JPH083137B2 - Corrosion resistant aluminum base alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention has high hardness and strength, high heat resistance, high wear resistance, and excellent corrosion resistance, and has various industrial fields. It relates to an aluminium-based alloy that can be used for.

[Prior Art] Conventional aluminum-based alloys include pure Al-based and Al-Mg
Systems, Al-Cu-based, Al-Mn-based and other component-based alloys are known, and depending on their material properties, for example, as members of aircraft, vehicles, ships, etc., and also for exterior materials for construction, sashes, It is used in a wide range of applications as roofing materials, seawater equipment components, nuclear reactor components, etc.

[Problems to be Solved by the Invention] In a conventional aluminum-based alloy, a passive film capable of protecting a metal material in a mild environment is also easily destroyed in an aqueous hydrochloric acid solution or an aqueous sodium hydroxide solution, and
It cannot be safely used for a long time in an aqueous sodium chloride solution (seawater, etc.). In particular, the hydrochloric acid aqueous solution and the sodium hydroxide aqueous solution have a strong corrosive action and there is no metal material that can be used safely, and the above-mentioned conventionally known aluminum-based alloys are naturally difficult to use for such purposes, and are corrosive environments (prone to corrosion). It has been earnestly desired to develop a new aluminum-based alloy that can withstand long-term use under environmental conditions. Therefore, in view of the above, the present invention, under the corrosive environment, has a high hardness, a high strength, a high heat resistance, a high wear resistance, and a novel aluminum-based alloy having excellent corrosion resistance at a relatively low cost. It is intended to be provided.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention uses an Al alloy that is difficult to produce by a usual melt casting method as a non-uniform crystalline alloy with high corrosion resistance and high resistance. It is obtained as an amorphous alloy having abrasion resistance and the like.

That is, the present invention provides a compound represented by the general formula: Al _a M _b Mo _c Hf _d Cr _e where M is one or more metal elements selected from Ni, Fe and Co, and a, b, c, d and e are 50% ≦ a ≦ 88% 2% ≦ b ≦ 25% 2% ≦ c ≦ 15% 4% ≦ d ≦ 20% 4% ≦ e ≦ 20% in atomic percent, amorphous or It is a corrosion resistant aluminum-based alloy consisting of at least 50 percent (volume ratio) of a composite of amorphous and crystalline.

Normally, the alloy is crystallized in the solid state, but if a method that does not form long-period regularity in the atomic arrangement in the process of solid formation is applied, such as limiting the alloy composition and solidifying from the molten state by rapid quenching, An amorphous structure that does not have a structure and is similar to a liquid is obtained, and an alloy having such a structure is called an amorphous alloy. Amorphous alloys are mostly single-phase alloys with a supersaturated solid solution and have a significantly higher strength than conventional practical metals, and exhibit various excellent properties such as extremely high corrosion resistance depending on the composition.

The aluminum-based alloy of the present invention can be obtained by rapidly solidifying a melt of the alloy having the above composition by a liquid quenching method. The liquid quenching method refers to a method of rapidly cooling a molten alloy, for example, a single roll method, a twin roll method, a rotating submerged spinning method, etc. are particularly effective, and in these methods 10 ⁴ ~ 10 ⁷ k A cooling rate of about / sec can be obtained. In order to produce a ribbon material by the single roll method, the twin roll method, etc., the molten metal is applied to a roll made of, for example, copper or steel having a diameter of 30 to 300 mm rotating at a constant speed in the range of about 300 to 10000 rpm through a nozzle hole. Gush out. This gives a width of about 1-30
Various ribbon materials having a thickness of 0 mm and a thickness of about 5 to 500 μm can be easily obtained. In addition, in order to produce fine wire material by the spinning submerged spinning method, the back pressure of argon gas is passed through the nozzle hole
A fine wire material can be easily obtained by jetting a molten metal into a solution refrigerant layer having a depth of about 1 to 10 cm held by a centrifugal force in a drum rotating at 50 to 500 rpm. At this time, it is preferable that the angle between the molten metal ejected from the nozzle and the refrigerant surface is about 60 to 90 degrees, and the relative velocity ratio between the ejected molten metal and the solution refrigerant surface is about 0.7 to 0.9.

Further, in the aluminum-based alloy of the present invention, a material compounded to have the composition represented by the above general formula is attached to the surface of the substrate by using a thin film forming means such as sputter deposition, vacuum deposition, or ion plating, and a thin film of the above composition is formed. Can be obtained by forming.

