JPS6233738A - Heat resistant aluminum alloy for powder metallurgical processing and its manufacture - Google Patents

Abstract

PURPOSE:To obtain an Al alloy undergoing little reduction in the strength or elongation even after long-time use at high temp. by adding specified elements to a molten Al alloy contg. Fe as the principal added element and by cooling the resulting molten alloy under specified conditions. CONSTITUTION:The composition of a molten Al alloy is composed of 5-17wt% Fe as the 1st added element, 1-7wt% Zr as the 2nd added element, 1-7wt% Mo and/or W as the 3rd added element and the balance Al with inevitable impurities. In the composition, the amount of the 1st added element is made larger than the amount of the 2nd added element and the amount of the 3rd added element. The molten Al alloy is cooled at <=10<5> deg.C/sec cooling rate to form particles, flakes, a fine wire or a ribbonlike thin strip. This product is worked optionally after crushing to pieces.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to heat-resistant aluminum powder metallurgical alloys. The alloy products according to the present invention have little loss in strength and elongation even after long-term use at high temperatures, so they are useful as aircraft parts, automobile engine parts, electrical equipment parts, hydraulic and pneumatic equipment parts, and even as high-temperature structural materials. I'll go.

Prior Art and Intermediate Aluminum and its alloys generally have low strength at high temperatures, and particularly high strength at room temperature.So-called high-strength aluminum alloys have a significant decrease in strength at high temperatures. In addition, aluminum alloy (AA201
8.2218.2618.4032 etc.), 2
If the temperature exceeds 00°C, the strength will drop significantly.

Regarding thermal stability, for example, after being exposed to a temperature of 150° C. or higher for a long time, it is inevitable that the strength at room temperature will decrease significantly.

In the case of SAP, which has aluminum oxide uniformly dispersed in aluminum, although it has excellent annealing softening resistance, it is difficult to say that it is satisfactory in terms of strength, toughness, etc., and is of little practical use. .

In recent years, various transition elements have been added to aluminum for a time exceeding the solid solubility limit, the molten metal is solidified ultra-rapidly at a cooling rate of 105°C/second or more, and the resulting powder or ribbon-like ribbon is formed by powder metallurgy to produce aluminum. A method of forming an alloy has been proposed (U.S. Pat. Nos. 4,347,076 and 4,464,199).
issue). Although the aluminum powder metallurgical alloy thus obtained has excellent strength and thermal stability at high temperatures, its major drawbacks are low elongation and lack of ductility.

As a result of various studies conducted in view of the current state of the technology as described above, the present invention is based on the addition of specific additive elements to an aluminum alloy whose main additive element is iron. The aluminum powder metallurgical alloy obtained by blending and cooling the molten metal under specific conditions not only has excellent strength at high temperatures, but also has the unique property of exhibiting extremely small decreases in strength and elongation after exposure to high temperatures. It was discovered that it has the following. That is, the present invention provides the following alloy and its manufacturing method.

■(i) 5 to 17% by weight of Fe as the first additive element, (i
i) 1 to 7% by weight of Zr as the second additive element, and 1 to 7% by weight of at least one of Mo and W as the third additive element, with the remainder consisting of Al and unavoidable impurities;
A heat-resistant aluminum powder metallurgy characterized in that the content of the additive element is greater than the content of each of the second and third additive elements, the tensile strength is 40 km mm2 or more, and the elongation is 5% or more. alloy.

■(i) 5 to 17% by weight of Fe as the first additive element, (i
i) 1 to 7% by weight of Zr as the second additive element, and (iii) 1 to 7% by weight of at least one of Mo and W as the third additive element, with the remainder consisting of Al and unavoidable impurities;
The content of the additive element is substantially 105
It is characterized by forming particulates, flakes, thin wires, or ribbon-like thin strips at a cooling rate of less than °C/SeC, and molding them as they are or further cut into pieces as necessary. A method for producing a heat-resistant aluminum powder metallurgy alloy.

■(i) 5 to 17% by weight of Fe as the first additive element, (i
i) 1 to 7% by weight of Zr as the second additive element, (iii
) at least one of Mo and W as the third additive element;
7% by weight, and (iv) not exceeding 5% by weight of Mn as the fourth additive element, with the remainder consisting of Al and unavoidable impurities;
The content of the additive element is larger than the content of each of the second, third, fourth, and fourth additive elements, and the tensile strength is 40 kmMmm.
A heat-resistant aluminum powder metallurgical alloy characterized by an elongation of 2 or more and an elongation of 5% or more.

