Patent ID: 8522645

Claim:
A blade member comprising a plurality of blade groups, the blade groups each containing a laminate of a plurality of blades arranged in a horizontal direction; edges of blades of the blade groups having an evenly sharpened and hardened layer along an entire edge line of the edges to the depth of 0.1 to 1.5 μm from a pointed end of the edge and to a depth of 0.1 to 1.5 μm in a thickness direction of the edge by ion beam treatment and plasma ion implantation; the edges of the blades of the blade groups prior to the ion beam treatment and plasma ion implantation initially having an edge angle of 10 to 35 degrees and a burr height of 0.1 to 10 μm, and while the plurality of blade groups rotate and orbit relative to each other, the edges of the group of blades are: subjected to ion beam treatment using a plasma ion gun, in which argon is used as a medium, and subjected to ion plasma implantation of nitrogen plasma using a plasma ion implantation gun in a vacuum chamber, in which the pressure of the nitrogen is 0.5 to 5 Pa, a bias voltage applied to the blade group is 0.1 to 1000 V, a filament current is 100 to 200 A, and the processing time is 10 to 1000 minutes, resulting in the edges of the blades of the blade groups having the evenly sharpened and hardened layer along the entire edge line of the edges to the depth of 0.1 to 1.5 μm from the pointed end of the edge and to the depth of 0.1 to 1.5 μm in the thickness direction of the edge.