Micro-Grinding of Poly Crystalline Diamond Insert Using a Controlled force Technique

Increasing use of Poly Crystalline Diamond (PCD) for cutting tools and wear parts is vividly seen in automobile, aerospace, marine and precision engineering applications. The PCD inserts undergo series of manufacturing processes such as: grinding to form the required shape and polishing to give a fine finish. These operations are not straight forward as PCD is extremely resistant to grinding and polishing. Single crystal diamond tools can be easily ground by choosing a direction of easy abrasion, but grinding PCD imposes serious difficulties as the grains are randomly oriented. Prior studies on PCD grinding using a vitrified bond diamond wheel produces surface defects such as: micro-grooving, edge chipping, cracks, and gouge marks. In this project, a new Micro-grinding technology that applies controlled amount of grinding force was attempted for PCD inserts grinding. The experimental results indicate that the developed method has produced ductile or partial ductile modes of fractures on the ground surface of PCD insert in the form of fine grooves and steaks. Also while applying a controlled force of value 66.75∼80 N a surface finish (R_a) 0.1 ∼0.11 μm was achieved.