研磨压力对固结聚集体磨料垫自修正影响

Effect of lapping load on self-conditioning performance of fixed agglomerated abrasive pad

固结磨料研磨过程中磨料的微破碎是实现固结磨料垫自修正特性的主要途径,研磨压力是影响磨粒微破碎的关键参数。选用单晶金刚石和聚集体金刚石作为磨粒制备固结磨料垫,在15 kPa压力下以石英玻璃为加工对象进行研磨实验,比较两者的材料去除率及加工稳定性;制备了4种陶瓷结合剂含量的聚集体金刚石,并制备成固结聚集体金刚石磨料垫,探索了不同压力下的固结聚集体金刚石磨料垫的自修正性能;分析了研磨后的工件表面粗糙度和表面微观形貌。结果表明:采用固结聚集体金刚石磨料垫,研磨后工件表面粗糙度低,去除效率稳定;在15~21 kPa的压力下,结合剂含量次高的聚集体金刚石研磨效率高,材料去除率达到8.94~12.43μm/min,加工性能较稳定,研磨后的工件表面粗糙度R a在60 nm左右;在3.5~7 kPa压力下,结合剂含量次低的聚集体金刚石研磨性能较稳定,材料去除率在2.67~3.12μm/min,研磨后的表面粗糙度R a在40 nm左右。高结合剂含量的聚集体金刚石磨粒更适合高研磨压力条件,而低结合剂的聚集体金刚石磨粒更适合于低研磨压力。

During the process of fixed abrasive(FA)lapping,the micro-fracture of abrasives is the main approach to realize the self-conditioning process of the FA pad;the lapping load is one of the key parameters that affects it.The FA pads were prepared by using single diamond(SD)and agglomerated diamond(AD)abrasives.Marathon lapping tests were carried out,using quartz glass as the workpiece under a lapping load of 15 kPa.The material removal rate(MRR)and machining stability of the two FA pads were comparedtogether.Four kinds of AD abrasives with different concentrations of the ceramic binder were prepared and chosen as the abrasives to prepare the corresponding fixed AD abrasive(FADA)pads;their self-conditioning performance was evaluated under different lapping loads.The surface roughness(R a)and morphology of the lapped quartz glass were observed.The results show that:the R a of quartz glass lapped using the FADA pad is lower than of that lapped using fixed SD abrasive(FSDA)pad and that the former has a greater machining stability.Under a higher lapping load of 15-21 kPa,the FADA pad with the second highest ceramic binder concentration has the highest lapping efficiency;its MRR is 8.94-12.43μm/min and R a is approximately 60 nm.Under a lower load of 3.5-7 kPa,the FADA pad with the second lowest ceramic binder concentration is the most stable;its MRR is 2.67-3.12μm/min;the R a is approximately 40 nm.AD abrasive with a high ceramic binder concentration is more suitable as the abrasive for a FA pad in high-load applications,while that with a low concentration is more suitable for low-load applications.