Technology And Experimental Study On Roll Surface Texturing With Pulse RF CO₂ Laser

The rolls textured by laser have a lot of advantageous properties such as even roughness, controllability, regardless of material, and the rolled steel sheets with good stamping performance and fine brightness after painting. The equipment for roll texturing is developed based on RF CO2 laser, which has a lot of advantages as easy modulation of laser pulse, compacted configuration, low-cost for implement, operation and maintaining. Therefore, it is meaningful to production for studying the RF CO2 laser texture technology.In this paper the thermophysical process of laser texture is studied, including theoretical models of heat conduction, material melt and vaporization due to laser-material interaction. In the same time, the technology parameters chosen principle in roll laser texture is analyzed.The system components of RF CO2 laser texture are described, including the function and performance of RF CO2 laser, beam delivery system, controlling system and machine. A RF laser modulator is designed to control the output of laser pulses, electrical circuit and principle has being analyzed.The influence of beam character to laser texture is analyzed, the beam quality in the flying optical path and influence of parameter M2 to the beam behavior in processing are discussed. Finally using ZEMAX simulates the optical path of the delivery system, the size, energy distribution and aberration of the beam spot on the focal plane are plotted.Effects of the technology parameters to laser texture are studied in experiments. With appropriate assist gas pressure and reasonable defocus, results show that the remarkable effects to the size and shape of textured spots are the frequency, width of laser pulse and the velocity of process. The microstructure of textured spots is studied with microscope. The shape of the spot is a W-type, which is different to the traditional crater shape. The results show dense microstructure in the textured spot, which brings about the improvement of the hardness, wear and corrosion resistance.