Abstract
The variation of the roughness of the finished surface in turning of cast iron was investigated in reference to the cutting time from the viewpoint of the tool wear and tool vibration.
The following conclusions were drawn from the experimental study :
(1) The increase of surface roughness immediately after the beginning of cut is caused by the wear of the end cutting edge and side cutting edge which are greater than the wear of the nose cutting edge.
(2) The surface roughness decreases during the operation when the nose cutting edge is worn out faster than other parts of the cutting edges, so that the actual nose radius increases.
(3) The final increase of the surface roughness near the end of the tool life is brought about by the excessive tool wear and the increase of horizontal vibration of the tool.
