JP2942299B2 - Additive for surface hardening of aluminum - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filler metal, and more particularly to a filler metal used for hardening the surface of an aluminum material to form an aluminum alloy material having excellent wear resistance.

In this specification, the term aluminum is used to include its alloy.

2. Description of the Related Art As is well known, aluminum is not only significantly lighter than general-purpose iron-based materials and the like, but also has excellent heat conduction characteristics and excellent corrosion resistance. It has been widely used as a mechanical part.

However, aluminum is generally inferior in wear resistance as compared with iron-based materials, and this has been a major obstacle in replacing iron-based members with Al alloy members for the purpose of weight reduction in automobiles and the like.

Therefore, conventionally, as a measure for improving the wear resistance of an aluminum material applied to a part where wear resistance is required, an attempt has been made to form a surface hardened layer having excellent wear resistance on the surface of the aluminum material. As one of the methods of forming such a surface hardened layer, the present applicant has previously conducted laser irradiation on one or two or more metals and one or two or more hard particles supplied from the outside on the surface of an aluminum material. A method was proposed in which a surface of an aluminum material was alloyed by irradiating a high-density energy heat source such as a beam to locally melt the material (Japanese Patent Application No. 63-304518). According to this method, a surface alloyed layer having high hardness can be obtained, and there is no danger of peeling of the layer. Therefore, it is possible to provide an aluminum material suitable as a wear-resistant component.

Problems to be Solved by the Invention However, the above method has the following disadvantages when forming an alloyed layer.

In other words, in the above method, the surface hardening metal or hard particles are supplied to the aluminum material surface by applying this to a mixed powder and applying it to the aluminum material surface using a binder before irradiation with a laser beam or the like, It is performed by directly feeding the mixed powder into the melting portion during irradiation with a laser beam or the like. However, in the former coating method, the applied powder may fall or peel off depending on the welding posture. Also, the coating workability was not good. Furthermore, depending on the type of the binder, there is a possibility that defects such as pores remain in the surface hardened layer.
On the other hand, in the latter direct injection method, it is difficult to continuously and stably supply the powder to the molten portion, and particularly when the amount is small, the difficulty is particularly increased. As one of the direct injection methods, there is a method of supplying the powder by placing it on a carrier gas of a melting heat source. In this case, it is necessary to supply the powder to the target position without affecting the irradiation of the heat source. There were drawbacks such as difficulty.

The present invention has been made to solve such disadvantages all at once, and is capable of stably supplying a mixed powder for forming a surface hardened layer to a target position without being restricted by a welding position. An object of the present invention is to provide a material for the purpose of reliably and efficiently forming a surface hardened layer on a surface.

Means for Solving the Problems As a material for achieving the above-mentioned object, the invention according to claim 1 uses a tubular aluminum skin material (2) having a hollow portion (2a) in the axial direction as shown in FIG. The hollow part (2a)
Is provided with an aluminum core (5) extending in the axial direction, and a hollow portion (2a) between the aluminum skin material and the aluminum core material (5) is provided with one other than Al.
A mixed powder (3) of at least one kind of metal powder for forming an intermetallic compound and at least one kind of hard particles is housed in a filled state, and a solution for hardening a surface of an aluminum material is provided. It is to provide additional material. Further, the invention according to claim 2 is characterized in that one or more kinds of boride or silicide powders together with the mixed powder are mixed with the hollow portion (2) between the aluminum shell material and the aluminum core material (5).
The object of the present invention is to provide a surface hardening filler material contained in a).

In addition, as shown in FIG. 5, the invention according to claim 3 is characterized in that each hollow portion (2a) of a thin aluminum sheath material (2) having a plurality of hollow portions (2a) in the axial direction is made of a material other than Al. For hardening the surface of an aluminum material, a mixed powder (3) of one or more metal powders for forming an intermetallic compound and one or more hard particles is contained in a filled state. This is to provide a filler material. Further, the invention according to claim 4 provides a surface hardening filler comprising one or more kinds of boride or silicide powders together with the mixed powder contained in the aluminum shell and each hollow part (2a). Materials.

In this specification, the term “metal powder” is B, S
It is used so as not to include so-called metalloid powders such as i and Ge.

