Vickers indentation fracture toughness test Part 1 Review of literature and formulation of standardised indentation toughness equations

Ponton, C. B.; Rawlings, R. D.

doi:10.1179/mst.1989.5.9.865

Cited by 560 publications

(123 citation statements)

References 18 publications

Supporting

Mentioning

122

Contrasting

Order By: Relevance

“…In the case of a Vickers indentation, one usually considers that this is the case for radial cracks for which c/a > 2, where a is the half diagonal of the plastic mark and c is the crack length. For smaller cracks, (i.e., for smaller c/a ratio) deviations are systematically observed, but among the long list of proposed relations (Ponton and Rawlings 1989a) between F and c no general conclusions are derived in this regime. Note that for such lengths, possible Palmqvist (or lateral) cracks may have been generated.…”

Section: Introductionmentioning

confidence: 86%

“…For the chosen loading range, it was checked that the radial-median crack system is predominant, following a c/a criterion Rawlings 1989a, Ponton andRawlings 1989b). In the case of alumina, additional observations have been performed to check that indentationgenerated cracks (for an applied mass of 1 kg) remained connected to the plastic mark after polishing, thus discriminating the radial-median crack system from a Palmqvist one.…”

Section: Experimental Materials and Methodsmentioning

confidence: 99%

“…Last, ξ 0 is a dimensionless constant that remains slightly dependent on the plastic constitutive law of the material. Ample experimental data show that for large loads, such a scaling relation between F and c holds (Ponton and Rawlings 1989a). In the case of a Vickers indentation, one usually considers that this is the case for radial cracks for which c/a > 2, where a is the half diagonal of the plastic mark and c is the crack length.…”

Section: Introductionmentioning

confidence: 96%

See 2 more Smart Citations

Material-independent crack arrest statistics: application to indentation experiments

et al. 2006

View full text Add to dashboard Cite

An extensive experimental study of indentation and crack arrest statistics is presented for four different brittle materials (alumina, silicon carbide, silicon nitride, glass). Evidence is given that the crack length statistics is described by a universal (i.e., material independent) distribution. The latter directly derives from results obtained when modeling crack propagation as a depinning phenomenon. Crack arrest (or effective toughness) statistics appears to be fully characterized by two parameters, namely, an asymptotic crack length (or macroscopic toughness) value and a power law size-dependent width. The experimental knowledge of the crack arrest statistics at one given scale thus gives access to its knowledge at all scales.

show abstract

Section: Introductionmentioning

confidence: 86%

Section: Experimental Materials and Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

See 1 more Smart Citation

Material-independent crack arrest statistics: application to indentation experiments

et al. 2006

View full text Add to dashboard Cite

show abstract

“…The fracture toughness was determined by measuring the length of the crack generated when the polished surface of the pellet was indented with a Vickers indenter with an applied load of 60N by universal testing machine attached with Vickers indenter (UTM, ZWICK/Roell Z005) The toughness values were calculated using the equation proposed by Evans and Charles [7].…”

Section: Methodsmentioning

confidence: 99%

Synthesis, Sintering and Microstructural Characterization of Nanocrystalline Hydroxyapatite Composites

et al. 2004

View full text Add to dashboard Cite

Nanocrystalline hydroxyapatite (HAp) exhibits better bioactivity and biocompatibility with enhanced mechanical properties compared to the microcrystalline counterpart. In the present work, nanocrystalline hydroxyapatite was synthesized by wet chemical method. Sintering was carried out with nanocrystalline alumina as additive, the content of alumina being varied from 10 to 30 wt% in the composite. For 20 and 30 wt % A1 2 0 3 , hydroxyapatite decomposed into tricalcium phosphate (TCP) above the sintering temperature of 1 100C. The fracture toughness of nano HAp-nano A1 2 0 3 composite is anisotropic in nature and reached a maximum value of 6.9 MPa m 12 .

show abstract

“…The technique of indentation fracture toughness measurement, described in detail by Ponton and Rawlings [13], can be successfully used for evaluation of thick brittle coatings [14][15][16]. In this case, the model of Lawn and Swain [17] was used to determine the number of K Ic .…”

Section: Indentation Fracture Toughnessmentioning

confidence: 99%

The influence of the spraying angle on properties of thermally sprayed HVOF cermet coatings

Houdková

Zahálka

Kašparová

2009

WIT Transactions on Engineering Sciences

View full text Add to dashboard Cite

The tribological properties of the surfaces of parts, namely their wear resistance and friction properties, are in many cases decisive for their proper function. To improve surface properties, it is possible to create hard, wear resistant coatings by thermal spray technologies. Using these versatile coatings it is possible to increase the lifetime, reliability and safety of parts. For proper function of the surface treatment it is necessary to find and keep the optimal condition and parameters during preparation, deposition and further processing of the sprayed part. The spraying angle is one of the deposition parameters that influence the quality of thermally sprayed coatings. According to the theory, with decreasing spraying angle the process deposition efficiency decreases, whereas the porosity of coatings increases, being a cause of aggravated microstructure and mechanical properties. In this paper, the microstructure together with the basic mechanical properties and wear of WC-Co and Cr 3 C 2 -NiCr HVOF sprayed coatings were investigated in dependence of the spraying angle. For each coating, the marginal spraying angle that can be used without a significant decrease of the coating's quality was identified. With respect to the change in coating properties as well as to process deposition efficiency, the maximum 30° diversion from a normal spray direction is recommended in the case of WC-Co and 15° diversion in the case of Cr 3 C 2 -NiCr.

show abstract

Vickers indentation fracture toughness test Part 1 Review of literature and formulation of standardised indentation toughness equations

Cited by 560 publications

References 18 publications

Material-independent crack arrest statistics: application to indentation experiments

Material-independent crack arrest statistics: application to indentation experiments

Synthesis, Sintering and Microstructural Characterization of Nanocrystalline Hydroxyapatite Composites

The influence of the spraying angle on properties of thermally sprayed HVOF cermet coatings

Contact Info

Product

Resources

About