The sputter vapor deposition method includes a two-pole sputtering method, a three-pole, four-pole sputtering method, a magnetron sputtering method, a facing target sputtering method, an ion beam sputtering method, a dual ion beam sputtering method, and the like. There are an application type and a high frequency application type.

Explaining the sputter deposition method, the sputter deposition method is a method in which an ion source generated by an ion gun or plasma is made to collide with a target having the same composition as the thin film material to be formed, and the atomic state generated from the target by the impact. Various types of known ones are produced by depositing molecular or cluster neutral particles or ionic particles on a substrate.

Among them, the ion beam sputtering method, the plasma sputtering method, etc. are particularly effective. In these methods, 10 ⁵ to 10 ⁷ K /
A cooling rate of about sec can be obtained. Such a cooling rate makes it possible to produce an alloy thin film having an amorphous phase of at least 50 percent (volume ratio). The thickness of the thin film can be controlled by the length of processing time, and the thickness is usually formed at a forming rate of 2 to 7 μm per hour.

Further, the case of carrying out the present invention using the magnetron plasma sputtering method will be described in detail. An electrode (+ electrode) is provided in a container in which the sputtering gas is kept at a low pressure of 1 × 10 ⁻³ to 10 × 10 ⁻³ mbar. Targets (-electrodes) having the above composition are opposed to each other with an interelectrode distance of 40 to 80 mm, 200 to 500 V is applied between the electrodes, and plasma is generated between the electrodes. A substrate on which a thin film is to be deposited is arranged in or near the plasma region to form the thin film.

Note that the quenched powder can be obtained by various atomizing methods such as a high-pressure gas atomizing method and the spraying method instead of the above method.

Whether or not the obtained quenched aluminum-based alloy is amorphous can be determined by the usual X-ray diffraction method based on whether or not there is a halo pattern peculiar to the amorphous structure.

In the aluminum-based alloy of the present invention represented by the above general formula, a, b, c, d, and e are limited in atomic% as described above. Therefore, it becomes difficult to perform bending, and it is impossible to obtain a composite composed of an amorphous phase of at least 50% (volume ratio) by an industrial means such as sputter deposition.

The M element is a metal element selected from Ni, Fe, and Co, and the M element, Mo element, and Hf element have an effect of improving the amorphous forming ability, and also improve hardness and strength.
It also improves heat resistance. In particular, the Hf element is useful for improving the amorphous forming ability of the alloy system of the present invention.

The Cr element has the important effect of adding Mo and Hf in the alloy.
By coexisting with the element, an effect of improving the corrosion resistance of the alloy by forming a passive film by the interaction of both elements. Here, another reason why the atomic% of the Cr element (e) is limited as described above is that when the Cr element is less than 4 atomic%, improvement in corrosion resistance, which is the object of the present invention, cannot be expected.
On the other hand, if the content of Cr element is more than 20 atomic%, the alloy becomes too brittle to be industrially used and impractical.

When the aluminum-based alloy of the present invention is used as a thin film, it has a high degree of viscosity depending on its composition, and even if it is adhered and bent at 180 °, no cracks occur or peeling from the substrate does not occur.

[Examples] Examples of the present invention will be described below.

Example 1 A molten alloy 3 having a predetermined composition was prepared in a high frequency melting furnace, and a small hole 5 (hole diameter:
0.5mm) into a quartz tube 1 and heated and melted,
Place the quartz tube 1 directly above the copper roll 2 and rotate at 50 rpm.
Under high speed rotation of 00 rpm, the molten alloy 3 in the quartz tube 1 was pressurized with argon gas (0.7 kg / cm ² ) to make the small holes 5 in the quartz tube 1.
And is rapidly cooled and solidified by contacting the surface of the roll 2 to obtain the alloy ribbon 4.

Under the above manufacturing conditions, an alloy ribbon was obtained, and as a result of X-ray diffraction, it was confirmed that the resulting alloy had an amorphous property. Further, the ribbon composition was subjected to quantitative analysis with an X-ray microanalyzer after rapid solidification. It is a thing.

Here, a thin strip of the aluminum-based alloy of the present invention was cut into a certain length and immersed in a 1N hydrochloric acid aqueous solution at 30 ° C. to perform a corrosion resistance test against hydrochloric acid. Further, this aluminum-based alloy thin film cut into a certain length was immersed in a 1N sodium hydroxide aqueous solution at 30 ° C. to perform a corrosion resistance test against sodium hydroxide. Table 1 shows the results. In the table,
The corrosion resistance was evaluated by the corrosion rate, and commercially available 4N-A1 (99.99% A1) and A1-Cu alloy (duralmin) were used for comparison. Table 1 shows that the aluminum-based alloy of the present invention exhibits superior corrosion resistance to an aqueous hydrochloric acid solution and an aqueous sodium hydroxide solution as compared with a commercially available aluminum-based alloy.

