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Protection and Restoration
economical, AM can be used for rapid production of this tool (Pfähler et al., 2019).
On the other hand, AM technologies enable producing tools of complex geometry,
for example, a drill base body with coolant ducts shaped spirally along flutes without
weakening the drill core (Tyczynski et al., 2019). This is related to the efficient product concept, which stands for implementation of additional product utility which is
made possible by AM through, for example, freedom of design (Pfähler et al., 2019).
Pfähler et al. (2019) also note production of spare parts on demand, which is
becoming an increasingly relevant application area of AM. Spare parts can be manufactured directly when and where required, avoiding unfavorable storage costs and
eliminating the need for transportation. Moreover, AM can be used to repair wearing parts instead of replacing an entire component with a new one. An area that
needs to be repaired can be fixed using an additive technology, e.g., laser deposition
welding.
Concluding their survey, Pfähler et al. (2019) observe that a majority of participating companies are active in areas like rapid prototyping, rapid tooling, rapid manufacturing, and efficient product. Considerably fewer companies are currently active
in the remaining fields of application such as repair of wear parts and spare parts
on demand. However, the authors believe that the two latter categories show notable
potential for future usage.
Le et al. (2017) describe two potential scenarios for manufacturing parts from
existing components using AM technologies. The first scenario included hybridization of additive and subtractive processes, as well as the inspection process. In this
scenario, an existing used-up part is utilized again directly as a workpiece to produce
a new part or final part. The metal powder required to produce the final part is made
of raw material by the gas atomization process, while chips generated in the subtractive phases of manufacturing are recycled into a raw material. Sintered and/or nonmelted powders in AM processes are also recycled for reuse in the next production
cycle. As part of the second scenario, an existing part is first recycled into raw materials which will be used for producing workpieces by conventional methods such as
casting or forging, and the final part is made from the workpiece by a sequence of
machining and inspection operations. In this scenario, the chips are also recycled
into a raw material for a new production cycle. In both scenarios, final inspection is
applied to verify the required quality. If the dimensions of manufactured part are out
of tolerances, a decision will be made to continue processing the part according to
the first or second scenario.
In their study, Le et al. (2017) propose a direct manufacturing approach according
to the first scenario. Utilizing benefits of combined additive and subtractive technologies, this approach can give a new life to existing metallic or non-metallic parts by
transforming them into final parts intended for another product. The authors focus
on the metal-based AM techniques, in particular, DED and PBF, and existing parts
as components extracted from an EoL product. The existing part has been identified
in terms of material quality, size, and shape, which are compatible to produce a final
part of different features. This enables not only reusing material of an existing part
effectively, but also avoiding the material recycling phase and several subtractive and
additive operations to achieve the geometry and quality of the final part intended for
Protection and Restoration
economical, AM can be used for rapid production of this tool (Pfähler et al., 2019).
On the other hand, AM technologies enable producing tools of complex geometry,
for example, a drill base body with coolant ducts shaped spirally along flutes without
weakening the drill core (Tyczynski et al., 2019). This is related to the efficient product concept, which stands for implementation of additional product utility which is
made possible by AM through, for example, freedom of design (Pfähler et al., 2019).
Pfähler et al. (2019) also note production of spare parts on demand, which is
becoming an increasingly relevant application area of AM. Spare parts can be manufactured directly when and where required, avoiding unfavorable storage costs and
eliminating the need for transportation. Moreover, AM can be used to repair wearing parts instead of replacing an entire component with a new one. An area that
needs to be repaired can be fixed using an additive technology, e.g., laser deposition
welding.
Concluding their survey, Pfähler et al. (2019) observe that a majority of participating companies are active in areas like rapid prototyping, rapid tooling, rapid manufacturing, and efficient product. Considerably fewer companies are currently active
in the remaining fields of application such as repair of wear parts and spare parts
on demand. However, the authors believe that the two latter categories show notable
potential for future usage.
Le et al. (2017) describe two potential scenarios for manufacturing parts from
existing components using AM technologies. The first scenario included hybridization of additive and subtractive processes, as well as the inspection process. In this
scenario, an existing used-up part is utilized again directly as a workpiece to produce
a new part or final part. The metal powder required to produce the final part is made
of raw material by the gas atomization process, while chips generated in the subtractive phases of manufacturing are recycled into a raw material. Sintered and/or nonmelted powders in AM processes are also recycled for reuse in the next production
cycle. As part of the second scenario, an existing part is first recycled into raw materials which will be used for producing workpieces by conventional methods such as
casting or forging, and the final part is made from the workpiece by a sequence of
machining and inspection operations. In this scenario, the chips are also recycled
into a raw material for a new production cycle. In both scenarios, final inspection is
applied to verify the required quality. If the dimensions of manufactured part are out
of tolerances, a decision will be made to continue processing the part according to
the first or second scenario.
In their study, Le et al. (2017) propose a direct manufacturing approach according
to the first scenario. Utilizing benefits of combined additive and subtractive technologies, this approach can give a new life to existing metallic or non-metallic parts by
transforming them into final parts intended for another product. The authors focus
on the metal-based AM techniques, in particular, DED and PBF, and existing parts
as components extracted from an EoL product. The existing part has been identified
in terms of material quality, size, and shape, which are compatible to produce a final
part of different features. This enables not only reusing material of an existing part
effectively, but also avoiding the material recycling phase and several subtractive and
additive operations to achieve the geometry and quality of the final part intended for