Detection of cracks in scratching tests in ceramic materials through acoustic emission
- 1 September 2005
- journal article
- research article
- Published by SAGE Publications in Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture
- Vol. 219 (9), 685-693
- https://doi.org/10.1243/095440505x32616
Abstract
The mechanisms of material removal and the interactions among scratches performed in ceramic materials were investigated using acoustic emission signals, and scanning electron microscopy, in scratching experiments. Several testing conditions were used to produce different types of removing mechanism on a glass as well as on a polycrystalline alumina sample composed by heterogeneous grain size. It is known that the material removing process on a polycrystalline ceramic involves intergranular microfracture and grain dislodgement, unlike the chipping produced by the extension of lateral cracks in non-granular materials, such as glass. Distinct settings for velocities, loads, and two types of diamond indenter were tested. The material removal was carried out by three different methods of scratching: single passes, repeated overlapping passes, and parallel scratches. As a general result, there was a clear relationship between the acoustic emission signals and the damage intensity occurred in the material removal. More specifically there were differences in the acoustic emission signal levels in the scratches made on the alumina and on the glass owing to the material removal mechanisms associated with the structure of these materials. A gradual increase in the acoustic emission levels was observed when the number of repeated passes was increased as a result of the damage accumulation process followed by severe material removal. It was also noticed that the acoustic emission signals were capable of reflecting the interactions between two parallel scratches.Keywords
This publication has 20 references indexed in Scilit:
- Influence of Grinding Direction on Fracture Strength of Silicon NitrideJournal of Engineering Materials and Technology, 1996
- Transitions in the mechanism of material removal in abrasive wear of aluminaWear, 1996
- Machining of advanced ceramicsTribology International, 1995
- Microfracture and material removal in scratching of aluminaJournal of Materials Science, 1995
- Damage processes in ceramics resulting from diamond tool indentation and scratching in various environmentsWear, 1995
- Chip Topography for Ductile-Regime Machining of GermaniumJournal of Engineering for Industry, 1994
- Ductile-regime machining model for diamond turning of brittle materialsPrecision Engineering, 1991
- Grinding Mechanisms and Strength Degradation for CeramicsJournal of Engineering for Industry, 1989
- The nature of machining damage in brittle materialsProceedings of the Royal Society of London. Series A - Mathematical and Physical Sciences, 1983
- Microfracture about scratches in brittle solidsProceedings of the Royal Society of London. Series A - Mathematical and Physical Sciences, 1979