当前申请(专利权)人地址：
6 Carlton Gardens, LONDON, SW1Y 5AD, United Kingdom
摘要：
A method of forming a metallic component 3 by additive layer manufacturing where metal is added to a weld pool formed on the component 3. While the component 3 is being formed, stress in the component 3 is measured and if it is greater than a predetermined value then the component 3 is stress relieved. Stress can be measured by measuring the distortion across at least a substantial portion of the component 3, for example using load cells 13 & 14 to measure the force experienced by the component 3 where it is clamped to the apparatus on which it is formed. Stress relief can be by high frequency peening using a pulsed laser or ultra-sonic impact, annealing or creep forming. The component 3 can be cooled before it is stress relieved.
权利要求：
CLAIMS1. A method of forming a metallic component by additive layer manufacturing including the steps of:-a) mounting a work piece to ALM manufacturing apparatus including measuring means to measure stresses tending to distort the work piece, b) using a heat source to apply heat to a portion of a surface of the work piece sufficient to melt said portion; c) adding metallic material to the melted portion and moving the heat source relative to the work piece whereby progressively to form a layer of metallic material on the work piece; d) repeating steps b) and c) as required, whereby progressively to form the component; e) while progressively forming the component, measuring stresses tending to distort the work piece with the measuring means and, if such stresses are measured to be above a predetermined threshold, stress relieving the work piece while mounted to the apparatus whereby to reduce distortion to a predetermined level, and repeating steps b) to e) as required whereby to form the component.
2. A method as in claim 1 including positioning the measuring means in the region of extremities of the work piece and measuring distortion across at least a substantial portion of the work piece.
3. A method as in claim 2 in which the step of mounting the work piece to the apparatus includes clamping the work piece to the apparatus at least partly by means of the measuring means.
4. A method as in any preceding claim in which the steps of measuring stresses tending to distort the work piece and stress relieving the work piece include measuring clamping loads applied to the work piece to clamp it in position on the apparatus before ALM manufacture commences and after forming a predetermined number of layers of added material on the work piece, stress relieving the work piece, -14-measuring the clamping loads again and, if the clamping loads exceed a predetermined said threshold, further stress relieving the work piece.
5. A method as in any preceding claim in which the step of stress relieving the layer comprises applying a peening step to the layer.
6. A method as in claim 5 in which the peening step comprises high frequency peening.
7. A method as in claim 6 in which the high frequency peening step comprises applying a pulsed laser to the layer.
8. A method as in claim 6 in which the high frequency peening step comprises applying ultra-sonic impact treatment to the layer.
9. Additive layer manufacturing apparatus for forming a metallic component, the apparatus including mounting means to mount a work piece to the apparatus, a heat source to apply heat to a portion of a surface of the work piece sufficient to melt said portion; means to add metallic material to the melted portion and means to move the heat source relative to the work piece whereby progressively to form a layer of metallic material on the work piece, measuring means to measure stresses tending to distort the work piece and stress relieving means to relieve stress in the work piece while mounted to the apparatus whereby to reduce distortion of the work piece during forming of the component.
10. Apparatus as in claim 9 in which the measuring means is positioned in the region of extremities of the work piece whereby to measure distortion across at least a substantial portion of the work piece.
11. Apparatus as in claim 9 or 10 including clamping means to clamp the work piece to the apparatus in which the measuring means forms part of the clamping means.
12. Apparatus as in any of claims 9 to 11 including cooling means to cool the work piece before operation of the stress relieving means.
13. Apparatus as in any of claims 9 tol 2 in which the stress relieving means comprises a pulsed laser whereby to apply laser peening to the added layer.
14. Apparatus as in any of claims 9 to 12 in which the stress relieving means comprises ultrasonic impact treatment means.
15. Apparatus as in any of claims 9 to 14 including a computer programmed to control the heat source; the means to add metallic material to the melted portion of the surface of the work piece, the means to move the heat source relative to the work piece, and the stress relieving means in dependence upon stresses in the work piece measured by the measuring means.
16. A computer programmed to carry out the method of any of claims 1 to 8.
17. A computer programme product containing a computer programme adapted to cause the computer of claim 14 to carry out the method of any of claims ito 8.
18. A method of forming a metallic component by additive layer manufacturing substantially as herein described.
19. Additive layer manufacturing apparatus for forming a metallic component substantially as described herein with reference to the accompanying drawings.
20. A computer substantially as herein described with reference to the accompanying drawings.