Master thesis: Effects of the PBF-LB manufacturing process on ultrasonic

Master thesis: Effects of the PBF-LB manufacturing process on ultrasonic signal response from internal defects.

A Snapshot of Your Day

The use of additive manufacturing (AM) is increasing rapidly, both in terms of raw number of manufactured components, but also in the domain in which it is applied. This ongoing development in manufacturing techniques makes new product designs possible, but it also introduces more uncertainties about structural integrity as there is inherently less knowledge about the processes.

Non-destructive Evaluation (NDE) is a discipline which enables post-manufacturing and in-service inspection of components without damaging or otherwise negatively influence the usefulness of it. NDE gives information about the component which enables design of components without unnecessary redundant structural mass by ensuring there are no internal flaws exceeding a critical size which would otherwise cause failure of the component. Ultrasonic testing is a well-established NDE method to evaluate internal and surface-breaking defects. The method relies on the reflection and refraction of sound waves when transitioning between materials of differing acoustic impedance, e.g., at the location of a flaw such as a crack or inclusion. Information contained in the acquired signals can be used to deduce information about flaw size and location.

 

How You’ll Make an Impact

This thesis aims to increase the understanding about the specific macro material characteristics (surface structure, internal cavity properties) related to the Powder Bed Fusion – Laser Beam (PBF-LB) process and the effects that these have on the signal response from virtual flaws as well as classes of CAD-seeded defects.
* Investigate the effect of un-melted or partially melted powder on the ultrasonic testing signal response from internal flaws.
* Investigate the effect of external surface structure (from the unprocessed PBF-LB part) on the ultrasonic testing signal response from standardized artificial flaws.
* Investigate the viability of using artificial flaws manufactured using the PBF-LB method as reference reflectors (i.e., the variance of signal response from equivalent reflectors).
* Investigate the validity of existing sizing methods of indications for the specific process and material.

Working at the research environment PTC (Produktionstekniskt Centrum) the student will make use of equipment for non-destructive testing, i.e., a TOPAZ64 phased array ultrasonic system, as well as have indirect access to perform test with XCT (X-ray Computed Tomography). Manufacturing of custom test samples will be done in collaboration with Siemens Energy. Parts of the work will be performed at the materials technology department at Siemens Energy in Finspång with use of equipment available at the lab and in the workshop.

 

What You Bring   
* You study for a Master of Science in a relevant field.
* You are interested in performing both theoretical and practical work.

 

About the Team

You will be joining a diverse team consisting of approx. 25 persons with different backgrounds supporting all materials related topics.

Through our Generation division, we enhance and innovate conventional and renewable power supply. Currently, we're reducing carbon emissions of existing assets and developing technologies that transform power generation applications.

What’s it like to work at Siemens Energy? Take a look: https://bit.ly/3hD9pvK

 

Who is Siemens Energy?

At Siemens Energy, we are more than just an energy technology company. We meet the growing energy demand across 90+ countries while ensuring our climate is protected. With more than 92,000 dedicated employees, we not only generate electricity for over 16% of the global community, but we’re also using our technology to help protect people and the environment.

Our global team is committed to making sustainable, reliable, and affordable energy a reality by pushing the boundaries of what is possible. We uphold a 150-year legacy of innovation that encourages our search for people who will support our focus on decarbonization, new technologies, and energy transformation.

 

Our Commitment to Diversity

Lucky for us, we are not all the same. Through diversity, we generate power. We run on inclusion and our combined creative energy is fueled by over 130 nationalitie...