Ductile cutting of tungsten carbide

Tungsten carbide as a super hard and high wear-resistant material has been used widely in industry. The common method for producing tungsten carbide c omponents is by powder metallurgy technology. However, for small quantity p roduction, such as product prototyping, this method is obviously too costly and time consuming. It is expected to make the prototypes by material remo val process, such as cutting, if the ductile cutting of tungsten carbide ca n be achieved. In this paper, a theoretical and experimental study on the d uctile cutting of tungsten carbide is presented. Theoretical analyses are g iven on the characteristics of tungsten carbide as functions of temperature and on the critical conditions for ductile mode chip formation in the cutt ing of tungsten carbide. An energy model for ductile chip formation in the cutting of tungsten carbide is developed, in which the critical undeformed chip thickness for ductile chip formation in the cutting of tungsten carbid e can be predicted from the workpiece material characteristics, tool geomet ry and cutting conditions. The model is verified with experimental results from the cutting of tungsten carbide on a CNC laths using CBN tools. The ma chined workpiece surfaces and their topographic details are examined using a scanning electron microscope (SEM) and an optical measurement inspection system (OMIS). The depth of cut at the transition region of the machined gr oove is measured using a surface profiler It is shown that the predicted re sults for the critical undeformed chip thickness corresponding to ductile c utting agree well with the experimental results. (C) 2001 Elsevier Science B.V. All rights reserved.