Friction-welded assembly with interlocking feature and method for forming the assembly

A method for forming a first and a second interlocking feature for retaining a first component with respect to a second component using a spin-welding process, the method comprising:

• providing the first component with an opening and a circumferential groove defining an annular shelf, and with a plurality of inwardly-projecting teeth disposed within the circumferential groove;
• inserting the second component into the opening of the first component;
• applying a first axial compressive force to the first and second components;
• rotating one of the first and the second components with respect to the other while the first axial compressive force is being applied to thereby form an outflow of molten flash;
• admitting the outflow of molten flash at least partially into the circumferential groove and underneath the annular shelf, and into enveloping contact with the teeth;
• and
• cooling the molten flash to thereby form a flow pattern, the flow pattern providing as the first interlocking feature a feature which prevents axial motion of the first component with respect to the second component, and providing as the second interlocking feature a feature which prevents a relative rotation of the first component with respect to the second component.