Experimental investigations on enhanced alternating-magnetic field-assisted finishing of stereolithographic 3D printing zirconia ceramics

Abstract

Zirconia ceramic components have great applications in the fields of medical, aerospace, and energy. Stereolithographic (SLA) 3D printing technology is widely employed for zirconia ceramic fabrication. However, the surface quality of manufactured components by direct SLA 3D printing is hard to meet stringent requirements of industrial application. In this work, an enhanced alternating-magnetic field-assisted finishing (A-MFAF) method was proposed for SLA printed zirconia ceramics. The A-MFAF was achieved using a flexible alternating-magnetic-field generator, integrating a rectangular magnetic pole and radial magnetic column. The novel finishing tool was fabricated to regulate finishing media behaviors for ensuring desirable finishing force. The unique construction of the magnetic field generator provided a controllable alternating magnetic field in the finishing zone. The magnetic control characteristics were investigated with finite element analysis (FEA). A serial of finishing experiments were carried out to verify the feasibility of the proposed A-MFAF method for SLA printed zirconia ceramics. The finishing efficiency with the developed magnetorheological shear thickening finishing (MSTF) media was improved by over 24% compared to that with the conventional magnetorheological finishing (MRF) fluids. The variation of surface roughness was qualitatively evaluated under different finishing conditions. The surface roughness of 89 nm was obtained from the initial 1.79 μm at 0.6 mm working gap and 700 r/min spindle rotational speed. Digital microscope, optical profiler and surface hydrophobicity measuring instrument were employed to investigate the surface characteristics of the finished SLA printed zirconia ceramics. Ultra-smooth surface with slight defects and deformations was obtained. The feasibility of A-MFAF method for the ultra-precision finishing of SLA printed zirconia ceramics was verified.