Magnesium alloy and method of manufacturing a seat frame for an automobile using the same

Abstract

The present invention provides a magnesium alloy used in manufacturing a seat frame for an automobile and a method for manufacturing the seat frame using the same. More specifically, this invention provides a novel extrusion technology as well as a bending technology for manufacturing an automobile seat frame using an extruded magnesium alloy with superior absorptivion against vibration and shock while also providing a 25-35% improvement in weight reduction over aluminum alloy products and a 60-70% improvement in weight reduction over conventional steel products.

1 . A method of manufacturing a seat frame using magnesium alloy comprising the steps of: 
 (a) manufacturing an extruded billet by melting AZ31 magnesium alloy by loading said AZ31 magnesium alloy into a stainless steel furnace at a predetermined temperature, thereby forming a molten AZ31 magnesium alloy, and then solidifying said AZ31 magnesium alloy by water-cooling;    (b) manufacturing an extruded magnesium alloy having a certain shape from said extruded billet by adjusting a mold temperature, a container temperature, and a billet temperature; and    (c) molding said extruded magnesium alloy into a shape of a seat frame via a bending process as well as a stretching process.    
     
     
         2 . The method of  claim 1 , wherein said step of manufacturing an extruded billet further comprises a coating process wherein a gas mixture of CO 2  and SF 6  is continuously sprayed on a surface of said molten AZ31 magnesium alloy to prevent oxidation.  
     
     
         3 . The method of  claim 1 , wherein said mold temperature, said container temperature, and said billet temperature are set at a range of about 250-450° C. and a ram speed is set at a range of about 0.5-5 inch/min.  
     
     
         4 . The method according to claims  1  or  3 , wherein said extruded magnesium alloy is formed into a U-shape, I-shape, or a rectangular shape.  
     
     
         5 . The method of  claim 1 , wherein said bending process is performed at about 250-450° C. and said stretching process is performed at a pressure of about 200-350 kg f .  
     
     
         6 . A magnesium alloy comprising: 
 (a) magnesium as a major component;    (b) an AZ31 alloy comprising about 2.5 to 3.5 weight % of aluminum, about 0.6 to about 1.4 weight % of zinc, and about 0.2 to about 1.0 weight % of manganese; and    (c) an AZ61 alloy comprising about 5.8 to about 7.2 weight % of aluminum, about 0.04 to about 1.5 weight % of zinc, and about 0.15 to about 0.5 weight % of manganese.