Characterization of Si3N4/SiC Microstructure Derived from UV curable polymer ceramic precursor pyrolyzing
The microstructure of Si<inf>3</inf>N<inf>4</inf>/SiC derived from the pyrolysis of UV curable polymer ceramic precursor was analyzed and characterized by TGA-DTA, XRD, FE-SEM, Electron Spectrometer, and TEM. It was found that two distinct weight loss rate peaks at 358°C and 450°C in TGA curve were identical with two DTA endothermic peaks. The total weight loss was 45wt%. The degree of crystallinity reached 91.25% after annealing at 1600°C for 2h with the composition of SiO<inf>2</inf>: Si<inf>3</inf>N<inf>4</inf>: SiC = 3:26:71 in pyrolysate. Not only did the degree of crystallinity increase, but also the change from α-Si<inf>3</inf>N<inf>4</inf> to β -Si<inf>3</inf>N<inf>4</inf> took place with the increase of holding time. Irregular whisker of Si<inf>3</inf>N<inf>4</inf> was explored by SEM after pyrolyzing at 1400 °C for 24 h.