Fabrication, microstructure, and properties of Dy-doped (Y1-xDyx)3Si2C2 ceramics fabricated by in situ reactive spark plasma sintering

Dysprosium (Dy)-doped (Y1-xDyx)(3)Si2C2 (x = 0, 0.1, 0.3, 0.5) solid solution ceramics were successfully fabricated using an in situ reaction spark plasma sintering technology, for the first time. The effect of various Dy doping contents (x) on the microstructure, mechanical, and thermal properties of (Y1-xDyx)(3)Si2C2 ceramics was investigated. The (0 2 0) crystal plane spacing of (Y0.5Dy0.5)(3)Si2C2 was 7.813 & Aring;, which was smaller than that of Y3Si2C2, due to the fact that the atomic radius of Dy is smaller than that of Y. The Dy doping facilitated the consolidation of (Y1-xDyx)(3)Si2C2, thus a highly dense (Y0.5Dy0.5)(3)Si2C2 ceramic material with a low open porosity of 0.14% was successfully obtained at a relatively low temperature of 1 200 degrees C. As the content of Dy doping (x) increased from 0 to 0.5, the purity of (Y1-xDyx)(3)Si2C2 ceramics increased from 88.3 to 90.7 wt.%, while the grain size of (Y1-xDyx)(3)Si2C2 ceramics decreased from 0.59 to 0.46 mu m. As a result, the Vickers hardness and thermal conductivity of the (Y0.5Dy0.5)(3)Si2C2 material was 7.1 GPa and 9.8 W center dot m(-1)center dot K-1, respectively.