SCALPEL BLADE HAVING HIGH SHARPNESS AND TOUGHNESS

摘要

A scalpel blade (20) is made by depositing a coating (32) onto a tapered region (26) of a substrate (22) which is tapered with an included angle of from about 10 to about 25 degrees to an edge. The substrate (22) is made of surgical-grade stainless steel hardened to a Rockwell C hardness of at least 54 and then annealed to a Rockwell C hardness of from about 46 to less than about 53. The coating (32) overlying the tapered region (26) has a thickness of from about 0.1 to about 2.5 micrometers and includes a first coating layer (34) of a first metal, and a second coating layer (36) overlying the first coating layer (34). The first coating layer (34) is preferably zirconium or a zirconium-base alloy, and the second coating layer (36) is preferably zirconium nitride. The edge may be atomically sharpened by applying a large negative voltage to the substrate (22) relative to the deposition source while a portion of the thickness of the second coating layer (36) is being deposited.