1. A method of depositing a material onto a substrate, comprising the steps of:
feeding a material solution to an outlet to provide a stream of droplets of the material solution;
applying a potential difference between the outlet and a substrate to electrostatically attract the droplets from the outlet towards the substrate;
heating the substrate to provide an increase in temperature between the outlet and the substrate; and
progressively increasing the temperature of the substrate during material deposition.
2. A method according to claim 1, comprising the step of relatively rotating andor translating the outlet and the substrate during material deposition.
3. A method according to claim 1, comprising the step of varying the material solution composition andor concentration during material deposition.
4. A method according to claim 1, comprising the step of reversing the polarity of the electric field between the outlet and the substrate at intervals during material deposition.
5. A method according to claim 1, comprising the step of locally heating areas of the substrate to enhance material deposition at the heated areas.
6. A method according to claim 1, wherein the outlet is charged to approximately from 4 to 15 kilovolts with respect to the substrate.
7. A method according to claim 1, wherein the temperature is increased to a temperature in the approximate range of from about 650 to about 850 C.
8. A method according to claim 1, comprising the step of depositing layers of material having different thermal andor mechanical properties by changing the composition of the material solution andor the deposition conditions during material deposition.
9. A method according to claim 1, comprising the step of periodically varying the flow of the material solution to the outlet during material deposition.
10. A method according to claim 1, in which the material solution comprises one or more precursor compounds and a solvent.
11. A method according to claim 10, in which the solvent is acetylacetone andor butanol.
12. A method according to claim 1, in which the material is deposited as a plurality of adjacent columns of material.
13. A method according to claim 1, in which the applied potential is such that a corona discharge is formed around the outlet.
14. A method according to claim 1, in which the material solution is a sol solution.
15. A method according to claim 1, in which the process parameters are selected to tailor the molecular microstructure.
16. A method according to claim 1, in which the method is used for depositing material onto large areas andor complex shapes.
17. A method according to claim 1, in which material deposition is controlled using computer controlled multiple nozzles andor by rotating the substrate.
18. A method according to claim 1, comprising the step of electrostatically andor magnetically steering the stream of droplets in transit from the outlet to the substrate.
19. A method according to claim 1, in which the method is used in forming solid oxide fuel cell components.
20. A method according to claim 1, in which the method is used in coating gas turbine blades.
21. A method according to claim 1, in which the method forms a thermal barrier coating.
22. A method according to claim 1, in which the method forms a thick coating.
23. A method according to claim 1, wherein the material is deposited as a film.
24. A method according to claim 23, wherein the film is one of a multicomponent oxide film, a simple oxide film or a doped film.
25. A method according to claim 23, wherein the film is one or more of a structural film, a functional film and an electroceramic film.
26. A method according to claim 1, in which the material is deposited as a powder.
27. A method according to claim 1, in which the material solution is a polymer solution.
28. An apparatus for depositing a material onto a substrate, comprising: an outlet;
feeding means for feeding a material solution to the outlet to provide a stream of droplets of the material solution;
a voltage source for applying a potential difference between the outlet and the substrate to electrostatically attract the droplets from the outlet towards the substrate;
heating means for heating the substrate to provide an increase in temperature between the outlet and the substrate;
a heating controller for controlling the heating means; and
a temperature detector for detecting the temperature of a material-receiving surface on the substrate;
wherein the heating controller is configured so as to be responsive to the temperature detector to control heating of the substrate to maintain a substantially constant temperature at the material-receiving surface.
29. An apparatus according to claim 28, in which the temperature detector is an optical temperature detector.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. Aircraft propeller (1) comprising a turbomachine (8) housed in a nacelle (10) and a cooler (14) capable of being traversed by a hot fluid, which is to be cooled by thermal exchange with cold air external to the cooler, the propeller (1) comprising an air vein (13) (13b) capable of directing pressurized air towards an air duct (20) realized between an outer wall (6) and an inner wall (60) of the nacelle (10), the cooler (14) comprising:
a first cooling means, called first surface cooling means (145), on a first surface, called outer surface (141), arranged at the outer wall (6) of the propeller (1) nacelle (10),
a second cooling means, called second surface cooling means, on a second surface (146), called inner surface (142), arranged at a wall (23) of the air duct (20),
wherein the air duct (20) comprises an air inlet (21) arranged at the front of the propeller to create an additional air inlet.
2. Aircraft propeller according to claim 1, wherein:
the first surface cooling means (145) is sized so as to be sufficient to ensure the desired cooling when the aircraft is in flight, within preselected environmental and speed conditions,
the second surface cooling means (146) is sized so as to be sufficient to ensure the desired cooling when the aircraft is at low or zero speed, within preselected environmental conditions.
3. Aircraft propeller according to any one of the preceding claims, wherein an air inlet (11) is located at a 1st stage of an air compressor of the turbomachine (8) and in that the associated air vein (13) emerges upstream of cooler (14).
4. Aircraft propeller according to any one of claims 1 to 2, wherein an air inlet (11b) is located downstream from an air compressor of the turbomachine (8) and in that the associated air vein (13b) emerges downstream from the cooler (14).
5. Aircraft propeller according to claim 4, wherein the air vein (13b) comprises, at the air duct (20), an ejector, which ejects pressurized air into said air duct (20).
6. Aircraft propeller according to one of claims 1 to 2, comprising two air veins (13, 13b) and a valve (12, 12b) associated with each vein, an air vein (13) emerging upstream of the cooler (14) and an air vein (13b) emerging downstream from the cooler, the valves (12,12b) controlling the entry of pressurized air according to one vein or the other.
7. Aircraft propeller according to any one of the preceding claims, wherein at least one of the first (145) and second (146) surface cooling means is a set of fins extending from the outerinner surface, and oriented mostly parallel to the direction of the airflow.
8. Aircraft propeller according to any one of the preceding claims, wherein the first and second surface cooling means (145, 146) are of similar architecture.
9. Aircraft comprising a propeller according to any one of the preceding claims.