Effects of the Sintering Atmosphere and Ni Content on the Liquid-phase Sintering of $TiB_2$-Ni

  • Suk-Joong L. Kang (Materials Interface Laboratory, Department of Materials Science and Engineering, Korea Advanced Institute for Science and Technology) ;
  • Baung, Jin-Chul (Now, with Samsung Electro-Mechanics) ;
  • Park, Yeon-Gyu (Now, with Sam-Young Technology Research Institute, Korea Insulators Industrial Co.) ;
  • Kang, Eul-Son (Agency for Defense Development) ;
  • Baek, Yong-Kee (Agency for Defense Development) ;
  • Jung, Sug-Woo (Materials Interface Laboratory, Department of Materials Science and Engineering, Korea Advanced Institute for Science and Technology)
  • Published : 2001.03.01

Abstract

The effects of the sintering atmosphere and Ni content on t도 densification of TiB$_2$-Ni have been investigated. TiB$_2$powder compacts containing 10, 20, and 30 wt% Ni were liquid-phase sintered at 1500-1$700^{\circ}C$ in vacuum or in flowing Ar. The densification was enhanced as Ni content increased. For a given Ni content, the densification was faster in compacts in compacts with larger grain size. These densification behaviors agree well with the prediction of the recently developed pore-filling theory. For samples containing high Ni contents, 80TiB$_2$-20Ni and 70TiB$_2$-30Ni, the densification was faster in vacuum than in Ar. In particular, 70TiB$_2$-30Ni was fully densified at 1$700^{\circ}C$ for 60min in vacuum. The suppressed densification in Ar was due to the entrapped Ar in the isolated pores. On the other hand, for 90TiB$_2$-10Ni, the Ar-sintering resulted in higher densification than did the vacuum-sintering. This result was attributed to the suppression of Ni volatilization by the Ar in the furnace and a retarded isolation of pores due to the limited amount of liquid in the sample. Therefore, vacuum sintering is recommended for the preparation of TiB$_2$-Ni with a high Ni content while Ar sintering is recommended for the preparation of TiB$_2$-Ni with a low Ni content.

Keywords

References

  1. Science of Hard Materials Structure-Property Correlations for TiB₂-Based Ceramics Densified Using Active Liquid Metals V.J.Tennery;C.B.Finch;C.W.Yust;G.W.Clark;R.K.Viswanadham(ed.)
  2. J.Am.Ceram.Soc. v.67 no.7 Mechanical Properties of Densely Sintered High-Purity Titanium Diborides in Molten Aluminum Environments H.R.Baumgartner
  3. Mater. Sci. Prog. Annual Report;Metals and Ceramic Div. Structural Ceramics P.F.Becher
  4. Boron and Refractory Borides Use of Boron Compounds in Light Weight Armor M.L.Wilkins;Y.L.Matkovlch(ed)
  5. J. Am. Ceram. Soc. v.66 no.1 Effect of Microstructure on the Properties of TiB₂Ceramics M.K.Ferber;P.F.Becher;C.B.Finch
  6. New Developments and Applications in Composites, Trans. AIME Enhancement of Mechanical Strength in Hot-pressed TiB₂ Composites by the Addition of Fe and Ni C.F.Yen;C.S.Yust;G.W.Clark
  7. Am.Ceram.Soc.Bull. v.59 no.4 NiP Binder for TiB₂-Based Cermets T.Watanabe
  8. J. Am. Ceram. Soc. v.67 no.3 Sintering and Properties of Titanium Diboride Made from Powder Synthesized in a Plasma-Arc Heater H.R.Baumgartner;R.A.Steiger
  9. Adv. Ceram. Mater. v.1 no.1 Effect of Impurities on the Densification of Submicrometer TiB₂Powders C.B.Finch;P.F.Becher;P.Angelini;S.Baik;C.E.Bamberger;J.Brynestad
  10. J. Am. Ceram. Soc v.70 no.8 Effect of Oxygen Contaminatior on Densification of TiB₂ S.Baik;P.F.Becher
  11. J. Am. Ceram. Soc. v.72 no.10 Effect of Iron and Boron Carbide on the Densificatior and Mechanical Properties of Titanium Diboride Ceramics E.S.Kang;C.W.Jang;C.H.Lee;C.H.Kim;D.K.Kim
  12. J. Mater. Sci. v.31 Two-step Sintering of a TiB₂-Ni Cermet W.-J.Kim;D.-H.Kim;E.S.Kang;D.K.Kim;C.H.Kim
  13. Acta Mater. v.46 no.9 Theoretical Analysis of Liquid-Phase Sintering:Pore-filling Thoery S.-M.Lee;S.-J.L.Kang
  14. Acta mater Growth Mechanism of Rounded-edged NbC Grains in Co Liquid H.-S.Moon;B.-K.Kim;S-J.L.Kang
  15. J. Phys. Chem. Solids v.19 The Kinetics of Precipitation from Supersaturated Solid Solutions I.M.Lifshitz;V.V.Slyozov
  16. Z. Electrochem. v.65 Theory of Precipitate Change by Redissolution C.Wagner
  17. J. Am. Ceram. Soc. v.72 Elimination of Large Pores during Gas-pressures Sintering of Sialon S.-J.L.Kang;P.Greil;M.Mitomo;J.-H.Moon
  18. Proceedings of Sintering 99 v.99 Liquid Phase Sintering:Grain-growth Induced Densification S.-J.L.Kang;S.-M.Lee
  19. J.Appl.Phys. v.30 Densification during Sintering in the Presence of a Liquid Phase. I. Theory W.D.Kingery
  20. M.S.Thesis,KAIST A Study on the Sintering Behavior of TiB₂-Ni based Ceramics W.-J.Kim
  21. Metall.Trans.A v.17A Effect of Entrapped Inert Gas on Pore Filling during Liquid Phase Sintering S.-J.Cho;S.-J.L.Kang;D.N.Yoon
  22. Proceedings of Sintering'85 Formation of Residual Porosity during Liquid Phase Sintering of W-Ni-Fe S.-J.L.Kang;B.S.Hong;Y.G.Cho;N.M.Hwang;D.N.Yoon;G.C.Kuczynski(ed);D.P.Uskokovic(ed);Hayne Palmour(ed.);M.M.Ristic(ed.)
  23. J.Am.Ceram.Soc. v.71 Effect of Grain Growth on Pore Coalescence during the Liquid-Phase Sintering of MgO-CaMgSiO₄Systems U.-C.Oh;Y.-S.Chung;D.-Y.Kim;D.N.Yoon