Al2O3/ZrO2/Y3Al5O12 Composites: A High-Temperature Mechanical Characterization

Materials

Paola Palmero¹  Giovanni Pulci²  Francesco Marra²  Teodoro Valente²  Laura Montanaro¹ 

[1] Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, INSTM R.U. PoliTO, Laboratorio di Tecnologia ed Ingegnerizzazione dei Materiali Ceramici (LINCE), Corso Duca degli Abruzzi, 24, 10129 Torino, Italy; E-Mail:;Dipartimento di Ingegneria Chimica Materiali e Ambiente, Sapienza Università di Roma, Laboratorio di Ingegneria dei Trattamenti Superficiali, INSTM, Via Eudossiana, 18, 00184 Roma, Italy; E-Mails:

关键词: Al₂O₃/ZrO₂/YAG;    elaboration;    microstructure;    high-temperature bending test;    mechanical properties;    thermal stability;   

DOI  :  10.3390/ma8020611

来源: mdpi

【 摘 要 】

An Al₂O₃/5 vol%·ZrO₂/5 vol%·Y₃Al₅O₁₂ (YAG) tri-phase composite was manufactured by surface modification of an alumina powder with inorganic precursors of the second phases. The bulk materials were produced by die-pressing and pressureless sintering at 1500 °C, obtaining fully dense, homogenous samples, with ultra-fine ZrO₂ and YAG grains dispersed in a sub-micronic alumina matrix. The high temperature mechanical properties were investigated by four-point bending tests up to 1500 °C, and the grain size stability was assessed by observing the microstructural evolution of the samples heat treated up to 1700 °C. Dynamic indentation measures were performed on as-sintered and heat-treated Al₂O₃/ZrO₂/YAG samples in order to evaluate the micro-hardness and elastic modulus as a function of re-heating temperature. The high temperature bending tests highlighted a transition from brittle to plastic behavior comprised between 1350 and 1400 °C and a considerable flexural strength reduction at temperatures higher than 1400 °C; moreover, the microstructural investigations carried out on the re-heated samples showed a very limited grain growth up to 1650 °C.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.