Quasicrystalline phase-reinforced Mg-based metallic alloy with high warm and hot formability and method of making the same

Abstract

Disclosed is a quasicrystalline phase-reinforced Mg-based metallic alloy with high warm and hot formability, and making method thereof. The metallic alloy comprises a composition of Mg-1˜10 at % Zn-0.1˜3 at % Y, in which a two-phase region consisting of a quasicrystalline phase and a magnesium-based solid solution phase exists. Constituting a matrix structure, the Mg-based solid solution phase (α-Mg) is formed as a primary solid phase upon solidification. The quasicrystalline phase serves as a second phase and forms, together with the Mg-based solid solution phase, a eutectic phase, thereby reinforcing the matrix. The materials obtained through the hot rolling or extrusion of the cast alloy have an increased volume % of the second phase and thus show significantly increased strength.

What is claimed is:  
     
         1 . A quasicrystalline phase-reinforced magnesium-based metallic alloy with warm and hot formability, comprising a composition of 1-10 at % Zn, 0.1-3 at % Y and the remainder Mg, in which a two-phase region consisting of a quasicrystalline phase and a metal solid solution phase exists.  
     
     
         2 . The quasicrystalline phase-reinforced magnesium-based metallic alloy as set forth in  claim 1 , wherein the amount of the quasicrystalline phase is 30% by volume or less.  
     
     
         3 . A method of making a quasicrystalline phase-reinforced magnesium-based metallic alloy, comprising the steps of: 
 casting a quasicrystalline phase-reinforced magnesium-based metallic alloy consisting of 1-10 at % Zn, 0.1-3 at % Y, and the remainder Mg into a mass, in which a two-phase region consisting of a quasicrystalline phase and a metal solid solution phase exists; and    warm or hot forming the mass to separate and disperse quasicrystalline particles throughout the matrix, so as to provide the quasicrystalline phase-reinforced magnesium-based metallic alloy with improved strength and elongation.    
     
     
         4 . The method as set forth in  claim 3 , further comprising the step of forming the warm- or hot-formed mass into a final product at the temperatures higher than one third of the melting temperature to further homogeneously distribute the quasicrystalline particles.  
     
     
         5 . The method as set forth in  claim 3 , wherein the warm or hot forming step is carried out at a temperature ranging from half the melting point to the melting point and the quasicrystalline phase is present in an amount of 30% by volume or less.