Role of Shim-Induced Passive Damping on Surface Roughness Optimization in Face Milling

Resumo

The presence of machining induced vibrations in face milling has a severe impact on surface roughness and, therefore, effective passive damping is a critical part of process stability and surface integrity. This research work examines how passive damping effect of shim material is a prevailing factor in control of surface roughness (SR), in addition to depth of cut, feed rate and cutting speed. A Response Surface Methodology using a Central Composite Design was utilized to predict surface roughness with three shim conditions which are no shim, stainless steel shim, and carbide shim. The findings reveal that carbide shims are more effective in damping vibrations and always produce lower surface roughness as compared to the other designs. The optimum cutting speed of 200 m/min, depth of cut of 0.8 mm, and feed rate of 0.1 mm/tooth produced surface roughness of 0.189 µm, and this is close to the predicted value. The model was highly predictive with a coefficient of determination (R²) of 98.59%. These findings prove that the choice of shim material, especially use of carbide shims is a vital factor in improving surface finish during face milling processes.