JPH06192817A - Al or al alloy member surface-modified by metal ion implantation - Google Patents

Abstract

PURPOSE:To provide a modified surface excellent in resistance to corrosion and wear by forming a layer enriched with a special metal element on the surface of an Al member by ion implantation. CONSTITUTION:One or more kinds of metal elements selected from groups IIIA, IVA, VA, VIA; VIII and VIB are ion-implanted in the surface of an Al or Al alloy member to form a layer enriched with the elements on the member surface. The metal ion alone or the metal ions are preferably implanted at 1X10<15>ions/cm<2>. As a result, a surface-modified Al or Al alloy member, which is not pitted in a corrosive environment contg. a halogen ion such as chlorine ion and exhibits excellent wear resistance even when slid, is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an Al or Al alloy member whose surface has been modified by metal ion implantation, and particularly to prevent pitting corrosion even in a corrosive environment in which halogen such as chlorine ions exists. Excellent corrosion resistance,
The present invention relates to a surface-modified Al or Al alloy member that exhibits excellent wear resistance even in a sliding environment.

[0002]

2. Description of the Related Art Since Al and Al alloys are lightweight, beautiful and have excellent mechanical properties, they are widely used in various fields such as cans, automobiles, building materials and home appliances.

Al and Al alloys basically have good corrosion resistance, and this corrosion resistance is achieved by an oxide film formed on the surface by natural oxidation. However, Al
In Al and Al alloys, in a corrosive environment where halogens such as chlorine ions are present, the above oxide film is easily destroyed and active A
There is a disadvantage that the surface is exposed and pitting corrosion occurs relatively easily at that portion. Therefore, it is required to prevent the occurrence of pitting corrosion in Al and Al alloys, and corrosion-resistant Al alloys to which various metal elements are added have been proposed, but Al alloys having satisfactory properties have not been developed. Is the reality. In addition, as a pitting corrosion prevention technology for Al and Al alloys, (1)
Although alumite treatment, (2) Zn coating treatment, (3) resin coating, etc. have been carried out, none of them are effective means for preventing pitting corrosion. On the other hand, Al and Al alloys have the drawback of being inferior in wear resistance, so that the fields of application have been significantly limited.

[0004]

The present invention has been made in view of these circumstances, and its purpose is to provide excellent corrosion resistance such that pitting corrosion does not occur even in a corrosive environment in which halogen such as chlorine ions exists. Another object is to provide a surface-modified Al or Al alloy member that exhibits excellent wear resistance even in a sliding environment.

[0005]

According to the present invention which has achieved the above object, the surface of an Al or Al alloy member has IIIa, IV
a, Va, VIa, VIII and IVb are ion-implanted with at least one metal element selected from the group consisting of
1 is an Al or Al alloy member surface-modified by metal ion implantation, which is characterized in that a concentration-enriched layer of the above metal element is formed on the surface of the l alloy member.

[0006]

The ion implantation method used in the present invention is carried out by implanting accelerated high-energy ions to a target depth and forming an Al or Al alloy member (hereinafter, represented by an Al member).
In addition to being used as an impurity doving means in the field of semiconductors, its application is also being advanced for surface modification of metal materials centering on steel (see, for example, Japanese Patent Laid-Open No. Hei 3- 6362), except for the semiconductor field, so far no practical progress has been made.

The Al member according to the present invention uses such an ion implantation method for surface modification of the Al member, and a non-thermal equilibrium substance layer is formed on the surface layer of the Al member by ion implantation. That is, in the alloying by the thermal process that has been performed so far, an alloy layer in a thermal equilibrium state is formed, and since the alloy layer is a thermal equilibrium substance layer, there is a limit to the improvement of the substance. On the other hand, in the present invention,
By forming the non-thermal equilibrium material layer, it is possible to obtain properties that cannot be predicted conventionally. In other words, even if an Al alloy to which the same element as the ion-implanted element is added is formed, it cannot be expected to exhibit the corrosion resistance and wear resistance as the Al alloy of the present invention.

In order to improve the characteristics of the Al member, it is not necessary to implant ions into the Al member, but specific elemental ions are selected according to the characteristics to be improved, and the implantation amount and It is necessary to set the implantation energy appropriately. As a result of the inventors performing ion implantation experiments on various elemental ions,
In order to significantly improve the corrosion resistance of Al members, IVa, V
It has been found that ion implantation may be performed with at least one metal element selected from the group consisting of a, VIa and VIII groups. In order to improve wear resistance, IIIa, IVa, Va, VI
It has also been found that it is sufficient to ion-implant one or more metal elements selected from the group consisting of a, VIII and IVb groups.
Therefore, by ion-implanting at least one metal element selected from the group consisting of IVa, Va, VIa and VIII groups, the corrosion resistance and the wear resistance are improved. In any case, on the surface of the Al or Al alloy member, depending on the characteristics to be improved,
Ions may be implanted with at least one metal element selected from the group consisting of IIIa, IVa, Va, VIa, VIII and IVb groups.

