JPH05179386A - Finely crystallized product-containing aluminum alloy manufactured by spray deposition method - Google Patents

Abstract

PURPOSE:To provide an aluminum alloy manufacturable at a low cost by a spray deposition method and having excellent mechanical strength (particularly, in tensile strength and toughness at a high temp.). CONSTITUTION:The objective finely recrystallized product-contg. aluminum alloy manufactured by a spray deposition method has a compsn. constituted of, by weight, 0.2 to 5% Cu, 0.1 to 5% Mg, 3 to 20% Si, 0.5 to 13% of at least one kind among Fe, Cr, Mn, Ni, Co, W and Mo and 0.5 to 10% of at least one kind among V, Zr, Ce and Y, and the balance Al with inevitable impurities. Moreover, 0.05 to 1% of at least one kind of Ti and B may be incorporated therein.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine crystallized product-containing aluminum alloy produced by a spray deposition method, and more particularly to an aluminum alloy having a fine crystal structure and having excellent mechanical strength.

[0002]

2. Description of the Related Art Conventionally, aluminum alloys have been manufactured by casting, forging, powder metallurgy and the like. Of these, the casting method is a method of manufacturing an aluminum alloy member by injecting a molten aluminum alloy melted to a predetermined composition into a mold having a desired shape. In the forging method, an aluminum alloy member is manufactured by mechanically forging a cast aluminum alloy. In all of these methods, since the molten aluminum alloy is solidified in the mold, there is a problem that the solidification rate is slow and a fine crystal structure cannot be obtained. There is also the problem that it is difficult to improve.

The powder metallurgy method developed as a solution to the above problems of the casting method (forging method) sprays a molten aluminum alloy having a predetermined composition together with an inert gas from a nozzle to form fine particles. By forming a powder and hot working the powder into a predetermined shape, an aluminum alloy molded product is obtained. Since this powder metallurgy method can produce an aluminum alloy having a fine crystal structure, it is used to produce aluminum products having various compositions that cannot be produced by a casting method or a forging method.

However, in the powder metallurgy method, since the aluminum alloy powder is once formed, it is reheated and hot-worked to form the aluminum alloy member, so that the manufacturing cost is high. ..

Therefore, it is an object of the present invention to provide an aluminum alloy which can be manufactured at low cost by the spray deposition method and has excellent mechanical strength (in particular, tensile strength and toughness at high temperature).

[0006]

As a result of earnest research in view of the above object, the present inventors have found that Fe, Cr, Mn, Ni, C can be added to aluminum alloys containing Cu, Mg and Si as essential components.
The alloy structure is refined by adding at least one metal selected from the group consisting of o, W and Mo and at least one metal selected from the group consisting of V, Zr, Ce and Y. As a result, they have found that they exhibit good mechanical strength, and have conceived the present invention.

That is, the first fine crystallized aluminum alloy according to the present invention is produced by the spray deposition method and has Cu: 0.2 to 5% by weight and Mg: 0.1 to 5% by weight.
And Si: 3 to 20% by weight, Fe, Cr, Mn, Ni,
At least one of Co, W and Mo: 0.5 to 13% by weight
And at least one of V, Zr, Ce and Y: 0.5-10
It is characterized by having a composition consisting of weight% and Al and unavoidable impurities: balance.

The second aluminum alloy containing fine crystallized substances of the present invention is produced by the spray deposition method, and Cu:
0.2 to 5% by weight, Mg: 0.1 to 5% by weight, Si: 3
To 20% by weight and at least one of Fe, Cr, Mn, Ni, Co, W and Mo: 0.5 to 13% by weight, V, Zr,
At least one of Ce and Y: 0.5 to 10% by weight, and Ti
And at least one of B: 0.05 to 1% by weight, Al and unavoidable impurities: the balance.

[0009]

The present invention will be described in detail below. [1] Composition of aluminum alloy

(A) Cu: 0.2-5% by weight Cu is an element having an action of improving tensile strength,
If it is less than 0.2% by weight, the effect cannot be sufficiently exhibited. On the other hand, when the Cu content exceeds 5% by weight,
The growth will be reduced. The preferable Cu content is 1.
It is 0 to 3.0% by weight.

(B) Mg: 0.1 to 5 wt% Mg is an element having an action of improving tensile strength,
If it is less than 0.1% by weight, the effect cannot be sufficiently exhibited. On the other hand, when the content of Mg exceeds 5% by weight,
Charpy impact strength decreases. The preferable Mg content is 1.5 to 3.0% by weight.

