Abstracts Book - IMRC 2018

• SWS-O021
ASSESSMENT OF THE THERMAL SHOCK RESISTANCE AND
RELATIONSHIP BETWEEN SINTERING METHODS AND PHYSICAL
PROPERTIES OF THE LOW POSITIVE THERMAL EXPANSION
MATERIAL AL2W3O12
Bojan Marinkovic 1 , Luciana Prates Prisco 1 , Patricia Pontón 1 , Mayara Marzano 1 , Carl Romao 2 ,
Mary A White 2
1 Pontifícia Universidade Católica do Rio de Janeiro, Department of Chemical and Materials
Engineering, Brazil. 2 Dalhousie University, Department of Chemistry, Canada.
Zero thermal expansion phases from the A2M3O12 and related thermomiotic
(negative thermal expansion) families are natural candidates for applications
where high thermal shock resistance is the principal requirement. However,
their mechanical properties are largely unknown, as are sintering routes for
consolidation into bulk objects. Therefore, a preliminary study on the eï¬Â€ect
of microstructure on mechanical strength and thermal shock resistance of
Al2W3O12 has been performed. All thermal and mechanical properties
necessary for calculation of thermal shock resistance ï¬Â•gures of merit have
been measured experimentally. The Hasselman ï¬Â•gure of merit for thermal
shock resistance for severe heating conditions of Al2W3O12 was 120 K,
comparable to sapphire, the state-of-the-art material for some advanced
thermal shock resistance applications.
However, considering their inherently low thermal conductivity, the bulk forms
of A2M3O12 have to present Young’s moduli and mechanical strength close to
100 GPa and 100 MPa, respectively, in order to compete with the state-of-theart
materials used to avoid thermal shock. Bulk samples of dense Al2W3O12 (96
%TD) have been obtained by pressureless three-stage sintering (TSS) and spark
plasma sintering (SPS). The Young’s moduli and hardness of samples prepared
by SPS were 50% higher than that measured for TSS samples and more than
100% in comparison to the Al2W3O12 bulk (91 %TD) obtained by conventional
pressureless sintering.
Keywords: spark plasma sintering, mechanical properties, zero thermal expansion.
Presenting authors email: bojan@puc-rio.br