1 research outputs found
Effect of sintering technology in beta-eucryptite ceramics: Influence on fatigue life and effect of microcracks
β-eucryptite ceramics with low negative or near-zero coefficient of thermal expansion
(CTE) with excellent mechanical properties, such as Young’s modulus 100 GPa, have
attracted attention for many important industrial applications. The extremely anisotropic
thermal expansion behaviour of this material leads to thermal residual stresses, and
causes spontaneous microcracking. These microcracks cause large negative CTE with
mechanical weaknesses. The appearance of microcracks is due to different factors. The
most important are prolonged sintering time and heating source used.
The present work shows experimentally the evolution of grain microcracks and residual
stresses of the sintered -eucryptite material going through many thermal fatigue cycles
(3600). The effect of stresses applied on β-eucryptite crystals due to the thermal
cycling could be considered for explaining the small change observed of β-eucryptite to
β-spodumene phase, which is higher in the samples obtained by microwave sintering.
Therefore, the study of residual stresses has suggested that the heating source employed,
such as conventional or microwave, has a great influence on thermal fatigue life and the
final mechanical and thermal properties. The microwave heating has a significant
impact on β-eucryptite materials lifetime.A. Borrell, acknowledges the Spanish Ministry of Science and Innovation for a Juan de la Cierva contract (JCI-2011-10498) and the Polytechnic University of Valencia (UPV) for financial support received under project SP20120677. The authors would like to thank the SCSIE team of the University of Valencia.Benavente MartĂnez, R.; Salvador Moya, MD.; MartĂnez-Amesti, A.; Fernández, A.; Borrell Tomás, MA. (2016). Effect of sintering technology in beta-eucryptite ceramics: Influence on fatigue life and effect of microcracks. Materials Science and Engineering: A. 651:668-674. https://doi.org/10.1016/j.msea.2015.11.013S66867465