Patent ID: 8330070
Filing Date: 2012-12-11
Classification: B23K

Abstract:
1. A laser shock hardening method for carrying out surface processing of workpiece in contact with a liquid by irradiating through the liquid the surface of the workpiece with a pulsed laser beam intermittently emitted from a laser irradiation head, the method comprising: providing the laser irradiation head with a liquid jet nozzle for jetting a liquid transparent to the wavelength of the irradiating laser coaxially with the laser beam and a driving device for moving the laser irradiation head relative to the workpiece along the surface of the workpiece; fixing the laser irradiation device in a position where the workpiece, exposed in an atmospheric environment, is positioned in a higher position than the laser irradiation device; covering the surface of the workpiece with a liquid transparent to the wavelength of the irradiating laser by jetting the liquid from the exit of the liquid jet nozzle; and irradiating the laser beam intermittently to the irradiation portion on the surface of the workpiece, while irradiation points on the surface of the workpiece is kept being covered with the liquid jetted from the jet nozzle coaxially with the laser beam, thereby shock-hardening the surface of the workpiece.