Dynamic stabilization of machining process based on local metastability in controlled robotic systems of CNC machines
The paper describes an effective method, which permits to control the machining of hard-to-handle materials under local pre-strain and facilitates generation of structural metastability on the outer layer of the process material. Authors propose a new approach to creating local metastability in the machined material using thermal, plastic and cryogenic treatment. Changes in material properties, occurring under local deformation, are presented in a widely used graphic form of a stress-strain curve. In experimental tests, performed under local plastic strain, the authors observed normal vibration displacement of the tool in relation to the surface of the workpiece, made of medium-carbon steel (0.45 % C). Theoretical and experimental results confirmed the possibility to control the cutting process and to deliver dynamic stability for high-precision machining. The study allows to improve existing technologies for a wide range of materials and cutting modes, to implement segmentation and breaking of the chip in the shear zone, and to apply controlled robotic systems on CNC machines.