Evaluation by indentation of fracture toughness of ceramic materials

Liang, Kai Ming; Orange, G.; Fantozzi, Gilbert

doi:10.1007/bf00544209

Cited by 176 publications

(94 citation statements)

References 19 publications

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“…The Vickers indentation test can be used to determine the K 1c of ceramics and glasses from empirical relationships, as demonstrated in references [8] to [17]. Advantages of the Vickers hardness test are the costeffectiveness and ease of set-up, and it is one of the simplest and least time-consuming in comparison with the other techniques available to determine the K 1c of ceramics.…”

Section: Vickers Indentation Techniquementioning

confidence: 99%

Fracture Toughness of a Zirconia Engineering Ceramic and the Effects Thereon of Surface Processing with Fibre Laser Radiation

Shukla

Lawrence

2010

Proceedings of the Institution of Mechanical Engineers, Part B:

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Vickers hardness indentation tests were employed to investigate the near-surface changes in the hardness of a fibre laser-treated and an as-received ZrO 2 engineering ceramic. Indents were created using 5, 20, and 30 kg loads to obtain the hardness. Optical microscopy, white-light interferometry, and a coordinate measuring machine were then used to observe the crack lengths and crack geometry. Palmqvist and half-penny median crack profiles were found, which dictated the selection of the group of equations used herein. Computational and analytical approaches were then adapted to determine the K 1c of ZrO 2 . It was found that the best applicable equation was:1/2 (P/c 3/2 ), which was confirmed to be 42 per cent accurate in producing K 1c values within the range of 8 to 12 MPa m 1/2 for ZrO 2 . Fibre laser surface treatment reduced the surface hardness and produced smaller crack lengths in comparison with the as-received surface. The surface crack lengths, hardness, and indentation loads were found to be important, particularly the crack length, which significantly influenced the end K 1c value when K 1c ¼ 0.016 (E/H) 1/2 (P/c 3/2 ) was used. This is because, the longer the crack lengths, the lower the ceramic's resistance to indentation. This, in turn, increased the end K 1c value. Also, the hardness influences the K 1c , and a softer surface was produced by the fibre laser treatment; this resulted in higher resistance to crack propagation and enhanced the ceramic's K 1c . Increasing the indentation load also varied the end K 1c value, as higher indentation loads resulted in a bigger diamond footprint, and the ceramic exhibited longer crack lengths.

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Section: Vickers Indentation Techniquementioning

confidence: 99%

Fracture Toughness of a Zirconia Engineering Ceramic and the Effects Thereon of Surface Processing with Fibre Laser Radiation

Shukla

Lawrence

2010

Proceedings of the Institution of Mechanical Engineers, Part B:

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“…The observed indentation fracture toughness is about 3.2 MPa·m 1/2 . Liang et al [25] also obtained similar values of approximately 3 MPa·m 1/2 for polycrystalline SiC using indentation methods that are verified using SENB experiments. Figure 5a,b shows the variation of c/a and the P/c 1.5 ratios at various loads (P) for different pyramidal indenters when the SiC-6H single crystal samples are indented in the <0001> direction.…”

Section: Fracture Toughness Measurement In Sic-6h(0001)mentioning

confidence: 52%

“…The observed indentation fracture toughness is about 3.2 MPa·m 1/2 . Liang et al [25] also obtained similar values of approximately 3 MPa·m 1/2 for polycrystalline SiC using indentation methods that are verified using SENB experiments. Applying the Laugier and the Jang and Pharr models (based on the Lawn model) for fracture toughness measurements with pyramidal indenters with different centerline-to-face angles requires accurate constants.…”

Section: Fracture Toughness Measurement In Sic-6h(0001)mentioning

confidence: 52%

Fracture Toughness Evaluation and Plastic Behavior Law of a Single Crystal Silicon Carbide by Nanoindentation

2018

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Nanoindentation-based fracture toughness measurements of ceramic materials like silicon carbide (SiC) with pyramidal indenters are of significant interest in materials research. A majority of currently used fracture toughness models have been developed for Vickers indenters and are limited to specific crack geometries. The validity of the indentation-cracking method for the fracture toughness measurement of single crystal SiC, the elastic-plastic anisotropy and orientation dependence around the c-axis when indented in the <0001> direction is examined using nanoindentation with different pyramidal indenters. The residual impressions are analyzed using scanning electron microscopy to measure the crack lengths and the validity of existing fracture toughness measurement methods and equations is analyzed. A combination of nanoindentation with different pyramidal indenters to produce a wide range of effective strains and finite element simulation is used to extract flow properties of single crystal SiC in the <0001> direction. It is observed that there is no orientation dependence around the c-axis when SiC-6H is indented in the <0001> direction with a Berkovich indenter, i.e., it is transversely isotropic. It is also found that for a Berkovich indenter, the Jang and Pharr model, which is based on the Lawn model for cone/halfpenny cracks, gives approximately constant values at low loads (<1 N), while at higher loads (>1 N), the Laugier model gives constant fracture toughness values. Finite element analysis using equivalent cones is used along with measured hardness values to estimate the yield strength, the work hardening exponents and the stress-strain curve for single crystal SiC-6H in the <0001> direction.

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“…In our works we have used, for determining the values of fracture toughness, a relationship that is independent of the crack profile and allows you to evaluate different types of materials or a type of material in a wide range of applied loads. This relationship was presented by Liang et al (in 1990) and is expressed as follows:…”

Section: Physical and Metallurgical Characteristics Of Fiber Reinforcmentioning

confidence: 99%

Physical and Metallurgical Characteristics of Fiber Reinforced Ceramic Matrix Composites

Jonšta¹,

Bolaňos²,

Hrabalová³

et al. 2011

Advances in Ceramics - Characterization, Raw Materials, Processing, Properties, Degradation and Healing

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Evaluation by indentation of fracture toughness of ceramic materials

Cited by 176 publications

References 19 publications

Fracture Toughness of a Zirconia Engineering Ceramic and the Effects Thereon of Surface Processing with Fibre Laser Radiation

Fracture Toughness of a Zirconia Engineering Ceramic and the Effects Thereon of Surface Processing with Fibre Laser Radiation

Fracture Toughness Evaluation and Plastic Behavior Law of a Single Crystal Silicon Carbide by Nanoindentation

Physical and Metallurgical Characteristics of Fiber Reinforced Ceramic Matrix Composites

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