Speaker
Description
The rapid repair of damaged military equipment is often essential for the sustainment of operational capabilities. Whenever the damage is beyond repair and logistics are not ready to deliver spare parts in reasonable time, the manufacturing of crucial spare parts near the battlefield is offering a suitable solution. Additive manufacturing has been instigated and tested for these purposes successfully in recent years. While the utilisation of polymer based AM equipment was shown successfully both by stationary as well as mobile equipment, the deployable manufacturing of metal parts by AM is still under development.
Our investigations focused on resembling an in-field repair activity using wire-arc additive manufacturing. In this matter we designed and manufactured a generic, half-sized sprocket wheel derived from military tracked vehicles.
The first activity of this research was to define an efficient build strategy of this design. Two main variations were considered in detail: firstly, the one-step approach from the one outer diameter to the other side; secondly, the generation of a left and right half mirrored by a symmetric plane, which itself was introduced as a remaining baseplate. The later was chosen and realized from grade 316L alloy.
The main focus was set to define process parameter allowing a high process stability as well as increase the level of automation. A specific feature was the usage of data derived from inline camera pictures for process control.
The alloy applied for the wire-arc process was a solid wire of G 18 8 Mn type, offering mechanical properties of the weld metal of 370 MPa yield strength, 600 MPa ultimate strength and ductility of 35 % (A5).
Several more processing details were established, including intermediate machining strategies as well as the path planning under consideration of a limitation of the interlayer temperature of 250°C. This was specifically influencing the building sequence of the sprocket layers.
Based on the experience from manufacturing this defence related demonstrator, a repair use case was studied, again taking into account the capabilities of a mobile, deployable container which includes both WAAM and CNC milling facilities, enabling alternating additive and subtractive processing, on-site finishing and postprocessing.
| Speaker Country | Austria |
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| Would you like to publish your paper in the special issue of BHM "Berg- und Hüttenmännische Monatshefte" | Yes |