Abstract: A method for producing a high strength workpiece material includes the steps of: placing an alloy material 10 into a central space of a cylindrical mold 2; vertically compressing both end faces of the material in the central space with a press member 5 and a first support member 3, thereby causing one lengthwise end of the material to flow radially outward along an end face of the cylindrical mold 2 to form an expanded part; bringing the press member 5 into contact with a lengthwise end face of the expanded part so as to press the expanded part against the end face of the cylindrical mold 2; and increasing the distance between the press member 5 and the end face of the cylindrical mold 2 while decreasing the distance between the press member 5 and the first support member 3, thereby continuously causing the radially outward flow from one end to another end of the material to gradually increase the thickness of the expanded part.

Abstract: When starting raw material powder is passed through a pair of rolls (2a), plastic working is applied to the starting raw material powder, and the crystal grain diameter of a metal or alloy constituting a matrix of the powder particle after processed is miniaturized. According to the thus provided alloy powder raw material, the maximum size of the powder particle is not more than 10 mm and the minimum size of the powder particle is not less than 0.1 mm, and the maximum crystal grain diameter of the metal or alloy constituting the matrix of the powder particle is not more than 30 ?m.

Abstract: A raw magnesium alloy powder material having a relatively small crystal grain diameter is obtained by subjecting a starting material powder having a relatively large crystal grain diameter to a plastic working in which the powder is passed through a pair of rolls to undergo compressive deformation or shear deformation. The starting material powder is a magnesium alloy powder having a fine intermetallic compound (21) precipitated and dispersed in a base (22) by a heat treatment. A work strain (22) is formed around the precipitated intermetallic compound (21) in the magnesium alloy powder after processed by the plastic working. The magnesium alloy powder after processed by the plastic working has a maximum size of 10 mm or less and a minimum size of 0.1 mm or more, and the magnesium particle constituting the base (20) has a maximum crystal grain diameter of 20 ?m or less.