Abstract
TEM examination showed a non-uniform distribution of cerium ions in SPS sintered Ce-alpha'-SiAlON material with addition of 1 wt% yttrium alpha'-SiAlON seeds. Most of the incorporated Ce ions segregated near domain boundary sites where enlarged interstices were formed upon a 1/3 < 10bar10 > type translation. Formation of domain boundaries thus provides a new stabilisation mechanism for the large-metal doped alpha'-SiAlON. Moreover, an increasing amount of incorporated Ce ions resulted in an increasing density of domain boundaries, which consequently modified the crystal structure and growth habit. Rod-like Ce-alpha'-SiAlON crystallites formed, indicative of the development of a self-reinforced microstructure. The added yttrium alpha'-SiAlON seeds were found to be a prerequisite for the formation of elongated Ce-alpha'-SiAlON grains. 9 refs.