Contact damage and residual strength in polycrystalline diamond (PCD)
| Autor: | Kasonde Maweja, F. García-Marro, A. Mestra, S. Ozbayraktar, V. Kanyanta, Luis Llanes |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Scanning electron microscope 020502 materials Mechanical Engineering 02 engineering and technology General Chemistry 021001 nanoscience & nanotechnology Microstructure Polycrystalline diamond Electronic Optical and Magnetic Materials body regions Residual strength 0205 materials engineering Flexural strength Indentation otorhinolaryngologic diseases Materials Chemistry Fracture (geology) Electrical and Electronic Engineering Composite material 0210 nano-technology Damage tolerance |
| Zdroj: | Diamond and Related Materials. 65:131-136 |
| ISSN: | 0925-9635 |
| DOI: | 10.1016/j.diamond.2016.03.004 |
| Popis: | The tolerance to contact damage of polycrystalline diamond (PCD) composites is investigated. Three different PCD grades are considered. Contact damage is extrinsically introduced by spherical indentation techniques, an approach well-established to evaluate damage tolerance issues in other hard materials. Such damage is induced on the surface of polished specimens, under both monotonic and cyclic loading conditions, and is characterized by optical and scanning electron microscopy. Residual strength is used as discriminative parameter for evaluation of damage tolerance. Hence, non-indented (reference) and indented specimens are fractured by means of biaxial ball-on-three-ball flexure testing. Results show that tolerance to contact damage is dependent on the microstructural characteristics of each PCD grade. Hence, although fine PCD grade exhibits the highest reference strength, corresponding indented specimens show pronounced fracture resistance decay for relatively high applied loads or number of cycles. On the other hand, the bimodal and coarse PCD variants are found to be more tolerant to contact damage, i.e. fracture strength shows only slight changes as cracks are introduced. The trends discerned are discussed on the basis of relative discontinuous character and sharpness of the induced damage, as well as effective depth of corresponding cracks, all of them directly dependent on the PCD microstructure assemblage. |
| Databáze: | OpenAIRE |
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