Papers by Author: J. Tang

Abstract: Water-jet guided laser micromachining is the new development of laser machining. This paper analysis the action mechanism of the plasma shock wave and hollow erode effects in water-jet guided laser machining processing, on the base of the thermal effects of the laser and water-jet. And the numerical model on the action effects between the water-jet guided laser and the material was founded. Using the software ANSYS, the processing of the water-jet guided laser micromachining was simulated. This paper gave the investigation on the distributing of temperature field in processing of water-jet guided laser micromachining. And the results of the correlative experiment correspond with the simulation results.

Abstract: Water-jet guided laser micromachining is the new development orientation of laser machining. This paper set up the numerical model on the action between the water-jet guided laser and the material. By using the software ANSYS, simulated the processing of the water-jet guided laser micromachining. This paper gave the investigation on the machining laws and the distributing of temperature fielding in processing of water-jet guided laser micromachining. And the results of the correlative experiment prove the model aright. The result provided the theoretical foundation for the next research on the water-jet guided laser machining.

Abstract: In this paper, the comparative experimental research on DPSS UV laser (wavelength is 355nm) and high-pressure water-assisted YAG laser dicing SiC wafer was done. The results show that is strict with the performance of laser source and the dicing technique parameters in UV laser dicing the SiC wafer, and the dicing surface of good quality can be obtained only when the parameters of laser source and dicing technology vary in a narrow range. Contrarily, the SiC wafer dicing technology using high-pressure water-assisted YAG laser has a perfect flexibility with the laser source and dicing apparatus, and the good dicing surface can be obtained even if the process parameters vary in a wide range.

Abstract: The processing effect using water-jet guided laser micromachining technology is determined by the accurate coupling of focused laser and high speed water-jet. In order to realize the effective coupling, based on the analysis and calculation, a coupling unit with special structures was designed. The maximum angle of incidence was researched, which determined whether the total reflection occurred when laser transported in the water-jet. By the aid of fluid dynamical simulation, the coupling unit with uniform distribution of inner-cavity fluid field was designed. The attenuation of laser energy in water-jet fiber was investigated. Using appropriate laser wavelength, pulse energy and filtered and de-ionized water, energy attenuation in fiber was reduced. Experimental results showed that applying this coupling technology, perfect water-jet guided laser micromachining can be achieved.