Abstract
Rigid-Polyvinylchloride (R-PVC) cutting mechanism has been studied. Especially, generating mechanism and condition for periodical surface irregularities have been investigated. The cutting forces are affected by cutting speeds and tool rake angle. The maximum cutting forces exist between 4 and 10 m/min cutting speeds which are called critical cutting speeds. At these speeds, the cutting mechanism changes from continuous to discontinuous chip formation. Above these speeds the periodical irregularities are generated on the machined surface by less than 30° rake angle cutting. The periods depend upon depth of cut and the rake angle. Smooth surface can not be obtained at the critical rake angle. Rake angle 30° cutting produces continuous chip, however relatively smooth machined surface has some big damages caused by cracking. The cutting model offered by author can explain characteristic R-PVC cutting phenomena well.
