A refractory ceramic material possessing a solidus temperature between 2500° C. and 2800° C., having a compactness greater than 85%, and a microstructure such that the material is composite of: (a) hafnium dioxide HfO2 grains having a monoclinic structure (1); (b) hafnium dioxide HfO2 grains having a cubic structure (2) which is stabilized by yttrium oxide Y2O3, the yttrium oxide Y2O3 representing 0.5 mol % to 8 mol % relative to the total number of moles of hafnium dioxide HfO2; (c) closed pores (3); (d) non-interconnected open pores. The process of manufacturing the material and a structural part incorporating the material are also set forth.