小口径非球面光学模具斜轴磨削加工试验研究

Experimental Study on Inclined Rotational Grinding for Small Aspherical Optical Mould

小口径非球面光学模具采用超精密斜轴磨削加工避免传统直交磨削法中砂轮轴与工件发生干涉的问题.选用碳化钨和不锈钢材料作为工件,采用斜轴磨削法,对小口径非球面光学模具磨削加工进行试验研究.结果表明:碳化钨模具获得的表面粗糙度和面形精度分别为R_a1 nm和PV 182 nm,不锈钢模具获得的表面粗糙度和面形精度分别为R_a4 nm和PV 304 nm,说明碳化钨模具的磨削效果明显优于不锈钢模具,且磨削后表面质量随工件转速、砂轮转速及砂轮粒度增加而变好,随磨削深度及进给深度增加而变差.

To avoid the interference between the workpiece and the grinding-wheel in conventional vertical grinding process,an inclined rotational grinding process was used for ultra-precision machining of small aspherical optical mould.Some inclined rotational grinding experiments were conducted on selected tungsten carbide and stainless steel workpieces.The results showed that the roughness value and the form accuracy from the ground tungsten carbide mould were 1 nm in Raand 182 nm in PV in comparison to those of 4 nm in Raand 304 nm in PV from the ground stainless steel mould,demonstrating the grinding performance on tungsten carbide was better than that on stainless steel.The ground surfacequality got better with the increase in workpiece rotation speed,grinding rotation speed and abrasive grid,but got worse with the increase in grinding depth and feed speed.