5th International Congress on 3D Materials Science (3DMS 2021): Wednesday Plenary
Program Organizers: Dorte Juul Jensen, Technical University of Denmark; Erica Lilleodden, Fraunhofer Insitute for Microstructure of Materials and Systems (IMWS); Scott Barnett, Northwestern University; Keith Knipling, Naval Research Laboratory; Matthew Miller, Cornell University; Akira Taniyama, The Japan Institute of Metals and Materials; Hiroyuki Toda, Kyushu University; Lei Zhang, Chinese Academy of Sciences
Wednesday 10:00 AM
June 30, 2021
Room: Virtual A
Location: Virtual
Session Chair: Keith Knipling, Naval Research Laboratory
10:00 AM Plenary
Acoustic Emission Measurements of Damage Accumulation and Crack Initiation in Metals at the Micron-scale: Jaafar El-Awady1; 1Johns Hopkins University
Recent advances in small scale experiments have significantly improved the ability to quantify the mechanisms that control deformation and failure in metals. In this talk a new methodology coupling acoustic emission measurements and high frequency in-situ scanning electron microscopy experiments to quantify the evolution of damage and crack initiation in nickel microcrystals will be presented. Mechanical properties are continuously monitored during the cyclic loading through analysis of the different instrument signals. Through the in-situ observations the nucleation and propagation speeds of persistent slip bands (PSBs) was quantified, while postmortem characterizations have led to an unprecedented understanding of the origin of these PSBs. Additionally, quantification of crack initiation and propagation was also analyzed from acoustic emission measurements, and the statistics of these events at different stages of crack propagation (i.e. short crack and long crack regimes) are quantified. Challenges and limitations of the methodology will also be discussed.
11:00 AM Break