The study of process and material characterization of high porosity NiAl intermetallics by combustion synthesis
| Autor: | Yi-huang Tang, 唐溢隍 |
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| Rok vydání: | 2009 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 97 This paper is to study the processes of porous NiAl intermetallic compound made by combustion synthesis. The investigated processing parameters include compacting pressure and amount of TiH2 additions (0~1wt%). The effects of process parameters on the combustion synthesis reaction, microstructural development, phase transformation during sintering, and the porosity of products are discussed. The techniques including differential scanning calorimeter (DSC), differential thermal analyzer (DTA), thermogravimetric analyzer (TGA), thermal analyzer-mass spectrometry (TA-MS), Optical Microscope (OM), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) were used in this study. The results also show that more TiH2 addition did not always help the increase of porosity. Only in the conditions with compacting pressure 100MPa or 200MPa, the porosity of products increased with the increase of TiH2 content. In the condition with compacting pressure 500MPa, the porosity of products decreased significantly with the increase of TiH2 content. Without the addition of TiH2, TA-MS results show that H、O、H2O、CO、HO、N2、O2 and CO2 were generated from specimens during sintering process. Higher compacting pressure increased the density of green compact, trapped more generated gas during sintering, and finally increased the porosity of products. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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