Application of zirconium in preparation of
polycarbosilane derived ceramics①
polycarbosilane derived ceramics①
(State Key Laboratory of Novel Ceramic Fibers and the Composites,
College of Aerospace and Materials Engineering, National University of Defense Technology,
Changsha 410073, P.R.China)
College of Aerospace and Materials Engineering, National University of Defense Technology,
Changsha 410073, P.R.China)
Abstract: The metallic zirconium (Zr) powder as active filler was applied in polycarbosilane (PCS) preceramic precursor derived ceramics. It was found that the addition of Zr decreases the porosity of the green compact and, since Zr can react with N2to produce nitride, the ceramic productivity is increased. The ceramic productivity will be 100% when the volume fraction of Zr/PCS is 44%. Zr also enhances the three-point bending strength of the ceramic with the strength of 104MPa when the volume fraction of Zr/PCS is 60%. However, the addition of Zr in PCS can not restrain the linear shrinkage upon pyrolysis, the linear shrinkage increases with increasing the volume fraction of Zr/PCS. Phase composition was analyzed using X-ray diffraction (XRD). Fracture surfaces of the specimens after three-point bending tests were examined on the scanning electron microscope
Key words: active filler; zirconium (Zr); polycarbosilane (PCS); ceramics