JP3005672B2 - Method for producing multi-phase Al-Si-Fe alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The invention of this application relates to a multi-phase Al
The present invention relates to a method for producing a Si—Fe alloy. More specifically, the invention of this application is intended to produce a multi-phase Al-Si-Fe alloy having high strength and high ductility as well as cold workability and enabling production as a wrought material and a forged material. It is about the method.

[0002]

2. Description of the Related Art Conventionally, Al-Si-Fe
Alloys, Al-Si alloys, Al-Si-Cu alloys,
It has been known that, for Al-Fe-Mn-based alloys and the like, a second phase that is difficult to deform and has a brittleness, such as a coarse acicular intermetallic compound or a coarse hexagonal plate-like Si crystal, is generated. When this second phase is formed, the mechanical properties of each alloy are not good and the cold workability is poor, so that it has been difficult to apply the alloy to wrought materials and forged materials.

On the other hand, in order to improve the mechanical properties of Al alloys, various refinement treatments by addition of specific elements and finer structure by hot working near the eutectic temperature and spheroidization of the second phase have been attempted. I have. However, it is difficult to divide and crush the second phase, and fine dispersion into the parent phase has not been realized. In addition, there is a problem that the spheroidization of the second phase requires a heat treatment for a long time, for example, about 8 hours.

[0004] In general, it is said that most of the work by processing is lost as thermal energy, and energy stored as lattice defects such as dislocations is less than 10%.
Further, Al has a high stacking fault energy and facilitates the cross-slip of screw dislocations, so that dynamic deformation occurs as the deformation proceeds. In order to suppress such dynamic recovery and accumulate higher strain energy, processing at cryogenic temperature is effective. By combining with rapid heating, recrystallized grains of Al matrix can be refined. Sex is pointed out.

[0005] The invention of this application is based on the above-mentioned prior art, and has a high strength and a high ductility, and also has a cold workability, and is capable of being manufactured as a wrought material and a forged material.
An object of the present invention is to provide a method for producing an Fe-based alloy.

[0006]

Means for Solving the Problems The present invention solves the above-mentioned problems by providing a multi-phase Al-Si-Fe alloy material having a ductile Al matrix and a second phase which is hardly deformed. A multi-phase Al which is cooled to a cryogenic temperature lower than the liquid nitrogen temperature, introduces microcracks into the second phase by multi-pass cold working, and divides and crushes them, and finely disperses them in the matrix.
A method for producing a Si-Fe alloy (claim 1) is provided.

[0007] The invention of the present application discloses a multi-phase Al-Si
-The Fe-based alloy material is produced by the spray deposition method (Claim 2), and the multi-pass cold working is performed in combination with the recovery heat treatment, the crack is eliminated by the recovery heat treatment, and the second heat treatment is performed again. Second by cold working
It is provided as a preferred embodiment that the phase separation / crushing is advanced and the phase is finely dispersed more uniformly in the mother phase.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An Al-Si-Fe alloy has a coarse Fe-rich intermetallic compound and a coarse hexagonal plate-like Si crystal as a second phase which is hardly deformed, together with a ductile Al matrix. It is a two-phase alloy. In this Al-Si-Fe alloy, the brittle cracks of the second phase are problematic during cold working. In the invention of this application, such a multiphase A
The l-Si-Fe alloy material is cooled to a cryogenic temperature lower than the temperature of liquid nitrogen and subjected to multi-pass cold working to introduce minute cracks into the second phase, which is divided and crushed to form a matrix. Finely disperse.

[0009] The hardness and strength of the Al matrix are increased at low temperatures. Dynamic recovery is suppressed, the hardness difference with the second phase is reduced, and deformation stress is generated not only in the Al matrix but also in the second phase by cold working. As a result, the second phase is easily separated and crushed, and finely dispersed in the Al matrix. Also, Al
The parent phase has a fine structure that allows higher strain energy to be stored. The cold working is performed in multiple passes, and the working degree and the number of working times are determined by the multi-phase Al-Si-F to be worked.
It can be determined based on the composition of the e-based alloy material, hardness under cooling, and the like. Generally, the processing draft is 4 to 20%.
The degree and the number of times of processing can be set to about 5 to 10 times. Examples of the multi-pass cold working include swaging under relatively light pressure, groove rolling, and flat rolling.

