Spark plasma sintering of UO2 nanopowders: Pressure,heating rate and current effects |
| |
Affiliation: | 1. CEA, DES, CAD, IRESNE, DEC, F-13108 Cedex Saint-Paul-lez-Durance, France;2. Université Grenoble Alpes, 621 Avenue Centrale, 38400 Saint-Martin-d′Hères, France;3. European Commission, Joint Research Centre (JRC), Karlsruhe, Germany |
| |
Abstract: | We analysed with different methods the densification of UO2 nanopowders in SPS under constant heating rate (CHR) and isothermal sintering conditions. The apparent activation energy of densification in SPS (75 kJ/mol with CHR method) is significantly smaller than in conventional sintering. It is shown that this is likely not an effect of the applied current. We also observed a threshold stress at 64 MPa for the transition from pressure-insensitive sintering (stress exponent n≈0) to pressure-assisted sintering, suggesting that the contribution of the capillary stresses in such nanopowders is comparable with the typical stress applied in SPS. |
| |
Keywords: | Spark Plasma Sintering (SPS) Electric Field Assisted Sintering (EFAST) Nanopowders Sintering mechanisms CHR Isothermal MSC |
本文献已被 ScienceDirect 等数据库收录! |
|