High strength Mg alloy and method for producing same

Patent metadata

Field	Value
Publication number	US-9523141-B2
Application number	US-201214356502-A
Country	US
Kind code	B2
Filing date	Nov 6, 2012
Priority date	Nov 7, 2011
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

Provided is an Mg alloy and a method for producing same able to demonstrate high strength without requiring an expensive rare earth element (RE). The high-strength Mg alloy containing Ca and Zn within a solid solubility limit and the remainder having a chemical composition comprising Mg and unavoidable impurities is characterized in comprising equiaxial crystal particles, there being a segregated area of Ca and Zn along the (c) axis of a Mg hexagonal lattice within the crystal particle, and having a structure in which the segregated area is lined up by Mg 3 atomic spacing in the (a) axis of the Mg hexagonal lattice. The method for producing the high-strength Mg alloy is characterized in that Ca and Zn are added to Mg in a compounding amount corresponding to the above composition and, after homogenization heat treating an ingot formed by dissolution and casting, the above structure is formed by subjecting the ingot to hot processing.

First claim

The invention claimed is:

1. A high strength Mg alloy characterized by
having a chemical composition which contains Ca in an amount of from 0.15 to 0.3 at % and Zn in an amount of 0.6 at % or less, and the balance comprised of Mg and unavoidable impurities, and
having a structure comprising equiaxial crystal grains and having segregated regions of Ca and Zn along the c-axis direction of the Mg hexagonal lattice in the crystal grains, wherein the segregated regions are arranged at intervals of three Mg atoms in the a-axis direction of the Mg hexagonal lattice,
wherein the contents of Ca and Zn are in the relation of Ca:Zn=1.2 at atomic ratio.

2. A method of producing a high strength Mg alloy according to claim 1 , characterized by
adding Ca and Zn to Mg in amounts which correspond to the above composition,
melting and casting them to form an ingot,
subjecting the ingot to a homogenizing heat treatment, and subsequently
subjecting the ingot to hot working to generate the structure as defined in claim 1 .

3. The method of producing a high strength Mg alloy according to claim 2 characterized by performing the hot working at least one time at a temperature of 300° C. or more.

Assignees

• Washio Kota
• Kato Akira
• Mukai Toshiji
• Singh Alok
• Somekawa Hidetoshi
• Toyota Motor Co Ltd
• Nat Univ Corp Kobe Univ
• Nat Inst For Materials Science

Inventors

• Washio Kota
• Kato Akira
• Mukai Toshiji
• Singh Alok
• Somekawa Hidetoshi

Classifications

• C22C23/00

  Alloys based on magnesium · CPC title

• C22C23/04

  with zinc or cadmium as the next major constituent · CPC title

• C22F1/06 Primary

  of magnesium or alloys based thereon · CPC title

• C22C1/02

  by melting {(C22C1/1036 takes precedence)} · CPC title

• C22F1/00

  Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working (apparatus for mechanical working of metal B21, B23, B24) · CPC title