Study Of The Experiment And Numerical Simulation On Laser Drilling For0Cr18Ni9Stainless Steel

Compared with traditional machining, the technique of laser drilling has manyadvantages, such as highly efficient, no tools loss, little holes made with a few microns,universally available, notable economic benefits. At present, it was used widely inmachining little holes.In this paper,0Cr18Ni9stainless steel plate was taken as the experimental material,and the Gauss heat source model was applied. The finite element analysis softwareANSYS was used to make numerical simulation of temperature field in the process oflaser drilling, on the condition of different power and spot radius, get the distributing oftransient temperature field, and to acquire the relationship curve between HAZ, holedepth, upper hole diameter and time. The research demonstrated that with the increasingof time, HAZ was decreasing, upper hole diameter and depth were increasing; Whenspot radius was fixated, with the increasing of laser power, HAZ was decreasing, holedepth and upper hole diameter were increasing; When laser power was fixated, with theincreasing of spot radius, HAZ was increasing, hole depth and upper hole diameter weredecreasing.The0Cr18Ni9stainless steel with0.5mm and1.0mm thickness and the CO2laserswere chosed to make the experiment of drilling holes with laser, and the toolmicroscope was used to measure the upper hole diameter and lower hole diameter. Then,acquired the variation diagram of hole diameter and taper by the ORIGIN software. Astudy was distributed to make clear how laser power, pulse width, defocus and auxiliarygas influence the upper hole diameter, lower hole diameter and taper.The experimental results indicated that with the increasing of laser power, upperhole diameter, lower hole diameter and taper were all increasing, but if the laser powerwas too lager, the entrance of holes would be damaged seriously. With the increasing ofpulse width, upper hole diameter and lower hole diameter were all decreasing, but thechanging of taper was not obvious, if the smaller pulse width was taken, which couldget the shape rule holes; When the defocus was positive, with the increasing of defocus,upper hole diameter, lower hole diameter and taper were all decreasing, when thedefocus was negative, with the increasing of defocus, upper hole diameter, lower holediameter and taper were all increasing. If the focus was under the workpiece’s uppersurface too long distance, which could cause the wall of holes melted seriously, theincreasing of upper hole diameter was obvious, material’s evaporated effect was weak, it would appear blind holes; If the focus was up the workpiece’s upper surface too longdistance, because of reducing of power density, material could not get enough power,though the upper hole diameter was smaller, but material’s evaporated effect wouldbecome very weak, which would lead to appear blind holes, So, they could not bepicked. On the same condition, with the increasing of material’s thickness, the upperhole diameter, lower hole diameter and taper were all decreasing. If the auxiliary gaswas used, which could get clean workpiece’s upper surface and holes of higher quality.The forming mechanism of holes in laser drilling was studied preliminarily.Analyzed the deviation of simulation and experimental data, the mutative trendwas unanimous, validated the feasibility of simulation analysis, which could provide thetheory gist for the selection of experimental parameters of drilling holes with laser.