Influence of Y2O3 addition on the Ti/Al2O3 cermets by hot pressing sintering

The Ti/Al2O3 composites are fabricated by hot pressing sintering, and the effect of Y2O3 on the microstructure andmechanicalproperty of Ti/Al2O3 composites has been studied by means of SEM, EDS and XRD. The results show that the Al2O3 decomposition to Al and O first, and then Al diffusion to Ti form...

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Bibliographic Details
Published inJournal of alloys and compounds Vol. 628; pp. 413 - 415
Main Authors Shi, Guopu, Wang, Zhi, Liu, Luhao, Wang, Chenguo
Format Journal Article
LanguageEnglish
Published Elsevier B.V 15.04.2015
Subjects
Hot pressing sintering
Mechanical properties
Thermodynamics
Ti/Al2O3 composites
Y2O3
Mechanical properties
Thermodynamics
Hot pressing sintering
Ti/Al2O3 composites
Y2O3
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Summary:The Ti/Al2O3 composites are fabricated by hot pressing sintering, and the effect of Y2O3 on the microstructure andmechanicalproperty of Ti/Al2O3 composites has been studied by means of SEM, EDS and XRD. The results show that the Al2O3 decomposition to Al and O first, and then Al diffusion to Ti formed the intermetallics such as Ti3Al and TiAl phases in the composites. Thermodynamics calculation shows us the Gibbsfreeenergy are −120.23kJ/mol and −73.44kJ/mol for Ti3Al phase and TiAl phase, respectively. The addition of yttria to the composites makes enthalpy changes, reduces the amount of Ti3Al phase. The effect of Y2O3 addition on the microstructures and mechanical properties of the Ti/Al2O3 composite was characterized. When the Y2O3 content is 1.0vol%, the flexural strength, fracture toughness, Vickers hardness and relative density of the composite reach the maximum values of 302.73MPa, 6.45MPam−1/2, 16.78GPa and 98.63%, respectively, and the fracture mode changes from intergranular to transgranular.
ISSN:0925-8388
1873-4669
DOI:10.1016/j.jallcom.2014.12.014