Drilling and cutting experiments in magnesium alloy sheet were conducted using water-jet guided laser. Morphology characteristics in processing areas were analyzed and compared with that of the conventional laser processing. The results show the processing areas are clean, with almost no molten residues attached and negligible heat damage in water-jet guided laser processing. The hole walls and cut surfaces are smooth and have some degree of slope, and are completely covered with dense protruding particles at microcosmic scale. However, with conventional laser, the processed areas are attached with a large number of residues, and obvious secondary solidified layers.

Water-jet guided laser processing is a kind of material processing technology using variable-length water jet optical waveguide. In this paper, by means of the finite element method (FEM), the simulation on drilling with water-jet guided laser was carried out based on thermal effect of laser and mechanical effect origining from shock pressure of shock wave caused by heat-induced explosion and impact of high-speeds water jet. The results show that evaporation and mechanical ablation of molten material is the main form of the material removal, the mechanical effect only contributes the slight deformation to the material with temperature gradient, the rapid water jet cooling after laser pulse played a quenching role in the processing area. In addition, the paper also analyzed the variable tendency of the impact of water jet to workpiece and clarified the scope and trend of the role of water jet.

In this work, a porcelain enamel coating material for high temperature resistant on 1Cr18Ni9Ti stainless steel is designed and processed. The structure and properties of the material are analyzed by SEM, EDAX, XRD and FTIR. The results show that the surface of the enamel glaze and the enamel coating are smooth and bright, there is no obvious crystallization characteristics in porcelain enamel. There is litter oxidation and inter-diffusion in the interface between 1Cr18Ni9Ti stainless steel and porcelain enamel coating material after coating enamel.

Water-jet guided laser machining is a kind of material processing technology using water optical waveguide which is formed by coupling a high energy laser beam into variable-length water jet. In order to design the coupling unit and form the effective energy-jet, the research on the distribution of output intensity is beneficial to understand the structure of the coupling unit and improve the coupling efficiency of laser energy. This paper lists the different coupling misalignments in the coupling unit when laser couplings into water-jet. In this paper, the distribution of energy output intensity in water-jet guided laser is simulated with the ray trace theory under several different types of coupling misalignments with ZEMAX software, the results show that misaligned coupling provide various morphology of energy output intensity distribution: center peak morphology, ring peak morphology, and uniform peak morphology, which provides a method to optimize the energy output intensity distribution of water-jet guided laser.

Titanium is a class of material difficult to common machine. Laser processing is a feasible method for machining of titanium. This paper presents cutting investigation of industry pure titanium sheet with conventional laser and water-jet guided laser, and analyses their processing features by means of the surface morphology of kerf obtained from Scanning Electron Microscope. The result shows that the machining quality and cleanliness of water-jet guided laser processing is much better than conventional laser processing. The impact and cool effects of the high-speeds water jet are more effective to trim the cut surface and remove molten waster.