Experimental study on lapping ceramic balls with variable-radius groove plate

Abstract

The method of lapping precision ball with variable-radius groove is developed in recent years. An experimental study on lapping ceramic balls with variable-radius groove was carried out. Taguchi method was used to design the orthogonal experiment of rough lapping, and the material removal rate ( MRR ) and the roundness were selected as evaluation indicators. The signal to noise ratio (S/N) and the analysis of variance were used to analyze experimental results. The optimal parameters combination with load pressure of 2.5 N/Ball, abrasive concentration of 10 wt% and rotation speed of 15 rpm was obtained. During rough lapping, the maximum reduction rate of average roundness is 50%, the maximum reduction rate of roundness deviation is 81%, the MRR is 16.9 μm/h, and the reduction rate of variation of ball lot diameter ( V DWL ) is 90%. After semi-lapping and polishing, the best surface roughness is up to 10 nm, the best roundness is 0.128 μm, and the V DWL is 0.24 μm. The surface roughness and V DWL of the five balls tested all meet the requirements of ceramic ball with G5 grade, and the roundness value is close to the requirement of G5. The variable-radius groove lapping method is very suitable for improving the precision of batch lapping for ceramic balls.