Thixomolding material, method for manufacturing thixomolding material, and thixomolded article

Abstract

A thixomolding material includes: a metal body that contains Mg as a main component; and a coating portion that is adhered to a surface of the metal body via a binder and contains Si particles containing Si as a main component. An average particle diameter of the Si particles is 1 μm or more and 100 μm or less, and a mass fraction of the Si particles in a total mass of the metal body and the Si particles is 1.0 mass % or more and 30.0 mass % or less. The binder may contain waxes. A content of the binder may be 0.001 mass % or more and 0.200 mass % or less.

What is claimed is: 
     
         1 . A thixomolding material comprising:
 a metal body that contains Mg as a main component; and   a coating portion that is adhered to a surface of the metal body via a binder and contains Si particles containing Si as a main component, wherein   an average particle diameter of the Si particles is 1 μm or more and 100 μm or less, and   a mass fraction of the Si particles in a total mass of the metal body and the Si particles is 1.0 mass % or more and 30.0 mass % or less.   
     
     
         2 . The thixomolding material according to  claim 1 , wherein the binder contains waxes. 
     
     
         3 . The thixomolding material according to  claim 1 , wherein a content of the binder is 0.001 mass % or more and 0.200 mass % or less. 
     
     
         4 . A method for manufacturing a thixomolding material, comprising:
 a preparation step of preparing a mixture containing a metal body containing Mg as a main component, Si particles containing Si as a main component, a binder, and a solvent;   a stirring step of stirring the mixture; and   a debindering step of removing, by heating the stirred mixture, at least a part of the binder contained in the mixture to obtain a thixomolding material, wherein   a mass fraction of the Si particles in a total mass of the metal body and the Si particles is 1.0 mass % or more and 30.0 mass % or less, and   a content of the binder in the thixomolding material is 0.001 mass % or more and 0.200 mass % or less.   
     
     
         5 . A thixomolded article comprising:
 a matrix portion that contains Mg as a main component; and   a particle portion that is dispersed in the matrix portion and contains Mg 2 Si as a main component, wherein   a maximum particle diameter of the particle portion is 1.0 μm or more and 50.0 μm or less, and   when observing a cross section, |As−Ac|/Ac is 30.0% or less where As [%] is an area fraction of the particle portion in a range of 500 μm square starting from a surface, and Ac [%] is an area fraction of the particle portion in a range of 500 μm square centered on a point at a depth of 1 mm from the surface.   
     
     
         6 . The thixomolded article according to  claim 5 , wherein an average aspect ratio of the particle portion is 3.0 or less. 
     
     
         7 . The thixomolded article according to  claim 5 , wherein
 a tensile strength is 100 MPa or more and 350 MPa or less, and   a Young's modulus is 44 GPa or more and 80 GPa or less.