Further, the alloy of the present invention is Al _70.0 Fe _9.4 Mo _4.7 Hf _9.4 Cr _6.5.
About ribbon and Al _74.8 Ni _6.5 ribbon 30g / -NaCl at 30 ℃
The results measured in an aqueous solution are shown in Table 2 and also Al _74.8 Ni
_The polarization curves of _6.5 Mo _4.7 Hf _7.5 Cr _6.5 soaked in a 1N aqueous hydrochloric acid solution for 24 hours and a soaked in a 1N aqueous sodium hydroxide solution for 8 hours were measured at 30 ° C.
-The corrosion resistance was evaluated by measuring in a NaCl aqueous solution. The results are shown in Table 2, FIG. 2 and FIG. In Table 2, the evaluation of the corrosion resistance is represented by the pitting potential, and is also commercially available for comparison.
4N-Al was used. According to Table 2, the aluminum-based alloy of the present invention is 30 g / 30 ° C at 30 ° C as compared with the commercially available aluminum-based alloy.
By forming a strong passivation film by self-passivation in an aqueous solution containing sodium chloride, by further dipping in an aqueous solution of hydrochloric acid or an aqueous solution of sodium hydroxide, by self-passivating the alloy of the present invention. Further, a strong passive film can be formed. In particular, the alloy (Al _74.8 Ni _6.5 M
o _4.7 Hf _7.5 Cr _6.5 ) immersed in 1N hydrochloric acid aqueous solution for 24 hours has a pitting potential of +380 mV and is a precious metal Cu
It is a value comparable to (copper). From these, it can be seen that the aluminum-based alloy of the present invention is an aluminum-based alloy having extremely high corrosion resistance.

Example 2 By grinding or cutting the amorphous alloy of the present invention obtained by the production method of Example 1 above into a powder, when this is used as a pigment for a metallic paint, corrosion in the paint is prevented. A metallic coating having excellent durability that can withstand a long period of time can be obtained.

EFFECTS OF THE INVENTION As described above, the aluminum-based alloy of the present invention is at least
Since it is a composite with 50% amorphous, it has excellent characteristics of amorphous alloy such as high altitude, high strength, high heat resistance and high wear resistance, and also stable protection with self-passivation. The coating is extremely resistant to corrosion because it can withstand a long period of time even in a severely corrosive environment containing chloride ions in an aqueous solution of hydrochloric acid, sodium chloride, etc. or hydroxide ions in an aqueous solution of sodium hydroxide, etc. .

[Brief description of drawings]

FIG. 1 is an explanatory view of an example of the production method of the present invention, and FIG. 2 is an alloy of the present invention immersed in a 1N HCl aqueous solution at 30 ° C. for 24 hours at 30 ° C. in a 30 g / NaCl aqueous solution. FIG. 3 is a polarization curve measured with the alloy of the present invention for 8 hours at 30 ° C. and 1N.
It is the polarization curve which what was immersed in a -NaOH aqueous solution was measured at 30 ° C and a 30g / -NaCl aqueous solution. 1 ... Quartz tube, 2 ... Copper roll, 3 ... Molten alloy, 4 ...
… Quenching ribbon, 5… Small holes.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsumasa Odera 4-11-20 Chuorinkan, Yamato City, Kanagawa Prefecture (72) Inventor Kazuo Aikawa 526-2 Kamikoizumi, Namekawa City, Toyama Prefecture (72) Inventor Madoka Nakajima Hyogo Prefecture 6-6 Maikodai, Tarumi-ku, Kobe (72) Inventor Keiko Yamagata 1008 Dogenji, Tateyama-cho, Nakashinkawa-gun, Toyama Prefecture (56) Reference JP-A-1-47831 (JP, A)

Claims (1)

[Claims] 1. A general formula: Al _a M _b Mo _c Hf _d Cr _{e wherein} M is one or more metal elements selected from Ni, Fe and Co, and a, b, c, d and e are atoms. Percentage 50% ≤ a ≤ 88% 2% ≤ b ≤ 25% 2% ≤ c ≤ 15% 4% ≤ d ≤ 20% 4% ≤ e ≤ 20% with an amorphous or at least A corrosion resistant aluminum-based alloy consisting of a 50% (volume ratio) composite of amorphous and crystalline.