Next Article in Journal
Smart Tactile Sensing Systems Based on Embedded CNN Implementations
Previous Article in Journal
Vertical Leakage in GaN-on-Si Stacks Investigated by a Buffer Decomposition Experiment
Open AccessArticle

Mechanical Behavior Investigation of 4H-SiC Single Crystal at the Micro–Nano Scale

School of Mechanical and Precision Instrument Engineering, Xi’an University of Technology, Xi’an 710048, China
*
Authors to whom correspondence should be addressed.
Micromachines 2020, 11(1), 102; https://doi.org/10.3390/mi11010102
Received: 11 December 2019 / Revised: 7 January 2020 / Accepted: 15 January 2020 / Published: 17 January 2020
In this paper, theoretical models of the critical indentation depth and critical force on brittle materials using cleavage strength and contact theory are proposed. A Berkovich indenter is adopted for nanoindentation tests on a 4H-SiC single crystal sample to evaluate its mechanical behaviors. The stages of brittle material deformation (elastic, plastic, and brittle) can be characterized by the load versus indentation depth curves through the nanoindentation test. The curve of the elastic deformation stage follows the Hertz contact theory, and plastic deformation occurs at an indentation depth of up to 10 nm. The mechanism of 4H-SiC single crystal cracking is discussed, and the critical indentation depth and critical force for the plastic–brittle transition are obtained through the occurrence of the pop-in point. This shows that the theoretical results have good coherence with the test results. Both the values of the elastic modulus and hardness decrease as the crack length increases. In order to obtain more accurate mechanical property values in the nanoindentation test for brittle materials such as SiC, GaN, and sapphire, an appropriate load that avoids surface cracks should be adopted. View Full-Text
Keywords: 4H-SiC single crystal; critical indentation depth; plastic–brittle transition; hardness; modulus; deformation 4H-SiC single crystal; critical indentation depth; plastic–brittle transition; hardness; modulus; deformation
Show Figures

Figure 1

MDPI and ACS Style

Chai, P.; Li, S.; Li, Y.; Liang, L.; Yin, X. Mechanical Behavior Investigation of 4H-SiC Single Crystal at the Micro–Nano Scale. Micromachines 2020, 11, 102.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop