当前申请(专利权)人地址：
Rowley Mills, Penistone Road, Lepton, Huddesfield, HD8 0LE, United Kingdom | Lepton, Huddesfield, HD8 0LE, United Kingdom
摘要：
An additive layer manufacturing apparatus 10 in vacuum chamber 12 housing 11, with at least one window 23 for monitoring a region 13 of the chamber in which additive layer manufacturing is to be carried out by an electron beam column 17 generating an electron beam for action on successive layers 16 of fusible powder material, particularly metallic material e.g. a Ti-Al alloy, to produce an article 15. To combat the problem of deposition on the window of material escaping from the layer as gaseous phase constituents in the high temperature vacuum, the apparatus additionally comprises an optical element e.g. a prism or lens 26 to block and intercept such liberated gaseous phase constituents, to shelter the window(s) 23A, 23B, or to guard and protect other elements such as a refractive prism or mirror 26C which directs light to the associated window 23C; while allowing light to pass through. To prevent condensation of the intercepted constituents a heating element 26 is included with the shielding optical elements, e.g. around the perimeter. Behind the windows sensors 25, e.g. cameras, using lasers or the IR spectrum, may be located. Optical characteristics of the elements are preferably maintained up to at least 700 degrees Celsius.
权利要求：
CLAIMS
1. Additive layer manufacturing apparatus comprising
a housing bounding a vacuum chamber and having a window for monitoring a region of the chamber in which additive layer manufacturing is to be carried out,
electron beam generating and transmitting means for generating an electron beam and transmitting the beam through the chamber to the region for action on successive layers of fusible powder material to produce an article therefrom,
an optical element arranged in the chamber to intercept liberated gaseous phase constituents of the material travelling along an optical path between the region and the window
and heating means for heating the optical element to a temperature substantially preventing condensation thereon of the intercepted constituents.
2. Apparatus according to claim 1, wherein the window is arranged in line of sight of a zone of action of the beam in the chamber region and the optical element is optically transmissive and arranged in the optical path to screen the window from the zone.
3. Apparatus according to claim 2, wherein the optical element provides low-loss transmission in the infrared spectrum.
4. Apparatus according to claim 2 or claim 3, wherein the optical element is a pane or lens.
3. Apparatus according to claim 4, wherein the heating means is arranged at a perimeter of the pane or lens.
6. Apparatus according to claim 1, wherein the window is arranged out of line of sight of a zone of action of the beam in the chamber region and the optical element is optically reflective or refractive and defines the optical path.
7. Apparatus according to claim 6, wherein the optical element provides low-loss reflectance or refraction in the infrared spectrum.
8. Apparatus according to claim 6 or claim 7, wherein the optical element is a mirror or prism.
9. Apparatus according to claim 8, wherein the heating means is arranged over a side of the mirror or prism remote from the chamber region.
10. Apparatus according to any one of the preceding claims, wherein the housing has a plurality of such windows and the apparatus comprises a respective such optical element associated with each window and respective such heating means for heating each optical element.
11. Apparatus according to any one of the preceding claims, wherein the optical element consists of a material having a melting point of at least substantially 700 degrees centigrade.
12. Apparatus according to any one of the preceding claims, wherein the optical element consists of a material having substantially unchanged optical characteristics up to at least substantially 700 degrees centigrade.
13. Apparatus according to any one of the preceding claims, comprising monitoring means for monitoring at least one parameter of additive layer manufacture carried out in the chamber, the monitoring means being arranged outside the chamber to monitor via the or each window and respectively associated optical path.
14. Apparatus according to claim 13, the monitoring means comprising a camera for capturing an image within the chamber region.
15. Apparatus according to claim 13, the monitoring means comprising measuring means for measuring the at least one parameter.
16. Apparatus according to claim 13, the measuring means comprising a laser measuring instrument.
Amendment to the claims have been filed as follows
CLAIMS
i Additive layer manufacturing apparatus comprising
a housing bounding a vacuum chamber and having a window for monitoring a region of
the chamber in which additive layer manufacturing is to be carried out,
electron beam generating and transmitting means for generating an electron beam and
transmitting the beam through the chamber to the region for action on successive layers of
fusible powder material to produce an article therefrom,
an optical element arranged in the chamber to intercept liberated gaseous phase
constituents of the material travelling along an optical path between the region and the
window
and heating means for heating the optical element to a temperature substantially
preventing condensation thereon of the intercepted constituents.
2. Apparatus according to claim 1, wherein the window is arranged in line of sight of a
zone of action of the beam in the chamber region and the optical element is optically
transmissive and arranged in the optical path to screen the window from the zone.
3. Apparatus according to claim 2, wherein the optical element provides transmission
in the infrared spectrum.
4, Apparatus according to claim 2 or claim 3, wherein the optical element is a pane or
lens.
5. Apparatus according to claim 4, wherein the heating means is arranged at a
perimeter of the pane or lens.
6. Apparatus according to claim 1, wherein the window is arranged out of line of sight
of a zone of action of the beam in the chamber region and the optical element is optically
reflective or refractive and defines the optical path.
7. Apparatus according to claim 6, wherein the optical element provides reflectance or refraction in the infrared spectrum.
8. Apparatus according to claim 6 or claim 7, wherein the optical element is a mirror or prism.
9. Apparatus according to claim 8, wherein the heating means is arranged over a side of the mirror or prism remote from the chamber region.
10. Apparatus according to any one of the preceding claims, wherein the housing has a plurality of such windows and the apparatus comprises a respective such optical element associated with each window and respective such heating means for heating each optical element.
11. Apparatus according to any one of the preceding claims, wherein the optical element consists of a material having a melting point of at least 700 degrees centigrade.
12. Apparatus according to any one of the preceding claims, wherein the optical element consists of a material having substantially unchanged optical characteristics up to at least 700 degrees centigrade.
13. Apparatus according to any one of the preceding claims, comprising monitoring means for monitoring at least one parameter of additive layer manufacture carried out in the chamber, the monitoring means being arranged outside the chamber to monitor via the or each window and respectively associated optical path.
14. Apparatus according to claim 13, the monitoring means comprising a camera for capturing an image within the chamber region.
156. Apparatus according to claim 13, the monitoring means comprising measuring means for measuring the at least one parameter.
16. Apparatus according to claim 13, the measuring means comprising a laser measuring instrument.