Optimum Design of Sintered Silicon Nitride Ceramics Specimen with Projections for High-Temperature Creep Test

• Published in: JSME International Journal Series A Solid Mechanics and Material Engineering Vol. 41; no. 3; pp. 345 - 351
• Main Authors: HATANAKA, Kenji, OSHITA, Kenichi, SHIOTA, Hirohisa
• Format: Journal Article
• Language: English
• Published: Tokyo The Japan Society of Mechanical Engineers 1998; Japan Society of Mechanical Engineers; Japan Science and Technology Agency
• Subjects: Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Condensed matter: structure, mechanical and thermal properties; Creep; Exact sciences and technology; Finite-Element Method; General studies; High-Temperature Creep; Measurement of Tensile Creep Strain; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Optimum Design of Tensile Creep Specimen with Projections; Physics; Silicon Nitride Ceramics; Steady-State Creep Constitutive Equation; Technical ceramics; Constitutive equation; Stress concentration; High strain; Creep; Tensile tests; Measuring methods; Thermomechanical properties; Ceramics; High temperature; Test bar; Optimization; Finite element method; Creep testing; Silicon nitrides; Modelling
• ISSN: 1344-7912; 1347-5363
• DOI: 10.1299/jsmea.41.345

A tensile creep specimen with projections was designed to measure creep displacement by means of the laser-beam displacement meter at temperatures elevated over 1000°C. Stress/strain concentrations, however, occur around the root of projections in this specimen. The high-temperature creep strain was determined from the measurement of tensile displacement between the two projections by correcting influence of the projections. The procedures used to determine the steady-state creep constitutive equation of Si3N4 ceramics was proposed by combining a high-temperature creep test using the specimen with projections and the finite-element method(FEM) calculations for the specimen. Furthermore, the method for designing the optimum creep specimen with projections was determined via the FEM calculations using the steady-state creep constitutive equation.