Abstract
Sintering and deformation were studied in nano-grained (n-)TiO2 and n-TiAl as part of a program to develop materials for near-net shaping and superplasticity applications. An important concern for processing nano-grained materials is the control of grain growth during both densification and deformation. In this study, the effectiveness of doping n-TiO2 with yttrium for controlling grain growth during isothermal annealing was examined. In addition, an empirical constitutive law for the densification of n-TiO2 was determined. Comparison of sinter-forming in n-TiO2 with larger grained oxide ceramics shows many similar features. The studies on TiAl examined the hardness as a function of grain size, indentation time and temperature. At large grain sizes, the hardness obeys the Hall-Petch relation, but below a critical grain size, approximately 30 nm, the hardness decreases with decreasing grain size. Finally, the potential for synthesizing metallic glasses with nanoscale amorphous particles is discussed.
Original language | English (US) |
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Pages (from-to) | 169-177 |
Number of pages | 9 |
Journal | Materials Science and Engineering A |
Volume | 166 |
Issue number | 1-2 |
DOIs | |
State | Published - Jul 15 1993 |
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering