Synthesis and phase stability of precursor derived HfO2/Si–C–N–O nanocomposites

Phase evolution of SiOC‐based ceramic nanocomposites derived from a polymethylsiloxane modified by Hf‐ and Ti‐alkoxides

“…Figure (left) shows the FTIR spectra of the ceramic nanocomposites after oxidation. Accordingly, weak absorption bands assigned to Si–O–C at ~1025 cm −1 and sharp and intense bands related to Si–O–Si at ~1100 cm −1 , as well as other bands due to Si–C bonds at ~800 cm −1 suggest the oxidation of the SiOC matrix with strong decrease in the carbon content and rearrangement of the amorphous structure to SiO 2 and SiC.…”

“…This phenomenon has to be discussed in terms of the specific reactivity of the used metal alkoxide, M(O i Pr) 4 and M(O n Bu) 4 , resulting in different distribution of the Si-O-M fraction in the single-source-precursor. 19,28 However, this experimental result has to be further studied to explain the underlying mechanisms related to the phase evolution in our SiOC/HfO 2 nanocomposites.…”

Room temperature strain rate sensitivity in precursor derived HfO2/Si-C-N(O) ceramic nanocomposites

“…The detailed synthesis procedures of each of these materials were discussed elsewhere. [18][19][20] The thermolysed ceramics were ground and sieved to fine powders of particle size less than 125 μm. Henceforth, the powder particles were sintered and pellets of ∼ 20 mm diameter and ∼ 4 mm thickness were produced using a pulsed electric current sintering machine (Sumitomo Coal Mining Co. Ltd, Japan).…”

Crack Evolution and Estimation of Fracture Toughness of HfO2/SiCN(O) Polymer Derived Ceramic Nanocomposites

“…The details of the synthesis procedure were discussed elsewhere. [2] The as-thermolysed ceramics were sintered using pulsed electric current sintering (Sumitomo Coal Mining Co. Ltd, Japan) to produce pellets of diameter 20 mm. [3] Sintering was carried out at in vacuum at 1500°C and will be referred to as SiHfCNO1500.…”

“…[1][2][3][4][5] Due to their exciting properties these materials have been envisaged for various structural and functional applications. However, due to the inherent brittle nature, the applications of PDC materials as structural materials are limited.…”