| 摘要 |
A drill bit matrix is provided that contains a powdered abrasive material and a refractory metal powder in which the refractory metal powder is a coated powder in which each granule of the refractory metal powder is coated by a coating material. A core drill bit is further provided, containing a powdered abrasive material, a refractory metal powder and a steel tube onto which the powdered abrasive material and refractory metal powder are alloyed. The refractory metal powder is a coated powder in which each granule of the refractory metal powder is coated by one or more coating materials. A method is finally provided for manufacturing a core drill bit. First a matrix is formed by mixing together a powdered abrasive material and a coated refractory metal powder. The matrix is placed in a mould and a steel tube is placed on top of the mould to form a drill bit assembly. The drill bit assembly is then heated under atmospheric conditions. The steel tube is then hot pressed into the heated matrix and the drill bit assembly is allowed to cool before releasing the cooled drill bit from the mould. |
