US 5,790,620 A · Underwater laser processing method and apparatus

Abstract

An underwater laser processing method is carried out by irradiating, through a laser beam irradiation apparatus, a laser beam having a high output, a short pulse and a visible wavelength to a surface of a structure immersed in a water to improve residual stress of a material of the surface of the structure and remove a crack or a CRUD thereof. The laser beam irradiation apparatus comprises a pulse laser device suspended into a water in which a metal material is accommodated from an upper side thereof for irradiating a laser beam having a visible wavelength to a processing position, a beam strength adjusting device for adjusting an output per 1 pulse of a laser beam generated by the pulse laser device and a mechanism for adjusting a spot diameter and a multiplexing ratio of an irradiated beam.

Claims5

Dependent claims

An underwater laser processing method, comprising:

providing a laser beam having a visible wavelength;
forming said laser beam into laser beam pulses of a duration of 100 nanoseconds or less and a peak power output of 0.1-10 GW/cm.sup.2 ;
irradiating said laser beam pulses onto a surface of a structure immersed in water;
and
controlling a diameter of the laser beam pulses irradiated on the surface and providing a multiplexing ratio of 100% or greater so as to improve residual stress on a material forming said surface while also providing for the removal of an unwanted deposit from the surface.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application

08/593,970Filed 30 Jan 1996

Priority

JP 7-01388031 Jan 1995

Granted

4 Aug 1998

Term ends

Not estimatedThe source records don’t support an estimate.

Classification11 codes

B23K 26/0608
By a combination of beams: in the same heat affected zone [HAZ]
B23K 26/082
Devices involving relative movement between laser beam and workpiece: scanning systems, i.e. devices involving movement of the laser beam relative…
B23K 26/0821
Scanning systems, i.e. devices involving movement of the laser beam relative to the laser head: using multifaceted mirrors, e.g. polygonal mirror
B23K 26/1224
In a special environment or atmosphere, e.g. in an enclosure: in vacuum

Underwater laser processing method and apparatus

Life of this patent

Underwater laser processing method and apparatus

Life of this patent

Abstract

Claims5