JPH06116671A - Al sintered alloy member excellent in high temperature strength - Google Patents

Abstract

PURPOSE:To provide an Al sintered allay member excellent in high temp. strength. CONSTITUTION:The Al sintered allay member is constituted of a material subjected to the hot plastic working of a green compact or a temporally sintered body having a compsn. constituted of, by weight, 15 to 35% Si, 0.1 to 3% Mn, 0.5 to 8% rare earth elements, 0.5 to 8% Ni, and the balance Al with inevitable impurities or constituted of 15 to 35% Si, 0.1 to 3% Mn, 0.5 to 8% rare earth elements, 0.5 to 8% Ni, 0.1 to 2% Zr and the balance Al with inevitable impurities.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an Al sintered alloy member having excellent high temperature strength.

[0002]

2. Description of the Related Art Conventionally, as described in, for example, Japanese Patent Application Laid-Open No. 2-61023, Si: 5-35%, Mn: 0..35% by weight (hereinafter,% means% by weight).
3 to 10%, Ce: 0.1 to 5%, Fe:
1 to 15%, Al and unavoidable impurities: The remaining melt is formed into powder, flakes, ribbons, etc. by a rapid solidification method, all of which are primary crystal Si and Al of Al and the above alloy components. The powder, flakes, and ribbons having a structure in which the base composite compound is dispersed and crystallized in the Al matrix are press-molded into a green compact in a state where the particle size is adjusted by subjecting the powder to fine powder, and if necessary, the green compact described above. Tentatively sintered,
Then, an Al sintered alloy member formed by subjecting the green compact or the pre-sintered body to a predetermined shape by subjecting it to hot plastic working such as hot forging and hot extrusion is used as a rocker arm of an internal combustion engine or It is well known that it is practically used as a vane of a compressor.

[0003]

On the other hand, in recent years, the performance and speed of various mechanical devices have been remarkably high, and along with this, the operating environment of, for example, compressors and internal combustion engines has become even more severe. The members such as vanes and rocker arms are uncertainly put into practical use in high temperature environments. However, when these structural members are composed of the above conventional Al sintered alloy members, due to lack of high temperature strength, these high temperature environments It is the current situation that we are not able to fully satisfy the practical application in the.

[0004]

Therefore, the present inventors have
From the above viewpoints, as a result of research to develop an Al sintered alloy member having excellent high temperature strength,
The composition of the sintered alloy member is as follows: (1) Si: 15-35%, Mn: 0.1-3%, rare earth element: 0.5-8%, Ni: 0.5-8%, Al And unavoidable impurities: remaining (2) Si: 15 to 35%, Mn: 0.1 to 3%, rare earth element: 0.5 to 8%, Ni: 0.5 to 8%, Zr:
0.1 to 2%, Al and unavoidable impurities: The rest, if constituted by the above (1) or (2), primary crystal Si in the Al base material.
In addition to the Al-Si-Mn-rare earth element-based composite compound, an Al-Ni-based compound, an Al-Zr-based compound, and an Al-Ni-Zr-based compound have a crystallized structure. According to the above-mentioned research results, the crystallization of the Al-Ni-based compound, the Al-Zr-based compound, and the Al-Ni-Zr-based compound provides excellent high temperature strength.

The present invention has been made on the basis of the above research results. (1) Si: 15 to 35%, Mn: 0.1 to 3%, rare earth element: 0.5 to 8%, Ni: 0.5-8%, Al and unavoidable impurities: the rest, (2) Si: 15-35%, Mn: 0.1-3%, rare earth elements: 0.5-8%, Ni: 0.5 ~ 8%, Zr:
Al having excellent high-temperature strength, which is made of a hot-working material such as a green compact or a pre-sintered body having a composition of 0.1 to 2%
It is characterized by a sintered alloy member.

Next, the reason why the component composition of the Al sintered alloy member of the present invention is limited as described above will be explained. (A) Si The Si component disperses and crystallizes in the Al base as fine primary crystal Si to improve the wear resistance of the member and suppress the thermal expansion coefficient to a low level, but its content is 15 When the content is less than%, the desired effect cannot be obtained, while when the content exceeds 35%, the strength and toughness are deteriorated, so the content is defined as 15 to 35%.

(B) Mn and rare earth element These components form an Al-Si-Mn-rare earth element-based composite compound that combines with Al and Si and crystallizes finely in an Al matrix to form a crystal. Although it has the effect of improving the high temperature strength, if the contents of Mn: less than 0.1% and the rare earth element: less than 0.5% respectively, the desired high temperature strength cannot be secured, while the contents of Mn:
If the content exceeds 3% and the rare earth element: 8%, the toughness will decrease, so the content of Mn: 0.1-3
%, Rare earth element: 0.5 to 8%.

(C) Ni The Ni component forms an Al-Ni-based compound that binds to Al and crystallizes finely in the Al matrix to form crystals.
Coexistence with the Mn-rare earth element-based composite compound has the effect of further improving the high temperature strength, but the content thereof is 0.
If it is less than 5%, the desired high temperature strength cannot be obtained. On the other hand, if the content exceeds 8%, the ductility tends to decrease. Therefore, the content is set to 0.5 to 8%.

