Simulation Of Laser Cutting Drilling Ti-6Al-4V Titanium Alloy And Experimental Research

Most of the titanium alloy thin-walled components in the aerospace industry are in harsh environments such as high temperatures and high pressure for a long time.High-precision machining is needed to ensure that quality problems will not cause losses when used.Laser drilling technology has prepared high-quality micropores and improved the all-around performance of micropores.The laser drilling method has enhanced from the traditional laser shock drilling to the laser ring-cutting drilling stage,which provides more options for improving the quality of micropores.At present,there is a lack of research on laser trepanning drilling of Ti-6Al-4V titanium alloy sheet.Based on this background,this paper uses a nanosecond laser as a heat source to carry out ring-cutting drilling on the surface of Ti-6Al-4V titanium alloy substrate and carries out the following research contents:By constructing the finite element physical model of laser trepanning drilling,the temperature field distribution of laser trepanning drilling under different pulse numbers were simulated and analyzed and simulated the micropore morphology.The influence of laser power,laser scanning speed,and obtained laser repetition frequency on the quality of micropores by simulation analysis.The range of experimental parameters was screened by aperture change:the selection range of laser power was P=48W to 60W;the selection range of laser scanning was v=300mm/s to 400mm/s;the selection range of laser repetition frequency is f=100kHz to 200kHz,which provides a theoretical basis for laser drilling experiments.The nanosecond laser is used to design the experimental optical path,and the variable control method is used to analyze the relationship between the technical parameters of laser trepanning drilling(laser power,laser scanning speed,defocusing amount,and repetition frequency)and the hole size,morphology and quality of laser trepanning drilling.The process parameters in laser trepanning drilling are optimized:when the laser power is 54w,the laser scanning speed is 375mm/s,the laser repetition frequency is 150kHz,and the defocusing amount is 0mm,the quality of trepanning drilling is better.The samples,after drilling,were tested by scanning electron microscopy(SEM)to analyze the influence of processing time on the degree of ablation.The effects of process parameters such as laser power,scanning speed,and defocusing amount on the microstructure of the pore surface were analyzed.To obtain the micropores with smooth pore walls and good surface roughness,smaller laser power,larger laser scanning speed,and negative defocusing distance should be selected.The XPS energy spectrum was used to analyze the element content of the surface layer of the micropore after the circumferential drilling.It was concluded that laser ablation would cause a sharp increase in the local temperature,causing the titanium element to react with oxygen and nitrogen in the air.Still,it had little effect on the quality of the micropore.