Method and apparatus for peening the internal surface of a non-ferromagnetic hollow part

A method for peening an internal surface of a non-ferromagnetic hollow part, comprising the steps of:

• (a) inserting a plurality of ferromagnetic peening elements into the non-ferromagnetic hollow part;
• (b) creating a first magnetic field through the non-ferromagnetic hollow part, thereby causing said ferromagnetic peening elements to contact a first portion of the internal surface of the non-ferromagnetic hollow part;
• (c) eliminating said first magnetic field;
• (d) creating a second magnetic field through the non-ferromagnetic hollow part, thereby causing said ferromagnetic peening elements to contact a second portion of the internal surface of the non-ferromagnetic hollow part;
• (e) eliminating said second magnetic field;
• and
• (f) repeating steps (b) through (e).

An apparatus for peening a non-ferromagnetic hollow part having an exterior and interior, the exterior and interior both having a top and a bottom surface, comprising:

• (a) ferromagnetic peening elements disposed within the interior of said non-ferromagnetic hollow part;
• (b) an electromagnet disposed adjacent to the top exterior surface of the non-ferromagnetic hollow part;
• and
• (c) a switch having a first position and a second position, wherein said electromagnet creates a magnetic field causing said peening elements to impact the top interior surface of the non-ferromagnetic hollow part when said switch is in said first position and wherein the magnetic field is eliminated when said switch is in said second position.

An apparatus for peening a non-ferromagnetic hollow part having an exterior and interior, the exterior and interior both having a top and a bottom surface, comprising:

• (a) an electromagnet having a first pole and a second pole, the non-ferromagnetic hollow part disposed between said first and second poles, each pole having a different polarity and creating a magnetic field through the non-ferromagnetic hollow part, said magnetic field having a direction;
• (b) ferromagnetic peening elements disposed within said interior of said hollow part;
• and
• (c) means for alternating the direction of the magnetic field, thereby causing said peening elements to alternately impact the top and bottom interior surfaces of the hollow part.