Experimental study on magnetic ball-assisted magnetic abrasive finishing for irregular spherical internal cavity of waveguide formed by selective laser melting
Abstract
In order to improve the surface roughness of the spherical internal cavity of the special-shaped waveguide which was formed by selective laser melting (SLM) and explore the influence of the main processing parameters of magnetic ball-assisted magnetic abrasive finishing (MAF) on the finishing quality, the structure of the waveguide was analyzed, and a profiling AlSi10Mg test sample based on the structure of waveguide was developed; the self-developed magnetic ball-assisted magnetic abrasive finishing device was used to carry out single-factor experiments on the processing time, the size of magnetic abrasive particles (MAPs), the workpiece rotation speed, and the processing clearance at five levels each. The surface roughness reduction rate was selected as the evaluation index to analyze the influence law of each processing factor on the surface roughness reduction rate and surface morphology which was detected by laser confocal. Then the single-factor experiments were carried out to reveal the evolution of surface morphology in MAF for the spherical internal cavity of the special-shaped waveguide formed by SLM. The results show that the surface roughness reduction rate of sample first increases and then decreases with the increase of processing time, workpiece rotation speed and size of MAPs, and significantly decreases with the increase of processing clearance. Through analysis results of the internal surface of the spherical cavity detected by the laser confocal, the surface roughness of the spherical internal cavity was reduced to 0.694 mu m with a reduction rate of 93.94% when the processing time is 20 min, the workpiece rotation speed is 500 r/min, the MAP size is 750 mu m, the processing clearance is 1 mm. A large number of unfused powder protrusions attached to the surface were effectively removed, and the surface morphology was greatly improved. The surface quality of spherical internal cavity of irregular waveguide can be significantly improved, and the surface roughness can be effectively reduced by magnetic Ball-assisted magnetic abrasive finishing with appropriate processing parameters.
