Automated ultrasound in-process NDE of wire + arc additive manufacture

  • Rastislav Zimermann

Student thesis: Doctoral Thesis

Abstract

The global metal Additive Manufacturing (AM) market was valued at € 2.02 billion in 2019 and is expected to increase at a rate of up to 27.9% annually until 2024. In the latest industrial revolution, Industry 4.0, where smart factories capable of creating high-quality customized items at a low cost are in high demand, AM technology plays a key role. This demand can be satisfied by research of metal AM techniques such as Wire + Arc Additive Manufacturing (WAAM). WAAM utilizes industrial robotics and arc-based welding processes to produce components on a layer-by-layer basis. This enables automated, time and material-efficient production of high-value and geometrically complex metal parts. To strengthen these benefits, the demand for robotically deployed in-process Non-Destructive Evaluation (NDE) has risen, intending to eventually replace convectional manually deployed inspection procedures after the whole part completion. This thesis presents novel research that contributes to the field of automated in-process inspection of as-built WAAM components. By deployment of a novel automated high-temperature dry-coupled ultrasound roller-probe, the challenges of coupling to an as-built WAAM in-process, are solved. However, the inspection approach lacks suitable imaging techniques to accommodate for multiple refractions through unknown arbitrary interfaces. Therefore, in this thesis, a novel Synthetic Aperture Focusing Technique (SAFT) based surface finding linked to the three-layer adaptive Total Focusing Method (TFM) package is developed to process the acquired ultrasound Full Raw Data (FRD) called Full Matrix Capture (FMC). The developed system is then deployed in-process, delivering, for the first time, ultrasound in-process inspection of as-built titanium WAAM components. Lastly, realizing the drawbacks limiting the NDE deployment, the advanced FRD technique, called Virtual Source Aperture (VSA), is linked to the SAFT-TFM imaging package to increase the maximum inspection speed, reduce the size of the data and increase the energy levels retrieved from the sample.
Date of Award4 Aug 2022
Original languageEnglish
Awarding Institution
  • University Of Strathclyde
SponsorsEPSRC (Engineering and Physical Sciences Research Council) & University of Strathclyde
SupervisorCharles Norman MacLeod (Supervisor) & Ehsan Mohseni (Supervisor)

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