电镀单层CBN薄片砂轮磨粒分布的实验研究

Experimental Study on Abrasive Distribution of Electroplating Single-layer CBN Thin-grinding-wheel

提出一种电镀单层CBN砂轮磨粒浓度和分布均匀性的评价计算方法,通过建立数学模型推导出磨粒在单层分布状态下的面积百分比浓度最大值。结合实验分析了脉冲占空比和植砂时间与砂轮浓度及分布均匀性之间的关系,得出不同的占空比和植砂时间下砂轮磨粒浓度及分布均匀性的变化规律。实验结果表明:当阴极均值电流密度取0.6A/dm2,且占空比为0.4～0.6时,磨粒分布的不均匀性主要表现形式为堆挤磨粒比面积在各观测区域的差异和未堆积磨粒在各观测区域数量上的差异;当阴极均值电流密度取0.2A/dm2,且占空比为0.1～0.3时,磨粒分布的不均匀性表现为未堆积磨粒在不同观测区域数量上的差异。此外,在均值电流恒定时,延长植砂时间可有效提高砂轮磨粒浓度,但磨粒分布均匀程度会显著降低。

A new method for evaluating the density and uniformity on electroplating single layer CBN thin-grinding-wheel was mentioned herein.The maximum area-percentage-concentration of CBN abrasive was derived by means of establishing mathematical model under the condition of single layer distribution.Combining the experimental results,the relationships among the space-factor,planting-grit time and grinding-wheel density and among the space-factor,planting-grit time and uniformity were analyzed.Then the changing regular of grinding-wheel density and uniformity were obtained at the different space-factor and planting time.It is shown in the experimental results that the nonuniformity of the grit distribution mainly presents the specific surface difference of crowded grit and the amount difference of non-crowded grit in each observation area when the average current density value is 0.6A/dm2 and the duty factor is from 0.4 to 0.6.When the average cathode current density value is 0.2A/dm2,and the duty factor is from 0.1 to 0.3,the nonuniformity of the grit distribution mainly presents the amount difference of non-crowded grit in each observation area.In addition,extending plant-grind-time can increase the density of grinding wheel effectively when the average value electric current is a constant,but the abrasive distribution level of uniformity will be reduced obviously.