Self-sharpening cutting elements, earth-boring tools including such cutting elements, and methods of forming such cutting elements

An earth-boring tool, comprising:

• a body;
• and
• at least one cutting element attached to the body, the at least one cutting element comprising:
• a cutting table comprising a polycrystalline superabrasive material, the cutting table comprising an at least substantially planar cutting face;
• and
• a substrate attached to the cutting table, the substrate comprising at least one metal or metal alloy material selected from the group consisting of CoCr, CoCrMo, CoCrW, wherein a wear rate of the substrate is faster than a wear rate of a similarly configured substrate comprising cobalt-cemented tungsten carbide, and wherein the substrate is at least substantially free of composite material.

A method of forming a cutting element for an earth-boring tool, comprising:

• disposing a substrate comprising at least one metal or metal alloy material selected from the group consisting of CoCr, CoCrMo, CoCrW in a container;
• disposing particles of superabrasive material in the container;
• and
• sintering the particles of superabrasive material with the substrate in the container to form a cutting table comprising a polycrystalline superabrasive material, the cutting table comprising an at least substantially planar cutting face, the cutting table attached to the substrate, wherein a wear rate of the substrate is faster than a wear rate of a similarly configured substrate comprising cobalt-cemented tungsten carbide, and wherein the substrate is at least substantially free of particle-matrix composite material.