Study on the Effect of Tool Polarity and Tool Rotation during EDM of Non-Conductive Ceramics

Abstract:

The ability to machine advanced ceramic materials such as ZrO₂, SiC, and AlN is of high interest for various industries because of the extraordinary material properties that these ceramics possess. Once sintered, these ceramics are characterized with high mechanical strength, high thermal stability and high chemical inertness. Therefore it is extremely difficult to machine these ceramics with dimensions in few microns using traditional techniques. Electrical discharge machining (EDM) is an electro-thermal machining process used to structure conductive materials. By applying a conductive layer on top of the non-conductive material, the EDM process can also be used to machine the non-conductive material. This paper presents a study on the effect of tool polarity and tool rotation on the material removal rate and electrode wear ratio during the EDM process of non-conductive SiC, ZrO₂ and AlN ceramics. The reasons for the variation in the material removal rates among the different ceramics are examined by comparing the material properties. Relatively lower value of flexural strength, fracture toughness and melting temperature is the reason for AlN ceramic to have the higher MRR than SiC and ZrO₂ ceramics.

• Periodical: Advanced Materials Research (Volumes 941-944)
• Pages: 2127-2133
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.941-944.2127
• Online since: June 2014
• Authors: Nirdesh Ojha*, Florian Zeller, Claas Mueller, Holger Reinecke
• Keywords: Aluminum Nitride (AlN), EDM, Non-Conductive Ceramics, Silicon Carbide (SiC), Tool Polarity, Tool Rotation, Zro₂

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