Method of testing a polycrystalline diamond compact cutter

A method for determining fracture toughness of a cutting element, comprising the steps of:

• clamping a first cutting element into a fixture in a first orientation, said first cutting element being comprised of a first diamond table and a first substrate;
• exerting a first confining pressure on said first diamond table by said fixture, said confining pressure being radial to said first diamond table and across a first top surface of said first diamond table;
• applying a first load at a first distance from a first perimeter of said first diamond table;
• increasing said first load to a first level sufficient to fracture said first diamond table;
• recording said first level sufficient to fracture said first diamond table;
• releasing said first cutting element from said fixture;
• re-clamping said first cutting element into said fixture in a second orientation, said first orientation being spaced from said second orientation;
• exerting a second confining pressure on said first diamond table by said fixture, said second confining pressure being radial to said first diamond table and across said first top surface of said first diamond table;
• applying a second load at a second distance from said first perimeter of said first diamond table;
• increasing said second load to a second level sufficient to fracture said first diamond table a second time;
• recording said second level sufficient to fracture said first diamond table said second time;
• and
• forming a profile of cutting elements manufactured under said same set of conditions as said first cutting element, said profile being comprised of data related to distance, load, and level sufficient to fracture said first diamond table,
• wherein fracture in said first orientation is isolated from fracture in said second orientation.

A device for determining fracture toughness, comprising:

• a fixture holding a cutting element, said cutting element being comprised of a diamond table and a substrate;
• a clamp comprised of a spacer, said cutting element being mounted in said clamp adjacent to said spacer in a first orientation, said clamp being mounted on said fixture, said space having a complementary profile to said cutting element so as to fit in said fixture;
• means for exerting a confining pressure on said diamond table, said confining pressure being radial to said cutting element and lateral across a top surface of said diamond table;
• and
• a load bearing means at a first distance from a perimeter of said diamond table,
• wherein said load bearing means is moveable to a second distance from said perimeter.