Research On High Power Diode Laser Surface Modification Technology And Equipment For Pump And Valve Industry

With properties of high efficiency, stable performance, good reliability, long life, small size, light weight and easiness to combine with the robotic arm, high power diode laser has opened up many areas which conventional lasers can't be involved in. So it has been more and more attention in the field of industrial application.This thesis is based on the research of the Industry bottlenecks which are faced by the traditional pump and valve industry in Wenzhou, Zhejiang province. U sing theoretical research and experiments,there have been several aspects studied:the design of high power diode laser equipment, the interaction between laser, powder and objects and the simulation of temperature field, the effect of plume, the optimization of process parameters, the defect analysis and quality control methods. Details are as follows:(1)The processing objects in the valve industry have been classified, and a high power diode laser system has been designed to improve the valve surface processing technology. Then 3KW diode laser, beam shaping, cooling systems, power technology and the simultaneous machining system have been analyzed.(2)The reaction between laser, powder and objects has been preliminarily analyzed, and a high-power diode laser temperature field model has been established to take a simulation under conditions of laser power 1KW, the scanning speed of 5mm / s; laser power 2KW, the scanning speed of 5mm / s; laser power 2KW, the scanning speed of 10 mm / s. the influence of laser power and scanning speed has been Studied.(3)The effect of the plume to beam shape and the focal spot position has been theoretical analyzed in both absorption and refraction. By constructing a mathematical model of the particle density and using the ABCD optical matrix, it has been found that the impact of the plume can be equivalent to a gradient index lens to make the focus down, the spot size large, and the energy reduced by 90%.(4)The parameters of the valve surface treatment process has been analyzed, and a preliminary optimization of process parameters has been made and verified by using the neural network algorithm. The surface hardness of the valve plate sample is 378.8HV when the laser power is 1.8KW, scanning speed of 6mm/s, which is consistent with the facts. Then the defects of samples during high power diode laser surface treatment application have been studied, and several methods have been proposed to reduce the defects.