Abstract
In this paper, the study on damage evolution of sapphire induced in scratching process using acoustic emission (AE) technology was carried out. Single-grit scratches with ramp scratch depth were conducted on C-plane of sapphire with AE signal monitoring. Groove microstructure after scratching shows that the damage evolution process is mainly determined by the interactions among cracks, specimen surface and groove boundary. To evaluate the damage evolution, the AE waveform indexes, i.e. fractal and frequency characteristics, were fully analyzed and correlated with groove microstructure of specimen after tests. It is found that the fractal dimension (FD) can identify the three basic damage modes as well as various damage behaviors during scratching process. In addition, the model of damage evolution is further proposed. The frequency characteristics of AE signals are distinctive to various damage behaviors during their evolution, especially to the occurrences of the critical damages and removal modes. Furthermore, the characteristic frequency band (CFB) of AE signals was extracted. It is found that FD of the reconstructed AE signals in CFB (86.8–161.4 KHz herein) can highlight damage details and features during initial damage stage of sapphire in scratch test effectively. © 2020 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
| Original language | English |
|---|---|
| Pages (from-to) | 26085-26099 |
| Journal | Ceramics International |
| Volume | 46 |
| Issue number | 16, Part A |
| Online published | 9 Aug 2020 |
| DOIs | |
| Publication status | Published - Nov 2020 |
| Externally published | Yes |
Funding
This work is supported by the National Natural Science Foundation of China (Grant No.: 51875135), National Natural Science Foundation of Heilongjiang Province (Grant No.: E2018037), and National Key R&D Program of China (Grant No.: 2018YFA0703400).
Research Keywords
- Acoustic emission
- Damage evolution
- Fractal theory
- Sapphire
- Single-grit scratch