Densification and polymorphic transition of multiphase Y2O3 nanoparticles during spark plasma sintering

Rachel Marder (1) , Rachman Chaim (1) , Geoffroy Chevallier (2) , Claude Estournès (2)

1 Department of Materials Engineering
2 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux

Multiphase (MP) monoclinic and cubic Y2O3 nanoparticles, 40 nm in diameter, were densified by spark plasma sintering for 5-15 min and100 MPa at 1000 °C, 1100 °C, and 1500 °C. Densification started with pressure increase at room temperature. Densification stagnated during heating compared to the high shrinkage rate in cubic single-phase reference nanopowder. The limited densification of the MP nanopowder originated from the vermicular structure (skeleton) formed during the heating. Interface controlled monoclinic to cubic polymorphic transformation above 980 °C led to the formation of large spherical cubic grains within the vermicular matrix. This resulted in the loss of the nanocrystalline character and low final density.

Mots clés: Spark plasma sintering; Phase transformation; Densification; Y2O3

Domaines: Matériaux

Rachel Marder, Rachman Chaim, Geoffroy Chevallier, Claude Estournès. Densification and polymorphic transition of multiphase Y2O3 nanoparticles during spark plasma sintering. Materials Science and Engineering: A, 2011, vol.528, pp. 7200-7206. ⟨10.1016/j.msea.2011.06.044⟩. ⟨hal-00720725⟩