Development of New PCD Made Up of Boron Doped Diamond Particles and its Machinability by EDM

Abstract:

This paper deals with a new PCD named EC-PCD which is made up of boron doped diamond particles and its properties related to EDM machinability. For the purpose of improving various properties of standard PCD including resistance to heat, wear and reactivity, a new PCD (EC-PCD) was manufactured on a trial basis using electrically conductive diamond particle as a basic ingredient. Grain size, resistivity and thermal conductivity of the boron doped diamond used are 10μm, 5~37×10Ω•m and 440~580W/m•K. In this report, machinability of newly developed PCD (EC-PCD) by wire EDM was investigated in comparison with that of standard PCD. In wire cutting of 2 types of PCD in water under the condition of open gap voltage: ue=80V, set peak current: iP=0.8A and pulse condition: te/to=20/20μs, it was found that roughness of the first cut surface of standard PCD was approximately 8μm Rz, while that of EC-PCD was far better such as 3μm. Also in finish cut (7th cut), the latter achieved the value of Rz=1.7μm while the former achieved only the value of Rz=2.7μm. Expecting better performance, EC-PCD was tested also in oil. As a result, the best achieved roughness was improved to Rz=0.4μm with no chipping on the edge. To explore a reason for such a good roughness obtained, the cut samples were observed on the SEM, which revealed that the diamond particles in EC-PCD were flattened by electro discharge.

• Periodical: Advanced Materials Research (Volumes 76-78)
• Pages: 684-689
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.76-78.684
• Online since: June 2009
• Authors: Kiyoshi Suzuki, Yoichi Shiraishi, Nobuhiro Nakajima, Manabu Iwai, Shinichi Ninomiya, Yukinori Tanaka, Tetsutaro Uematsu
• Keywords: Boron Doped Diamond Particle, Electrically Conductive PCD, Polycrystalline Diamond (PCD), Wire EDM

References

[1] Catalogue from Element Six Co. Ltd.

[2] Y. Seki, K. Suzuki, T. Uematsu, T. Makizaki, F. Nabata, A. Ide: Application of PCP to grinding wheel - 1st report, Proceedings of ABTEC Conference (1996) pp.349-352. (in Japanese).

[3] K. Suzuki, S. Sano, M. Iwai, W. Pan, A. Sharma, T. Uematsu: A New Application of PCD as a Very Low Wear Electrode Material for EDM, Proceedings of 2nd International Industrial Diamond Conference (2007).

DOI: 10.4028/www.scientific.net/kem.291-292.549

[4] K. Suzuki, S. Sano, W. Pan, M. Iwai, S. Ninomiya, T. Uematsu: Precise Profile Forming by Combining EDM and Grinding with a Same PCD Tool, Proceedings of 2nd International Industrial Diamond Conference (2007).

[5] Technical data from FACT Co. Ltd. (a) Surface (b) Edge Figure 6 Finish cut surface of EC-PCD by wire EDM in oil (12th cut).