Binderless or catalyst-free revolving pdc cutter

A downhole tool, comprising:

• a body having a central axis extending longitudinally therethrough;
• a blade extending outwardly from the body;
• a pocket formed in an outer surface of the blade;
• and
• a revolving cutting element rotatably mounted in the pocket, the revolving cutting element comprising:
• an upper body, comprising:
• a cutting face bordered by a cutting edge;
• a side surface extending from the cutting edge, wherein an upper body diameter is measured between the side surface;
• and
• a catalyst-free polycrystalline diamond (CFPCD) portion forming the cutting face, the cutting edge, and at least a portion of the side surface,
• wherein the CFPCD portion extends at least 1 mm from the cutting face;
• and
• a shaft extending from a lower side of the upper body opposite the cutting face, the shaft comprising:
• a circumferential groove extending around a circumference of the shaft;
• and
• a shaft diameter less than the upper body diameter;
• a locking mechanism positioned between the pocket and the shaft, wherein the locking mechanism extends into the circumferential groove.

A method, comprising:

• forming a revolving cutting element, comprising:
• forming a catalyst-free polycrystalline diamond (CFPCD) body, comprising:
• subjecting a volume of diamond powder to ultrahigh pressure and high temperature (UHPHT) sintering without the presence of a catalyst or binder material, the UHPHT sintering comprising:
• an ultrahigh pressure ranging from 14 to 35 gPa;
• and
• an ultrahigh temperature ranging from 1,730 to 2,730° C.,
• wherein the CFPCD body forms a cutting face, a cutting edge, and at least a portion of a side surface of the revolving cutting element, and
• wherein the revolving cutting element comprises a shaft having a circumferential groove extending around a circumference of the shaft;
• and
• installing the revolving cutting element in a pocket formed in an outer surface of a cutting tool, comprising:
• inserting the shaft of the revolving cutting element into the pocket;
• and
• providing a locking mechanism between the shaft and the pocket, wherein the locking mechanism extends into the circumferential groove of the shaft.