JPH02149682A - Production of aluminum alloy material having superior wear resistance - Google Patents

Abstract

PURPOSE:To produce an Al alloy material having superior wear resistance and durability by locally melting the surface of an Al or Al alloy base material together with a boride or silicide to form a hard alloyed layer in the surface of the base material. CONSTITUTION:A shallow groove 2 is cut in the surface of an Al or Al alloy base material 1 and powder 3 of one or more kinds of borides such as TiB2 or one or more kinds of silicides such as Mg2Si is fed from the outside of the base material 1 and embedded in the groove 2. The surface of the base material 1 is locally melted together with the powder 3 by irradiation with laser beams 4. The molten part solidities in a short time, a hard alloyed layer 5 contg. the borides or silicides dispersed uniformly and densely in the Al matrix is formed and an Al alloy material having superior wear resistance is obtd. The alloyed layer 5 bonds to the base material 1 in one body, does not cause exfoliation at all and ensures satisfactory durability.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to the production of aluminum alloy materials with excellent wear resistance, which are used as parts materials that require wear resistance in automobiles, office machines, general machinery, etc. Regarding the method.

As is well known in the art, aluminum or aluminum alloys are much lighter than commonly used iron-based materials, have excellent thermal conductivity, and have excellent corrosion resistance, so they have recently been used in automobiles. It has come to be widely used as various machine parts such as. However, aluminum or aluminum alloys generally have inferior wear resistance compared to iron-based materials, and this has been a major obstacle when replacing iron-based parts with Aρ alloy parts for the purpose of reducing weight in automobiles, etc. .

Therefore, as a measure to improve the wear resistance of aluminum alloy materials used in areas where wear resistance is required, surface treatments such as plating, anodizing, or thermal spraying have been applied to create a highly wear-resistant surface treatment layer. Attempts have been made to form a steel sheet, but none of them have yet been able to fully satisfy the requirements for wear resistance. Moreover, in both cases, the adhesion of the surface treatment layer to the base material is insufficient, resulting in the drawback that sufficient durability cannot be ensured when used under high surface pressure.

This invention was made against this technical background, and it is an aluminum alloy material that has excellent wear resistance and sufficient durability even when used under high surface pressure. The purpose is to produce and provide.

Means for Solving the Problems In order to achieve the above object, the present invention provides a surface of an aluminum or aluminum alloy base material that is supplied from the outside of the base material.
By locally melting the seed or two or more borides or silicides, a hard alloyed layer in which the Al matrix and the boride or silicide particles are alloyed is formed on the surface of the base material. The purpose is to improve wear resistance.

The composition of aluminum or aluminum alloy used as the base material is not particularly limited, and is based on JIS1000.
In addition to standard pure aluminum, various aluminum alloys can be used that have the required mechanical properties and processing characteristics depending on the application.

Further, the shape of the base material may be arbitrarily designed depending on the shape of the part to which it is applied.

The surface of the aluminum or aluminum alloy base material may be melted by a melting means using a high-density energy source such as laser beam, electron beam, TIG arc, or the like. By using such means, only the surface layer of the base material can be melted to reduce the thermal influence on the base material, and only a part of the base material can be locally alloyed.

- A laser beam is often used inside the film, specifically a YAG laser (wavelength: 1.06 μm).

Pulse oscillation) or CO2 laser (wavelength: 10.6 μm, 5 continuous oscillations) are mainly used. Further, melting may be carried out on a region where wear resistance is required, but when the region is spread over a wide range, it may be necessary to adjust the oscillation width of a laser beam or the like or sequentially irradiate the material.

The surface of the base material is melted while accompanying the melting of boride or silicide, that is, a compound of a metal element and boron or silicon, supplied from outside the base material. 1 of supply modes of boride and silicide
One example is the case where the powder is made into powder and a coating layer is formed in advance at a desired location before irradiation with a laser beam or the like. The coating layer is formed by wet plating, C
This can be done by VD, PVD, thermal spraying, etc., or by applying powder using various binders such as ethyl alcohol. In addition, as another supply mode, the powder may be directly introduced into the melting zone during irradiation with a laser beam or the like.

Either method may be used, but in the case of the direct injection method,
Since it is troublesome to adjust the supply rate, etc., a coating method, especially a powder coating method using a binder, is superior in terms of simplicity.

As mentioned above, after the surface of the base material is melted together with boride or silicide by irradiation with a laser beam or the like, the melted portion solidifies briefly, and the boride or silicide particles are uniformly and densely dispersed in the Al matrix. It becomes a lumpy alloyed layer. Since borides and silicides themselves have extremely high hardness, the alloyed layer as a whole exhibits high hardness and has excellent wear resistance. Borides and silicides are equivalent to each other in terms of producing this effect, and it is sufficient to melt at least one of these compounds. Examples of preferred borides include TiB2, ZrB2, NbB2, C
Examples include rB2, TaB2, NiB, and the like. On the other hand, examples of preferable silicides include Mg2 S 1STiSi2, M
Examples include oSi2, NbSi2, CrSi2, etc. As described above, borides or silicides are essential components for improving the hardness of the alloyed layer, but if they are simply used to improve the hardness, carbides such as WC and Tic, which also have high hardness, TiN, It is also possible to use a nitride such as ZrN. However, the reason why borides or silicides are used in this invention is as follows. That is, even if powders such as WC or TiN are melted together with a base material, they have poor wettability with the base material and cannot form a good alloyed layer, but when borides or silicides are used, This is because it has good wettability with the base material, has a smooth surface, and can form an extremely good alloyed layer. This is B in boride and S in silicide.
This is thought to be because i has an effect of improving wettability with the base material Al. The thickness of the alloyed layer can be easily controlled from several tens of μm to several mm by changing the irradiation conditions of the laser beam, such as output, irradiation speed, focal position, etc.

