A systematic study on single-sided lapping of Al2O3 ceramic surfaces using SLS fabricated tools
摘要
This paper presents the technological effects of one-sided lapping of Al2O3 technical ceramic samples using special, additively manufactured tools. The prototype abrasive segments forming the lapping wheels were fabricated by the SLS (selective laser sintering) method on an EOS Formiga P100 printer from PA 2200 polyamide powder. In each of the conducted series of experimental tests, the values of linear Δh and mass Δm material losses of ceramic samples, as well as their surface quality based on the roughness Ra and waviness Wa parameters, were analysed. In addition, the surface topography of the samples was evaluated after machining tests using a 3D optical profilometer. The use of SLS tools and the adopted process parameters resulted in efficient machining, with an average material removal MRRdm of 31.24 mg/min and MRRdh of 9.58 µm/min. Furthermore, the surface quality of ceramic samples was improved significantly, from an initial roughness Ra of 1.67 µm to 0.49 µm, resulting in uniform surface topography. The comparison of the obtained results for a particular series of machining, together with a statistical evaluation of the results, demonstrate that the lapping process of technical ceramics is reproducible and stable. The flat surface of the polyamide tool, permanently reinforced with diamond grains, allowed it to cut hard ceramics for more than 10 h while using only a single dosage of abrasive material.