29th Symposium on Fusion Technology (SOFT 2016)

P2.092 Metrology of an additively manufactured coil frame for stellarators

6 Sep 2016, 14:20

1h 40m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 92

Poster E. Magnets and Power Supplies P2 Poster session

Speaker

Vicente Queral (National Fusion Laboratory)

Description

Coil casings and coil frames for stellarators are geometrically complex components at high accuracy. A method of additive manufacturing combined with fibre-reinforced resin casting has been recently experimented [1] for the fabrication of complex coil frames. The method is named 3Dformwork and consists of additive fabrication of a hollow thin shell which is filled with resins or other appropriate materials. However, the accuracy of additive manufacturing for coils frames is a concern. Accuracy of 0.1% or higher is required for components defining the magnetic field of the fusion device. In this framework, the deviation between drawing dimensions and real additively manufactured coil frames is investigated. A coil frame of around 0.35 m long was designed and fabricated by Selective Laser Sintering (SLS) additive manufacturing in polyamide. Subsequently, the part was measured by an accurate Coordinate Measuring Machine (CMM). A contraction of 0.4% in vertical dimension and 0.35% in one horizontal dimension was measured. Also, additive manufacturing of type Stereolithography (SLA), which is based on photopolymers, is being studied as a possible more accurate fabrication method. It may achieve accuracy around 0.1%. Thus, standard SLS additive manufacturing still achieves lower accuracy than required for stellarator coil frames and other high precision fusion components. The paper reports the features of the sample coil frames, the used metrology methodology, the performed measurements and the resulting geometrical deviations. [1] V. Queral, 3D-printed fusion components concepts and validation for the UST_2 stellarator, Fusion Engineering and Design 96–97 343–347, 2015.