Papers by Keyword: Reversible Cutting

Abstract: Reversible cutting method is a new research thesis proposed to shorten processing route, decrease tool number and handling time, increase machining efficiency. Based on nonlinear hardening during reverse loading and the change of the Bauschinger effect factor with plastic strain, reverse loading released strain energy of elastic responses of machined underlayer. The chip formation model of reversible finish cutting was established. The difference between the advance and return stroke was analyzed in crystal slipping and elongating, residual stress, micro-hardness of machined surface. Experimental research indicted that the results of micro-hardness of reversible fine machining technique are smaller than that of general fine machining, the circumferential residual stress at the finished surface is compressive, the surface roughness of machined surface are smaller than that of general fine machining. The kinematic hardening models of the advance and return stroke finishing cutting based on Bauschinger effect is presented.

Abstract: Reversible cutting method is a new research thesis proposed to shorten processing route, decrease tool number and handling time, increase machining efficiency. The aim of the presented work was to analysis the effects of reversible fine machining sequence on surface integrity in machined layer. Nonlinear hardening during reverse loading and the change of the Bauschinger effect factor with plastic strain were properly taken into account. In experiments, the residual stresses have been measured using the X-ray diffraction technique (at the surface of the workpiece and in depth). Moreover, micro-hardness and surface roughness of machined surface are presented. Experimental data for the range of cutting parameters tested showed that the reversible fine machining produce the tensile residual stresses at the surface, which are critical in the performance of the machined components. The experimental results of micro-hardness of reversible fine machining technique are smaller than that of general fine machining show that decreased plastic deformation of the surface layer and work-hardening. Surface roughness of machined surface with reversible finishing is discussed. Research results indicted that it can be adopted such planning which rough machining during advance stroke and fine machining or semi-finishing during return stroke in machining process. In this way, it has such advantages that increase machining efficiency and machining accuracy, decrease bending deformation.

Abstract: Reversible cutting method is a research thesis proposed to shorten processing route, decrease tool number and handling time, increase machining efficiency. There are three movement ways, i.e. reversible feed motion, reversible primary motion and reversible composite motion. Primary motion is done by workpiece, conventional or reversible feed motion is done by cutting tool in the way of reversible feed motion, e.g. turning. Cutting velocity is passed to cutting tool, clockwise or anti-clockwise cutting movement is done by cutting tool in the way of reversible primary motion, e.g. milling, shaping, drilling (spade drill), reaming. Primary and feed motions are all reversible in composite motion, e.g. turn-milling. Chip deformation and machined surface with reversible finishing is discussed. A mechanical analysis is carried out to the workpiece deformation of slender shaft turning in normal direction and reversible direction. The result has been verified by experiments. Experimental data for the range of cutting parameters tested showed that the reversible fine machining produce the compressive residual stresses at the surface, which are critical in the performance of the machined components. Experimental research indicted that the results of micro-hardness of reversible fine machining technique are smaller than that of general fine machining show that decreased plastic deformation of the surface layer and work-hardening. It can be adopted such planning which rough machining during advance stroke and fine machining during return stroke in machining process.