id: NTAwMTgyOCA3

reference: 5001828

documentId: 5001828

connectionPointId: 7

lastModificationDate: 1559910626460

stillingsbetegnelse:
PhD scholarship in Residual Stress Measurement and Design of Advanced Metal Microstructures

jobbeskrivelse:

Department of Mechanical Engineering, the section for Manufacturing Engineering at the Technical University of Denmark has a vacant 3-year PhD position in a recently granted project by Danmarks Frie Forskningsfond (DFF). The position is to be filled as soon as possible.

The Section for Manufacturing Engineering performs theoretical, numerical, and experimental research in the field of manufacturing engineering. It covers a wide range of manufacturing processes and modelling approaches, metrology at all scales, micro/nano manufacturing, and additive manufacturing. The research is based on a multidisciplinary use of process technology, materials science, solid and fluid mechanics as well as thermodynamics and heat transfer in the analysis, modelling, and development of manufacturing processes.

Research field

Residual stresses develop locally in materials during manufacturing and service. They are crucial for the mechanical and physical properties including strength, ductility and fatigue lifetime, but are often overlooked. To optimize the materials performance and to design advanced materials, it is essential to determine non-destructively the local residual stresses and relate them to the local materials inhomogeneities in 3D. So far, such measurements are rare and can only be done at large international synchrotron facilities. In this DFF project, a new laboratory based X-ray diffraction technique, LabXRS, will be developed. This technique will be a game-changer enabling many more scientists to perform local residual stress measurements than is possible at synchrotron facilities.

This project aims at using this new technique, supplemented by synchrotron measurements, to quantify for the first time systematically the level of local residual stresses and to investigate their influence on the mechanical properties of multiphase materials.

The specific aims of the PhD project are to:

• Characterize the level and distribution local residual stress in different phases in metals after different thermo-mechanical processing, and relate the stress to the local microstructures. The metals to be investigated include advanced multilayered steel and duplex steel.
• Develop a new crystal plasticity finite element model to predict the residual stress and to investigate its effects on the plastic deformation and mechanical properties
• Provide guidelines for design of advanced metals with superior mechanical properties by tailoring the microstructure and local residual stresses.

Responsibilities and tasks

To achieve the goals, LabXRS and synchrotron x-ray techniques will be used to quantify the microstructure and local residual stress after different thermo-mechanical processing of the selected metals. Advanced crystal plasticity finite element modeling will be developed incorporating real 3D microstructures and stress states. This will be in corporation with an external partner in France.

Some of the research questions this project will address are:

• What is the magnitude and distribution of the local residual stress within different phase of the metal?
• How does the stress build up during manufacturing?
• How does annealing relax stresses?
• What is the relation between the local residual stress and microstructure parameters, e.g. texture and grain size?
• How does the local residual stress affect the local plastic deformation during tensile and fatigue tests, and thus the mechanical properties of the material?

The PhD student will work in close collaboration with a group of senior scientists, technicians as well as Post Docs and other PhDs at DTU and with the Danish Company Xnovo Technology ApS. The external stay will be at Ecoles des Mines at Saint Etienne in France.

Qualifications

Candidates should have a two-year master's degree (120 ECTS points) or a similar degree with an academic level equivalent to a two-year master's degree.

Experience within one or more the following topics are an advantage:

• Materials characterization
• X-ray diffraction
• Numerical modeling
• Materials mechanics
• Experiments in the laboratory.

Good communication skills in English, both written and spoken, are essential. You should also have the ability to work independently, to plan and carry out complicated tasks.

Approval and Enrolment

The scholarship for the PhD degree is subject to academic approval, and the candidate will be enrolled in one of the general degree programmes at DTU. For information about our enrolment requirements and the general planning of the PhD study programme, please see the DTU PhD Guide. http://www.dtu.dk/english/Education/PhD/Rules/PhDguide

Assessment

The assessment of the applicants will be made by Senior Researcher Dr. Yubin Zhang and Professor Dorte Juul Jensen.

We offer

DTU is a leading technical university globally recognized for the excellence of its research, education, innovation and scientific advice. We offer a rewarding and challenging job in an international environment. We strive for academic excellence in an environment characterized by collegial respect and academic freedom tempered by responsibility.

Salary and appointment terms

The appointment will be based on the collective agreement with the Danish Confederation of Professional Associations. The allowance will be agreed upon with the relevant union. The period of employment is 3 years.

The work will be carried out both at DTU Lyngby Campus and DTU Risø Campus (about half time each place).

You can read more about career paths at DTU here. http://www.dtu.dk/english/about/job-and-career/working-at-dtu/career-paths

Further information

Further information may be obtained from senior researcher, Yubin Zhang, e-mail: yubz (at) mek.dtu.dk.

You can read more about Department of Mechanical Engineering at www.mek.dtu.dk/english. http://www.mek.dtu.dk/english

Application

Please submit your online application no later than 30 June 2019 (local time). Applications must be submitted as one PDF file containing all materials to be given consideration. To apply, please open the link "Apply online", fill out the online application form, and attach all your materials in English in one PDF file. The file must include:

• A letter motivating the application (cover letter)
• Curriculum vitae
• Grade transcripts and BSc/MSc diploma
• Excel sheet with translation of grades to the Danish grading system (see guidelines and Excel spreadsheet here) http://www.dtu.dk/english/Education/phd/Applicant/Pre_acceptance-1-

Candidates may apply prior to obtaining their master's degree but cannot begin before having received it.

Applications and enclosures received after the deadline will not be considered.

All interested candidates irrespective of age, gender, race, disability, religion or ethnic background are encouraged to apply.

DTU Mechanical Engineering covers the fundamental engineering disciplines within Solid mechanics, Fluid mechanics, Coastal and Maritime Engineering, Energy systems and energy conversion, Materials and Surface Engineering, Manufacturing Engineering, Engineering design and Product development. The department has a scientific staff of about 140 persons, 100 PhD students and a technical/administrative support staff of about 80 persons.

DTU is a technical university providing internationally leading research, education, innovation and scientific advice. Our staff of 6,000 advance science and technology to create innovative solutions that meet the demands of society, and our 11,200 students are being educated to address the technological challenges of the future. DTU is an independent university collaborating globally with business, industry, government and public agencies.


numberOfPosts: 1

jobCategoriesCodes_0: http://data.europa.eu/esco/isco/C2310

abstractJV_contact_0: Please apply using one of the specified channels

positionTypeCode: directhire

contractTypeCodes_0: fulltime

Arbejdsgiver Navn: Danmarks Tekniske Universitet

source: DK-STAR