JP2002241877A - Aluminum alloy material having excellent thermal conductivity and brightness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum alloy material which has high thermal conductivity, is also excellent in the brightness of an anode oxide coating, and has good appearance. SOLUTION: The aluminum alloy material has a composition containing, by weight, 0.5 to 1.5% Co, and, if required, further containing at least one kind selected from 0.002 to 0.08% B, <=0.5% Fe, <=0.5% Ni and <=0.2% Cu, and the balance aluminum with inevitable impurities.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum alloy material having excellent heat conductivity and brilliancy, and more particularly, to a heat radiating component of an electronic device, in particular, a material of a heat radiating component which is also required to have an aesthetic appearance. The present invention relates to an aluminum alloy material useful for use as an aluminum alloy.

[0002]

2. Description of the Related Art Aluminum alloys are used in various fields on the basis of their characteristics because they are lightweight and have excellent electric and thermal conductivity. 2. Description of the Related Art In recent years, the performance of electronic devices has been improved, and high heat dissipation efficiency has been required for components such as heat sinks that are heat dissipating components and housings that are outer frames of the devices. In addition, a visible component such as a housing is required to have a heat radiation property and an aesthetic appearance (brilliance) in appearance, and the surface thereof is usually anodized and glossed. These parts made of aluminum alloy are mainly manufactured by die casting. In this case, JIS alloy ADC1 or ADC12 is a general alloy for die-casting, but the thermal conductivity of these alloys is poor, and is insufficient as a material of a heat-radiating component requiring a high heat-radiating effect. In addition, when anodized, the glitter is very poor and cannot be applied to parts requiring appearance.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an aluminum alloy material having high thermal conductivity and excellent brightness of an anodic oxide film.

[0004]

Means for Solving the Problems The present inventors aimed at an aluminum alloy which simultaneously satisfies the thermal conductivity and the brilliancy of the anodic oxide film, and as a result of various studies on the elements added to the aluminum alloy, The present inventors have found that an alloy to which a certain amount of Co is added is useful, and reached the present invention. That is,
The gist of the present invention is to contain 0.5 to 1.5 wt% of Co,
Aluminum alloy material characterized by the balance consisting of aluminum and unavoidable impurities.
0.5-1.5 wt%, and B0.002-
0.08 wt%, Fe 0.5 wt% or less, Ni 0.5 w
An aluminum alloy material containing at least one selected from t% or less and Cu 0.2 wt% or less, with the balance being aluminum and unavoidable impurities.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The aluminum alloy material of the present invention
It maintains the excellent thermal conductivity of aluminum and has the property of producing an oxide film with high light brightness when subjected to anodizing treatment, and contains Co as an essential element. Co can be added as a predetermined amount to an aluminum alloy to increase the strength of the alloy without significantly lowering the thermal conductivity of the alloy. Therefore, Co is suitable as a metal to be added to an aluminum alloy for heat dissipation components. Further, the aluminum alloy to which Co is added has a feature that the alumite film formed by the anodic oxidation treatment is excellent in glitter. The amount of Co added to the aluminum alloy of the present invention is appropriately selected in the range of 0.5 to 1.5 wt%, preferably 0.7 to 1.2 wt%. If the addition amount is less than 0.5 wt%, the strength of the alloy is insufficient, while if it exceeds 1.5 wt%, the brilliancy of the anodic oxide film deteriorates, and in some cases, the thermal conductivity may decrease.

[0006] In the aluminum alloy material of the present invention,
Co-added Al-Co alloy has another element, namely,
By adding a predetermined amount of at least one element selected from B, Fe, Ni and Cu, performance such as conductivity or strength can be further improved. B, which is further added to Co, has an effect of improving the electrical conductivity of the Al—Co-based alloy by its addition. B is added in an amount of 0.002 to 0.1.
08 wt%, preferably in the range of 0.005 to 0.03 wt%. If the addition amount is less than 0.002 wt%, the effect of improving thermal conductivity is not sufficiently achieved.
If it exceeds 8 wt%, B becomes excessive, and conversely, the effect of improving the thermal conductivity is reduced. In the aluminum alloy of the present invention, by adding B in the above-mentioned predetermined amount range, the conductivity can be increased without adversely affecting the glitter of the anodized film.

[0007] Like Co, Fe, Ni and Cu added to the alloy material of the present invention are elements that can increase the strength of the aluminum alloy without significantly lowering the thermal conductivity of the aluminum alloy. Added. The amount of Fe to be added is 0.5 wt% or less, preferably 0.1 to 0.35%.
It is appropriately selected in the range of wt%. If it exceeds 0.5% by weight, the glitter of the anodic oxide film deteriorates. The amount of Ni added is
0.5 wt% or less, preferably 0.1 to 0.35 wt%
Is selected as appropriate within the range. If it exceeds 0.5% by weight, the glitter of the anodic oxide film deteriorates. Cu addition amount is 0.2w
t% or less, preferably in the range of 0.05 to 0.15 wt%. If it exceeds 0.2 wt%, the thermal conductivity is reduced and the glitter of the anodic oxide film is deteriorated.

