Investigation of Microstructure and Mechanical Property of the Machinable B₄C/BN Composites Fabricated by Hot-Pressing Process

Abstract:

The B₄C/BN composites were fabricated by hot-pressing process in this research. The B₄C/BN composites included the B₄C/BN microcomposites and the B₄C/BN nanocomposites. The B₄C/BN microcomposites were fabricated by hot-pressing process, and the B₄C/BN nanocomposites were fabricated by chemical reaction and hot-pressing process. In this research, the phase composition, microstructure, mechanical property and machinability of the B₄C/BN microcomposites and B₄C/BN nanocomposites were investigated. The XRD patterns results showed that there existed B₄C phase and h-BN phase in the hot-pressed composites. The microstructure of the B₄C/BN composites was investigated by SEM and TEM. The B₄C/BN microcomposites and the B₄C/BN nanocomposites sintered bulks exhibited the homogenous and compact microstructure, and the h-BN particles were homogenously distributed in the B₄C matrix. The mechanical property of the B₄C/BN microcomposites and the B₄C/BN nanocomposites decreased gradually with the increase of h-BN content. The mechanical property of the B₄C/BN nanocomposites was remarkably improved in comparison with the B₄C/BN microcomposites. The machinability of the B₄C/BN microcomposites and the B₄C/BN nanocomposites increased gradually with the increase of h-BN content, the drilling rates of the B₄C/BN composites specimens increased gradually with the increase of h-BN content. The relationship between the microstructure and machinability of the B₄C/BN composites was analyzed. The microstructure showed that the weak interface of B₄C/BN and cleavage behavior of laminate structured h-BN particles remarkably improved the machinabilty of B₄C/BN composites.

• Periodical: Advanced Materials Research (Volumes 415-417)
• Pages: 335-338
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.415-417.335
• Online since: December 2011
• Authors: Tao Jiang
• Keywords: B₄C/BN Composites, Hot-Pressing Process, Microstructure

References

[1] E.H. Heian, S.K. Khalsa and J.W. Lee: J. Am. Ceram. Soc. Vol. 87 (2004), p.779.

[2] H. Lee and R.F. Speyer: J. Am. Ceram. Soc. Vol. 86 (2003), p.1468.

[3] M.W. Chen, J.W. McCauley and J.C. Lasalvia: J. Am. Ceram. Soc. Vol. 88 (2005), p.1935.

[4] U.A. Tamburini and Z.A. Munir: J. Am. Ceram. Soc. Vol. 88 (2005), p.1382.

[5] T. Kusunose, T. Sekino and Y.H. Choa: J. Am. Ceram. Soc. Vol. 85 (2002), p.2678.

[6] T. Kusunose, T. Sekino and Y.H. Choa: J. Am. Ceram. Soc. Vol. 85 (2002), p.2689.

[7] T. Kusunose and Y.H. Kim: J. Mater. Res. Vol. 20 (2005), p.183.

[8] X.D. Wang, et al: J. Am. Ceram. Soc. Vol. 87(2004), p.565.

[9] Y.L. Li, et al: Mater. Res. Bull. Vol. 37(2002), p.1401.

[10] Y.L. Li, et al: Mater. Sci. Eng. A. Vol. 397(2005), p.35.

[11] T. Hagio, K. Nonaka and T. Stato: J. Mater. Sci. Lett. Vol. 16(1997),p.795.

[12] G.J. Li and L. Gao: J. Mater. Chem. Vol.13(2003),p.628.