| 摘要 |
<p>Provided is a cutting tool constituted of a sintered cermet having high toughness and thermal shock resistance. The cutting tool is constituted of a sintered cermet composed of rigid phases (11) comprising one or more members selected from carbides, nitrides, and carbonitrides each containing titanium as a major component and a bonding phase (14) comprising at least one of cobalt and nickel. The tool is a chip (1) having a cutting blade (4), which is the edge where a rake face (2) and a relief face (3) intersect, and having noses (5) formed thereon. The rigid phases (11) are composed of two phases, i.e., a first rigid phase (12) and a second rigid phase (13). When the rake face (2) is examined for residual stress by the 2-D method, the first rigid phase (12) has a residual stress (s11[1r]) of 50 MPa or lower in terms of compressive stress in the direction (direction s11) which is parallel to the rake surface (2) and to the direction extending from the center of the rake face (2) to the nose located nearest to the examination point (s11[1r] = -50 to 0 MPa), and the second rigid phase (13) has a residual stress (s11[2r]) of 150 MPa or higher in terms of compressive stress in the direction (s11) (s11[2r]=-150 MPa).</p> |
