光纤激光抛光模具钢研究

发布时间：2018-04-19 03:12

  本文选题：模具制造 + 激光抛光　； 参考：《北京工业大学》2015年硕士论文

【摘要】：抛光能提高模具耐磨性和耐腐蚀性以及工件精度,延长其使用寿命和维护周期,因此,模具抛光是模具制造过程中非常重要的加工工序,但模具表面精加工一直是模具加工领域中一个未能很好解决的难题。目前,模具自动抛光技术仍存在很多问题,如电抛光、电化学抛光和磨削等会导致边角变圆,较深区域未被加工等,因此,当前自动抛光技术无法实现非平整表面模具和有边角的模具的加工。模具表面精加工主要依靠手工研磨来完成,也是模具钳工劳动强度大的重要原因之一。激光具有独特的加工优势,激光抛光因其加工的诸多优点,被广泛认为是一种极具潜力的抛光方法。而光纤激光器的能量转化率较高,且寿命长,适合工业应用,因此本文采用了连续模式的光纤激光研究了抛光模具钢的加工工艺。基于控制能量密度的考虑,本文研究了低离焦量低功率和高离焦量高功率两种情况,采用固定功率和扫描速度,通过变化离焦量来改变能量密度,进行2316模具钢单光束单道扫描试验。研究表明在这两种情况下,随着离焦量增大,重熔表面的粗糙度呈现先降低后增大的趋势,该现象与SSM(surface shallow melting)机制和SOM(surface over melting)机制吻合。随离焦量增大,相同离焦量和扫描速度下,表面凸起会更加明显,同时,与低离焦量低功率加工条件相比,高离焦量高功率下熔融区域更宽。激光热导焊模型的分析结果揭示了该现象的成因,因此,高离焦量高功率的加工条件更利于单道激光抛光。进一步采用正交试验设计的方法,研究了激光功率、扫描速度、扫描间隔和离焦量对平面抛光的影响。实验结果表明:1)激光参数对平面抛光的加工效果影响顺序为:扫描间隔激光功率扫描速度离焦量。2)比较扫描速度为70 mm/s和100 mm/s这两种加工条件,平面抛光的加工效果差异很小,因此,为了提高效率,应选择较高的速度。3)在适当的激光功率、扫描速度和扫描间隔下,较大的离焦量能够实现较好的激光抛光加工效果。4)在最佳参数下,2316模具钢的粗糙度Ra约为1.000μm降到了0.231μm。
[Abstract]:Polishing can improve the wear resistance and corrosion resistance of the die, as well as the precision of the workpiece, prolong its service life and maintenance period, therefore, the die polishing is a very important processing procedure in the mould manufacturing process.However, die surface finishing is a difficult problem in die processing field.At present, there are still many problems in automatic polishing of mould, such as electric polishing, electrochemical polishing and grinding, etc.Current automatic polishing technology can not realize the processing of non-smooth surface mould and die with edge angle.The finishing of die surface mainly depends on manual grinding, which is one of the important reasons for the labor intensity of die pliers.Laser has a unique processing advantage. Laser polishing is widely regarded as a potential polishing method because of its many advantages.The energy conversion of fiber laser is high, and its life is long, so it is suitable for industrial application. Therefore, the continuous mode fiber laser is used to study the processing technology of polishing die steel.Based on the consideration of the control energy density, the low and high defocus power conditions are studied in this paper. The fixed power and scanning speed are used to change the energy density by changing the defocusing amount.The single beam single channel scanning test of 2316 die steel was carried out.The results show that the roughness of the remelted surface decreases first and then increases with the increase of defocus, which is consistent with the mechanism of SSM(surface shallow melting and SOM(surface over melting.With the increase of defocusing amount, the surface bulge will be more obvious at the same defocusing amount and scanning speed. At the same time, compared with the low defocus and low power processing conditions, the melting region will be wider under the high defocusing and high power conditions.The analysis results of laser thermal conductivity welding model reveal the cause of this phenomenon. Therefore, the processing conditions with high defocus and high power are more favorable to single pass laser polishing.Furthermore, the effects of laser power, scanning speed, scanning interval and defocus on planar polishing were studied by orthogonal design.The experimental results show that the order of influence of laser parameters on the machining effect of planar polishing is: scanning interval laser power scanning speed defocus amount. 2) compared with scanning speed of 70 mm/s and 100 mm/s, the processing effect of plane polishing is very small.Therefore, in order to improve efficiency, choose a higher speed. 3) at the appropriate laser power, scanning speed and scanning interval,A larger defocus can achieve a better laser polishing effect. 4) under the optimum parameters, the roughness Ra of the die steel is about 1.000 渭 m and 0.231 渭 m.
【学位授予单位】：北京工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG142.45
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本文编号：1771319