A thin plate-shaped substrate molding device for pressing molding a pre-molded article to a prescribed irregular shape. The thin plate-shaped substrate molding device comprises a first die, a second die, a plurality of tensioning portions and a controller. The first and second dies are movably disposed to be moved towards and away from each other. The second die has protruding portions that protrude towards the first die for forming stretched portions and forming bent portions. The controller controls the first die, the second die and the tensioning portions. The bent portions are tensioned and stretched by the tensioning portions, while the stretched portions of the pre-molded article are still pressed by the first die and the protruding portions of the second die, to impart the shape of the protruding portions to the pre-molded article along the side edges of the protruding portions.

A thin plate-shaped substrate molding device for pressing molding a pre-molded article to a prescribed irregular shape. The thin plate-shaped substrate molding device comprises a first die, a second die, a plurality of tensioning portions and a controller. The first and second dies are movably disposed to be moved towards and away from each other. The second die has protruding portions that protrude towards the first die for forming stretched portions and forming bent portions. The controller controls the first die, the second die and the tensioning portions. The bent portions are tensioned and stretched by the tensioning portions, while the stretched portions of the pre-molded article are still pressed by the first die and the protruding portions of the second die, to impart the shape of the protruding portions to the pre-molded article along the side edges of the protruding portions.

A sheet metal blank is formed into a helical turbine blade by stretching an outer portion of the blank by creating indents and detents thereon. Then the stretched side is flattened and the stretched structure is formed into a helical shape.

A sheet metal blank is formed into a helical turbine blade by stretching an outer portion of the blank by creating indents and detents thereon. Then the stretched side is flattened and the stretched structure is formed into a helical shape.