针对传统固结磨盘因其表面沟槽形式单一而难以保证蓝宝石等硬脆性材料加工质量的问题,提出了一种螺旋-同心圆双图案非均匀耦合结构的新型固结磨盘(DPP)设计,并进行了实验研究。DPP采用螺旋槽作为排屑槽,降低了磨盘表面的堵塞程度,以保证加工表面获得低粗糙度,延长工具使用寿命;采用同心圆槽调整磨盘表面磨粒分布,提高了磨盘对工件材料的去除均匀性,以保证加工表面获得更高的平坦度。基于该设计原理,制备了用于蓝宝石加工的新型磨盘,并与传统网格槽型盘(GGP)进行对比。实验结果表明:采用DPP加工时工件表面的凹坑划痕数量更少,约为GGP的35%;研磨后磨盘表面堵塞程度更低,约为GGP的30%。虽然,采用DPP加工时工件材料去除率较GGP低14%,但是材料去除厚度非均匀性为0.0494,比GGP低32%,表面粗糙度为129.4 μm,比GGP低16.2%。因此,采用DPP加工时工件材料去除分布更均匀,工件表面质量更好。实验结果证明:DPP不仅可以获得更好的工件表面质量,还可以延长磨盘的使用寿命,可满足对高质量表面、大规模生产蓝宝石等脆硬材料的精密研磨加工需求。

Traditional fixed abrasive pads (FAPs) present difficulty in guaranteeing the workpiece machining quality in the lapping of hard and brittle materials owing to the single form of grooves fabricated on the pad surface. To address this problem, in this study, a new type of FAP design called DPP, which has a non-uniform coupling and spiral concentric structured pattern, was proposed and tested. To reduce debris blockage on the DPP surface, spiral grooves were used as chip disposal grooves to ensure that the machined workpiece surface had a lower roughness and thus prolonged DPP life. Moreover, concentric circular grooves were used to adjust the distribution of abrasives on the DPP surface, which can improve the material removal uniformity and surface flatness of the machined workpiece. Based on the proposed design principle, the DPP for sapphire lapping was fabricated and compared with a traditional grid grooved pad (GGP). Experimental results show that the number of pits and scratches on the machined workpiece surface is much fewer when using DPP, which is ~35% of that of GGP, and the degree of blockage of the DPP after lapping is lower, which is ~30% of that of GGP. In lapping with DPP, the material removal rate is ~14% lower than that of GGP, but the nonuniformity of material removal thickness is ~0.0494, which is 32% lower than that of GGP. The surface roughness is ~129.4 μm, which is ~16.2% lower than that of GGP. Therefore, when DPP is used for sapphire lapping, the distribution of material removal is more uniform and the surface quality of the workpiece is much better. The test results prove that DPP can not only facilitate better workpiece surface quality but also prolong the pad service life, which meets the efficient and precision machining requirements for high-quality surfaces and large-scale production of brittle and hard materials such as sapphire.