NSUF 18-1529: Correlation between In-situ TEM Observations of Radiation Damage of an Advanced Ferritic/Martensitic Alloy under Dual-Beam Ion Irradiation and its Mechanical Properties through In-situ Nanomechanical Testing

The objective of the work is to correlate the microstructure evolution observed under ion irradiation with the alteration of the mechanical properties and deformation behavior in advanced Ferritic/Martensitic alloy HT9 under dual ion irradiation. The specimens will be in-situ irradiated at 470˚C up to 20 dpa in the microscope using 4 MeV Au2+ ions. Meanwhile, 10 KeV He ions will be co-implanted into the specimens with respecting the different ratios of He concentration and damage (0.22, 2.2 and 22 appm He/dpa). The microstructure evolution under dual ion irradiation will be followed and characterized using the in-situ TEM technique. The through-focal bright field TEM imaging is utilized to capture the nucleation of helium bubbles. And, the (g, 3g) weak beam dark field TEM imaging is utilized to follow the radiation-induced defects during irradiation. Furthermore, videos with a frame rate of 15 frames/s are recorded for subsequent frame-by-frame analysis. Similarly, the real-time observation of the evolution of material deformation will be performed using the in-situ nanomechanical testing. The influence of compression on radiation-induced defects (e.g. dislocations and dislocation loops) in material are observed in real-time, meanwhile, the corresponding yield strength is measured and the stress-strain curves are plotted. The experimental work will be completed within two weeks at the user facility. subsequent data analysis will be performed at the university. The achievement of this work will contribute to demonstrate that the ion irradiation induced microstructure and corresponding mechanical behavior emulate effectively results from neutron exposure in the appropriate reactor environment. The experimental work will be completed in 2 weeks at the NSUF facility with subsequent data analysis done at the university.

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Abstract The objective of the work is to correlate the microstructure evolution observed under ion irradiation with the alteration of the mechanical properties and deformation behavior in advanced Ferritic/Martensitic alloy HT9 under dual ion irradiation. The specimens will be in-situ irradiated at 470˚C up to 20 dpa in the microscope using 4 MeV Au2+ ions. Meanwhile, 10 KeV He ions will be co-implanted into the specimens with respecting the different ratios of He concentration and damage (0.22, 2.2 and 22 appm He/dpa). The microstructure evolution under dual ion irradiation will be followed and characterized using the in-situ TEM technique. The through-focal bright field TEM imaging is utilized to capture the nucleation of helium bubbles. And, the (g, 3g) weak beam dark field TEM imaging is utilized to follow the radiation-induced defects during irradiation. Furthermore, videos with a frame rate of 15 frames/s are recorded for subsequent frame-by-frame analysis. Similarly, the real-time observation of the evolution of material deformation will be performed using the in-situ nanomechanical testing. The influence of compression on radiation-induced defects (e.g. dislocations and dislocation loops) in material are observed in real-time, meanwhile, the corresponding yield strength is measured and the stress-strain curves are plotted. The experimental work will be completed within two weeks at the user facility. subsequent data analysis will be performed at the university. The achievement of this work will contribute to demonstrate that the ion irradiation induced microstructure and corresponding mechanical behavior emulate effectively results from neutron exposure in the appropriate reactor environment. The experimental work will be completed in 2 weeks at the NSUF facility with subsequent data analysis done at the university.
Award Announced Date 2018-09-17T12:01:17.083
Awarded Institution University of Wisconsin
Facility University of Wisconsin Ion Beam Laboratory
Facility Tech Lead Kumar Sridharan, Michael Starr
Irradiation Facility None
PI Djamel Kaoumi
PI Email [email protected]
Project Type RTE
RTE Number 1529