单颗金刚石磨粒切削氮化硅陶瓷仿真与试验研究

发布时间：2019-05-09 06:54

【摘要】：为探索氮化硅陶瓷单颗磨粒切削加工的机理,进行单颗金刚石磨粒切削氮化硅陶瓷的仿真与试验。选用截角八面体模拟金刚石磨粒,基于Johnson-Holmquist ceramic硬脆材料本构模型,采用有限元网格法进行单颗磨粒直线切削仿真,分析工件材料的切屑去除、划痕形貌、应力动态变化与分布、切削力变化等现象,以及工艺参数对切削力的影响。制备单颗金刚石磨粒工具,在平面磨床上进行单颗磨粒切削氮化硅陶瓷的试验,进一步分析划痕形貌、切削力的变化,并验证有限元仿真的正确性。研究表明,划痕光直平整,塑性隆起很少,边缘存在较大尺寸的破碎,划痕内有局部小尺寸的破碎;划痕的深度和宽度比磨粒的切削深度和宽度尺寸略大。应力与切削力存在动态波动。随着砂轮速度的增加,切向力和法向力减小;随着切削深度的增加,切向力和法向力增大。切削力比在4~6之间变化。
[Abstract]:In order to explore the mechanism of single abrasive cutting of silicon nitride ceramics, the simulation and experiment of cutting silicon nitride ceramics with single diamond abrasive particles were carried out. Using angle octahedral to simulate diamond abrasive particles, based on Johnson-Holmquist ceramic hard and brittle material constitutive model, the finite element grid method is used to simulate the straight line cutting of single abrasive particles, and the chip removal and scratch morphology of workpiece materials are analyzed. The dynamic change and distribution of stress, the change of cutting force and the influence of process parameters on cutting force. A single diamond abrasive tool was prepared and the experiment of cutting silicon nitride ceramics with a single abrasive particle was carried out on a plane grinder. The scratch morphology and cutting force were further analyzed, and the correctness of the finite element simulation was verified. The results show that the scratches are smooth and smooth, the plastic bulges are few, the edges are broken in a larger size, and there are local small sizes in the scratches, and the depth and width of the scratches are a little larger than the cutting depth and width of the abrasive particles. There are dynamic fluctuations in stress and cutting force. With the increase of grinding wheel speed, the tangential force and normal force decrease, and with the increase of cutting depth, the tangential force and normal force increase. The cutting force ratio varies from 4 to 6.
【作者单位】：湖南大学机械与运载工程学院;湖南科技大学机电工程学院;湖南科技大学难加工材料高效精密加工湖南省重点实验室;
【基金】：国家自然科学基金(51505144,51405152) 难加工材料高效精密加工湖南省重点实验室开放基金(E21539) 高等学校博士学科点专项科研基金(20110161110032)资助项目
【分类号】：TG501

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