In ion implantation, high energy ions are replaced with Al.
Although it is forcibly driven into the surface layer of the member, it does not mean that another material layer is formed on the surface layer, so unlike the case where a coating of a material different from the base material is adhered, as in the case of surface treatment such as plating, ion implantation The integrity of the surface layer portion with the base material layer is extremely good, and the problem of peeling does not occur.

The Al member according to the present invention has the above-mentioned effects, and in order to obtain these effects, it is desirable to implant the above metal ions alone or in a total of 1 × 10 ¹⁵ ions / cm ² or more. . On the other hand, if the implantation is excessive, the surface cutting phenomenon due to the spattering phenomenon becomes remarkable depending on the implantation energy. Therefore, the implantation energy and the implantation amount must be carefully determined. From this point of view, it is desirable that the implantation energy is about 5 to 250 KV, and the implantation amount is suppressed to 5 × 10 ¹⁸ ions / cm ² or less alone or in total.

The present invention will be described in more detail with reference to the following examples, but the following examples are not intended to limit the present invention, and any design changes that may be made in view of the spirits of the preceding and the following are not intended to limit the present invention. It is included in the technical scope.

[0012]

【Example】

Example 1 Various metal ions were injected into a pure Al substrate (thickness: 1 mm), and corrosion resistance of various metal ion-implanted Al members was evaluated from the pitting corrosion generation potential based on the measurement of the anodic polarization curve. The ion implantation conditions and the corrosion resistance test conditions at this time are as follows. (Ion implantation condition) Acceleration voltage: 70 KV Injection amount: 1 × 10 ¹⁷ ions / cm ² Injection surface: 25 × 25 (mm) surface (Implanted on one surface) (Corrosion resistance test condition) Solution: 3% NaCl (30 ± 1 ° C.) ) Sweep speed: 30 mV / min Test area: 1 cm ²

The results of the corrosion resistance test are shown in FIG. For comparison, FIG. 1 also shows the pitting corrosion generation potential of a pure Al substrate which was not ion-implanted. As is clear from this result, Zr, Ti, Nb, V, Mo, W, Cr, Ni, P
It can be seen that when the metal element such as d is ion-implanted, the pitting corrosion generation potential becomes more noble than that of the untreated pure Al substrate, and the corrosion resistance is improved. Particularly, when Ti, Nb, Mo, etc. are ion-implanted, the pitting corrosion generation potential becomes 100 mV or more noble, and it is understood that the ion implantation effect of these is extremely high.

Example 2 A disk-shaped Al alloy (A6061, diameter: 50 mm, thickness:
8 mm), various metal ions were injected, and the wear resistance was evaluated from the dynamic friction coefficient based on the reciprocating sliding ball-on-disk wear test (the wear amount is proportional to the dynamic friction coefficient). Ion implantation conditions and wear resistance test conditions at this time are as follows. (Ion implantation conditions) Acceleration voltage: 70 KV (however, C is 30 KV) Implantation amount: 1 × 10 ¹⁷ ions / cm ² (However, in the case of compound implantation, each is 1 × 10 ¹⁷ ions / cm ² ) Implantation surface: φ50 mm Surface (one side only) (Abrasion resistance test conditions) Sliding speed: 12.7 mm / min Sliding width: 5 mm Load: 20 gf Sliding frequency: 17 times Ball indenter: SUS440C (diameter: 10 mm) Test environment: room temperature, no lubrication

The results of the abrasion resistance test are shown in FIGS. 2 and 3. For comparison, FIGS. 2 and 3 also show the dynamic friction coefficient of the above Al alloys without ion implantation. As is clear from this result, the dynamic friction coefficient is 0.7 when the injection is not performed.
However, Pd, Ta, Mo, Ni, (Ti
It can be seen that in the case of ion-implanting a metal element such as + C) or (C + Y), the dynamic friction coefficient can be reduced to 0.23 or less (1/3 or less of the non-implanted material), and the wear resistance is improved.

[0016]

EFFECTS OF THE INVENTION The present invention is configured as described above, and an Al (or Al alloy) member having excellent corrosion resistance and wear resistance can be obtained by forming an implantation layer in metal ions. Thus, it can be suitably used even in a corrosive environment or a sliding environment, which has been difficult to use in the past, and it is expected that the applicable range of Al and Al alloy members will be greatly expanded.

[Brief description of drawings]

FIG. 1 is a graph showing the corrosion resistance test results of various metal ion-implanted Al members.

FIG. 2 is a graph showing an example of wear resistance test results of various metal ion-implanted Al members.

FIG. 3 is a graph showing another example of wear resistance test results of various metal ion-implanted Al members.

Claims (1)

[Claims] 1. A surface of an Al or Al alloy member is provided with III
a, IVa, Va, VIa, VIII and IVb, wherein at least one metal element selected from the group consisting of groups is ion-implanted to form a concentration-enriched layer of the metal element on the surface of the Al or Al alloy member. An Al or Al alloy member whose surface is modified by metal ion implantation.