■(+) 5 to 17% by weight of Fe as the first additional element, (i
i) Zr1-7% as the second additive element, (iii
>At least one of Mo and W as the third additive element 1~
(iv) not exceeding 5% by weight of Mn as the fourth additive element, the remainder consisting of Al and unavoidable impurities;
The content of the additive element is substantially 1% from the Al alloy molten metal whose content is greater than the respective contents of the second, third, and fourth additive elements.
Forming particulates, flakes, thin wires, or ribbon-like thin strips at a cooling rate of less than 05°C/SeC, and molding them as they are or further cut into pieces as necessary. A method for producing a heat-resistant aluminum powder metallurgy alloy.

In the present invention, aluminum contains 5 to 17% Fe as the first additive element and Zr as the second additive element.
1 to 7% by weight and at least one of Mo and W as the third additive element, and 1 to 7% by weight, and the content of the first additive element is adjusted to the content of each of the second and third additive elements. It is essential that it be larger than I. If any of these conditions are not satisfied, the desired effect will not be achieved, as is clear from the Examples and Comparative Examples described later.

In addition, in the present invention, M is further added as a fourth additive element in an amount not exceeding 5% by weight and less than the first additive element.
By adding n, the tensile strength can be improved although the elongation is slightly reduced.

The aluminum powder metallurgy alloy of the present invention is produced, for example, as follows. A material obtained by solidifying a molten aluminum alloy containing Fe, Zr, Mo and/or W in a predetermined proportion, or further containing Mn at a cooling rate of less than 105°C/sec, was cold preformed according to a conventional method. After that, by hot working, the product has a density of approximately 100%. The lower limit of the cooling rate is preferably 105°C/sec.

The method for cooling the molten metal is not particularly limited, but an atomization method is exemplified as a typical method. In addition, by adopting conditions that increase the thickness or diameter of ribbon-like thin strips, thin wire-like objects, or flake-like objects formed by melt spinning methods, melt extraction methods, etc. that belong to ultra-rapid solidification methods, , it is possible to obtain materials with desired properties with cooling rates of less than 105° C./sec. In this case, if necessary, the product, such as a ribbon, is crushed prior to the subsequent shaping process. Furthermore, in the twin roll method or the spray roll method in which a rapidly solidified material is obtained by colliding atomized particles with a rotating drum, it is possible to achieve a predetermined value by adjusting the materials of the rolls and drums, the distance between the rolls, the size of the atomized particles, etc. It is possible to obtain flakes having the desired properties as the cooling rate increases. Note that the materials obtained by these manufacturing methods also contain extremely fine particles, and the cooling rate of these extremely fine particles may be 105° C./second or more. However, in the present invention, even if such particles are contained to some extent, the desired effect can be achieved.

Cold preforming and hot processing conditions during forming processing are as follows:
Although not particularly limited, after molding a material with a particle size of about 40 mesh or less at a pressure of 700 km cm2 ·G or more,
Hot working may be performed at a temperature of about 200°C. The cold preforming may be carried out by any method that allows a molded product to be handled when proceeding to the subsequent hot working step, and may be carried out, for example, by mechanical pressing, isostatic pressing, or the like. Examples of hot working methods include hot extrusion, hot rolling, hot forging, hot pressing, and hot isostatic pressing.

In addition, the molding process may be performed by the conform method in which cold or hot extrusion is performed directly without going through a cold preforming process, and in this case, it is also possible to obtain a molded product with a density of approximately 100%. I'll go.

The aluminum powder metallurgical alloy of the present invention has excellent properties such as strength and elongation not only at room temperature but also at high temperatures, and most of its excellent properties are maintained even after long-term exposure to high temperatures. It can be maintained without damage.

EXAMPLES Hereinafter, Examples and Comparative Examples will be shown to further clarify the characteristics of the present invention.

Example 1 A molten metal containing the additive elements shown in Table 1 was atomized by an atomization method to obtain a powder of about 100 meshes or less at a cooling rate of about 10'C/sec.

Table 1 Note: Sample No. 6.8.10.12.14 and 16 are
It has a composition outside the scope of the present invention, No. 15
has the same composition as No. 2, but the cooling rate is 105~1
It was obtained by melt spinning at 07°C/sec.

