Overlay control for laser peening

A method of improving properties of a solid material by providing shock waves therein, comprising:

• applying an energy absorbing overlay to a portion of the surface of the solid material;
• measuring the thickness of said energy absorbing overlay during said application;
• terminating the application of said energy absorbing overlay upon reaching the specified range;
• applying the transparent overlay over said energy absorbing overlay;
• measuring the thickness of said transparent overlay;
• and
• when the thickness of said transparent overlay is in the specified range, directing a pulse of coherent energy to said coated portion of the solid material to create a shock wave.

A method of improving properties of a solid material by providing shock waves therein, comprising:

• applying a continuously flowing transparent overlay to a portion of the surface of the solid material;
• directing an air jet to divert said transparent overlay from said portion of said solid material;
• applying energy absorbing overlay to said portion of the solid material;
• terminating said air jet to allow said transparent overlay to again be applied to said portion and over said energy absorbing overlay;
• and
• directing a pulse of laser energy to said portion of the solid material to create a shock wave.

A method of modifying the thickness of the energy absorbing overlay and transparent overlay applied to the surface of solid material, comprising:

• applying an energy absorbing overlay to a portion of the said solid material;
• measuring the thickness of said energy absorbing overlay;
• tamping said energy absorbing overlay to the desired thickness;
• applying the transparent overlay over said energy absorbing overlay;
• measuring the thickness of said transparent overlay;
• tamping said transparent overlay to the desired thickness;
• and
• directing a pulse of laser energy to said coated portion of the solid material to create a shock wave.