Development of turning-burnishing process using variable nose radius tool

Abstract

The objective of this study is to develop a turning-burnishing process which can obtain a burnished surface with low roughness even if feed rate in burnishing is raised by making the nose radius variable in burnishing utilizing flank face. As a preparation stage, experiments were conducted using inserts with different nose radius in turning and burnishing, and the effect of nose radius and feed rate in burnishing on burnished surface was investigated. In this research, SCM 440 solid round bar of alloy steel was selected as the workpiece. Turning and burnishing were performed on hardened material and unhardened material. Inserts of non-coated cermet is used, and the nose radius R = 0.8 mm in turning. Nose radius in burnishing was changed at 4 levels: R = 1.2, 1.6, 2.0, 2.4 mm, and for each nose radius, feed rate in burnishing was changed at 5 levels: fb = 0.025, 0.05, 0.075, 0.1, 0.125 mm/rev. As a result, when feed rate in burnishing was fb = 0.125 mm / rev., there was a tendency for roughness to decrease by increasing the nose radius.