Relation between Particulate Chemistry and Ceramic Properties
Annual rept. 1 Jan-31 Dec 1971
AVCO CORP LOWELL MA SYSTEMS DIV
Pagination or Media Count:
Progress is described in the second year of a program designed to inter-relate the chemistry and morphology of the initial particulates with microstructure development and grain growth kinetics, impurity precipitate distribution and mechanical properties of the final product for both pure and doped MgO. Fine uniform grain size, high density 99.99 MgO samples were fabricated by vacuum hot pressing. Prior to this achievement an important inter- relationship between precursor and microstructure development was found. MgO crystallites derived from MgOH2 are crystallographically aligned with only small misorientations within an agglomerate which apparently is a relic of the parent brucite crystal. Powder derived from MgCO3 is unoriented and allows normal grain growth to proceed during consolidation. Equiaxed calcia-doped MgO samples were vacuum hot pressed from calcined coprecipitated MgCO3 powder. A dense calcia-doped specimen has been partially characterized.
- Ceramics, Refractories and Glass