Method for toughening surface of sinterred material cutting tool and sintered material cutting tool having long life
AssigneesJapan Science and Technology Agency, National University Corporation Nagoya University, Sintokogio, Ltd.
InventorsHiroyasu Saka, Won-Jin Moon, Shouji Uchimura, Toshiro Ito
Life of this patent
Estimating the term…
Abstract
A ceramics sintered material cutting tool, characterizing in that it has a dislocation structure which formed on the surface thereof in a straight line from and distributed uniformity in a dislocation density of 1×104 to 9×1013 cm−2. The cutting tool is improved in a fracture toughness value and the resistance to thermal shock and thus has a prolonged life. The above cutting tools include, in particular, a twist drill and a throw away tip.
Claims5
A method for surface toughening of a ceramics sintered material cutting tool comprising, forming uniformly distributed linear dislocation structure in the sub-surface regions of the ceramics sintered material cutting tool by using abrasives composed of fine particles having convexly curved surface and having an average particle size of 0.1 μm to 200 μm and a Vickers hardness (HV) of 500 or more and a hardness (HV) of +50 or less which is the hardness of said sintered material cutting tool.
A long life ceramics sintered material cutting tool possessing a structure whose dislocation density of uniformly distributed linear dislocation structure in the sub-surface regions of the ceramics sintered material cutting tool is in the range of from 1×104 to 9×1013 cm−2.
Dependencies are inferred from the claim text.