(C) Si: 3 to 20% by weight Si is an element having an action of improving mechanical strength, but if it is less than 3% by weight, its effect cannot be sufficiently exhibited. On the other hand, if the Si content exceeds 20% by weight, the elongation is reduced. The preferable Si content is 5 to 12% by weight.

(D) First additive element: 0.5 to 13% by weight In the first and second aluminum alloys of the present invention, Fe, Cr, Mn, Ni, Co and W are used as the first additive element. And at least one of Mo. These elements have the function of refining the crystal grains of the alloy, but 0.5% by weight
If it is less than that, the effect cannot be sufficiently exerted. On the other hand, when it exceeds 13% by weight, the ductility of the base material is deteriorated. The preferable content of the first additional element is 2.0 to 6.
It is 0% by weight.

(E) Second additive element: 0.5 to 10% by weight The first and second aluminum alloys of the present invention contain at least one of V, Zr, Ce and Y as the second additive element. Contains. These elements have a function of forming fine intermetallic compounds excellent in high temperature strength, but if the amount is less than 0.5% by weight, the effect cannot be sufficiently exhibited. on the other hand,
If it exceeds 10% by weight, segregation of intermetallic compounds having poor ductility will be caused. The preferable content of the first additional element is 3 to 7% by weight.

(F) Third additional element: 0.05 to 1% by weight The second aluminum alloy of the present invention further contains at least one of Ti and B as a third additional element.
These elements have a function of refining the crystal grains of the alloy, but if the amount is less than 0.05% by weight, the effect cannot be sufficiently exhibited. On the other hand, when it exceeds 1% by weight, the ductility of the base material is deteriorated. The preferable content of the third additional element is 0.1 to 0.4% by weight.

(G) Al and Inevitable Impurities: The Remaining Inevitable impurities include P, S, C, Pb and Be. The content of these unavoidable impurities is 0.03 in total for the purpose of preventing reduction in mechanical strength of the aluminum alloy.
It must be below wt%.

[2] Spray Deposition Method For producing the aluminum alloy of the present invention, for example, Japanese Patent Laid-Open No.
The spray deposition method described in JP-A-36631, JP-A-2-258935, JP-A-3-2345 and the like can be used.

In the spray deposition method, a tundish for melting an aluminum alloy, a nozzle for jetting an inert gas provided directly below the nozzle of the tundish, and a nozzle 5 to 30 cm below the jet nozzle are provided. And a means for collecting and depositing aluminum alloy fine particles. The inside of this device is placed in an inert gas atmosphere to prevent oxidation of the aluminum alloy.

In order to carry out the spray deposition method with such an apparatus, first, the aluminum alloy melted at 600 to 1000 ° C. in the tundish is discharged from the nozzle, and the inert gas is jetted at a high speed from the jet nozzle directly below. To do. Nitrogen gas, argon gas, helium gas or the like is used as the inert gas. The molten metal atomized by this high-speed inert gas becomes aluminum alloy fine particles,
It is deposited on the collecting means below about m. The obtained aluminum alloy fine particles usually have an average particle size of 0.5 to 150 μm.

The deposited aluminum alloy fine particles are still 50
The temperature is around 0 to 700 ° C, and it is not completely solidified.
Therefore, the aluminum alloy fine particles that are continuously deposited are fixed to form an aluminum alloy deposit. This deposition body, aluminum alloy particles are cooled at a rate of typically 10 ⁰ ~10 ³ ℃ / sec.

The aluminum alloy of the present invention is an element (Ti, B, Zr, V, Y,
Since it contains Ce and the like), it is possible to achieve a finer crystal structure even if the cooling rate is slow as described above. That is, it is possible to prevent the formation of acicular Fe-based precipitates and coarse particles of Si. In particular, although it is difficult to control the cooling rate by the spray deposition method, a fine crystal structure can be reliably obtained because it contains elements such as Ti, B, Zr, V, Y and Ce. In the aluminum alloy of the present invention having such a fine crystal structure, there is almost no precipitate having a grain size exceeding 3 μm.

The aluminum alloy deposit thus obtained is subjected to outer peripheral processing as required to obtain a preform having a predetermined shape. Then, hot working is applied to this preform. Examples of hot working include hot extrusion and swaging. In the case of hot extrusion, using an extruder with a die having a predetermined opening shape, 400 aluminum alloy deposits
It is carried out by extruding at an extrusion ratio of 7 to 25 (expressed by area ratio) at .about.500.degree. In the case of upsetting, the upsetting ratio (expressed by the height ratio) is 50 to 80% in the die at 400 to 500 ° C.

