Wear and Creep Characteristics of a Carbon-Derived Si3N4/SiC Micro/Nanocomposite

• Published in: Materialwissenschaft und Werkstofftechnik Vol. 34; no. 4; pp. 338 - 342
• Main Authors: Kašiarová, M., Rudnayová, E., Kovalčík, J., Dusza, J., Hnatko, M., Šajgalík, P., Merstallinger, A.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.04.2003; WILEY‐VCH Verlag; Wiley-VCH
• Subjects: Applied sciences; Creep; creep behavior; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Friction, lubrication, and wear; Materials science; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Physics; Si3N4/SiC nanocomposite; Treatment of materials and its effects on microstructure and properties; tribological properties; Creep; Pin on disk machine; Wear; Mechanical properties; Silicon carbides; Friction factor; Silicon nitrides; Nanocomposite; Wear testing; Activation energy
• ISSN: 0933-5137; 1521-4052
• DOI: 10.1002/mawe.200390071

In the presented work some properties of a recently developed Si3N4/SiC micro/nanocomposite have been investigated. The material was tested using a pin on disc configuration. Under unlubricated sliding conditions using Si3N4 pin at 50 % humidity, the friction coefficient was in the range of 0,6 ‐ 0,7. The reduction of humidity resulted in a lower coefficient of friction, in vacuum the coefficient of friction had a value of about 0,6. The wear resistance in vacuum was significantly lower then that in air. The wear patterns on the Si3N4+SiC disc revealed that mechanical fracture was the wear controlling mechanism. Creep tests were realized in four point bending configuration in the temperature interval 1200‐1400 °C at stresses 50,100 and 150 MPa and the minimal creep deformation rate was established for each stress level. The activation energy, established from the minimal creep deformation had a value of about 360 kJ/mol and the stress exponent values were in the range of 0.8‐1.28. From the achieved stress exponents it can be assumed that under the studied load/temperature conditions the diffusion creep was the most probable creep controlling mechanism.