ALEXANDRIA, Va., July 16 -- United States Patent no. 12,358,843, issued on July 15, was assigned to NTK CUTTING TOOLS Co. LTD. (Komaki, Japan).
"Cutting tool" was invented by Tatsuya Toda (Nagoya, Japan), Takuya Furuhashi (Nagoya, Japan) and Ryoji Toyoda (Nagoya, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A cutting tool (1) formed of a silicon nitride-based sintered body (2) including a matrix phase (3), a hard phase (4), and a grain boundary phase (10) in which a glass phase (11) and a crystal phase (12) exist. The sintered body (2) contains yttrium in an amount of 5.0 wt % to 15.0 wt % in terms of an oxide, and contains titanium nitride as the hard phase (4) in an amount of 5.0 wt % to 25.0 wt %....