Rapid sintering of TiB2 ceramics using Co as sintering aid under high pressure condition

Abstract The improved TiB2 ceramics were obtained in sintering process at the pressure of 5.5 GPa and temperature of 1550 °C in presence of metallic Co powder. The effect of Co content (ranging from 0 wt.% to 10.0 wt.%) on the phase composition, density, microstructure, Vickers hardness and thermal conductivity of TiB2 ceramics was analyzed. A small amount of new phase Co2B has been created in the reaction of TiB2 and Co. The relative density of sintered TiB2 ceramics reached 98.1 %. When the mass fraction of Co increased, the porosity increased, while the hardness first increased and then decreased. The maximal Vickers hardness values were equal to 33.3 GPa or 28.2 GPa when the used load was of 4.9 N or 9.8 N, respectively. The highest reached value of thermal conductivity was 88.9 W˙m−1 ˙ K−1. The dense TiB2 ceramics with improved hardness and thermal conductivity were ascribed to the high pressure sintering method and Co sintering aid. High pressure sintering method provides a new way for the preparation of ceramics materials.

[1]  Chuanzhen Huang,et al.  Microstructural development and mechanical properties of reactive hot pressed nickel-aided TiB2-SiC ceramics , 2016 .

[2]  D. Zuo,et al.  Influence of applied pressure on the microstructure and properties of Ti(C,N)–TiB2–Co cermets prepared in situ by reactive hot-pressing , 2016 .

[3]  Ľ. Bača,et al.  Effect of metallic dopants on the microstructure and mechanical properties of TiB2 , 2015 .

[4]  H. Baharvandi,et al.  Effect of different additives on the sintering ability and the properties of B4C–TiB2 composites , 2015 .

[5]  S. Chao,et al.  Titanium diboride composite with improved sintering characteristics , 2015 .

[6]  Yanming Ma,et al.  Exploring Hardness and the Distorted sp2 Hybridization of B–B Bonds in WB3 , 2014 .

[7]  H. Katsui,et al.  Rod-like eutectic structure of arc-melted TiB2–TiCxN1−x composite , 2014 .

[8]  Ye-hua Jiang,et al.  Elastic and electronic properties of XB2 (X=V, Nb, Ta, Cr, Mo, and W) with AlB2 structure from first principles calculations , 2014 .

[9]  M. Öveçoğlu,et al.  Influences of metallic Co and mechanical alloying on the microstructural and mechanical properties of TiB2 ceramics prepared via pressureless sintering , 2012 .

[10]  B. Bouhafs,et al.  Theoretical analysis of the spin effect on the electronic and magnetic properties of the calcium manganese oxide CaMnO3: GGA+U calculation , 2010 .

[11]  A. K. Suri,et al.  Processing and properties of monolithic TiB2 based materials , 2006 .

[12]  G. Zou,et al.  High-pressure pyrolysis study of C3N6H6: a route to preparing bulk C3N4 , 2002 .

[13]  R. Munro Material Properties of Titanium Diboride , 2000, Journal of research of the National Institute of Standards and Technology.

[14]  S. Torizuka,et al.  Effect of SiC on Interfacial Reaction and Sintering Mechanism of TiB2 , 1995 .