Corrosion of Additively Manufactured Ni-Superalloys

Applications are invited from graduates with a first class, or upper second-class degree in an appropriate discipline such as, materials science and engineering, physics, aerospace, nuclear materials, or mechanical engineering for a PhD project on the understanding the corrosion properties of additively manufactured Ni-superalloys

Project description

The manufacture of components from conventionally used Ni-alloys such as Inconel 625 with laser powder bed fusion (L-PBF) results in non-optimised microstructures for their intended mechanical and physical properties. IN625 is chosen for its high strength whilst offering excellent corrosion and oxidation resistance for many applications and environments, in particular at elevated temperatures. It is becoming recognised that using L-PBF for IN625 results in a microstructure with elemental segregation such as Cr and Nb which are expected to cause detrimental effects in corrosion and oxidation performance. It also remains unknown what the effect of surface treatments are on the corrosion behaviour, where internal and external microstructures are subjected to wide variation in processing through thermal gradient and the presence of roughness, crevices and surface fracture. Currently, these effects have not been understood in relation to the requirements of this material for in-service applications.

Project objectives
• Gain a detailed understanding of the as-built microstructure of L-PBF IN625, identifying the scale and severity of any segregation.

• Investigate the corrosion properties of IN625 in an as-built condition and after recommended standard thermal post-processing, under environmental conditions that would be expected of a service component for aerospace, high-performance automotive and space applications.

• Understand the microstructural mechanisms driving the corrosion properties in the as-built and standard post-processed conditions, for both internal and external microstructures.

• To understand the mechanisms by which surface finish affects corrosion properties of the material

• Develop the required thermal and finish post-processing cycles based on the understanding of microstructural mechanisms to balance optimised corrosion and oxidation resistance with the strength requirements normally expected.

The project will involve the use of advanced metallurgical characterisation techniques, including electron microscopy, X-ray micro-tomography, and mechanical testing, in addition to the state of the art facilities at the University of Birmingham and the Manufacturing Technology Centre. The student will be based in the advanced materials and processing laboratory, University of Birmingham, but will have the opportunity to spend time being based at the Manufacturing Technology Centre in Coventry.

http://www.birmingham.ac.uk/AMPLab
http://www.amplab-bham.com
http://www.the-mtc.org/



For those who are interested in this post, please send your CV Prof. Moataz Attallah ([Email Address Removed]) & Dr. Sam Cruchley ([Email Address Removed])