Small‐Scale Deformation of Pulsed Electric Current Sintered Silicon Oxycarbide Polymer Derived Ceramics

Abstract

The deformation behavior of pulsed electric current sintered silicon oxycarbide ceramics produced by the solid-state thermolysis of polyhydridomethylsiloxane at small-scale is investigated. The ceramics remained X-ray amorphous after sintering at 1300°C in vacuum and a high density of %2.35 g cm À3 is achieved. The elastic constants of these ceramics are determined using non-destructive ultrasonic testing method. The elasto-plastic deformation under contact loading is determined using depth sensing nanoindentation technique. An indentation hardness of %11 GPa and reduced elastic modulus of %105 GPa is observed. The load-displacement curves display significant elastic recovery with an elastic work ratio of %0.71. The evolution of Hertzian cone cracks upon microindentation indicates an anomalous deformation behavior.

Processing and characterization of polymer precursor derived silicon oxycarbide ceramic foams and compacts

“…The density of pyrolyzed samples is 1.4-1.5 g/cm 3 and geometric density is close to 1.5-1.6 g/cm 3 . Compared to the density values reported in the existing literatures for SiOC [29][30][31], the observed density is lower for the cold pressed and pyrolysed SiOC. This could be attributed to the presence of residual porosity due to the escapement of volatile matter during the thermolysis.…”

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).…”

Silicon oxycarbide glass for the immobilisation of irradiated graphite waste

“…It should be noted that the lack of obvious chemical interaction does not mean a b Although complete chemical incorporation of the graphite was the goal, the excellent physical properties of silicon oxycarbide glass [15] and good contact between glass and graphite mean that this glass could still be a viable host for encapsulation of irradiated graphite. The use of spark plasma sintering as a processing method also enabled the production of a high density wasteform; less than 3% porosity compares favourably with the literature [17,19] which would potentially increase the mechanical durability.…”