Magnesium alloy material and manufacturing method therefor

Abstract

Provided is a magnesium alloy material and a method for manufacturing the same. The magnesium alloy material includes: 0.8 to 1.8 wt % of Mn, 0.2 wt % or less (excluding 0 wt %) of Ca and the balance of Mg and inevitable impurities, for a total of 100 wt %. The magnesium alloy material has a recrystallized structure of 99 vol % or more for 100 vol % of the total microstructure of the magnesium alloy material.

1 . A magnesium alloy material containing 0.8 to 1.8 wt % of Mn, 0.2 wt % or less (excluding 0 wt %) of Ca and the balance of Mg and inevitable impurities, for a total of 100 wt %,
 wherein the magnesium alloy material has a recrystallized structure of 99 vol % or more for 100 vol % of the total microstructure of the magnesium alloy material.   
     
     
         2 . The magnesium alloy material according to  claim 1 , wherein an average diameter of the grains of the magnesium alloy material is 10 μm to 20 μm. 
     
     
         3 . The magnesium alloy material according to  claim 2 , wherein a thermal conductivity of the magnesium alloy material is 135 W/mK or more. 
     
     
         4 . A method for manufacturing a magnesium alloy material comprising the steps of continuously casting a molten alloy comprising 0.8 to 1.8 wt % of Mn, 0.2 wt % or less (excluding 0 wt %) of Ca and the balance of Mg and inevitable impurities, for a total of 100 wt %, to prepare a billet;
 subjecting the billet to homogenizing heat treatment;   preheating the homogenizing heat-treated billet;   hot extruding the preheated billet to manufacture an extruded material; and   subjecting the manufactured extruded material to heat treatment.   
     
     
         5 . The method for manufacturing a magnesium alloy material according to  claim 4 , wherein the step of subjecting the manufactured extruded material to heat treatment is a heat treatment at a temperature in the range of 200° C. to 400° C. 
     
     
         6 . The method for manufacturing a magnesium alloy material according to  claim 5 , wherein the step of subjecting the manufactured extruded material to heat treatment, is a heat treatment for 0.5 to 2 hours. 
     
     
         7 . The method for manufacturing a magnesium alloy material according to  claim 4 , wherein the step of hot extruding the preheated billet to manufacture an extruded material is a hot extrusion by a direct extrusion method. 
     
     
         8 . The method for manufacturing a magnesium alloy material according to  claim 7 , wherein the step of hot extruding the preheated billet to manufacture an extruded material is a hot extrusion at a temperature in the range of 350° C. to 550° C. 
     
     
         9 . The method for manufacturing a magnesium alloy material according to  claim 8 , wherein the step of hot extruding the preheated billet to manufacture an extruded material is a hot extrusion at a rate of 10 to 30 mpm. 
     
     
         10 . The method for manufacturing a magnesium alloy material according to  claim 4 , wherein the step of preheating the homogenizing heat-treated billet is a preheating in indirect heating type heating furnace. 
     
     
         11 . The method for manufacturing a magnesium alloy material according to  claim 10 , wherein the step of preheating the homogenizing heat-treated billet is a preheating to a temperature in the range of 350° C. to 550° C. 
     
     
         12 . The method for manufacturing a magnesium alloy material according to  claim 4 , wherein the step of subjecting the billet to homogenizing heat treatment is a homogenizing heat treatment at a temperature in the range of 400° C. to 500° C. 
     
     
         13 . The method for manufacturing a magnesium alloy material according to  claim 12 , wherein the step of subjecting the billet to homogenizing heat treatment is a homogenizing heat treatment for 10 hours to 16 hours. 
     
     
         14 . The method for manufacturing a magnesium alloy material according to  claim 4 , wherein the step of continuously casting a molten alloy comprising 0.8 to 1.8 wt % of Mn, 0.2 wt % or less (excluding 0 wt %) of Ca and the balance of Mg and inevitable impurities, for a total of 100 wt %, to prepare a billet is a continuous casting at a temperature in the range of 650° C. to 750° C. 
     
     
         15 . The method for manufacturing a magnesium alloy material according to  claim 14 , wherein the step of continuously casting a molten alloy comprising 0.8 to 1.8 wt % of Mn, 0.2 wt % or less (excluding 0 wt %) of Ca and the balance of Mg and inevitable impurities, for a total of 100 wt %, to prepare a billet is a continuous casting at a rate of 50 to 150 mm/min. 
     
     
         16 . The method for manufacturing a magnesium alloy material according to  claim 4 , wherein the magnesium alloy material has a recrystallized structure of 99 vol % or more for 100 vol % of the total microstructure of the magnesium alloy material. 
     
     
         17 . The method for manufacturing a magnesium alloy material according to  claim 4 , wherein an average diameter of the grains of the magnesium alloy material is 10 μm to 20 μm. 
     
     
         18 . The method for manufacturing a magnesium alloy material according to  claim 4 , wherein a thermal conductivity of the magnesium alloy material is 135 W/mK or more.