Magnesium alloy, magnesium alloy sheet, magnesium alloy structural member, and method for producing magnesium alloy

Abstract

A magnesium alloy contains, in mass %, from 1% to 12% inclusive of Al and from 0.1% to 5% inclusive of Mn and has a structure in which particles of compounds containing Al and Mn are dispersed. The average diameter of the particles of the compounds is from 0.3 μm to 1 μm inclusive, and the area ratio of the particles of the compounds is from 3.5% to 25% inclusive.

1 . A magnesium alloy comprising, from 1 mass % to 12 mass % inclusive of Al and from 0.1 mass % to 5 mass % inclusive of Mn,
 wherein the magnesium alloy has a structure in which particles of a compound containing Al and Mn are dispersed,   an average diameter of the particles of the compound is from 0.3 μM to 1 μm inclusive, and   an area ratio of the particles of the compound is from 3.5% to 25% inclusive.   
     
     
         2 . The magnesium alloy according to  claim 1 , wherein a maximum diameter of the particles of the compound is less than 2.5 μm. 
     
     
         3 . The magnesium alloy according to  claim 1 , wherein an average crystal grain size of the magnesium alloy is 10 μm or less. 
     
     
         4 . A magnesium alloy sheet formed from the magnesium alloy according to  claim 1 . 
     
     
         5 . A magnesium alloy structural member formed from the magnesium alloy according to  claim 1 , the magnesium alloy structural member having, in at least a part thereof, a plastically formed portion subjected to plastic forming. 
     
     
         6 . A method for producing a magnesium alloy, the method comprising the step of subjecting a melt of a magnesium alloy to continuous casting, the magnesium alloy containing, from 1 mass % to 12 mass % inclusive of Al and from 0.1 mass % to 5 mass % inclusive of Mn,
 wherein the temperature of the melt immediately before the melt comes into contact with a mold is from 630° C. to 690° C. inclusive, and   a cooling rate of the melt is 560° C./second or higher.