Patent ID: 8852363

Claim:
A magnesium alloy sheet material, being a sheet material comprising magnesium alloy, wherein: (a) the magnesium alloy forms a matrix that contains hard particles; and (b) when in the thickness direction of the sheet material, a region from each surface of the sheet material to a position away from the surface by 40% of the thickness of the sheet material is defined as a surface region and the remaining region is defined as the center region, hard particles existing in the center region have a maximum diameter of 40 μm or more and less than 50 μm and hard particles existing in the surface region have a maximum diameter of 20 μm or less, and wherein the hard particles include Al—Mg-family precipitated substances, Al—Mn-family precipitated substances, Mg—Zn-family precipitated substances, boron nitride, or diamond, and the diameter of the hard particles is smaller in the surface region than at the center region by at least controlling the cooling conditions in a casting step carried out during a production of the magnesium alloy sheet material.