High Temperature Miniature Specimen Test Methods

Wei Sun Ph.D DS.c was a Professor of Mechanical Engineering at the University of Nottingham, and has been working on creep, fatigue, cyclic plasticity, and the miniaturized specimen test methods at high temperatures for > 25 years. He has supervised 40 Ph.D projects (> 10 related to high temperature small specimen testing). He is an author of 260 international journal articles (63 related to high-temperature miniature specimen tests), 170 conference contributions (14 plenary/keynote lectures) and one textbook (Applied Creep Mechanics. McGraw-Hill 2013). He became Charted Engineer in 1998, a Fellow of The Institution of Mechanical Engineers in 2002, and a Fellow of The Institute of Materials in 2009. Prof. Sun has been an Emeritus Professor at the University of Nottingham since he retired in 2020, and currently is a member of EU CEN Impression Creep Standard Committe. Zhufeng Yue Ph.D is a Professor of Engineering Mechanics at the Northwestern Polytechnical University. Prof. Yue is a renowned expert on engineering mechanics, covering computational solid mechanics, high temperature structural integrity, fatigue, creep, plasticity, superplasticity, fretting and wear, computational methods in manufacturing process, and miniature specimen testing at elevated temperatures, with a focus on the multi-scale and multi-physics material modelling of single crystal superalloys. Prof. Yue has supervised 90 Ph.D students and is an author of 300 English journal articles, 260 conference contributions including 24 keynote lectures, 50 patents and 17 textbooks Prof. Yue has held adjunct professorships at Tongji University and Zhejiang University in China, and has been the Editor in Chief of the journal “Multidiscipline Modelling in Materials and Structure” since 2005. is a Professor of Mechanical Engineering at the East China University of Science and Technology. She has been working on high-temperature mechanics, related to creep and fatigue, thermal-mechanical coupling interaction, and miniature specimen testing. Prof. Zhou has developed several high-temperature miniaturized creep test methods and evaluation procedures using miniature beam and semi-circle ring specimens, which have been used in the structural integrity and safety assessment for turbine rotors, hydrogenation reactors and other equipment. Zhufeng Yue Ph.D is a Professor of Engineering Mechanics at the Northwestern Polytechnical University. Prof. Yue is a renowned expert on engineering mechanics, covering computational solid mechanics, high temperature structural integrity, fatigue, creep, plasticity, superplasticity, fretting and wear, computational methods in manufacturing process, and miniature specimen testing at elevated temperatures, with a focus on the multi-scale and multi-physics material modelling of single crystal superalloys. Prof. Yue has supervised 90 Ph.D students and is an author of 300 English journal articles, 260 conference contributions including 24 keynote lectures, 50 patents and 17 textbooks Prof. Yue has held adjunct professorships at Tongji University and Zhejiang University in China, and has been the Editor in Chief of the journal “Multidiscipline Modelling in Materials and Structure” since 2005. Ming Li is a Professor of Engineering Mechanics at the Northwestern Polytechnical University since 2021. He received his Ph.D in Mechanical Engineering in 2018 at the National University of Ireland, Galway, followed by a research fellow at University of Nottingham (2019-2021) in United Kingdom. During his Ph.D, he studied at University of Limerick as a visiting scholar in Ireland (2017-2018). Prof. Ming’s research interests focus on the multi-scale modelling method of high temperature superalloys. He has developed a high temperature fatigue test method by using a miniature thin-plate specimen for a supperalloy at high temperature. The miniaturized test method developed has exhibited a clear possibility to produce comparable low cycle fatigue behavior and creep-fatigue behavior with those which are normally obtained by conventional standard specimen tests.

• 1. Outlines test types and data processing used to estimate the material constants2. The most popular small punch test method, i.e. the small punch test3. Introduces the impression creep test method using a rectangular indenter4. Theoretical methods for data interpretation and typical test data are described5. These include the miniature ring creep test methods6. The miniature bar-type creep test method7. Miniature bending creep tests8. The more recently developed miniature thin-plate test creep and low cycle fatigue test methods 9. A specific topic related to the data interpretation is addressed in this chapter, in which the concept of the Equivalent Gauge Length (EGL) is introduced10. The determination of material properties from the miniature specimen11. Focuses on a specific application field on structural assessment of aero-engine gas turbine blades, where the assessment of anisotropy and lifing of service-aged gas turbine blades made of single-crystal nickel-based superalloy is particularly discussed12. Briefly addresses several requirements for the future development of the miniaturized specimen test method, which is related to material property characterization, component assessment, size effect and multi-scale modelling, as well as standardization