Each of these elements is selected within the above range. However, if the added amount of these elements is large, the glitter may be slightly lowered. It is preferable to select the amount of addition in consideration of the balance with the strength of the alloy. In that case, Co
The ratio (weight ratio) of each element to Fe / Co
Is 0.50 or less, preferably 0.30 or less. Ni / Co is at most 0.50, preferably at most 0.30, and Cu / Co is at most 0.20, preferably at most 0.1.
15 or less.

[0009] The aluminum alloy of the present invention contains unavoidable impurities in addition to the above-mentioned alloy components. If necessary, the aluminum alloy contains components added for improving other properties, for example, for improving strength and corrosion resistance. May be. Such components include, for example, Si, Mg, Zn, Mn, Zr, Cr,
Examples thereof include Ti, Sn, In, Ca, Sr, and Na, but 0.1% by weight or less because excessive addition of these components may cause a decrease in thermal conductivity and a deterioration in the brilliancy of the anodic oxide film. It is necessary to

The aluminum alloy of the present invention has excellent thermal conductivity and good strength, so that it can be used as a material for heat-radiating components such as heat sinks that require high heat-radiating properties. Further, since the glittering property of the anodic oxide film is also excellent, it is particularly useful as a material for a heat dissipation component that requires aesthetic appearance as well as thermal conductivity. Also, excellent thermal conductivity means excellent conductivity at the same time, and it can be used as a material for conductive parts such as electronic devices, particularly parts that require aesthetic appearance.

[0011]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. Since the thermal conductivity is proportional to the electrical conductivity, the electrical conductivity of the alloy (IAC)
S%) Since the thermal conductivity can be evaluated at the same time as the evaluation of the measurement,
In the following examples, the conductivity was measured.

Examples and Comparative Examples Alloys having the respective compositions shown in Tables 1 and 2 were cast into molds, and the conductivity of the ingot was measured. Aluminum having a purity of 99.8 wt% was used as aluminum for alloy preparation. Next, the surfaces of these alloy castings were subjected to surface grinding and degreasing, and then immersed in a 95 ° C. (phosphoric acid + nitric acid) aqueous solution for 2 minutes to carry out chemical polishing. After the treatment, the substrate was washed with water, and then a current of 1.5 A / dm ² was passed in an electrolytic solution (15% sulfuric acid, 20 ° C.) to form a 2 μm anodic oxide film on the surface. After washing with water, these were sealed with boiling water at 100 ° C. for 25 minutes. The appearance (brightness, color tone, uniformity) of the anodic oxide film thus obtained was visually evaluated. The criteria were as follows. ◎ Very good ○ Good △ Insufficient × Very bad

[0013]

[Table 1]

[0014]

[Table 2]

As shown in Table 1 above, in the examples of the present invention, a uniform silver-white anodic oxide film having high conductivity and good glitter was obtained at the same time. Although the comparative example in Table 1 also has relatively good conductivity, the glitter and uniformity of the anodic oxide film are insufficient. In the conventional die-casting alloys (ADC1 and ADC12) shown in Table 2, the conductivity is significantly reduced as compared with the invention examples. In addition, it is clear that the appearance of the anodic oxide film is very poor in both glitter and uniformity and cannot be applied to applications requiring high heat radiation efficiency and aesthetic appearance. Furthermore, in order to improve the conductivity and the appearance of the anodic oxide film, for example, even if the amount of Si added is adjusted, both the conductivity and the appearance of the anodic oxide film are simultaneously improved to reach the level of the alloy of the present invention. Can not.

[0016]

EFFECT OF THE INVENTION By using the aluminum alloy of the present invention, the heat radiation property is high and the appearance is beautiful (brightness).
Therefore, an industrial value is extremely large because a good heat radiation component can be provided.

Claims (2)

[Claims] 1. An aluminum alloy material containing 0.5 to 1.5 wt% of Co, the balance being aluminum and unavoidable impurities. 2. The composition contains 0.5 to 1.5 wt% of Co, and further contains at least one selected from the group consisting of 0.002 to 0.08 wt% of B, 0.5 wt% or less of Fe, 0.5 wt% or less of Ni, and 0.2 wt% or less of Cu. An aluminum alloy material comprising one type and the balance being aluminum and unavoidable impurities.