Method of making metal cutting inserts having superhard abrasive bodies

A method of making a metal-cutting insert having superhard cutting edges on respective sides thereof, comprising the steps of:

• A) positioning in a container a substrate arrangement comprised of a plurality of substrate layers including a first layer situated between a pair of second layers, each of said second layers having at least one recess formed in an outer peripheral edge thereof and extending for the full thickness of its respective second layer, each recess forming a space in said container;
• B) filling said spaces with a material possessing superhard abrasive particles;
• C) subjecting the container to elevated temperature and pressure conditions to cause said superhard particles in each space to become sintered together into a superhard body bonded to said first layer and said second layers;
• and
• D) slicing said substrate arrangement along lines passing through respective second layers in directions parallel to the planes thereof to form an insert comprised of said first layer, a portion of each second layer, and a portion of each superhard body, whereby each second layer forms a side of said insert and includes a superhard cutting edge formed by said portion of a respective superhard body.

A method of making a multi-cornered metal-cutting insert having superhard cutting edges on respective sides thereof, comprising the steps of:

• A) positioning in a container a substrate arrangement comprised of a plurality of substrate layers including round first layers and round second layers, each first layer alternating with a second layer, each of said second layers having at least two recesses in an outer periphery thereof arranged in superimposed relationship to said first layer, said recesses forming spaces in said container;
• B) filling said spaces with a material possessing superhard abrasive particles;
• C) subjecting said container to elevated temperature and pressure conditions to cause said superhard particles in each space to become sintered together into a superhard body bonded to a respective second layer and to said first layer;
• and
• D) slicing said substrate arrangement along lines passing through centers of respective second layers in directions parallel to the planes thereof to form an insert comprised of said first layer, halves of said second layers, and halves of said superhard bodies, whereby said insert includes two sides formed by respective second layers, each side including superhard cutting edges formed by halves of said superhard bodies;
• and
• E) machining said insert into a multi-cornered configuration wherein portions of said halves of said superhard bodies are disposed at respective corners on each side of said insert.