Earth-boring tools including rotatable cutting elements, rotatable cutting elements, and associated components and methods

An earth-boring tool comprising:

• a body;
• a rotatable cutting element secured to the body, the rotatable cutting element including:
• a sleeve secured to the body, the sleeve defining a cavity;
• a rotatable element disposed in the cavity of the sleeve, the rotatable element including a cutting table and a spindle, the spindle extending into the cavity;
• a retaining element extending between a retaining groove defined in the spindle and a retaining surface defined in the cavity, the retaining element comprising a shaped memory alloy.

A method of assembling a rotatable cutting element, the method comprising:

• training a shaped memory alloy ring to a conical shape;
• lowering a temperature of the shaped memory alloy ring to below a trigger temperature of the shaped memory alloy ring;
• compressing the shaped memory alloy ring into a retaining groove on a spindle of a rotatable portion of the rotatable cutting element;
• disposing the spindle of the rotatable portion into a cavity defined in a stationary portion of the rotatable cutting element;
• and
• heating the rotatable cutting element to a temperature above the trigger temperature of the shaped memory alloy ring.