The Research Of Coupling Principle Of Laser-Microjet And Experimentation

As a new compound machining technology, Laser-Microjet has been paid more and more attentions all around the world recently. Comparing with the conventional laser, this technology has many advantages such as long working distance, small heat-affect zone, high work efficiency and excellent cooling effect. It has been applied in micro-electronics, medical treatment, aviation manufacturing, etc.Based on research of the quality of Gaussian beam, the stability of water-jet, the laser attenuation underwater, the interaction of laser and material and the principle of Laser-Microjet. The key component of Laser-Microjet, the coupling unit was designed and the experimental system was built up. Then the machining experiments were done using single factor experiment method with Lumonics JK702 Nd:YAG solid laser. The experiments included drilling holes and cutting slots in stainless steel 1Cr18Ni9Ti, titanium alloy TC1, tool steel 65Mn, bakelite (hydroxybenzene aldehyde colophony) and silicon Si.The experiments results indicate: the nozzle diametrical size was restricted by energy of laser beam and the facular diameter, while the material and the diameter of nozzle influenced the energy of Laser-Microjet and machining quality. In this experiment, the 0.35mm nozzle which was made of TC1 was destroyed when the laser energy increased to some extent. When under proper laser energy, 0.18 mm nozzle which was made of copper can cut slot of 0.107mm width, which has no surface contamination, and no oxidation is visible. If other factors remained unchanged, the hole diameter and the slot width increased with decreasing laser energy intensity and increasing nozzle diameter, the machining surface is not plan and the machining depth are slow. The hole depth and slot width increased with increasing time. Because of the cooling effect during the machining process, the machining speed would decrease when reach a certain depth. The diameter of machined hole and width of slot increased while energy increased. As the increasing working distance, the efficiency of machining decreased. The efficiency of machining will stay high when working distance varies from 22 to 32 mm.Adopting optimized machining parameters of Laser-Microjet, higher cutting speed, higher surface quality, no surface contamination, and no oxidation is visible.