The base material with the hard alloyed layer formed on its surface is then machined into the final product shape as required, and put into practical use as a wear-resistant part.

DETAILED DESCRIPTION OF THE INVENTION As described above, the present invention provides the surface of an aluminum or aluminum alloy base material with a single layer supplied from outside of the base material.
By locally melting a seed or two or more borides or silicides, a hard alloyed layer in which the hemium matrix and the boride or silicide particles are alloyed is formed on the surface of the base material. Therefore, the aluminum alloy material produced according to the present invention has extremely excellent wear resistance, and can therefore be suitable as wear-resistant parts required for automobiles and the like. In addition, unlike conventional surface treatment layers such as plating, the alloyed layer is integrally bonded to the base material, so there is no risk of peeling of chips even when used under high surface pressure. , ensuring sufficient durability.

Examples (Example 1) As shown in FIG. 1, a test piece made of industrially pure Al (A1070) and having a thickness of 7.5 MX, a width of 40 mm, and a length of 100# was used as the base material (1).

Then, in the longitudinal direction of the center of this test piece, a depth of 0°5#,
Shallow grooves (2) with widths in order of 6 were dug, and TiSi2 powder (3) having a diameter of 1 to 10 czm was applied to the grooves in an embedded state using ethyl alcohol as a binder. Coating thickness is approximately 0.5#
ll! Met.

Next, using a 10kw class CO2 laser processing machine, the powder coated part of the test piece was irradiated with a laser beam (4), and the Ti
The Si2 powder and the substrate Al immediately below it were melted together. The irradiation conditions were an output of 51 (w).

Specimen moving speed 100rrrm/min, focal position +
30, beam oscillation was 5 Hz, and 5 m.

After melting by laser beam irradiation, the microstructure of the solidified test piece was examined, and it was found that the alloyed layer (5 rrm) with a thickness of about 1.3 rrm had a smooth surface and no defects throughout the groove.
) was formed.

Moreover, this alloyed layer had a portion where TiSi2 was relatively uniformly and densely dispersed and a portion where TiSi2 was in the form of a lump, and the hardness of the entire alloyed layer was Hv 81 to 824 (load: 100 g).

Furthermore, no cracks or pores were observed within the alloyed layer or at the interface between the alloyed layer and the Al base material.

(Example 2) A test was conducted under the same conditions as in Example 1 except that TiB2 powder with a diameter of 1 to 5 μm was used instead of TiSi2 powder, and the surface was similarly smooth with no defects and a thickness of about 0. ．．
A 5#III+ alloyed layer was formed. Moreover, the hardness of the alloyed layer was Hv250-3200 (load 50(1)).

(Example 3) A test was conducted under the same conditions as in Example 1, except that a mixed powder of ZrB2 powder with a diameter of 1 to 5 μm and MoSi2 powder with a diameter of 1 to 2 μm was used instead of TiSi2 powder. An alloyed layer with a thickness of about 0.5 mm was formed. The hardness of the alloyed layer was H150-2800 (load 500 g).

(Comparative Example 1) When a test was conducted under the same conditions as in Example 1 except that TiC powder with a diameter of 5 to 10 μm was used instead of TiB2 powder, tortoiseshell-shaped cracks were observed on the surface, and some parts It was found that there was peeling, and there was a melted region of only the base material Aρ directly below the alloyed layer, indicating poor wettability with Al.

(Comparative Example 2) When the hardness of the 1070 aluminum alloy used as the base material in each of the above examples was investigated, it was found to be 1 (v30 (
The load was 5 Ng).

As can be seen from the above test results, it has been confirmed that according to the present invention, it is possible to produce an aluminum material having an alloyed layer on the surface of the base material that has extremely high hardness and therefore naturally has excellent wear resistance. .

[Brief explanation of the drawing]

FIG. 1 is a perspective view schematically showing the alloying process in an embodiment of the present invention. (1)...Base material, (3)...TiSi2 powder, (4
)...Laser beam, (5)...Alloyed layer. Figure 1 above

Claims (1)

[Claims] The surface of the aluminum or aluminum alloy base material is locally melted together with one or more borides or silicides supplied from outside the base material, thereby alloying the Al matrix and the boride or silicide particles. A method for producing an aluminum alloy material with excellent wear resistance, which comprises forming a hard alloyed layer on the surface of a base material.