Hot hardness of Si3N4-based materials

✍ Scribed by R. F. Silva; J. M. Vieira

• Publisher: Springer
• Year: 1995
• Tongue: English
• Weight: 534 KB
• Volume: 30
• Category: Article
• ISSN: 0022-2461
• DOI: 10.1007/bf00351569

✦ Synopsis

The Vickers hardness of dense SiaN4 ceramics of the Si-Ce-AI-O-N system was investigated from room temperature to 1200~ A sloppy decrease of hot hardness occurred above 850-900 ~ C. A compensation law was observed between the pre-exponential factors of the hot-hardness dependence on the reciprocal of absolute temperature, and the values of the activation energy of hardness. This relationship shows that the low-temperature deformation mechanism, such as microplasticity, is competing in parallel with a grain-boundary diffusion-controlled creep process in the high-temperature range.