Magnesium alloy

Abstract

The present invention relates to a magnesium alloy having controlled corrosion resistance properties, which comprises magnesium (Mg) and an alloying element and includes a magnesium phase and a phase composed of magnesium and the alloying element, wherein the difference in electrical potential between the magnesium phase and the phase composed of magnesium and the alloying element is greater than 0 V but not greater than 0.2 V.

1 . A magnesium alloy having controlled corrosion resistance properties, which comprises magnesium (Mg) and an alloying element and includes a magnesium phase and a phase composed of magnesium and the alloying element, wherein the difference in electrical potential between the magnesium phase and the phase composed of magnesium and the alloying element is greater than 0 V but not greater than 0.2 V. 
     
     
         2 . The magnesium alloy of  claim 1 , wherein the magnesium alloy contains no aluminum. 
     
     
         3 . The magnesium alloy of  claim 1 , wherein the magnesium alloy contains no rare earth element. 
     
     
         4 . The magnesium alloy of  claim 1 , wherein the alloying element is one or more selected from among calcium (Ca), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), chromium (Cr), copper (Cu), cadmium (Cd), zirconium (Zr), silver (Ag), gold (Au), palladium (Pd), platinum (Pt), rhenium (Re), iron (Fe), zinc (Zn), molybdenum (Mo), niobium (Nb), tantalum (Ta), titanium (Ti), strontium (Sr), silicon (Si), phosphorus (P) and selenium (Se). 
     
     
         5 . The magnesium alloy of  claim 1 , wherein the magnesium alloy is represented by the following formula 1:
   Mg a Ca b X c   [Formula 1]
   
       wherein a, b and c represent the molar fractions of the respective components, a+b+c=1, 0.5≦a<1, 0≦b≦0.4, and 0≦c≦0.4; if at least one of b and c is greater than 0 and c is 0, the content of Ca is 5-33 wt % based on the total weight of the magnesium alloy; and X is one or more selected from among zirconium (Zr), molybdenum (Mo), niobium (Nb), tantalum (Ta), titanium (Ti), strontium (Sr), chromium (Cr), manganese (Mn), zinc (Zn), silicon (Si), phosphorus (P), nickel (Ni) and iron (Fe). 
     
     
         6 . The magnesium alloy of  claim 1 , wherein the magnesium alloy is represented by the following formula 2 and comprises, based on the total weight thereof, greater than 0 wt % but not greater than 23 wt % of calcium (Ca), greater than 0 wt % but not greater than 10 wt % of Y, and a balance of magnesium (Mg):
   Mg—Ca—Y  [Formula 2]
   
       wherein Y is Mn or Zn. 
     
     
         7 . The magnesium alloy of  claim 1 , wherein the magnesium alloy is represented by the following formula 3 and comprises, based on the total weight thereof, greater than 0 wt % but not greater than 40 wt % of Z and a balance of magnesium (Mg):
   Mg—Z  [Formula 3]
   
       wherein Z is one or more selected from among manganese (Mn), cobalt (Co), nickel (Ni), chromium (Cr), copper (Cu), cadmium (Cd), zirconium (Zr), silver (Ag), gold (Au), palladium (Pd), platinum (Pt), rhenium (Re), iron (Fe), zinc (Zn), molybdenum (Mo), niobium (Nb), tantalum (Ta), titanium (Ti), strontium (Sr), silicon (Si), phosphorus (P) and selenium (Se). 
     
     
         8 . The magnesium alloy of  claim 1 , wherein the magnesium alloy is surface-treated. 
     
     
         9 . A method for preparing a magnesium alloy having controlled corrosion resistance properties, the method comprising adding, to a magnesium alloy comprised of magnesium and an alloying element, a third element, thereby reducing the difference in electrical potential between a magnesium phase and a phase composed of magnesium and the alloying element to greater than 0 V but not greater than 0.2 V. 
     
     
         10 . The method of  claim 9 , wherein the magnesium alloy comprises magnesium and calcium, and the third element is zinc.