Magnesium alloy having high ductility and high toughness, and preparation method thereof

Abstract

A magnesium alloy having high ductility and high toughness, and a preparation method thereof are provided, in which the magnesium alloy includes 1.0-3.5 wt % of tin, 0.05-3.0 wt % of zinc, and the balance of magnesium and inevitable impurities, and a preparation method thereof. Magnesium alloy with a relatively small tin content is added with zinc, and optionally, with one or more alloy elements selected from aluminum, manganese and rare earth metal, at a predetermined content ratio. As a result, the alloy exhibits superior ductility and moderate strength due to the suppression of excessive formation of precipitates and some precipitates hardening effect, respectively. Accordingly, compared to extruded material prepared from conventional commercial magnesium alloys, higher ductility and toughness are provided, so that the alloy can be widely applied over the entire industries including automotive and aerospace industries.

We claim: 
     
         1 . A magnesium alloy having high ductility and high toughness comprising 1.0 to 3.5 wt % tin (Sn), 0.05 to 3.0 wt % zinc (Zn), remainder magnesium (Mg) and unavoidable impurities. 
     
     
         2 . The magnesium alloy as set forth in  claim 1 , wherein the magnesium alloy further comprises one or more alloying elements selected from the group consisting of aluminum (Al), manganese (Mn) and rare earth metal. 
     
     
         3 . The magnesium alloy as set forth in  claim 2 , wherein the aluminum is contained in an amount of 0.05 to 3.0 wt %. 
     
     
         4 . The magnesium alloy as set forth in  claim 2 , wherein the manganese is contained in an amount of 0.05 to 1.5 wt %. 
     
     
         5 . The magnesium alloy as set forth in  claim 2 , wherein the rare earth metal is contained in an amount of 0.05 to 1.5 wt %. 
     
     
         6 . The magnesium alloy as set forth in  claim 2 , wherein the rare earth metal is one or more selected from the group consisting of cerium (Ce), yttrium (Y) and gadolinium (Gd). 
     
     
         7 . A preparation method of a magnesium alloy having high ductility and high toughness, comprising:
 melting magnesium alloy raw material (Step 1);   casting the melt of magnesium alloy raw material of Step 1 (Step 2);   homogenizing the cast of magnesium alloy of Step 2 (Step 3); and   working the homogenized magnesium alloy cast of Step 3 (Step 4).   
     
     
         8 . The preparation method as set forth in  claim 7 , wherein the magnesium alloy raw material of Step 1 comprises 1.0 to 3.5 wt % tin (Sn), 0.05 to 3.0 wt % zinc (Zn), remainder magnesium (Mg) and unavoidable impurities. 
     
     
         9 . The preparation method as set forth in  claim 7 , wherein the magnesium alloy raw material of Step 1 further comprises: 0.05 to 3.0 wt % aluminum (Al); 0.05 to 1.5 wt % manganese (Mn); and 0.05 to 1.5 wt % rare earth metal. 
     
     
         10 . The preparation method as set forth in  claim 9 , wherein the rare earth metal is one or more selected from the group consisting of cerium (Ce), yttrium (Y) and gadolinium (Gd). 
     
     
         11 . The preparation method as set forth in  claim 7 , wherein the casting of Step 2 is performed at a temperature range of 650° C. to 750° C. 
     
     
         12 . The preparation method as set forth in  claim 7 , wherein the homogenizing of Step 3 comprises heat treatment at a temperature range of 400° C. to 550° C. for a duration of 0.5 hr to 96 hr, and quenching. 
     
     
         13 . The preparation method as set forth in  claim 12 , wherein the homogenizing of Step 3 is performed after pre-heating at a temperature range of 250° C. to 350° C. 
     
     
         14 . The preparation method as set forth in  claim 7 , wherein the working of Step 4 is performed after pre-heating at a temperature range of 200° C. to 450° C. 
     
     
         15 . The preparation method as set forth in  claim 7 , wherein the preparation method further comprises a step of performing aging treatment after Step 4. 
     
     
         16 . The preparation method as set forth in  claim 15 , wherein the aging treatment is performed at a temperature range of 150° C. to 250° C. for a duration of 1 hr to 360 hr. 
     
     
         17 . A magnesium alloy having high ductility and high toughness prepared by the method as set forth in  claim 7 .