Method for increasing the corrosion resistance of a component formed of a magnesium-based alloy against galvanic corrosion, and corrosion-resistant component obtainable by said method

Abstract

The invention relates to a method for increasing a corrosion resistance of a component formed with a magnesium-based alloy against galvanic corrosion, in particular micro-galvanic corrosion. According to the invention, an increase in a corrosion resistance against galvanic corrosion is achieved in a simple manner in that a surface layer of the component having a predefined thickness, which surface layer is formed with the magnesium-based alloy, is heated in order to configure the surface layer with a homogenized solid solution phase, whereupon the surface layer is cooled such that the surface layer is formed with a supersaturated solid solution phase. The invention furthermore relates to a corrosion-resistant component which is obtainable by a method of this type.

1 . A method for increasing a corrosion resistance of a component formed with a magnesium-based alloy against galvanic, in particular micro-galvanic, corrosion, wherein a surface layer of the component having a predefined thickness, which surface layer is formed with the magnesium-based alloy, is heated in order to configure the surface layer with a homogenized solid solution phase, whereupon the surface layer is cooled such that the surface layer is formed with a supersaturated solid solution phase. 
     
     
         2 . The method according to  claim 1 , wherein the surface layer is maximally heated up to a liquidus temperature of the magnesium-based alloy, in particular maximally up to 0.9 times a liquidus temperature of the magnesium-based alloy. 
     
     
         3 . The method according to  claim 1 , wherein the surface layer is cooled at a cooling rate of more than 10 K/s. 
     
     
         4 . The method according to  claim 1 , wherein the thickness of the surface layer is set to less than approximately 5 mm. 
     
     
         5 . The method according to  claim 1 , wherein the surface layer is heated using an electric arc in particular a welding arc, or by induction. 
     
     
         6 . The method according to  claim 1 , wherein the thickness of the surface layer is set by the power supplied for heating the surface layer. 
     
     
         7 . The method according to  claim 1 , wherein a cooling of the surface layer is carried out with a gas flow or with a liquid bath. 
     
     
         8 . The method according to  claim 1 , wherein the magnesium-based alloy contains aluminum as the second-largest amount in addition to magnesium as the main amount. 
     
     
         9 . A corrosion-resistant component, formed with a magnesium-based alloy, which corrosion-resistant component is obtainable in particular by a method according to  claim 1 , wherein the corrosion-resistant component comprises a surface layer having a defined thickness as well as an inner region adjoining the surface layer, which surface layer and inner region are formed with the magnesium-based alloy, wherein the surface layer is formed with a supersaturated solid solution phase and the surface layer and inner region have a different phase structure. 
     
     
         10 . The corrosion-resistant component according to  claim 9 , wherein the thickness of the surface layer is less than approximately 5 mm. 
     
     
         11 . The corrosion-resistant component according to  claim 1 , wherein the magnesium-based alloy contains aluminum as the second-largest amount in addition to magnesium as the main amount. 
     
     
         12 . The method according to  claim 1 , wherein the surface layer is cooled at a cooling rate of more than 20 K/s. 
     
     
         13 . The method according to  claim 1 , wherein the thickness of the surface layer is set to between 0.1 mm and 3.0 mm. 
     
     
         14 . The method according to  claim 1 , wherein the surface layer is heated using a welding arc or by induction. 
     
     
         15 . The corrosion-resistant component according to  claim 9 , wherein the thickness of the surface layer is between 0.1 mm and 3.0 mm.