The aluminum skin material (2) plays a role of holding the mixed powder (3) in an internal hollow portion to maintain a fixed state, and also plays a role of ensuring sufficient wettability of the mixed powder with the base material. The composition of the aluminum skin material (2) is not particularly limited, and pure Al, 5052 alloy, 5083 alloy, or other alloy is appropriately adopted in relation to the composition of the aluminum material for forming the surface hardened layer. Just use it.

The aluminum core material (5) shown in FIG. 1 plays a role in adjusting the ratio between the mixed powder (3) and the Al material in the filler material. For example, if the diameter of the aluminum core material (5) is increased, the aluminum skin material and the aluminum core material (5) are increased.
The amount of the mixed powder that can be accommodated in the hollow portion (2a) between the aluminum core material and the aluminum core material (5a) can be reduced simply and reliably. 5) The amount of the mixed powder that can be accommodated in the hollow portion (2a) between them can be simply and reliably increased. The aluminum core material (5) may have the same composition as the aluminum skin material (2) or may have a different composition.

Also, as shown in FIG. 5, when a plurality of hollow portions (2a) are provided in the aluminum skin material (2), the hollow portions (2a) are provided in the same manner as in the case where the aluminum core material (5) is provided. By changing the size and the number of the powders, the ratio of the mixed powder (3) and the Al material in the filler material can be easily adjusted.

Of the mixed powder (3) contained in the hollow portion (2a) of the aluminum shell material (2) in a filled state, the metal powder is crystallized as an intermetallic compound in the Al matrix of the aluminum material by melting, and is an extremely hard alloy. Plays the role of forming a chemical layer. Therefore, any metal may be used as long as it forms an intermetallic compound mainly with Al by melting. As an example, Ni, C with relatively good wettability with aluminum
Examples of the elements include u, Cr, Fe, Ti, Zr, Mn, V, Nb, Mo, Hf, and Ta. In addition, it is not always necessary to use a single metal, but it is supplied in the form of an intermetallic compound or an alloy,
To form an Al-based intermetallic compound. On the other hand, hard particles are
It plays a role of forming an extremely hard alloyed layer by dispersing and alloying in an Al matrix. As such hard particles,
Examples thereof include carbides such as TiC, WC, ZrC, and NbC; nitrides such as TiN, ZrN, and CrN; oxides such as TiO and Al ₂ O ₃ ; and other ceramics. These metal and hard particles may be used alone or in combination of two or more.

The ratio of the above mixed powder and Al coating material is, in the area ratio in the cross section of the filler metal, metal powder: Al coating material = 1: 10 to 10:
Should be set in the range of 1. If the amount of the mixed powder is less than the above range, the surface hardening effect of the base material after melting may be poor. On the other hand, if the amount of the mixed powder exceeds the above range, the wettability between the base material and the mixed powder is deteriorated, and the bonding strength between the base material and the alloyed layer may be reduced.

Further, as the surface hardening powder contained in the skin material hollow portion (2a), in addition to the above-mentioned mixed powder, one or more borides or silicides, that is, powders of a compound of a metal element and boron or silicon May be used together. Such a boride or a silicide also plays a role of forming a high-hardness alloyed layer by dispersing and alloying on the surface of the aluminum material by melting. Also, the addition of boride and silicide powders probably results in B in boride and Si in silicide.
Plays a role in improving the wettability with Al during the formation of the alloying layer, so that the wettability between the aluminum material and the mixed powder or boride or silicide powder is improved, and the surface is smooth and extremely good. There is also an advantage that the formation of the oxide layer is possible. Examples of preferred borides include TiB ₂ , ZrB ₂ , NbB ₂ ,
CrB ₂ , TaB ₂ , NiB and the like can be mentioned. On the other hand, examples of preferable silicides include Mg ₂ Si, TiSi ₂ , MoSi ₂ , NbSi ₂ , and CrSi ₂ . When a boride or silicide powder is used together with the mixed powder, the total amount thereof may be set so as to be in the range of 1:10 to 10: 1 in terms of the area ratio of the cross section to the Al coating material. The particle size of metal powder, hard particles, boride, silicide powder is
The thickness is preferably about 200 μm or less.

Also, together with the mixed powder to improve the wettability between the mixed powder and the base material, an Al powder having a particle size of about 50 to 200 μm
About 0% may be mixed.

