机械刻划槽形过挤压临界状态分析

Analysis of Grooves Over-squeezing Critical State During Mechanical Ruling

衍射光栅是重要的光学元件,机械刻划过程中的过挤压现象在一定程度上会对其槽形质量产生影响。针对刻划过程中的过挤压现象,本文建立了槽形顶角分别为钝角、直角和锐角三种情况下的滑移线场模型,并结合塑性变形体积不变准则确定了槽形过挤压临界点D的位置。得出了在光栅常数、槽形非闪耀角一定的条件下,D点的位置随着刻划深度和刻刀刀尖角度变化的规律。为光栅槽形过挤压现象的抑制以及槽形的控制提供了理论依据。

Diffraction grating is an important optical element,over-squeezing phenomenon in mechanical scratching process will affect its groove quality to a certain extent. In this paper,the slip-lines field model of the groove is established for the obtuse angle,the right angle and the acute angle,and the position of the critical point D is determined by this model with the volume invariant criterion in plastic deformation. In addition,thevariety law of the position of D atdifferent scratching depthand thenoseangleisobtainedunderthecertain constant and blazeangle of grating. These provide the theoretical basis for the grooves over-squeezing and the control of the shape of grooves.