| 摘要 |
A blank adapted to be mounted on a substrate to form a cutting insert is formed by preparing a crystal dispersion of super-hard crystals, such as diamond or cubic boron nitride crystals, and carbon black in a temporary binder, and a core dispersion of carbon fiber, carbon black and filler in a temporary binder. The crystal dispersion and the core dispersion are placed in a mold to respectively form a core dispersion layer and a crystal dispersion layer which forms a ring about the periphery of the core dispersion layer on the upper surface thereof. The crystal and core dispersion layers are compacted with a chamfered plunger applied to the lower surface of the core layer to form an intermediate composite having a recess at the lower surface thereby compressing the dispersions to a substantially uniform compaction throughout the intermediate composite. The intermediate composite is then heated to allow for the removal of the temporary binder and the infiltration of liquified silicon. The intermediate composite is then sintered to produce the blank, the crystal and core layers being bonded internally and to each other by a matrix of beta -silicon carbide and silicon.
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