(D) Zr Zr component is formed with Al-Zr type compound or Al-Ni-Zr type compound which is finely dispersed and crystallized in Al matrix like Ni component to further improve high temperature strength. Since it has a function of making it contained, it is contained if necessary, but if the content is less than 0.1%, the desired high temperature strength improving effect cannot be obtained,
On the other hand, when the content exceeds 2%, the toughness is remarkably deteriorated, so the content is set to 0.1 to 2%.

[0010]

EXAMPLES Next, the Al sintered alloy member of the present invention will be specifically described by way of examples. An Al alloy melt having the composition shown in Tables 1 and 2 was prepared by a normal melting method, and then (a) the melt was heated at 100 ° C. higher than the liquidus generation temperature to 10 ³ ° C./by an atomizing method. It is cooled at a cooling rate of sec to obtain a Si alloy powder having an average grain size of 80 μm and an average grain size of primary crystal Si of 5 μm. (B) At a temperature 100 ° C. higher than the liquid phase generation temperature of the molten metal,
A nozzle with a diameter of 1 mmφ is jetted at a pressure of 0.3 kgf / cm ² onto the surface of a water-cooled copper roll rotating at a peripheral speed of 24 m / sec to form a ribbon with dimensions of width: 4 mm × thickness: 60 μm. , The cooling rate in this case is 10 ⁶ ° C / sec,
The average grain size of primary crystal Si in this ribbon is 3 μm, and this ribbon is pulverized by a ball mill for 5 hours to obtain an Al alloy powder having an average grain size: 80 μm. (C) Similarly, the molten metal collides with the surface of a water-cooled copper roll rotating at a peripheral speed of 12 m / sec at a pressure of 0.5 kgf / cm ² from a nozzle having a diameter of 0.6 mm at a temperature 100 ° C. higher than the liquid phase generation temperature. Let (Atomize pressure in this case is 8kgf /
cm ² ; cooling rate: 10 ⁵ ° C / sec); plane: 5 mmφ x thickness: 60 μm.
A powder or flakes (hereinafter, both of them are collectively referred to as a powder) is formed by the powder forming means of any of the above (a) to (c), and these powders are used as a raw material. (1) The above powder having 6 ton / cm ² It is press-molded by pressure to obtain a green compact having a size of 11 mm × 57 mm in plane and 20 mm in thickness. Then, the green compact is heated to 500 ° C. and degassed. 1 at cm ² of pressure
Next hot forged, flat: 11.1mm x 57.1m
m, thickness: 16mm, followed by 8ton / c
Secondary hot forging process with pressure of m ² and plane: 14mm ×
The Al sintered alloy member has the dimensions of 60 mm and thickness: 12 mm. (2) The above powder was filled in a pure Al can and press-molded to have a diameter of 60 mmφ and a length of 100 mm, which was heated to 500 ° C. while being vacuumed, and the extrusion ratio was 12
Diameter: 18mm by hot extrusion under the conditions
Round bar-shaped Al sintered alloy member of The Al sintered alloy members 1 to 19 of the present invention and the conventional Al sintered alloy members 1 to 3 of the present invention were manufactured by the hot plastic working means described in (a) or (b) above.

Next, with respect to various Al sintered alloy members obtained as a result, at 200 ° C. for the purpose of evaluating high temperature strength.
The high temperature tensile strength was measured, and the measurement results are shown in Tables 1 and 2. Tables 1 and 2 also show room temperature tensile strength.

[0012]

[Table 1]

[0013]

[Table 2]

[0014]

From the results shown in Tables 1 and 2, the present invention A
It is apparent that all of the 1 sintered alloy members 1 to 19 have high temperature strength superior to the conventional Al sintered alloy members 1 to 3. As described above, the Al sintered alloy member of the present invention has excellent high-temperature strength. Therefore, when this Al sintered alloy member is applied as a structural member of various internal combustion engines, compressors, etc., it is particularly difficult to generate heat. Even when used below, it exhibits excellent performance over a long period of time.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toru Kono 1-297, Kitabukuro-cho, Omiya-shi, Saitama Prefecture Central Research Laboratory, Mitsubishi Materiality Co., Ltd.

Claims (2)

[Claims] 1. By weight%, Si: 15 to 35%, Mn: 0.1 to 3%, rare earth element: 0.5 to 8%, Ni: 0.5 to 8%, Al and inevitable impurities: the rest An Al sintered alloy member excellent in high-temperature strength, characterized in that it is made of a hot-plastic worked material of a green compact or a pre-sintered body having the composition of. 2. By weight%, Si: 15-35%, Mn: 0.1-3%, rare earth element: 0.5-8%, Ni: 0.5-8%, Zr: 0.1- 2%, Al and unavoidable impurities: The remainder is an Al sintered alloy member having excellent high-temperature strength, which is characterized by being constituted by a hot-plastic worked material of a powder compact or a pre-sintered body having the following composition.