Mechanical properties, strength physics and plasticity

Differentiation of acoustic emission sources during impact damage of uniaxially loaded quartz ceramics

I. P. Shcherbakov, A. E. Chmel

Ioffe Institute, St. Petersburg, Russia

Abstract: Uniaxially compressed quartz ceramic samples were subjected to point impact damage directed orthogonally to the compression. The shock-induced acoustic emission generation was recorded in two frequency ranges: 80–200 kHz and 300–500 kHz. The frequency of the acoustic pulse decreases with increasing size of the emission region, as well as with increasing values of the elastic characteristics of its source. It was found that energy distributions in time sweeps of acoustic emission recorded in the range of 80–200 kHz obey a power law typical for the process of cooperative microcrack formation, whereas distributions in the range of 300–500 kHz are described by an exponential function typical for random, non-interacting sources of acoustic emission such as deformation of ceramic grains. At compression close to the tensile strength limit, the impact caused “pre-threshold” macrofracture of the samples (trigger effect).

Keywords: ceramics, SiO$_2$, impact fracture, acoustic emission.

Received: 08.11.2023
Revised: 08.11.2023
Accepted: 10.11.2023

DOI: 10.61011/FTT.2024.01.56951.248

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