Also, in the invention of this application, the multi-phase Al-S
The i-Fe-based alloy material can be made by a spray deposition method. In the multi-phase Al—Si—Fe-based alloy material prepared by the spray deposition method, the second phase is uniformly dispersed with a size of several μm.
By cooling the Si-Fe-based alloy material to a cryogenic temperature lower than the liquid nitrogen temperature and performing multi-pass cold working, the second layer is more finely divided and crushed, and is uniformly and finely dispersed in the matrix. Is done.

Further, in the invention of this application, it is considered that the multi-pass cold working is combined with the recovery heat treatment and the recovery heat treatment and the cold work are repeatedly performed. The recovery heat treatment eliminates cracks introduced by cold working at extremely low temperatures,
(1) It enables mass transfer of the mother phase and enables uniform and fine precipitation of fine precipitates. Generally, the conditions are 450 to 550 ° C. for about 0.5 to 1.5 hours. Then, by cold working at an extremely low temperature after the recovery heat treatment, the second phase is again divided and crushed, and is uniformly finely dispersed by the Al matrix.

[0012] Thus, the invention of this application is to provide a multi-phase Al-Si-Fe alloy having high strength and high ductility applicable to various fields of cast material, forged material, and developed material as a practical Al alloy.
Enables production of base alloys. In the invention of this application, the multi-phase Al—Si—Fe-based alloy material to be subjected to cold working is considered even to those containing components such as Cu, Mn, Mg, Li, and Zn. Hereinafter, examples will be shown, and the invention of this application will be described in more detail.

[0013]

EXAMPLE No. 1 shown in Table 1 was used. Alloys 1 to 9 are φ30 ×
The test material was cast in a 200 mm ingot case.
In addition, No. An alloy No. 10 was prepared by a spray deposition method, and was formed into a test material by being formed into φ30 by hot extrusion.

[0014]

[Table 1]

Each test material was cooled in liquid nitrogen (77K) and immediately swaged. The rolling reduction in one cycle was about 20%. Table 2 shows the results of swaging.

[0016]

[Table 2]

As shown in Table 2, working at 77K at extremely low temperature is easier than working at room temperature (293K) for each test material, and the second phase is finely dispersed in the Al matrix. did.

[0018]

As described above in detail, according to the invention of this application, it is possible to produce a multi-phase Al-Si-Fe-based alloy applicable to various fields of cast material, forged material, and developed material as a practical Al alloy. Becomes High strength and high ductility of the wrought material by the Al-Si-Fe alloy are achieved, and the piston, VT
Al-Si-Fe alloys can be applied to various mechanical parts such as R cylinders, and the performance of these mechanical parts is expected to be improved.

Further, the invention of this application can be applied only by remodeling a part of the production line in the current industrial equipment, and therefore provides a cold-worked material of an Al-Si-Fe alloy at low cost. It is also possible.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI C22F 1/00 685 C22F 1/00 685Z 694 694A

Claims (3)

(57) [Claims] 1. A multi-phase Al—Si—Fe alloy material having a ductile Al matrix and a second phase that is difficult to deform is cooled to an extremely low temperature of liquid nitrogen temperature or lower, and the second phase is subjected to multi-pass cold working. A multi-phase Al-Si-Fe-based alloy, characterized in that microcracks are introduced into the matrix, the cracks are divided and crushed, and finely dispersed in a matrix. 2. The method for producing a multi-phase Al—Si—Fe alloy according to claim 1, wherein the multi-phase Al—Si—Fe alloy material is produced by a spray deposition method. 3. The multi-pass cold working is performed in combination with the recovery heat treatment, the cracks are eliminated by the recovery heat treatment, and the second phase is separated and crushed by the cold work again, and the fine phase is uniformly dispersed in the mother phase. The method for producing a multi-phase Al-Si-Fe alloy according to claim 1 or 2.