Cutting elements configured to reduce impact damage and mitigate polycrystalline, superabrasive material failure earth-boring tools including such cutting elements, and related methods

An earth-boring tool, comprising:

• a body;
• and
• a cutting element secured to the body, the cutting element comprising:
• a substrate;
• a polycrystalline, superabrasive material secured to an end of the substrate, the polycrystalline, superabrasive material comprising a curved, stress-reduction feature formed in a cutting face of the polycrystalline, superabrasive material, the curved, stress-reduction feature comprising:
• an undulating edge formed proximate an outer peripheral edge of the polycrystalline, superabrasive material;
• and
• a waveform extending from the undulating edge toward a center longitudinal axis of the cutting element;
• a first transition surface extending from an outer peripheral edge of the polycrystalline, superabrasive material and in a first direction oblique to a center longitudinal axis of the substrate, wherein the curved, stress-reduction feature is formed partially on the first transition surface;
• and
• at least one recess defined in the waveform of the curved, stress-reduction feature of the polycrystalline, superabrasive material and comprising:
• sidewalls intersecting with a front surface of the waveform of the curved, stress-reduction feature of the polycrystalline, superabrasive material and extending to a base wall within the polycrystalline, superabrasive material.

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

• attaching a polycrystalline, superabrasive material to a substrate;
• forming a first transition surface extending from an outer peripheral edge of the polycrystalline, superabrasive material and in a first direction oblique to a center longitudinal axis of the substrate;
• forming a curved, stress-reduction feature in a cutting face of the polycrystalline, superabrasive material and partially on the first transition surface, the curved, stress-reduction feature comprising:
• an undulating edge formed proximate an outer peripheral edge of the polycrystalline, superabrasive material;
• and
• a waveform extending from the undulating edge toward a center longitudinal axis of the substrate;
• and
• forming at least one recess in the curved, stress-reduction feature of the polycrystalline, superabrasive material, the at least one recess comprising:
• sidewalls intersecting with a front surface of the curved, stress-reduction feature of the polycrystalline, superabrasive material and extending to a base wall within the polycrystalline, superabrasive material.