Mg Alloys Containing Misch Metal Manufacturing Method of Wrought Mg Alloys Containing Misch Metal, and Wrought Mg Alloys Thereby

Abstract

There are provided a magnesium alloy with a misch metal, a method of producing a wrought magnesium alloy with a misch metal, and a wrought magnesium alloy produced thereby, in which a great deal of misch metal is added to magnesium, and thus refractory eutectic phases or multi-phases are formed into a stable network structure or a stable dispersed phase, thereby inhibiting deformation of a magnesium matrix at a high temperature to maintain a high strength. The magnesium alloy with the misch metal has the formula of Mg 100-x-y-g A x B y C z , where A is zinc (Zn) or aluminum (Al); B is the misch metal; C is at least one element selected from the group consisting of manganese (Mn), nickel (Ni), copper (Cu), tin (Sn), yttrium (Y), phosphor (P), silver (Ag), and strontium (Sr); and x, y and z are the compositions of 0 at %≦x≦6 at %, 0.8 at %≦y≦7 at %, and 0 at %≦z≦2 at %, respectively.

1 . A magnesium alloy with a misch metal, having the formula: Mg 100-x-y-z A x B y C z ,
 wherein   A is zinc (Zn) or aluminum (Al);   B is the misch metal;   C is at least one element selected from the group consisting of manganese (Mn), nickel (Ni), copper (Cu), tin (Sn), yttrium (Y), phosphor (P), silver (Ag), and strontium (Sr); and   x, y and z are the compositions of 0 at %≦x≦6 at %, 0.8 at %≦y≦7 at %, and 0 at %≦z≦2 at %, respectively.   
     
     
         2 . The magnesium alloy according to  claim 1 , further comprising calcium of 2 at % or less. 
     
     
         3 . The magnesium alloy according to  claim 1 , wherein the misch metal is a didymium-based misch metal or a cerium-based misch metal. 
     
     
         4 . The magnesium alloy according to  claim 3 , wherein the didymium-based misch metal is a rare earth alloy composition including neodymium (Nd) and praseodymium (Pr). 
     
     
         5 . The magnesium alloy according to  claim 3 , wherein the cerium-based misch metal contains 45 wt %≦Ce≦65 wt %, 20 wt %≦La≦30 wt %, 5 wt %≦Nd≦15 wt %, and 0 wt %≦Pr≦10 wt %. 
     
     
         6 . A method of producing a wrought magnesium alloy with a misch metal, the method comprising the steps of:
 fusion-casting a magnesium alloy composition having the formula of Mg 100-x-y-z A x B y C z , where A is zinc (Zn) or aluminum (Al); B is the misch metal; C is at least one element selected from the group consisting of manganese (Mn), nickel (Ni), copper (Cu), tin (Sn), yttrium (Y), phosphor (P), silver (Ag), and strontium (Sr); and x, y and z are the compositions of 0 at %≦x≦6 at %, 0.8 at %≦y≦7 at %, and 0 at %≦z≦2 at %, respectively; and   hot-extruding the cast, and refining grains through granulation and dispersion of other phases than magnesium in the cast, and recrystallization of a matrix.   
     
     
         7 . The method according to  claim 6 , further comprising a step of hot-rolling the hot-extruded product to form a plate. 
     
     
         8 . The method according to  claim 6 , wherein the hot-extruding step is performed under the extrusion conditions of a temperature range from 350° C. to 450° C., and a ratio of reduction in section of 5˜80:1. 
     
     
         9 . The method according to  claim 7 , the hot-rolling step is performed under the rolling conditions of a temperature range from 350° C. to 500° C., and a percentage of single reduction in thickness from 25% to 50%. 
     
     
         10 . A wrought magnesium alloy with a misch metal, produced by the steps of:
 fusion-casting a composition having the formula of Mg 100-x-y-z A x B y C z , where A is zinc (Zn) or aluminum (Al); B is the misch metal; C is at least one element selected from the group consisting of manganese (Mn), nickel (Ni), copper (Cu), tin (Sn), yttrium (Y), phosphor (P), silver (Ag), and strontium (Sr); and x, y and z are the compositions of 0 at %≦x≦6 at %, 0.8 at %≦y≦7 at %, and 0 at %≦z≦2 at %, respectively;   hot-extruding the cast, and refining grains through granulation and dispersion of other phases than magnesium in the cast, and recrystallization of a matrix; and   hot-rolling the hot-extruded product to from a wrought product.   
     
     
         11 . The wrought magnesium alloy according to  claim 10 , wherein the other phases than magnesium have a size of 20 μm or less. 
     
     
         12 . The wrought magnesium alloy according to  claim 10 , wherein the other phases than magnesium are contained from a solid-solution limit to a eutectic point or a hyper-eutectic area.