摘要：
Additive manufacturing apparatus 1 comprises a substrate heating device 2 configured to heat a sub-region of a substrate 12 and a substrate cooling device 3 having a nozzle 4 configured to direct a cooling fluid 6 onto the substrate sub-region 12 wherein an exhaust passage 5 to remove spent cooling fluid is coaxial with the nozzle 4. The nozzle may further comprise a plurality of flow channels 8 wherein the nozzle is maintained at a distance from the substrate up to twenty times the diameter of said flow channels and the channels are configured such that the flow rate of the cooling fluid varies between the flow channels 8. Also included is a method of post weld cooling using the apparatus 1.
权利要求：
CLAIMS1. A melt deposition additive manufacturing apparatus, the apparatus comprising: a substrate heating device configured to heat a sub-region of a substrate and a substrate cooling device, the cooling device comprising: a nozzle configured to direct a cooling fluid onto the substrate subregion; and an exhaust passage configured to remove spent cooling fluid, wherein the exhaust passage is coaxial with the nozzle.
2. An apparatus according to claim 1, wherein the apparatus comprises a material deposition device.
3. An apparatus according to any of claims 1 or 2, wherein the exhaust passage is configured to direct spent cooling fluid away from the substrate sub-region.
4. An apparatus according to any of claims 2 to 3, wherein the exhaust passage is configured to direct spent fluid in a direction away from a deposition path of the deposition device.
5. An apparatus according to any of claims 2 to 4, wherein the nozzle and/ or exhaust passage may be spaced from the substrate heating device and/ or material deposition device up to 200mm.
6. An apparatus according to any of claims 2 to 5, wherein the substrate heating device is arranged to direct heat into the deposition path of the deposition device.
7. An apparatus according to any of claims 2 to 6, wherein the deposition device is arranged to direct a deposition material into a heat path provided by the substrate heating device.
8. An apparatus according to any preceding claim, wherein the nozzle and/ or exhaust passage is spaced from the substrate, and the apparatus additionally comprises an actuation system to monitor and/ or alter the spacing.
9. An apparatus according to any of the preceding claims, wherein the nozzle comprises a plurality of flow channels.
10. An apparatus according to claim 9, wherein the nozzle is maintained at a distance from the substrate up to twenty times the diameter of the flow channels.
11. An apparatus according to any preceding claim, wherein the coaxially outer one of the nozzle and the exhaust passage is more closely spaced from the substrate than the other one of the nozzle and the exhaust passage.
12. An apparatus according to claim 9 or any claim dependent thereon, wherein the flow channels are configured such that mass flow rate of cooling fluid varies between the flow channels.
13. An apparatus according to any of the preceding claims, wherein the nozzle is configured such that the velocity of cooling fluid leaving the nozzle is at or about the speed of sound of the cooling fluid.
14. An apparatus according to claim9 or any claim dependent thereon, wherein the flow channels are shaped, angled or positioned relative to one another to preferentially direct cooling fluid through a subset of flow channels to preferentially direct cooling to a predetermined location.
15. An apparatus according to claim 14, wherein the flow channels are arranged as an array of holes such as a grid pattern, a series of slots, a circular pattern or a teardrop pattern.
16. An apparatus according to claim 15, wherein the flow channels are arranged as multiple clusters of holes.
17. An apparatus according to claim 9 or any claim dependent thereon, wherein the flow channels are arranged such that at least a substantial portion of the cooling fluid is directed away from a heat affected zone.
18. An apparatus according to any of the preceding claims, wherein the substrate heating device comprises a weld head configured to melt the sub-region of the substrate to provide a melt pool.
19. An apparatus according to any of the preceding claims, wherein the substrate heating device comprises a post weld heat treatment device.
20. A method of post-weld cooling using the apparatus described in claims 1 to 19, the method comprising the steps of: directing heat towards a sub-region of a substrate; depositing a deposition material onto the sub-region of the substrate; and locally applying a cooling fluid to at least a part of the substrate and/ or deposited material, the application of fluid including the steps of: directing the cooling fluid onto the sub-region; and, removing spent fluid.
21. An article formed by the method of claim 20.
22. An apparatus as hereinbefore described by reference to the accompanying drawings. 15 23. An article as hereinbefore described by reference to the accompanying drawings.