Deep laser peening
An embodiment includes a method, comprising: applying an overlay material to a portion of a rotatable shaft; directing a pulse of laser energy to contact the overlay material to produce a shock wave; and re-positioning one or more of the portion of the rotatable shaft and the pulse of laser energy to contact the overlay material at different positions to create a laser peened surface on the portion of the rotatable shaft; the pulse of laser energy comprising a pulse sufficient to create the laser peened surface having residual compressive stress to a depth exceeding about 3 mm. Other aspects are described and claimed.
1. A method, comprising:
applying an overlay material to a portion of a rotatable shaft;
directing a pulse of laser energy to contact the overlay material to produce a shock wave; and
re-positioning one or more of the portion of the rotatable shaft and the pulse of laser energy to contact the overlay material at different positions to create a laser peened surface on the portion of the rotatable shaft;
the pulse of laser energy comprising a pulse sufficient to create the laser peened surface having residual compressive stress to a depth exceeding about 3 mm.
2. The method of claim 1 , wherein the rotatable shaft comprises a crankshaft and further wherein the portion of the rotatable shaft comprises a crank shaft fillet.
3. The method of claim 2 , wherein the portion of the rotatable shaft comprises two or more crankshaft fillets joined together.
4. The method of claim 1 , wherein the pulse of laser energy comprises a pulse sufficient to create the laser peened surface having residual compressive stress to a depth exceeding about 4 mm.
5. The method of claim 1 , wherein the pulse of laser energy comprises a pulse sufficient to create the laser peened surface having residual compressive stress to a depth exceeding about 5 mm.
6. The method of claim 1 , wherein the pulse of laser energy comprises a pulse sufficient to create the laser peened surface having residual compressive stress to a depth exceeding about 6 mm.
7. The method of claim 1 , wherein the pulse of laser energy comprises a pulse sufficient to create the laser peened surface having residual compressive stress to a depth exceeding about 7 mm.
8. A rotatable shaft, comprising:
a rotatable shaft portion deep laser peened to produce a laser peened surface having residual compressive stress to a depth of about 3 mm or more.
9. The rotatable shaft of claim 8 , wherein the rotatable shaft comprises a crankshaft and the laser peened surface comprises a crank shaft fillet.
10. The rotatable shaft of claim 9 , wherein the laser peened surface comprises a joint area of two or more crankshaft fillets.
11. The rotatable shaft of claim 8 , wherein the laser peened surface has residual compressive stress to a depth exceeding about 4 mm.
12. The rotatable shaft of claim 8 , wherein the laser peened surface has residual compressive stress to a depth exceeding about 5 mm.
13. The rotatable shaft of claim 8 , wherein the laser peened surface has residual compressive stress to a depth exceeding about 6 mm.
14. The rotatable shaft of claim 8 , wherein the laser peened surface has residual compressive stress to a depth exceeding about 7 mm.