MICROCRYSTALLINE ALLOY, METHOD FOR PRODUCTION OF THE SAME, APPARATUS FOR PRODUCTION OF THE SAME, AND METHOD FOR PRODUCTION OF CASTING OF THE SAME

• US 20120168040A1
• Filed: 08/02/2010
• Published: 07/05/2012
• Est. Priority Date: 08/27/2009
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation), Toyota School Foundation (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation), Toyota School Foundation (Toyota Motor Corporation)
• Inventors: Furukawa, Yuichi, Tsunekawa, Yoshiki
• Granted Patent: US 8,992,705 B2
• Time in Patent Office: Days
• US Class Current: 148/538
• CPC Class Codes: C22C 21/02 with silicon as the next major constituent
• CPC Class Codes: C22C 21/06 with magnesium as the next major constituent
• CPC Class Codes: C22C 23/04 with zinc or cadmium as the next major constituent
• CPC Class Codes: C22F 1/043 of alloys with silicon as the next major constituent
• CPC Class Codes: C22F 1/047 of alloys with magnesium as the next major constituent
• CPC Class Codes: C22F 3/00 Changing the physical structure of non-ferrous metals or alloys by special physical methods, e.g. treatment with neutrons
• CPC Class Codes: C22F 3/02 by solidifying a melt controlled by supersonic waves or electric or magnetic fields

Abstract

During a process of cooling a hypereutectic Al—Si alloy melt, ultrasonic vibration is applied to the melt to crystallize primary crystal α-Al using, in combination, an ultrasonic transducer (8) that generates the ultrasonic vibration, an ultrasonic horn (7) that is connected to the ultrasonic transducer (8) and transmits the ultrasonic vibration in a specified direction, a treatment vessel (2) that holds the melt and is in contact with the ultrasonic horn (7), and a treatment vessel fixing device (3) that fixes the treatment vessel (2) by pressing the treatment vessel toward the ultrasonic horn (7).

Claims

1. An alloy that has a microcrystalline structure that is obtained by applying a melting step, applying a pressure to an alloy melt during a process of cooling the melt, quenching the melt after an eutectic temperature is reached, thereby a nonequilibrium α

-Al phase is crystallized, and then by crystallizing a fine primary crystal, wherein the alloy is one of an Al—

Si alloy, an Al—

Mg alloy and a Mg—

Zn alloy.

2. The alloy according to claim 1, wherein the alloy is the Al—

Si alloy or the Al—

Mg alloy, and the primary crystal is α

-Al.

3. The alloy according to claim 2, wherein the alloy is the Al—

Si alloy.

4. The alloy according to claim 3, wherein the Si content in the Al—

Si alloy is 12% or higher.

5. The alloy according to claim 4, wherein the Al—

Si alloy is hypereutectic.

6. The alloy according to claim 1, wherein the primary crystal is a refined, generally spherical crystal.

7. The alloy according to claim 1, wherein the pressure is applied using ultrasonic cavitation that is generated in the melt by applying ultrasonic vibration to the melt.

8. A method for the production of an alloy that has a microcrystalline structure, comprising:

a melting step in which an alloy is melted to obtain an alloy melt;

a pressure applying step in which a pressure is applied to the melt during a process of cooling the melt; and

p1 a cooling step in which the melt is quenched after an eutectic temperature is reached, thereby a nonequilibrium α

-Al phase is crystallized,

wherein the alloy is one of an Al—

Si alloy, an Al—

Mg alloy and a Mg—

Zn alloy.

9. The production method according to claim 8, wherein the alloy is the Al—

Si alloy or the Al—

Mg alloy; and

α

-Al that is the fine primary crystal is crystallized in the pressure applying step.

10. The production method according to claim 9, wherein the alloy is the Al—

Si alloy.

11. The production method according to claim 10, wherein the Al—

Si alloy is hypereutectic.

12. The production method according to claim 8, wherein, in the pressure applying step, the pressure is applied using ultrasonic cavitation that is generated in the melt by applying ultrasonic vibration to the melt.

13. An alloy that is produced by the production method according to claim 8.

14. A production apparatus for the production of an alloy that has a microcrystalline structure, wherein a fine primary crystal is crystallized by applying ultrasonic vibration to an alloy melt during a process of cooling the melt, wherein the melt is quenched after an eutectic temperature is reached, thereby a nonequilibrium α

-Al phase is crystallized, said production apparatus comprising;

an ultrasonic transducer that generates the ultrasonic vibration;

an ultrasonic transmitter that is connected to the ultrasonic transducer and transmits the ultrasonic vibration in a specified direction;

a treatment vessel that holds the melt and is in contact with the ultrasonic transmitter; and

a treatment vessel fixing device that fixes the treatment vessel by pressing the treatment vessel against the ultrasonic transmitter,

wherein the ultrasonic vibration is applied to the melt via the treatment vessel, and

wherein the alloy is one of an Al—

Si alloy, an Al-Mg alloy and a Mg—

Zn alloy.

15. The production apparatus according to claim 14, wherein the alloy is the Al—

Si alloy or the Al—

Mg alloy, and the primary crystal is α

-Al.

16. The production apparatus according to claim 15, wherein the alloy is the Al—

Si alloy.

17. A method for the production of a casting of an alloy having a microcrystalline structure, comprising:

a melting step in which an alloy is melted to obtain an alloy melt;

a pressure applying step in which a pressure is applied to the melt during a process of cooling the melt;

a casting step in which casting of the alloy casting is carried out using the melt in which a fine primary crystal has been formed during the cooling process; and

a quenching in which the melt is quenched after an eutectic temperature is reached, thereby a nonequilibrium α

-Al phase is crystallized,

wherein the alloy is one of an Al—

Si alloy, an Al—

Mg alloy and a Mg—

Zn alloy.

18. The production method according to claim 17, wherein the alloy is the Al—

Si alloy or the Al—

Mg alloy, and the primary crystal is α

-Al.

19. The production method according to claim 18, wherein the alloy is the Al—

Si alloy.

20. The production method according to claim 17, wherein the casting is centrifugal casting.

21. The production method according to claim 17, wherein a member that has a sliding surface in a cylinder block is produced as the alloy casting.

22. The production method according to claim 17, wherein the casting is die casting.