衍射光栅机械刻划过程的有限元仿真分析

研究关于衍射光栅机械刻划的槽形精度控制问题。衍射光栅机械刻划是一种在超精密刻划机上利用金刚石刀具对光栅铝膜进行微细挤压的成形技术,表面成形精度要求高。但是由于光栅机械刻划工艺复杂,刻划过程中铝膜材料的成形机理难以掌握,内部流动规律和变形特征无法认识。为了解决上述问题,首先根据铝膜压痕实验建立拟实条件,在Deform 3D金属成形仿真环境下通过实体模型导入时的缩小比例功能实现尖劈刻划刀的微刃口建模,并建立了机械刻划光栅铝膜的有限元仿真模型。通过和实验槽形结果的对比,验证了仿真模型的精确性。最终获得了铝膜材料在刻刀及其刀尖钝圆作用下的流动规律,揭示了机械刻划光栅过程中铝膜的弹塑性变形特征,为衍射光栅机械刻划工艺的研究提供了依据。

Finite Element Simulation Analysis of Mechanical Ruling of Diffraction Grating

This paper studied the precise control of grating groove by mechanical ruling.Mechanical ruling is a micro extrusion forming technology of forcing grating aluminium film to generate grooves by diamond ruling cutter on superprecision ruling engine,whose forming precision demand is high.But because of the complex technics,the forming mechanism of grating mechanical ruling is difficult to be mastered,besides,the inner flowing regularity and deformation characteristics of the grating aluminium film have not been understood.In this paper,the edge nose radius of the ruling cutter was first realized by reduction scaling function when imported into Deform 3D software,and a finite element model of mechanical ruling grating aluminium film was set up based on the aluminium film indentation experiments for reliable simulation,which validated the precision of the simulation model compared with the experiment results.Finally,the flowing regularity of the aluminium film formed by the ruling cutter and its edge nose was gained,which reveal the aluminium film nature of elasto-plastic deformation during grating mechanical ruling.The work in this paper lays a foundation for technics research of mechanical ruling grating.