The powder obtained above was cold preformed at a pressure of 2830 kg/cm2 to form a molded body with a diameter of 3 cm x a height of 7.6 cm, and then extruded at a pressure of 0.6 x 10' at 400'C at an extrusion ratio of 9.
Extrudates were obtained at ~1,2 x 10'kMccm''.

Table 2 shows the extruded material and the extruded material at 350'C.
The tensile strength and elongation at room temperature when annealed at 400° C. for 64 hours are shown. For sample No. 16, an ingot with a diameter of 3 cm and a height of 7.6 cm was extruded.

Table 2 As is clear from the results shown in Table 2, alloys having compositions outside the range of the present invention have low elongation, are difficult to hot extrude, and have limited fields of application.

Furthermore, since the melting point of the alloy becomes very high, it becomes difficult to prepare powder by the atomization method.

Furthermore, as is clear from the comparison between Sample Nos. 2 and 15, even if the composition is within the composition range of the present invention, if the cooling rate during powder production exceeds 105°C/sec, the elongation of the extruded material will decrease. small.

In contrast, the aluminum powder metallurgical alloy of the present invention can be easily prepared as a raw material powder by the atomization method, can be easily processed by hot extrusion, etc., and has excellent strength even after long-term exposure to high temperatures. and continues to maintain elongation properties.

(Above) Self-interest in writing procedural amendments 1. Indication of the case 1985 Patent Application No. 173695 2. Name of the invention Heat-resistant aluminum powder metallurgy alloy and its manufacturing method 3. Person making the amendment Relationship with the case Patent applicant Toyo Aluminum Co., Ltd. 4 Agent: Sawanotsuru Building, 2-10 Hirano-cho, Higashi-ku, Osaka, Japan 6 Section 7, “Detailed Description of the Invention” in the specification subject to amendment Contents of amendment 1 Contents of amendment 1 Page 12, line 8 of the specification ``Direct cold or hot extrusion'' is corrected to ``direct extrusion j''.

(that's all)

Claims (1)

[Claims] [1] (i) 5 to 17% by weight of Fe as the first additional element;
(ii) contains 1 to 7% by weight of Zr as a second additive element, and (iii) 1 to 7% by weight of at least one of Mo and W as a third additive element, with the remainder consisting of Al and unavoidable impurities;
A heat-resistant aluminum characterized in that the content of the additive element is greater than the content of each of the second and third additive elements, the tensile strength is 40 kg/mm^2 or more, and the elongation is 5% or more. Powder metallurgy alloy. [2] (i) 5 to 17% by weight of Fe as the first additional element,
(ii) contains 1 to 7% by weight of Zr as a second additive element, and (iii) 1 to 7% by weight of at least one of Mo and W as a third additive element, with the remainder consisting of Al and unavoidable impurities;
The content of the additive element is substantially 10^ from the Al alloy molten metal which is higher than the content of each of the second and third additive elements.
Forming particulates, flakes, thin wires, or ribbons at a cooling rate of less than 5°C/sec, and molding them as they are or further cut into pieces if necessary. A method for producing a heat-resistant aluminum powder metallurgy alloy. [3] (i) 5 to 17% by weight of Fe as the first additional element,
(ii) 1 to 7% by weight of Zr as the second additive element, (ii
i) At least one of Mo and W1 as the third additive element
~7% by weight, and (iv) not more than 5% by weight of Mn as the fourth additive element, with the remainder consisting of Al and unavoidable impurities;
The content of the additive element is higher than the content of each of the second, third, and fourth additive elements, and the tensile strength is 40 kg/mm^
A heat-resistant aluminum powder metallurgical alloy characterized by an elongation of 2 or more and an elongation of 5% or more. [4] (i) 5 to 17% by weight of Fe as the first additional element,
(ii) 1 to 7% by weight of Zr as the second additive element, (ii
i) At least one of Mo and W1 as the third additive element
~7% by weight, and (iv) not more than 5% by weight of Mn as the fourth additive element, with the remainder consisting of Al and unavoidable impurities;
The content of the additive element is substantially 1% from the molten Al alloy whose content is greater than the content of each of the second, third, and fourth additive elements.
A particulate material, a flake-like material, a thin wire-like material, or a ribbon-like thin material is formed at a cooling rate of less than 0^5°C/sec, and this is processed as it is or further cut into pieces as necessary. A method for producing a heat-resistant aluminum powder metallurgy alloy.