The proposed PhD thesis aims to develop wire arc additive manufacturing (WAAM) and post-processing for achieving near net shape deposit with selected material properties. The first challenge addressed in this research is the inherent variations in the WAAM process parameters which have a negative impact on the final shape of the product. The next addressed challenge is the high linear heat input and heating/cooling cycles of the material during the deposition. Therefore, to achieve the desired material properties in the case of 15-5 PH steel, heat treatment (solution annealing and aging) is required. However, heat treatment parameters are only known for conventionally produced 15-5 PH. Furthermore, even the basic mechanical properties of WAAM 15-5 PH have not yet been studied.
To address these challenges, an advanced WAAM system has been developed. The system enables near-net shape deposition of complex geometry parts by online monitoring of the layer height through electric parameters of the arc and in-process path replanning. The system’s operation was verified by deposition of thin-walled shell part. Additionally, appropriate destructive and non-destructive methods were used to develop and optimize the solution annealing and aging temperatures and times. The solution annealing process needs to be carried out for a longer time and at a higher temperature than conventionally produced 15-5 PH. The result is a homogenous solid solution that enables aging with comparable mechanical properties to conventionally produced 15-5 PH.
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