The hot-worked aluminum alloy is usually subjected to heat treatment. The heat treatment includes T6 treatment and T7 treatment. The T6 treatment is performed by subjecting the aluminum alloy to solution treatment at 430 to 540 ° C for 1 to 50 hours, and then aging at 90 to 170 ° C for a sufficient time (2 to 25 hours) to obtain almost maximum hardness. Become. Also, the T7 process becomes the T6 process.
Aging treatment (0.5 to 20 hours) at 150 to 190 ° C is added.

The present invention will be described in more detail with reference to the following specific examples.

Examples 1 to 14 and Comparative Examples 1 to 5 Nitrogen gas (a liquidus line in each composition + temperature of 200 ° C. in each composition) of a molten aluminum alloy having the composition shown in Table 1 was ejected from a nozzle having a diameter of 3.0 mm ( It was atomized at a gas pressure of 5 kg / cm ² ) to obtain an aluminum alloy powder having an average particle size of 40 μm, which was deposited on a collecting means at a spray distance of 150 mm. The aluminum alloy deposited body thus obtained is subjected to outer peripheral processing to have a diameter of 80 mm and a length of 70 mm.
Got the preform.

This preform was heated at 450 ° C. for 40 minutes and hot extruded at an extrusion ratio of 20. Next, as T6 treatment, solution treatment was performed at 470 ° C. for 1.5 hours, quenching by water administration, and aging treatment at 130 ° C. for 24 hours. For each heat-treated aluminum alloy, the average crystal grain size was determined from micrographs, and
A tensile test and an impact test (Charpy test) at ° C were performed. The results are shown in Table 2.

Table 1 Chemical composition (wt%) Example No. Si Cu Mg Fe Cr Ni Co Example 1 7 3.0 1.5 0.7 1.2 0.3 0.1 2 7 3.0 1.5 0.7 1.2 0.3 0.1 3 7 3.0 1.5 0.7 1.2 0.3 0.1 Comparative Example 1 7 3.0 1.5 0.7 1.2 0.3 0.1 2 7 3.0 1.5 0.7 1.2 0.3 0.1 3 7 3.0 1.5 0.7 1.2 0.3 0.1 Example 4 7 3.0 1.5 0.7 1.2 0.3 0.1 5 7 3.0 1.5 0.7 1.2 0.3 0.1 6 7 3.0 1.5 0.7 1.2 0.3 0.1 7 7 3.0 1.5 0.7 1.2 0.3 0.1 8 7 3.0 1.5 0.7 1.2 0.3 0.1 9 7 3.0 1.5 0.7 1.2 0.2 0.1 Comparative Example 4 7 3.0 1.5 0.7 1.2 0.3 0.1 5 7 3.0 1.5 0.7 1.2 0.3 0.1 Example 10 7 3.0 1.5 0.7 1.2 0.3 0.1 11 7 3.0 1.5 0.7 1.2 0.3 0.1 12 7 3.0 1.5 0.7 1.2 0.3 0.1 13 7 3.0 1.5 0.7 1.2 0.3 0.1 14 7 3.0 1.5 0.7 1.2 0.3 0.1

Table 1 (continued) Chemical composition (% by weight) Example No. V Ce Y Zr Ti B Example 1 0.5 − − − − − − 2 5.0 − − − − − 3 10.0 − − − − − Comparative Example 1 − − − − − − 2 0.3 − − − − − 3 12.0 − − − − − Example 4 4.0 0.2 − − − − 5 4.5 0.5 − − − − 6 4.0 3.0 − − − − 7 4.0 2.0 0.5 − − − 8 4.0 1.5 0.5 0.2 − − 9 4.0 1.5 0.5 0.8 − − Comparative Example 4 6.0 5.0 − − − − 5 5.0 2.5 2.0 1.0 − − Example 10 4.0 1.5 0.5 0.2 0.03 − 11 4.0 1.5 0.5 0.2 0.10 − 12 4.0 1.5 0.5 0.2 0.20 -13 4.0 1.5 0.5 0.2 0.20 0.005 14 4.0 1.5 0.2 0.2 0.15 0.010

