Non-Destructive Residual Stress Investigations of Natural Polycrystalline Diamonds

Abstract

Three natural polycrystalline diamond samples have been investigated non-destructively in their raw as-discovered forms. The samples originate from different locations in the world and possibly have different mechanisms of formation. The study reveals that the stones are primarily composed of cubic diamond with varying amounts of impurities that emanate from their excessive porosities and entrapped environmental contamination from the areas they were formed and subsequently discovered. Residual stress analyses with X-ray and neutron diffraction techniques of the diamond phase in the interior regions of the diamonds revealed low stress values.