Enhancement of surface quality using a newly developed technique in turning operations

Abstract

Every machining operation leaves characteristic evidence on the machined surface. This evidence takes the form of finely spaced micro irregularities left by the cutting tool. A two-pass technique was introduced for enhancing the surface roughness for different cutting conditions and workpiece materials based on the feed marks (pattern) left by the tool in the machining operation. An important drawback of this technique is that the time taken for its two passes represents twice the time of regular machining. Another drawback is the difficulty of adjusting the tool in the second pass with the appropriate accuracy. For solving these problems, a tool design is provided in this paper to achieve the same results of the two-pass technique in one pass. The objective of this research is to compare this technique using different methods (regular or one pass, two passes, new tool) using different cutting conditions and different workpiece materials. In addition to the surface roughness, straightness and roundness errors are measured for these methods (two passes, new tool) and compared with regular cutting. Improvement of surface roughness was shown as the straightness and roundness errors decrease by using this new technique. In practice, the new tool technique improves the surface roughness, straightness error, and roundness error by more than 58, 65, and 50 per cent respectively at the proposed cutting condition (50 m/min cutting speed, 0.2 mm/rev feed, and 1 mm depth of cut) for all workpiece materials used.