The effect of thermal shock on mechanical properties of lithium aluminosilicate (LAS) glass ceramic
Loading...
Date
2019-07
Authors
Muhamad Izzat Bin Bhasri
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Lithium Aluminosilicate (LAS) glass ceramic has been commonly used as
cooktop which is constant undergoes thermal gradient. It makes the mechanical properties
is significantly important in LAS glass ceramic. Therefore, attempt has been made to
increase the mechanical properties of LAS glass ceramic. The effect of soaking time (30
minutes, 1 hour and 2 hours) of sintering temperature was investigated. The effect of
thermal shock cycles on mechanical properties of LAS glass ceramic at different
temperatures (500℃, 600℃ and 700℃) was also investigated. Crystallization temperature
of the LAS glass ceramic was determined using Differential Scanning Calorimetry
(DSC). Effect of soaking time was determined through X-Ray Diffraction (XRD),
density, porosity, Field Emission Scanning Electron Microscopy (FE-SEM) with Energy
Dispersive X-Ray Spectroscopy (EDX) and Vickers hardness test, whereas effect of
thermal shock cycles was observed using flexural test and Scanning Electron Microscopy
(SEM). XRD observed two main crystalline phases present; 𝛽 -spodumene and 𝛽 -
eucryptite which is required to behave as high thermal resistance materials. The density
and porosity results show no significant as soaking time increase. FE-SEM images
equipped with EDX presented confirmed the presence of 𝛽-spodumene. The Vickers
Hardness test found that soaking time 1 hours shows the highest hardness. For the effect
of thermal shock on different temperature cycles, flexural strength at 600℃ give the
highest strength. For the Young modulus result, thermal shock cycles at 700℃ has the
highest thermal shock resistance. In conclusion, LAS glass ceramic produced from this
study, highest flexural strength at 600℃ for up to six thermal cycles with ability to resist thermal shock up to 700℃.