The production of the filler material (1) shown in FIG. 1 may be performed, for example, as follows. That is, a long plate-like aluminum skin material (2) having a predetermined thickness as shown in FIG. 2 is formed into a semicircular cross section as shown in FIG. 3 by roll forming, and the aluminum core material (5) is formed in a concave portion thereof. ) And filling with the powder (3), and then forming a circular cross section as shown in FIG. 4 and welding the both ends closed portion (4). After that, a drawing process or the like may be performed as needed.

The manufacturing of the filler material shown in FIG. 5 is performed, for example, by forming two or more hollow portions (2
After the product provided with a) is manufactured by an extrusion method, the hollow portion (2a) is filled with the mixed powder (3), and then this is drawn out to a small diameter.

The filler material thus produced is generally used as a welding rod or a welding core wire, and is weld-welded to a portion of the aluminum material to be hardened by welding means such as TIG welding or MIG welding. Normally, when used for TIG welding, the outer diameter is 2.4 to 3.2m
m, outer diameter 1.2 to 2.4 when used for MIG welding
It is set to about mm. After welding, the molten part of the aluminum material solidifies in a short time, and for example, TiAl ₃ , ZrAl ₃ , NiAl, NiAl ₃ , Ni2Al ₃ , F
An intermetallic compound such as eAl ₃ or Fe ₄ Al ₁₃ is crystallized uniformly or densely, and a hardened layer is formed in which hard particles dispersed uniformly or densely or in a lump are mixed. When the filler contains boride or silicide, boride or silicide particles are uniformly and densely dispersed together with the intermetallic compound or hard particles, or an agglomerated alloying layer is formed on the surface. . Since the intermetallic compound, boride and silicide particles themselves have extremely high hardness, the alloyed layer exhibits high hardness as a whole and has excellent wear resistance. The harder the intermetallic compound, hard particles, boride, and silicide particles in the Al matrix, the harder the alloyed layer.

The aluminum material having a hard alloyed layer formed on its surface is then machined into a final product shape, if necessary, and put into practical use as a wear-resistant part. Incidentally, the composition of the aluminum material as the base material is not particularly limited, and is not limited to pure Al, but also 2000 series and other aluminum wrought materials or AC.
An aluminum casting material such as 8A or AC2B can be used as appropriate.

Example 1 In the hollow part of the aluminum skin material made of A100,
A long filler metal in which a mixed powder of a metal powder and a hard particle having a composition as shown in the table or a powder of the mixed powder and a boride or silicide powder was housed was manufactured. Production of filler metal is second
As shown in FIG. 4 to FIG. 4, a large-diameter product was manufactured by roll forming, and thereafter, drawing was performed. The outer diameter of the filler material (1) is 2.0 mm, and the area ratio of the aluminum shell material (2) and the core material (5) to the powder (3) in the transverse section of the filler material is changed by changing the cross-sectional area of the aluminum core material. Is as shown in Table 1.

On the other hand, as an aluminum material to form a surface hardened layer
A test piece of 7.5 mm thick × 40 mm wide × 100 mm long made of AC8A cast alloy was prepared. Then, as shown in FIG. 6, a shallow groove (7) having a depth of 0.5 mm was formed in the longitudinal direction of the center of the test piece (6).

Next, as shown in the figure, using a TIG welding machine (8), a semi-automatic TIG was applied to the groove (7) of the test piece while continuously supplying the filler material from the filler material supply device (9). Welded. (10) in the figure is a welded portion. Welding speed is 100mm / min
And

After welding, the structure of the solidified weld was examined to find that an alloyed layer was formed over the entire groove. In addition, this alloyed layer is composed of an aluminum matrix containing intermetallic compounds and hard particles, and further, in the case of using boride and silicide powder, a portion where boride and silicide particles are relatively uniformly and densely crystallized or dispersed, and a mass. The hardness of the entire alloyed layer was as shown in Table 1. Also,
No. 4 and No. 5 mixed with boride and silicide powders had particularly smooth surfaces of the alloyed layers. On the other hand, when the hardness of the aluminum material alone was examined, it was Hv30 (load: 5 kg). The same results as described above were obtained for the filler material of the embodiment shown in FIG.

As can be seen from the above test results, the use of the filler material according to the present invention makes it possible to easily and reliably form an alloyed layer having extremely high hardness and thus naturally excellent wear resistance on the surface of an aluminum material. I was able to confirm that.

