@article{Li2023, 
author = {Wei Li and Zhaoju Yu and Leonore Wiehl and Tianshu Jiang and Ying Zhan and Emmanuel III Ricohermoso and Martin Etter and Emanuel Ionescu and Qingbo Wen and Christian Lathe and Robert Farla and Dharma Teppala Teja and Sebastian Bruns and Marc Widenmeyer and Anke Weidenkaff and Leopoldo Molina-Luna and Ralf Riedel and Shrikant Bhat},
title = {Hard and tough novel high-pressure γ-Si3N4/Hf3N4 ceramic nanocomposites},
year = {2023},
journal = {Journal of Advanced Ceramics},
volume = {12},
number = {7},
pages = {1418-1429},
keywords = {cubic silicon nitride (γ-Si3N4)/Hf3N4, ceramic nanocomposites, in situ synchrotron radiation, mechanical properties, thermal stability},
url = {https://www.sciopen.com/article/10.26599/JAC.2023.9220764},
doi = {10.26599/JAC.2023.9220764},
abstract = {Cubic silicon nitride (γ-Si3N4) is superhard and one of the hardest materials after diamond and cubic boron nitride (cBN), but has higher thermal stability in an oxidizing environment than diamond, making it a competitive candidate for technological applications in harsh conditions (e.g., drill head and abrasives). Here, we report the high-pressure synthesis and characterization of the structural and mechanical properties of a γ-Si3N4/Hf3N4 ceramic nanocomposite derived from single-phase amorphous silicon (Si)–hafnium (Hf)–nitrogen (N) precursor. The synthesis of the γ-Si3N4/Hf3N4 nanocomposite is performed at ~20 GPa and ca. 1500 ℃ in a large volume multi anvil press. The structural evolution of the amorphous precursor and its crystallization to γ-Si3N4/Hf3N4 nanocomposites under high pressures is assessed by the in situ synchrotron energy-dispersive X-ray diffraction (ED-XRD) measurements at ~19.5 GPa in the temperature range of ca. 1000–1900 ℃. The fracture toughness (KIC) of the two-phase nanocomposite amounts ~6/6.9 MPa·m1/2 and is about 2 times that of single-phase γ-Si3N4, while its hardness of ca. 30 GPa remains high. This work provides a reliable and feasible route for the synthesis of advanced hard and tough γ-Si3N4-based nanocomposites with excellent thermal stabililty.}
}