., Ltd., model number CIK-B030), and the power consumption (W) when the sample was heated was measured.

  As shown in Table 1, the specific resistance values of the Al alloy members of Examples 1 to 4 were 40 or more. On the other hand, the specific resistance values of the Al alloy members of Comparative Examples 1 to 5 were 31.8 or less.

  Moreover, it was confirmed that the Al alloy members of Examples 1 to 4 can exhibit power consumption of 100 W or more by electromagnetic induction heating. In contrast, the Al alloy members of Comparative Examples 3 to 5 had a power consumption of 98 or less. In addition, even if the Al alloy member of Comparative Example 1 and Comparative Example 2 was subjected to electromagnetic induction heating, no heating power was obtained, and the power consumption could not be measured.

  Further, in the Al alloy members of Examples 1 to 4, the area of the first phase occupying two mutually perpendicular surfaces (174 μm × 134 μm) is 60% or more and 90% or less, respectively. 5 Al alloy members were confirmed to be 51% or less, respectively.

  Further, in the Al alloy members of Examples 1 to 4, the number of second phases contained in two mutually perpendicular surfaces (174 μm × 134 μm) is 200 or more and 1000 or less, respectively. In the Al alloy member of ~ 3, it was 23 or less. Further, in the Al alloy members of Comparative Example 4 and Comparative Example 5, although the number of second phases on one surface was 200 or more, the second phase on the other surface perpendicular to this one surface. The number of was less than 100.

  Here, FIG. 1 is an image after binarization processing in the sample obtained from the Al alloy member of Example 2, and FIG. 2 is binarization in the sample obtained from the Al alloy member of Comparative Example 5. It is an image after processing.

  As shown in FIG. 1, in the Al alloy member of Example 2, the second phase (black area in the figure) is dispersed in islands by the first phase (white area in the figure). In addition, it was found that the number of second phases scattered on the surface was also large. On the other hand, as shown in FIG. 2, in the Al alloy member of Comparative Example 5, it is understood that many of the second phases are connected and the second phase is not divided by the first phase. It was.

  Moreover, in each Example, since the same structure | tissue state was observed in one surface and the other one surface perpendicular | vertical to this one surface, in Al alloy member, a 1st phase is a vertical direction It was also found that they were well dispersed in the horizontal direction. In addition, about the sample cut out from each Example, 50 areas of 174 μm × 134 μm in one surface, and 50 areas of 174 μm × 134 μm in another surface perpendicular to the one surface, When the tissue state was observed for each of the above, it was confirmed that the same tissue state was exhibited at any location.

  From the above, when the content of Mn in the Al alloy member is 18% by mass or more and 25% by mass or less, the second phase is suitably dispersed by being surrounded by the first phase. Therefore, it was inferred that a high specific resistance value can be exhibited, whereby a high power consumption amount can be exhibited, and thus a high calorific value can be exhibited. Moreover, since the 2nd phase is fully disperse | distributed to the vertical direction and a horizontal direction, it is estimated that it is excellent also in thermal conductivity.

  On the other hand, when the content of Mn in the Al alloy member is less than 18% by mass, since the content of the Al—Mn intermetallic compound is small, the proportion of the area of the first phase in the Al alloy member is For this reason, the second phase was not suitably dispersed, and as a result, it was assumed that the specific resistance value was lowered.

  Although the embodiments and examples of the present invention have been described as described above, it is also planned from the beginning to appropriately combine the configurations of the above-described embodiments and examples.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

Claims (4)

A first phase composed of an intermetallic compound of a first element and a second element;
An aluminum alloy member for a cooking device comprising a second phase different from the intermetallic compound and comprising the first element and the second element,
The first element is aluminum;
The second element is one or more selected from the group consisting of manganese, iron, silicon, magnesium, chromium and copper;
Content of the said 2nd element in the said aluminum alloy member for cooking utensils is an aluminum alloy member for cooking utensils which is 18 mass% or more and 25 mass% or less.   The area of the first phase occupying one surface having a size of 174 μm × 134 μm, and the area of the first phase occupying one other surface perpendicular to the one surface and having a size of 174 μm × 134 μm The aluminum alloy member for a cooking device according to claim 1, which is 60% or more and 90% or less.   The number of the second phases included in one surface having a size of 174 μm × 134 μm, and the second phase included in another surface having a size of 174 μm × 134 μm that is perpendicular to the one surface The number of each is the aluminum alloy member for heating cooking appliances of Claim 1 or Claim 2 which are 200 or more and 1000 or less, respectively.   The aluminum alloy member for heating utensils according to any one of claims 1 to 3, wherein the aluminum alloy member is a plate having a thickness of 500 µm or more and 5000 µm or less.

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