Table 2 Example of mechanical strength at room temperature No. σ _B ⁽¹⁾ σ _0.2 ⁽²⁾ Elongation ⁽³⁾ Charpy ⁽⁴⁾ K _IC ⁽⁵⁾ Example 1 32.4 28.1 5.9 4.2 21 2 34 30.2 6.3 4.3 22 3 35.2 32.8 5.1 4.0 21 Comparative Example 1 28 24.0 3.5 3.0 18 2 27 24.1 4.0 3.1 18 3 37 33.2 1.1 2.1 10 Example 4 35 30.4 6.1 3.7 21 5 39 33.2 5.8 4.5 24 6 48.2 45.6 5.2 4.0 20 7 39 37.2 5.9 4.1 22 8 41 38.6 6.3 4.8 23 9 42.3 38.9 5.5 4.2 22 Comparative Example 4 50 47.0 1.9 1.6 9 5 40.1 36.7 1.4 2.0 17 Example 10 41.2 38.2 6.3 5.0 23 11 41.8 38.3 6.5 5.2 24 12 42.9 39.2 6.9 5.3 24 13 43.7 39.5 7.5 6.1 26 14 45.3 41.2 7.2 6.5 26

[0030] Table 2 (continued) mechanical strength maximum precipitation particle size Example No. sigma _B ⁽¹⁾ at 200 ° C. sigma _0.2 ⁽²⁾ elongation ⁽³⁾ ≦ 3.0 [mu] m Example 1 21 12.9 12.9 ○ 2 21 13 13.1 ○ 3 24 16.1 12.4 ○ Comparative Example 1 16 12 11.2 × 2 15 11 11.8 × 3 28 17.2 11.9 × Example 4 22.7 18.2 12.1 ○ 5 29.1 27.3 15.3 ○ 6 34.2 28.1 12.7 ○ 7 24.0 20.1 13.2 ○ 8 31.0 27.5 15.1 ○ 9 35.1 31.0 14.3 ○ Comparative Example 4 29.0 25.9 10.3 × 5 21.2 17.1 10.0 × Example 10 32.1 28.2 13.9 ○ 11 33.1 29.1 15.0 ○ 12 33.9 29.3 15.9 ○ 13 35.2 31.2 16.8 ○ 14 36.3 33.3 17.2 ○

(Note): (1) Tensile strength (kgf / mm ² ). (2) 0.2% proof stress (kgf / mm ² ). (3) Growth (%). (4) Charpy impact value (kgfm / cm ² ). (5) Fracture toughness (MPa · m ⁻² ). (6) Maximum precipitated particle size (○ for those satisfying 3.0 μm or less, × for larger particles).

As is clear from Table 2, the aluminum alloy of the present invention has a fine crystal structure. Also tensile strength,
It can be seen that the aluminum alloy of the present invention is better than the aluminum alloy of the comparative example in any of 0.2% proof stress, elongation, impact strength and fracture toughness. Further, in the aluminum alloy of the present invention, as the second additive element and the third additive element are added, their mechanical strength is improved.

[0033]

As described in detail above, the aluminum alloy containing Si, Cu and Mg as essential components is further selected from the group consisting of the first additive element (Fe, Cr, Mn, Ni, Co, W and Mo). At least one selected element), a second additive element (at least one element selected from the group consisting of V, Zr, Ce and Y), and a third additive element (Ti and B) if necessary. By adding at least one element selected from the group consisting of (3), it is possible to obtain a finer crystal composition and, as a result, to exhibit excellent mechanical strength. Such an aluminum alloy of the present invention can be used for various machine parts, building materials, structural materials and the like, including automobile parts such as connecting rods and valves, which are required to be lightweight and have high mechanical strength.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenichiro Shiokawa Inventor Kenichiro Shiokawa 1-4-1 Chuo, Wako-shi, Saitama Stock Research Institute Honda Technical Research Institute

Claims (2)

[Claims] 1. An aluminum alloy containing fine crystallized substances produced by a spray deposition method, wherein Cu: 0.2-5 wt%
And Mg: 0.1-5 wt%, Si: 3-20 wt%,
At least one of Fe, Cr, Mn, Ni, Co, W and Mo: 0.5 to 13% by weight, at least one of V, Zr, Ce and Y: 0.5 to 10% by weight, Al and inevitable impurities: An aluminum alloy having a composition consisting of the balance. 2. In an aluminum alloy containing fine crystallized substances produced by a spray deposition method, Cu: 0.2-5 wt%
And Mg: 0.1-5 wt%, Si: 3-20 wt%,
At least one of Fe, Cr, Mn, Ni, Co, W and Mo: 0.5 to 13% by weight, at least one of V, Zr, Ce and Y: 0.5 to 10% by weight, and at least 1 of Ti and B. Species: 0.05 to 1% by weight, an aluminum alloy having a composition of Al and inevitable impurities: balance.