Study On Kerf Roughness Differences Between Line And Arc Analysis And Elimination Of Laser Precision Cutting

According to its advantages of low cost, high efficiency and high accuracy,the laser cutting technology is widely used to process templates in instrumentation, electronic and other precision industries. In order to improve the kerf roughness of laser cutting, a group of international and domestic academics carried out many researches on the processing parameters selection,and put forward a variety of optimization methods and theories, but these studies only attached great importance to the typical linear cutting kerfs and their ultimate purposes were to obtain the minimum roughness, which leave the law of the circular arc cutting roughness neglected. Based on this kind of situation, this paper launch a study on the analysis of the roughness difference between linear and circular kerfs and proposing the method to eliminate this differences.This research main contents are as follow:(1) Establish the mathematical model of the circular kerf roughness. Arcs on the 0.5 mm pure thick aluminum(1060) sheet are cut precisely by Nd: YAGpulse laser. The surface hanging slag and other sundries are wiped purify using alcohol before the Microstructure of kerf results obtained through microscope.Formulas to estimate the kerf surface roughnesses of these arcs are presented through geometric relation reasoning.(2) Discuss the law of cutting size affected on the roughnesses of circular arcs. Comparing the formula of linear cutting kerf with these of circular cutting kerfs, we find that these roughnesses of circular arc kerfs are not only affected by cutting speed, laser frequency and laser pulse, but also by the cutting arc size.The effect laws of radius size on the kerf surface roughness differences with the same cutting parameters are analyzed particularly. The results show that:decreasing the radius of outside arc, increasing the radius of inside arc, the kerf roughnesses are improved; the radius≤7 mm, the roughnesses of these two arcs are different significantly; while the radius≥7 mm, the differences of these roughnesses almost disappear.(3) Eliminate the roughness differences by using Response Surface Method optimization. Cutting experiments are designed by using the Design-Expert software, variance analysis of the quadratic regression equation that obtained by these experiments show that the model fitting degrees are high, the fitting effects are good, lack of fits are no significant, so the overall predictions are effective. At last, optimize the kerf roughnesses of all shapes by the Response Surface Method(RSM) minimize optimization and target optimization respectively to obtain the cutting parameters, the roughnesses of all shapes cutby above cutting parameters are almost same, therefore this method to eliminate the linear and circular roughness differences is feasible and effective.Above all, internal and external circular arc roughness models are established on the basis of laser precision cutting linear roughness model. The roughness differences between circular arc and linear cutting kerfs are proved by experiments and theoretical calculation. At last, the optimization cutting parameters are obtained by the Response Surface Method minimize optimization and target optimization, respectively. The actual cutting experiments validate these processing parameters can eliminate the roughness differences. This study provides a certain reference for the laser cutting parameters selection and the database establishment, moreover, the parameters variable laser cutting machine can get some theoretical supports.