Insert and cutting tool
AssigneeNgk Spark Plug Co., Ltd.
InventorsRyoji Toyoda, Yusuke Suzuki, Yuki Hatano
Life of this patent
Estimating the term…
Abstract
An insert includes a silicon nitride sintered body including β-Si3N4 as a main component, Mg, and a rare-earth element Re (Y, La, Ce, Er, Dy, Yb). A content of Mg in terms of MgO is 1.0-7.0 mol %, a content of Re in terms of an oxide thereof is 0.4-1.0 mol %, and a total content of Mg and Re is from 1.7 to less than 7.5 mol %. The insert has a graded composition in which oxygen content increases from a surface of the sintered body toward an inside thereof such that 0.8-1.5 mass % of oxygen is contained in a region of less than 0.5 mm inside from the surface, 1.1-2.3 mass % of oxygen is contained in a region of 0.5 mm or more inside from the surface, and a difference in oxygen content between the regions is 0.1-1.0 mass %.
Claims7
An insert comprising:
- a silicon nitride sintered body, including
- β-Si3N4 as a main component;
- Mg;
- and
- a rare-earth element Re (Y, La, Ce, Er, Dy, Yb),
- a content of Mg in terms of MgO being 1.0-7.0 mol %, a content of Re in terms of an oxide thereof being 0.4-1.0 mol %, and a total content of Mg and Re being from 1.7 to less than 7.5 mol %,
- wherein the insert has a graded composition in which oxygen content increases from a surface of the sintered body toward an inside thereof such that 0.8-1.5 mass % of oxygen is contained in a region of less than 0.5 mm inside from the surface, 1.1-2.3 mass % of oxygen is contained in a region of 0.5 mm or more inside from the surface, and a difference in oxygen content between the regions is 0.1-1.0 mass %.
A cutting tool comprising:
- a holder;
- and
- an insert attached to the holder, the insert including:
- β-Si3N4 as a main component;
- Mg;
- and
- a rare-earth element Re (Y, La, Ce, Er, Dy, Yb),
- a content of Mg in terms of MgO being 1.0-7.0 mol %, a content of Re in terms of an oxide thereof being 0.4-1.0 mol %, and a total content of Mg and Re being from 1.7 to less than 7.5 mol %,
- wherein the insert has a graded composition in which oxygen content increases from a surface of the sintered body toward an inside thereof such that 0.8-1.5 mass% of oxygen is contained in a region of less than 0.5 mm inside from the surface, 1.1-2.3 mass% of oxygen is contained in a region of 0.5 mm or more inside from the surface, and a difference in oxygen content between the regions is 0.1-1.0 mass%.
Dependencies are inferred from the claim text.