Cylindrical Wire Electrical Discharge Machining of Metal Bond Diamond Wheels- Part II: Wheel Wear Mechanism

McSpadden, SB

Oak Ridge National Laboratory

关键词: Removal;    36 Materials Science;    Grinding;    Machining;    Scanning Electron Microscopy;   

DOI  :  10.2172/814385
RP-ID  :  ORNL/TM-2001/217
RP-ID  :  AC05-00OR22725
RP-ID  :  814385

美国|英语

来源: UNT Digital Library

【 摘 要 】

The use of stereo scanning Electron Microscopy (SEM) to investigate the wear mechanism of the wire EDM true metal bond diamond wheel for ceramic grinding is presented. On the grinding wheel, a wedge-shape removal part was machined to enable the examination and measurement of the worn wheel surfaces using the stereo SEM. The stereo SEM was calibrated by comparing results of depth profile of a wear groove with the profilometer measurements. On the surface of the grinding wheel after wire EDM truing and before grinding, the diamond protruding heights were measured in the level of 35 {micro}m, comparing to the 54 {micro}m average size of the diamond in the grinding wheel. The gap between the EDM wire and rotating grinding wheel is estimated to be about 35 to 40 {micro}m. This observation indicates that, during the wire EDM, electrical sparks occur between the metal bond and EDM wire, which leaves the diamond protruding in the gap between the wire and wheel. The protruding diamond is immediately fractured at the start of the grinding process, even under a light grinding condition. After heavy grinding, the grinding wheel surface and the diamond protrusion heights are also investigated using the stereo SEM. The height of diamond protrusion was estimated in the 5 to 15 {micro}m range. This study has demonstrated the use of stereo SEM as a metrology tool to study the grinding wheel surface.