An investigation of the surface finishing action and resulting surfaces produced by the Cascade Finishing process
This paper presents the results of a systematic study of the Cascade Finishing Process with respect to its ability to improve surface finish. Although mainly used to deburr and clean castings and machined parts, the process was able to greatly improve the surface finish under the right operating conditions. Six major topics were investigated: The nature of the surface finish produced, the significance and effects of runtime, vibratory frequency and fixture clearance, the effects of four different media types, the effects of surface orientation, the effects of different initial surface finishes, and the integrity of the surfaces produced, including residual stresses and micro-hardness;Using abrasive media the vibratory action produced directional, matte surfaces with Ra values as fine as.27[mu]m Ra. Surfaces perpendicular to the vibratory motion were found to have undergone a peening action with surfaces having initial roughnesses of 6.7[mu]m Ra being smoothed to 1.5[mu]m under the proper operating conditions. Many profile tracings and micro-photographs of the surfaces produced by the process are included in this paper. Almen strip tests indicate that the peening action observed is less intense than standard shot peening. Run time, vibratory frequency, media type, initial surface roughness and surface orientation were all found to be major factors governing the process. Empirical models and main effect plots resulting from the experiments are also included.