| 1. |
- Andersson, Linnéa, et al.
(författare)
-
Colloidal processing and CO2-capture performance of hierarchically porous Al2O3-zeolite 13X composites
- 2012
-
Ingår i: Journal of Ceramic Science and Technology. - 2190-9385. ; 3:1, s. 9-16
-
Tidskriftsartikel (refereegranskat)abstract
- Hierarchically porous composites for CO2-capture have been produced by coating the inner walls of foam-like macroporous alumina monoliths, produced by templated synthesis, with microporous zeolite 13X particles. Homogeneous and dense coatings of the particulate adsorbent were obtained when the impregnation process was performed at a pH above 9. At this pH-level the colloidally stable suspensions of the negatively charged zeolite 13X particles could fill all the voids of the highly connected pore space of the alumina supports and attach to the monolith walls, which had been pre-coated with poly(ethylene imine). A CO2-uptake as high as 5 mmol CO2/g zeolite 13X was achieved for alumina-zeolite 13X composites through minimisation of the added inorganic binder, kaolin, to only 3.0 wt% with respect to zeolite content, and through optimisation of the thermal treatment.
|
|
| 2. |
- Gupta, Mohit Kumar, et al.
(författare)
-
A modelling approach to design of microstructures in thermal barrier coatings
- 2013
-
Ingår i: Journal of Ceramic Science and Technology. - 2190-9385. ; 4:2, s. 85-92
-
Tidskriftsartikel (refereegranskat)abstract
- Thermo-mechanical properties of TBCs are strongly influenced by coating defects, such as delaminations and pores, thus making it essential to have a fundamental understanding of microstructure-property relationships in TBCs to produce a desired coating. Object-Oriented Finite element analysis (OOF) has been shown previously as an effective tool for evaluating thermal and mechanical material behaviour, as this method is capable of incorporating the inherent material microstructure as an input to the model. In this work, OOF was used to predict the thermal conductivity and effective Young's modulus of TBC topcoats. A Design of Experiments (DoE) was conducted by varying selected spray parameters for spraying Yttria Stabilized Zirconia (YSZ) topcoat. Microstructure was assessed with SEM and image analysis was used to characterize porosity content. The relationships between microstructural features and properties predicted by modelling are discussed. The microstructural features having the most beneficial effect on properties were sprayed with another spray gun so as to verify the results obtained from modelling. Characterisation of the coatings included microstructure evaluation, thermal conductivity and lifetime measurements. The modelling approach in combination with experiments undertaken in this study was shown to be an effective way in achieving coatings with optimised thermo-mechanical properties.
|
|
| 3. |
- Jonnalagadda, Krisha Praveen, et al.
(författare)
-
Factors Affecting the Performance of Thermal Barrier Coatings in the Presence of V2O5 and Na2SO4
- 2016
-
Ingår i: JOURNAL OF CERAMIC SCIENCE AND TECHNOLOGY. - : GOLLER VERLAG GMBH. - 2190-9385. ; 7:4, s. 409-415
-
Tidskriftsartikel (refereegranskat)abstract
- This study investigates the influence of temperature, salt concentration and thickness on the corrosion resistance of seven YSZ thermal barrier coatings in the presence of V2O5 and Na2SO4. For this study, a thick, high-porosity APS coating (670 gm) using hollow spherical powder (HOSP) and a thin, low-porosity APS coating (300 pm) using agglomerated and sintered (Aamp;S) powder were fabricated. Corrosion tests were conducted at 750 degrees C and 900 degrees C with a mixture of Na2SO4 and V2O5 for four hours. At each temperature, salt concentrations of 4,10 and 20 mg/cm(2) were used. SEM and XRD investigations after the corrosion tests revealed that a combination of low temperature and high salt concentration resulted in higher corrosion-induced damage to the thin TBC coatings. With regard to the thick TBC coatings, all except one sample failed during the corrosion test. This suggests that thick TBC coatings with higher porosity may not be suitable in corrosive environments.
|
|
