2000 Volume 108 Issue 1256 Pages 350-356
(1) Poly-titanosilazanes were synthesized by chemical modification with Ti(X)4 [X=N(CH3)2, OCH(CH3)2]. The chemical structure of the synthesized precursors was studied using IR and 1H NMR techniques. The polytitanosilazanes were found to contain some N-Ti bonds.
(2) [Si-Ti-O-C-N] multicomponent amorphous powders were synthesized by pyrolysis of the poly-titanosilazanes at 1000°C in NH3.
(3) Amorphous Si3N4 in the [Si-Ti-O-C-N] was rather stable below 1400°C and titanium was found to be effective to suppress crystallization of Si3N4. Above 1600°C, the Si-Ti-O-N liquid phase enhanced the α-/β- phase transformation of Si3N4.
(4) The poly-titanosilazane derived from PHPS and Ti(N(CH3)2)4 yielded Si3N4-TiN ceramics by heat treatment at 1800°C in N2. TiN was observed as particles with diameter of smaller than 100nm. The poly-titanosilazane was found to be suitable for the synthesis of TiN nanopartitle-dispersed Si3N4-based ceramics.
