초록 ▼

The invention is a process for preparing a sintered polycrystalline compact of cubic boron nitride (CBN) with substantial intercrystalline bonding, together with the compact produced by the process. A carbon containing material, such as diamond or graphite, is added to a binder material which compri

The invention is a process for preparing a sintered polycrystalline compact of cubic boron nitride (CBN) with substantial intercrystalline bonding, together with the compact produced by the process. A carbon containing material, such as diamond or graphite, is added to a binder material which comprises elemental silicon. The carbon from the carbon containing material reacts with the silicon to form silicon carbide. Having silicon carbide as a constituent of the final product is preferable to having elemental silicon because the silicon carbide does not expand on cooling, and is also harder and more wear resistant than elemental silicon. In this way, the benefits of using elemental silicon in a binder system to enhance intercrystalline bonding of the CBN are realized while avoiding the disadvantages otherwise present. Another advantage is provided in the compact of this invention may be cut into precision shapes with a conventional Electric Discharge Machine (EDM).

대표청구항 ▼

A process for preparing a sintered polycrystalline CBN compact with substantial intercrystalline bonding which comprises: forming a mixture of grains of CBN with a minor amount of a binder material comprised of silicon, and a carbon containing material, wherein the amount of carbon containing materi

A process for preparing a sintered polycrystalline CBN compact with substantial intercrystalline bonding which comprises: forming a mixture of grains of CBN with a minor amount of a binder material comprised of silicon, and a carbon containing material, wherein the amount of carbon containing material is selected so as to provide an atomic ratio of carbon to silicon which is between 1:2 to 2:1; subjecting the mixture to elevated temperature and pressure conditions at which the CBN is thermodynamically stable; and maintaining the elevated conditions for a time sufficient to allow for substantial intercrystalline bonding to thereby sinter the compact. A process for preparing a sintered polycrystalline CBN compact with substantial intercrystalline bonding which comprises: forming a mixture of grains of CBN with a minor amount of a binder material consisting essentially of silicon, a carbon containing material, and an aluminum-containing material selected from the group consisting of aluminum alone, aluminum with aluminum nitride, aluminum with aluminum diboride, or aluminum with aluminum nitride and aluminum diboride; pressing the mixture to elevated temperature and pressure conditions at which conditions the CBN is thermodynamically stable; and maintaining the elevated conditions for a time sufficient to allow for substantial intercrystalline bonding to thereby sinter the compact.