Thermal shock study of a-alumina doped with 0.2% MgO

Panda, PK and Jaleel, VA and Lefebvre, G (2008) Thermal shock study of a-alumina doped with 0.2% MgO. Materials Science and Engineering A, 485 . pp. 558-561. ISSN 0921-5093

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    Abstract

    Thermal shock behaviour of �-alumina doped with 0.2% MgO is studied. A uniformly mixed powder of �-alumina, magnesia and 2% PVA solution is dried, granulated and uniaxially pressed into circular discs of 30mm diameter and 3mm thick. The discs are sintered at a maximum temperature in the range of 1500–1650 ◦C for 3 h. The thermal shock test is carried out by heating the sample with an oxy-hydrogen flame and by monitoring the crack formation by acoustic emission technique. In general, the samples possess high thermal shock resistance close to their melting temperature. The spinels formed due to MgO doping possess low fusion temperature which hinders the crack growth. The same has been confirmed from scanning electron microscope (SEM) studies. The samples sintered at lower temperature possess higher thermal shock resistance than those sintered at higher temperature. This is attributed to the higher porosity. The abnormal grain growth (AGG) associated with high sintering temperature might have contributed to lowering of thermal shock resistance. To summarize, MgO-doped alumina samples possess high thermal shock resistance by avoiding the catastrophic failure due to the formation of low fusion spinels.

    Item Type: Journal Article
    Additional Information: Copyright to this article belongs to M/s. Elsevier B.V.
    Uncontrolled Keywords: Thermal shock;Alumina;Oxy-hydrogen flame;Ascending mode
    Subjects: CHEMISTRY AND MATERIALS > Chemistry and Materials (General)
    Division/Department: Materials Science Division, Materials Science Division, Other
    Depositing User: Ms. Alphones Mary
    Date Deposited: 31 Oct 2012 09:49
    Last Modified: 31 Oct 2012 09:49
    URI: http://nal-ir.nal.res.in/id/eprint/11334

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