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).