Available online at www.sciencedirect.com Journal of the European Ceramic Society 31 (2011) 809–813 Spark plasma sintering of TiCN nanopowders in non-linear heating and loading regimes Ostap Zgalat-Lozynskyy a,∗ , Mathias Herrmann b , Andrey Ragulya a a Institute for Problems of Materials Science (IPMS), 3, Krzhizhanovsky Str., 03680 Kiev, Ukraine b IKTS, Winterbergstrasse 28, D-01277 Dresden, Germany Received 5 July 2010; received in revised form 15 November 2010; accepted 28 November 2010 Available online 17 December 2010 Abstract Consolidation of commercially available nanostructured titanium carbonitride (TiCN) powder has been performed by Spark Plasma Sintering (SPS) in the temperature range from 1300 to 1600 ◦ C. The effect of non-linear heating and loading regimes on consolidation of high melting point nanocomposites has been investigated. SPS consolidated TiCN material has demonstrated near fully dense and fine homogeneous microstructure with average grains size about 150 nm. Nanohardness and fracture toughness of the TiCN nanocomposite have been measured as 33 ± 0.9 GPa and 3.2 MPa m 1/2 respectively. © 2010 Elsevier Ltd. All rights reserved. Keywords: SPS/FAST; Nanocomposites; Microstructure 1. Introduction Spark plasma sintering (SPS) is a widely recognized field assisted sintering technique (FAST), enabling quite rapid con- solidation of desired materials, in a range of 2–15 min for a run including soaking time. High rate consolidation of various metals and ceramics during the SPS process makes this method attractive for the production of nanostructured materials. 1–6 In the SPS process, materials are subjected simul- taneously to a very fast heating, usually with heating rates in the range from 100 to 600 ◦ C/min, and to pressure loading up to 100–200 MPa, followed by a 1–3 min soak at maxi- mum temperature. This results in obtaining high relative density (95–98%) of the consolidated materials at temperatures, which are generally 150–200 ◦ C lower compared to the maximum processing temperatures for conventional sintering or hot press- ing techniques. 1,3,6 In spite of the fact that SPS has been extensively investigated over the past decades, the effect of heating rate and pressure on the consolidation of various mate- rials is still under the investigation. The development of novel ∗ Corresponding author. Tel.: +380 509868257; fax: +380 444242131. E-mail addresses: ostap@ipms.kiev.ua, ostap@materials.kiev.ua (O. Zgalat- Lozynskyy). technological approaches for SPS leading toward the improve- ment of final material properties and microstructure is still required. At pressureless sintering, the most effective way to control microstructure during densification is to control the heat- ing rate based on the current material’s densification rate. This phenomenological model was implemented to a rate- controlled sintering (RCS) technique and was successfully used for consolidation of different types of nanocrystalline or submicron materials such as TiN, AlN, BaTiO 3 , ZrO 2 etc. 7–9 On the other hand, the main advantage of SPS is the combination of very high heating rates with high pres- sure permitting consolidation of different materials much faster and without significant grain growth. 1–3,6,10 In this work, we applied the RCS technology 7 to the SPS consolidation method in order to investigate the influence of non-linear heating and loading regimes on TiCN microstructure forma- tion. TiCN nanopowder was selected as a sample material due to its commercial availability and due to the fact that parts fabricated from TiCN-based composites are widely used in industry. For example, additive-free titanium carbonitride- based bulk nanocomposites are the most promising materials for cutting tools due to their increased hardness (up to 30–32 GPa), high wear resistance, high edge strength and edge sharpness. 2 0955-2219/$ – see front matter © 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jeurceramsoc.2010.11.030