As described above, according to the present invention, an aluminum core (5) extending in the axial direction is provided inside the hollow portion of the thin aluminum shell material having a hollow portion in the axial direction. A hollow portion between the skin material and the aluminum core material (5) is filled with a mixed powder of one or more metal powders for forming an intermetallic compound other than Al and one or more hard particles other than Al. The present invention provides a filler for surface hardening of an aluminum material, characterized in that the filler is housed in a state. A hard alloyed layer in which the inter-compounds and the hard particles are alloyed with the Al matrix can be formed. In particular, by changing the outer diameter of the aluminum core material, the ratio of the mixed powder and the Al shell material in the filler material can be easily adjusted.

As a result, it is possible to provide an aluminum material suitable as a wear-resistant part required for automobiles and the like. In addition, when forming the surface hardened layer on the aluminum material, since the mixed powder is supplied as a filler material, the applied powder may drop or peel off depending on the welding position, unlike the conventional coating method. To solve the inconvenience
The hardened surface layer can be formed without being restricted by the welding position. For example, even when the aluminum material is a rotating object, the hardened surface layer can be formed.

Further, since it is not necessary to use any binder for applying and holding the powder, it is possible to eliminate the possibility that defects such as pores remain in the surface hardened layer. In addition, since the application step itself is not required, work efficiency can be improved, and thus productivity can be improved.
Further, in the application method, since the heat source is directly irradiated to the powder, the cleaning action of the aluminum material cannot be obtained. However, with the filler according to the present invention, the cleaning action of the aluminum material when an AC power supply or the like is used can be expected. Further, since the supply amount of the powder can be easily adjusted by supplying the powder as a filler, an arbitrary amount of powder can be continuously and stably supplied to a target position regardless of the supply amount.

Further, according to the filler material according to claim 2, in addition to the above effects, metal powder, hard particles, boride, silicide powder,
This has the effect of improving the leakage with the aluminum material, and forming an extremely good alloyed layer with a smoother surface.

According to the filler material according to the third aspect, similarly to the invention according to the first aspect, the ratio between the mixed powder and the Al shell material in the filler material is changed by changing the size and the number of the hollow portions. It can be easily adjusted.

According to the filler according to claim 4, in the filler according to claim 3, metal powder, hard particles, boride,
Improves wettability between silicide powder and aluminum material,
There is an effect that a very good alloyed layer can be formed with a smoother surface.

[Brief description of the drawings]

FIG. 1 is a cross-sectional perspective view showing an example of a filler material according to the present invention, and FIGS. 2 to 4 are diagrams for explaining a manufacturing process of the filler material shown in FIG. FIG. 3 is a cross-sectional view of an aluminum skin material in a plate state, FIG. 3 is a cross-sectional view of a semi-circular shape filled with powder, FIG. 4 is a cross-sectional view of a state where both ends of the aluminum material are closed, and FIG. The figure is a cross-sectional view showing another modified example, and FIG. 6 is a perspective view schematically showing a welding process of a test piece in the example. (1) ... filler metal, (2) ... aluminum skin material, (2
a) hollow part; (3) mixed powder; (5) aluminum core.

Claims (4)

(57) [Claims] 1. A tubular aluminum shell material (2) having a hollow portion (2a) in the axial direction inside said hollow portion (2a).
An aluminum core (5) extending in the axial direction is provided, and one or another material other than Al is provided in a hollow portion (2a) between the aluminum skin and the aluminum core (5).
A filler material for hardening a surface of an aluminum material, wherein a mixed powder (3) of at least one kind of metal powder for forming an intermetallic compound and at least one kind of hard particles is contained in a filled state. 2. A hollow portion (2a) between said aluminum shell (2) and said aluminum core (5), wherein one or more boride or silicide powders together with said metal powder and hard particles are provided. 3. The filler for surface hardening according to claim 1, wherein the filler is contained in the filler. 3. A hollow aluminum cladding (2) having a plurality of hollows (2a) in the axial direction, each hollow (2a) being provided with aluminum.
Mixed powder of one or more metal powders for forming an intermetallic compound and one or more hard particles other than the above (3)
A filler material for hardening a surface of an aluminum material, wherein the filler material is contained in a filled state. 4. The surface hardening solution according to claim 3, wherein one or more kinds of boride or silicide powders are accommodated in each hollow portion (2a) together with the metal powder and the hard particles. Additives.