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

Chai, Peng; Li, Shujuan; Li, Yan; Liang, Lie; Yin, Xincheng

doi:10.3390/mi11010102

Cited by 24 publications

(10 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The plastic deformation of brittle materials is well known. When the load applied to an indenter is small enough, the elasticity and plasticity behaviors of 4H-SiC single crystals can be verified via the nanoindentation test [28]. As the load is further increased, a median crack appears from the bottom of plastic zone, as shown in Figure 1.…”

Section: Indentation Crack System Of Brittle Materialsmentioning

confidence: 93%

“…The indentation hardness and indentation modulus of 4H-SiC single crystals on the (0001) face without cracks were 35.81 GPa and 461.3 GPa, respectively [28]. The results in Section 4.1 were used in Equations ( 5) and ( 6) and the fracture toughness results of 4H-SiC single crystals on the (0001) face were obtained, as shown in Figure 9.…”

Section: Determination Of the Fracture Toughnessmentioning

confidence: 99%

See 1 more Smart Citation

Study on Damage of 4H-SiC Single Crystal through Indentation and Scratch Testing in Micro–Nano Scales

Chai

et al. 2020

Applied Sciences

Self Cite

View full text Add to dashboard Cite

In this paper, a series of indentation tests in which the maximum normal force ranged from 0.4 to 3.3 N were carried out to determine the fracture toughness of 4H-SiC single crystals. The results indicated that an appropriate ratio of the distance from the indentation center to the radial crack tip to the distance from the indentation center to the indentation corner is significant to calculate fracture toughness of 4H-SiC single crystals. The critical condition with no cracks on the edge of the indentation was obtained through a fitting method. The surface morphologies of the groove were analyzed by scanning electron microscopy (SEM). Plastic deformation was observed and characterized by the smooth groove without cracks and ductile chips on the edge of the groove in the initial stages of scratch. With increased normal force, median cracks, radial cracks, and microcracks appeared in turn, followed by the crack system no longer being able to stably extend, causing the brittle fracture to dominate the material removal. The size of the edge damages were measured through SEM and the experimental data highly agreed with the predicted curve. A modified calculation model considering elastic recovery of the sample by the indenter during the scratching process was suggested. These results prove that elastic recovery of 4H-SiC single crystals cannot be ignored during ultra-precision machining.

show abstract

Section: Indentation Crack System Of Brittle Materialsmentioning

confidence: 93%

Section: Determination Of the Fracture Toughnessmentioning

confidence: 99%

Study on Damage of 4H-SiC Single Crystal through Indentation and Scratch Testing in Micro–Nano Scales

Chai

et al. 2020

Applied Sciences

Self Cite

View full text Add to dashboard Cite

show abstract

“…The size of the crack plays an important role in the characteristics of a material [39][40][41][42]. In real applications, fracture properties carry great significance as cracks and defects are common in materials.…”

Section: Crack Size Effectmentioning

confidence: 99%

Atomic Insights into Fracture Characteristics of Twisted Tri-Layer Graphene

2021

View full text Add to dashboard Cite

Graphene twistronics have recently gained significant attention due their superconductive behavior as a consequence of their tunable electronic properties. Although the electronic properties of twisted graphene have been extensively studied, the mechanical properties and integrity of twisted trilayer graphene (tTLG) under loading is still elusive. We investigated the fracture mechanics of tTLG with a twist angle of ±1.53° utilizing molecular dynamics simulation. This twist angle was chosen because it is known to exhibit highly superconductive behavior. The results indicate that tTLG does not preserve the excellent mechanical properties typically associated with graphene, with toughness and fracture strain values much lower in comparison. The Young’s modulus was an exception with values relatively close to pristine graphene, whereas the tensile strength was found to be roughly half of the intrinsic strength of graphene. The fracture toughness, fracture strain and strength converge as the crack length increases, reaching 0.26 J/m3, 0.0217 and 39.9 GPa at a crack length of 8 nm, respectively. The Griffth critical strain energy is 19.98 J/m2 and the critical stress intensity factor Kc is 4.47 MPa M1/2, in good agreement with that of monolayer graphene in the experiment. Our atomic insights might be helpful in the material design of twisted trilayer graphene-based electronics.

show abstract

“…Figure 10 shows the schematic diagram of the contact between the indenter and workpiece [27]. When the load is small, the tip of Berkovich indenter could be approximated to a sphere [28], and the scratch hardness can be defined by Eq. (1).…”

Section: Mechanism Of Materials Removal and Crack Propagationmentioning

confidence: 99%

EHTT2022-Material removal characteristics of single crystal 4H-SiC based on varied-load nanoscratch tests

Tang

Mao

et al. 2022

Preprint

View full text Add to dashboard Cite

The single crystal silicon carbides (SiC) have been widely applied in the extreme circumstances and conditions for their excellent physical and chemical properties. In order to obtain various components with high surface integrity and low surface damage, precision and ultra-precision machining methods were used to process single crystal SiC. However, as typical hard-to-machine materials, their good mechanical properties also resulted in the surface defects and subsurface damage. For improving the machining quality and prolonging the service life of components, the varied-load nanoscratch tests were systematically performed on single crystal 4H-SiC by a nanoindenter system with Berkovich indenter in this paper. The characteristics of material removal under different plane, indenter direction, normal loading rate and scratch interval were discussed. The surface morphology of nanoscratch grooves, the distribution of cracks, material deformations and fractures, and cross-section characteristics were analyzed by SEM and 3D profilometer. The mechanism of material removal and crack propagation of single crystal 4H-SiC were also studied. The results indicated that the Si-plane of single crystal 4H-SiC and indenter direction of edge forward were more suitable for material removal and machining. The normal loading rate had little effect on scratch depth, but the lower one would increase the ductile region and critical depth of transition. The increasing of scratch interval would postpone the greater fluctuation of depth-distance curves of second scratch, and curve changes showed high coincidence gradually. In addition, the propagation and interaction of radial, median and transverse cracks resulted in the material fractures and accumulation of chips. The proposed research provides the instruction to high efficiency and precision machining of single crystal SiC for the purpose of emission and carbon reduction.

show abstract

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

Cited by 24 publications

References 49 publications

Study on Damage of 4H-SiC Single Crystal through Indentation and Scratch Testing in Micro–Nano Scales

Study on Damage of 4H-SiC Single Crystal through Indentation and Scratch Testing in Micro–Nano Scales

Atomic Insights into Fracture Characteristics of Twisted Tri-Layer Graphene

EHTT2022-Material removal characteristics of single crystal 4H-SiC based on varied-load nanoscratch tests

Contact Info

Product

Resources

About