| 摘要 |
A drill is formed by a hard dispersed phase of WC and a B-1 type solid solution, and a bond metal phase of an iron family metal. The composition of the hard dispersed phase is expressed as (WaMb)(CxNy), where M represents Ti, or two or more metals, including Ti but excluding W, selected from the groups IVa, Va and VIa of the periodic table, and a, b, x and y represent molar fractions which are defined by relational expressions of a + b = 1, x + y = 1, x > 0, y >/= 0 and b >/= 0.4. The bond metal phase occupies at least 13 volume percent and not more than 30 volume percent of the cemented carbide. |
