Hostname: page-component-745bb68f8f-5r2nc Total loading time: 0 Render date: 2025-01-12T07:50:28.918Z Has data issue: false hasContentIssue false
  • English
  • Français

Preparation and Mechanical Properties of Si3N4 Ceramics With Dispersed NANO Sic Particles

Published online by Cambridge University Press:  15 February 2011

Tomohiro Yanail  and
K. Ishizaki
Tomohiro Yanail
Affiliation:
Nagaoka Gijutsu-Kagaku Daigaku (Nagaoka University of Technology), Nagaoka, Niigata 940-21, Japan permanent address : Technical Research & Development Institute, Japan Defense Agency, Setagaya, Tokyo 154, Japan
K. Ishizaki
Affiliation:
Nagaoka Gijutsu-Kagaku Daigaku (Nagaoka University of Technology), Nagaoka, Niigata 940-21, Japan
Get access

Abstract

The purpose of the present work is to toughen the grain boundary phase of Si3N4 ceramics by forming a nano composite grain boundary phase of SiC particles. The nano SiC particles form through a reaction between the coated carbon and the surface oxidation phase in Si3N4. The carbon is coated through thermal decomposition of CH4 gas. The sintcred bodies arc obtained by hot-pressing at 1800 °C for one h. By increasing the carbon content, both fracture toughness and bending strength initially increase, then reach the maximum value at the same amount of carbon content, and decrease. The carbon content at which the fracture toughness and bending strength exhibit the maximum value increases with the increase in the surface oxygen content. The precipitated SiC particles dispersed in a grain boundary phase, at a Si3N4-Si3N4 interface or in a Si3N4 grain. The locations and size (less than 30 nm) of the SiC particles are examined by TEM and HREM observations. As the grain boundary is toughened by the precipitated nano SiC particles in the grain boundary phase or at the Si3N4-Si3N4 interface to help Si3N4 grain bridging without any glassy phase, these SiC particles block or resist the intergranular fracture.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 362: Symposium J – Grain-Size and Mechanical Properties--Fundamentals and Applications , 1994 , 265
Copyright
Copyright © Materials Research Society 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Watari, K., Ishizaki, K. and Kawamoto, M., Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi, 96, 127, (1988); Mat. Sci. and Eng., A109, 89, (1989).Google Scholar
2. Watari, K. and Ishizaki, K., Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi, 96, 551, (1988).Google Scholar
3. Yanai, T. and Ishizaki, K., J. Ceram. Soc. Jpn., 101, 764, (1993).Google Scholar
4. Yanai, T. and Ishizaki, K., in Surface Modification Technology VII, edited by Sudarshan, T. S., Ishizaki, K., Takata, M. and Kamata, K. (The Institute of Materials, Cambridge, No.78, 1994) pp.955 Google Scholar
5. Ishizaki, K., Act. Meta. et Mat., 38, 2059, (1990).Google Scholar
6. Selsing, J., J. Am. Ceram. Soc., 44, 419, (1961).Google Scholar