Case made of magnesium alloy

Abstract

The present invention provides a high-quality magnesium alloy case having a complex shape in which formability is ensured by specifying the composition of the magnesium alloy and setting the amount of internal impurities to an appropriate value or below, and the present invention is a magnesium alloy case comprising a superplastica body formed by the superplastic forming of a magnesium alloy sheet material, which is containing 1.0 to 10.0 mass % of aluminum, 0.5 to 3.0 mass % of zinc, and 0.1 to 0.8 mass % of manganese as a part of added alloy elements and has an oxygen concentration of 300 mass ppm or less, and the case having a structure being inhibited in cavity formation during the superplastic forming, and in accordance with the present invention, it is possible to manufacture and provide a magnesium alloy case having a complex shape through superplastic forming by accurately regulating the composition and impurities content of the magnesium alloy sheet material. The magnesium alloy case in accordance with the present invention can be actively applied, for example, to cases of household electronic products.

1 . A magnesium alloy case characterized by comprising a superplastic body formed through the superplastic forming of a magnesium alloy sheet material, which is containing 1.0 to 10.0 mass % of aluminum, 0.5 to 3.0 mass % of zinc, and 0.1 to 0.8 mass % of manganese as a part of added alloy elements and has an oxygen concentration of 300 mass ppm or less and the case having a structure being inhibited in cavity formation during the superplastic forming is inhibited. 
   
   
       2 . The magnesium alloy case according to  claim 1 , wherein the case comprises a superplastically formed body of the magnesium alloy sheet material having an oxygen concentration of 100 mass ppm or less. 
   
   
       3 . The magnesium alloy case according to  claim 1  or  2 , wherein some portions of the magnesium alloy sheet material are formed through the superplastic forming. 
   
   
       4 . The magnesium alloy case according to  claim 3 , wherein the superplastic forming is a deep drawing. 
   
   
       5 . The magnesium alloy case according to  claim 3 , wherein the superplastic forming is a stretch forming. 
   
   
       6 . The magnesium alloy case according to  claim 3 , wherein the superplastic forming is a blow forming. 
   
   
       7 . The magnesium alloy case according to any one of  claims 1  to  6 , wherein some crystal grains of the magnesium alloy case have a size of 20 μm or less. 
   
   
       8 . A lightweight structural member characterized by comprising the magnesium alloy case defined in any one of  claims 1  to  7 .