JPS6047901B2 - High hardness aluminum alloy with excellent alumite dyeability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of Japanese Patent Application No. 13794/1983 regarding an aluminum alloy having good mechanical properties, particularly high hardness, and excellent alumite dyeability.

High-purity aluminum and aluminum alloys with a low alloying degree have excellent alumite dyeability, but as additive elements are added with the intention of improving tensile strength and hardness, as the degree of alloying increases, the alumite dyeability decreases. Deteriorate.

In other words, when a colorant is infiltrated into the hydroxide layer generated by surface oxidation and then fixed through a sealing process that converts it into an oxide, the colorant may have a color different from its original color. Conventionally, it was thought that the mechanical properties of aluminum alloys and the dyeability of alumite were incompatible. However, as the uses of aluminum alloys have expanded, there has been a demand for products colored in desired beautiful colors.

Therefore, the present inventor challenged the above-mentioned preconceptions and developed an Al-Zn material with high tensile strength and hardness called "ultra-super duralumin."
-Researched to achieve excellent alumite dyeing properties in Mg-Cu alloys, and published the results in a patent application filed in 1983-
137944 was proposed.

As a result of subsequent research, we have invented an aluminum alloy with even better dyeing properties, which we would like to propose here. The high-hardness aluminum alloy with excellent alumite dyeability of the present invention contains Zn: 5.5 to 6.5%, Mg:
2.5-3.5%, CU: 0.56-0.66%, Cr
:0.16~0.26%, Ti:0.011~0.02
1%, Zr: 0.08 to 0.18, Si: 0.09% or less, and Fe: 0.17% or less, with the remainder substantially consisting of N.

The role of each of the above alloying elements and the significance of the component composition are as follows.

Zn: 5.5-6.5% Along with Mg and Cu, it is a necessary component to obtain good mechanical properties, and the presence of at least 5.5% is required, but too much will reduce corrosion resistance. From, 6.5
Stop at %.

Mg: 2.5-3.5% As mentioned above, it is an important component along with Zn and Cu, and increases strength.

It is preferable to add it in an amount of 2.5% or more, especially in relation to Zn, so that the component ratio is around Zn:Mg=2:1.

Not only is it useful in itself to increase hardness, but
Cu also has the function of helping improve hardness. However, since the presence of a large amount makes the alloy brittle, the content should be within 3.5%. CU: 0.56-0.66% It is an essential component of a quaternary alloy consisting of N-Zn-Mg plus Cu, and is useful from the viewpoint of hardness and strength as described above.

Same as Mg, if too much, the material becomes brittle.
Furthermore, since black spots may occur during alumite treatment, the limit is set at 0.66%. Cr:0.16~0.2
6% The effect is almost the same as that of Cu, but when used in combination, a high effect can be obtained even with a small amount of Cu.

The above range was selected based on this effect and its influence on alumite dyeability. Si: 0.09% or less Fe: 0.17% or less Both are components that are unavoidable from entering the aluminum alloy as impurities, but Fe contributes to some extent to improving workability, especially malleability.

The above value was determined as an allowable limit for minimizing the adverse effect on alumite dyeability.

The extremely limited alloy composition described above is necessary to simultaneously satisfy the incompatible properties of good mechanical properties and excellent alumite dyeability, and was derived from the results of numerous experiments conducted by the inventor. It is.

By selecting the above-mentioned composition, the aluminum alloy of the present invention has a surface hardness of HRB = 78 to 83, which is higher than that of extra super duralumin (H5RB = 80 to 83).
The hardness is not much different from 95.

Of course, along with this, the tensile strength is also 55 to 57 kg nod.
Indicates a high degree of value. On the other hand, the dyeability of alumite is comparable to that of 3-9 grade high purity aluminum, so the surface of the product can be colored in any desired color. J The aluminum alloy of the present invention can be melt-produced according to methods established in the art. Processability is not bad either,
You can make products of various shapes. By subsequently applying solution treatment, the mechanical properties described above can be exhibited, so that alumite dyeing can also be performed using known techniques. The alloy of the present invention having such characteristics can be used for a wide range of applications.

Particularly suitable examples include mechanical parts for which beautiful coloring is desired, such as building materials for interior and exterior use, home appliances, and especially audio equipment. Example An aluminum alloy having the following composition was melted and prepared and cast.

(Unit: %) A comb material was made from this material by rolling and pressing, and subjected to solution treatment at 475°C x 1 hour and precipitation hardening at 120°C x 2@.

The surface hardness of the material at this time was HRT3=82, and the tensile strength was 56.6 kg/m1t. Next, a hydroxide layer was formed by electrolysis using a sulfuric acid bath and caustic soda treatment, and after coloring it red by applying aluminal red dye, a pore sealing treatment was added to fix this color.

This fixation resulted in a beautiful colored surface on which the color of the dye itself was perfectly fixed. Moreover, this colored surface exhibits even better dyeability than that of the patent application No. 55-1379. Similar good alumite dyeability was also confirmed when Basalox Brown, Basalox Yellow, and Aluminal Green were used as dyes to color brown, yellow, and green, respectively.

Claims (1)

[Claims] 1 Zn: 5.5 to 6.5%, Mg: 2.5 to 3.5%
, Cu: 0.56-0.66%, Cr: 0.16-0.
26%, Ti: 0.011-0.021%, Zr: 0.
08-0.18%, Si: 0.09% or less and Fe:
A high-hardness aluminum alloy containing 0.17% or less, with the remainder substantially consisting of Al and having excellent alumite dyeability. 2 Zn: 6.0%, Mg: 3.0%, Cu: 0.61
%, Cr: 0.21%, Ti: 0.016%, Zr: 0
．． Claim 1 containing 13%, Si: 0.04% and Fe: 0.12%, with the remainder substantially consisting of Al.
Section aluminum alloy.