High strength magnesium alloy with excellent flame retardancy, and method for producing same

Abstract

An aspect of the present disclosure relates to a high strength magnesium alloy with excellent flame retardancy, wherein the magnesium alloy comprises 2.0-13.0 wt % of Al, 0.1-0.5 wt % of Mn, 0.0015-0.025 wt % of B, and 0.1-1.0 wt % of Y with the remainder comprising Mg and other unavoidable impurities, and comprises 6.5% or more of an Mg—Al intermetallic compound in terms of volume fraction, the Mg—Al intermetallic compound having an average grain size of 20-500 nm.

1 . A high strength magnesium alloy having excellent flame retardancy, comprising:
 by weight %, 2.0 to 13.0% of aluminum (Al), 0.1 to 0.5% of manganese (Mn), 0.0015 to 0.025% of boron (B), 0.1 to 1.0% of yttrium (Y), a remainder of magnesium (Mg), and unavoidable impurities,   the magnesium alloy comprising a Mg—Al intermetallic compound in a volume fraction of 6.5% or more,   wherein the Mg—Al intermetallic compound has an average particle diameter of 20 to 500 nm.   
     
     
         2 . The high strength magnesium alloy having excellent flame retardancy of  claim 1 , wherein the magnesium alloy further comprises 0.5 to 1.5 weight % of zinc (Zn). 
     
     
         3 . The high strength magnesium alloy having excellent flame retardancy of  claim 1 , wherein the magnesium alloy further comprises one or more of an Al—Mn intermetallic compound and an Al—Y intermetallic compound, and a total content of the Al—Mn intermetallic compound and the Al—Y intermetallic compound is 5% or less in a volume fraction. 
     
     
         4 . The high strength magnesium alloy having excellent flame retardancy of  claim 1 , wherein the magnesium alloy has an ignition temperature of 700° C. or higher. 
     
     
         5 . The high strength magnesium alloy having excellent flame retardancy of  claim 1 , wherein the magnesium alloy is a hardness of 70 Hv or more. 
     
     
         6 . The high strength magnesium alloy having excellent flame retardancy of  claim 1 , wherein the magnesium alloy has a tensile strength of 130 MPa or more and an elongation of 3% or more. 
     
     
         7 . A method of producing a high strength magnesium alloy having excellent flame retardancy, the method comprising:
 preparing a molten metal including, by weight %, 2.0 to 13.0% of aluminum (Al), 0.1 to 0.5% of manganese (Mn), 0.0015 to 0.025% of boron (B), 0.1 to 1.0% of yttrium (Y), a remainder of magnesium (Mg), and unavoidable impurities;   casting the molten metal to obtain a magnesium alloy casting material;   subjecting the magnesium alloy casting material to a solution treatment at a temperature ranging from 370 to 490° C. for 2 to 20 hours to obtain a magnesium alloy;   cooling the magnesium alloy to 100° C. or lower; and   aging the magnesium alloy cooled in the cooling of the magnesium alloy at a temperature of 150 to 250° C. for 2 to 48 hours.   
     
     
         8 . The method of producing a high strength magnesium alloy having excellent flame retardancy of  claim 7 , wherein the molten metal further comprises, by weight %, 0.5 to 1.5% of Zn. 
     
     
         9 . The method of producing a high strength magnesium alloy having excellent flame retardancy of  claim 7 , wherein the preparing of the molten metal is performed by charging a crucible with Mn, B and Y mixed with Mg or Al in the form of a master alloy. 
     
     
         10 . The method of producing a high strength magnesium alloy having excellent flame retardancy of  claim 7 , wherein the preparing of the molten metal is performed by charging the crucible sequentially from an element having a low melting point. 
     
     
         11 . The method of producing a high strength magnesium alloy having excellent flame retardancy of  claim 7 , wherein the cooling is performed at a cooling rate of 1 to 100° C./second.