Electrical aspects of the spark-plasma sintering of TiN-Ti[B.sub.2] composite. I. Effect of electrical parameters of spark-plasma sintering on the structure and properties of TiN- Ti[B.sub.2] composite

• Published in: Powder metallurgy and metal ceramics Vol. 50; no. 9-10; p. 596
• Main Authors: Petukhov, A.S, Khobta, I.V, Ragulya, A.V, Derevyanko, A.V, Kovalchenko, A.M, Starchenko, V.V
• Format: Journal Article
• Language: English
• Published: Springer 01-01-2012
• Subjects: Analysis; Boron nitride; Ceramic materials; Ceramics; Electric properties; Hardness; Powders; Sintering
• ISSN: 1068-1302

The electrical aspects of spark-plasma sintering (SPS) of Ti[H.sub.2]-BN and Ti+BN powder mixtures for the production of a TiN-Ti[B.sub.2] ceramic composite material are studied, and the dependence of its properties on direct-current density at the initial stage of sintering is established. To determine the direct-current density, a method for calculating the effective cross-sectional area [S.sub.e[florin][florin]] of the die-sample circuit is proposed. At the initial stage of sintering, the major portion of the current flows through the graphite die because of the resistance of the contacts and the presence of [alpha] -BN dielectric. At the final stage of sintering, the current flows mainly through the sintered sample because of the synthesis and densification of the TiN+Ti[B.sub.2] composite and, consequently, the abrupt increases in the conductivity of the sintered sample. Increasing the initial direct-current density during the sintering of Ti[H.sub.x] hydride samples leads to an increase in relative density (conductivity), microhardness, fracture toughness, and abrasive wear resistance. Keywords: electrical parameters, ceramic composite material, TiN+Ti[B.sub.2], spark-plasma sintering.