Magnesium alloy material and method for manufacturing the same

Abstract

Disclosed is a magnesium alloy material which can be produced without the need of employing any specialized production facility or process and has excellent mechanical properties, particularly high elongation. Also disclosed is a process for producing the magnesium alloy material. The magnesium alloy material comprises a Mg—Gd—Zn alloy comprising 1 to 5 mass % of Zn and 5 to 15 mass % of Gd as essential ingredients, with the remainder being Mg and unavoidable impurities, wherein the Mg—Gd—Zn alloy has a long period stacking structure in its alloy structure and also has Mg 3 Gd and/or Mg 3 Zn 3 Gd 2 . The process for producing the magnesium alloy material comprises a melting/casting step and a forging processing step for subjecting the casted material to a hot forging processing at a predetermined processing rate.

1 . A magnesium alloy material comprising an Mg—Gd—Zn alloy including 1 to 5% by mass of Zn and 5 to 15% by mass of Gd as essential components, with the remainder being Mg and unavoidable impurities,
 wherein the Mg—Gd—Zn alloy has an alloy structure having a long period stacking ordered structure and having 4% or more of Mg 3 Gd and/or Mg 3 Zn 3 Gd 2 .   
   
   
       2 . The magnesium alloy material according to  claim 1 , wherein an area ratio of Mg 3 Gd and/or Mg 3 Zn 3 Gd 2  in the alloy structure is 53% or less. 
   
   
       3 . The magnesium alloy material according to  claim 1 , wherein provided that elongation (%) measured by JIS standard tensile test is defined as (x) and 0.2% yield strength (MPa) is defined as (y), the following formulae are satisfied.
   (−15.57 x )+467 <y <(−15.57 x )+555, and x<20   
   
   
       4 . A process for producing a magnesium alloy material comprising:
 a dissolving/casting step of dissolving and casting the Mg—Gd—Zn alloy according to  claim 1  to provide a cast material; and   a plastic forming step of subjecting the cast material to hot plastic forming at a predetermined processing rate to produce a processed material.