Bulk titanium nitride ceramics – Significant enhancement of hardness by silicon nitride addition, nanostructuring and high pressure sintering. Issue 10 (September 2015)

• Record Type: Journal Article
• Authors: Bläß, U.W.; Barsukova, T.; Schwarz, M.R.; Köhler, A.; Schimpf, C.; Petrusha, I.A.; Mühle, U.; Rafaja, D.; Kroke, E.
• Is Part Of: Journal of the European Ceramic Society. Volume 35:Issue 10(2015:Oct.)
• Page Start: 2733
• Page End: 2744
• Publication Date: 2015-09
• Subjects: Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2015.04.005
• Languages: English
• ISSNs: 0955-2219

Abstract

<abstract abstract-type="author" id="abs0005"> <title id="sect0005">Abstract</title> <sec> <p id="spar0005">Dense nanocomposites consisting of titanium nitride (TiN) and 1.7–8.1 mol% silicon nitride (a-Si₃N₄) have been prepared by high-pressure sintering at 6.5 GPa and at temperatures up to 1300 °C. Microstructure, hardness, indentation fracture toughness, elastic modulus and the correlation of these parameters to the silicon nitride content of the obtained TiN–Si₃N₄ ceramics have been determined. The results demonstrate that even the addition of small amounts of Si₃N₄ leads to a considerable increase in Vickers hardness to <italic>HV</italic>_{500 g} ∼ 25 GPa and indentation fracture toughness up to 6 MPa m^½. This significant enhancement of mechanical properties can be related to interfacial bonds between titanium nitride crystals strengthened by nano-size effects and amorphous silicon nitride forming an intergranular matrix. Realignment and rotation of such interlocked titanium nitride crystallites under deformational stress is suppressed and crack propagation reduced by a crack deflection mechanism.</p> </sec> </abstract>