Sliding microindentation fracture of brittle materials: Role of elastic stress fields

Ahn, Yonghan; Farris, T. N.; Chandrasekar, Srinivasan

doi:10.1016/s0167-6636(98)00012-x

Cited by 124 publications

(59 citation statements)

References 9 publications

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“…This corresponds to the decompression phase of the material during scratching, and these results are consistent with the literature. 7,53 Due to the uncertainties in the tip radius, calculations were performed for the two different measured radii and for the indentation and scratching process. The critical shear stresses were extracted from the computations for each case and are given in Table I.…”

Section: Discussionmentioning

confidence: 99%

Analysis of onset of dislocation nucleation during nanoindentation and nanoscratching of InP

et al. 2011

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Nanoindentation and nanoscratching of an indium phosphide (InP) semiconductor surface was investigated via contact mechanics. Plastic deformation in InP is known to be caused by the nucleation, propagation, and multiplication of dislocations. Using selective electrochemical dissolution, which reveals dislocations at the semiconductor surface, the load needed to create the first dislocations in indentation and scratching can be determined. The experimental results showed that the load threshold to generate the first dislocations is twice lower in scratching compared to indentation. By modeling the elastic stress fields using contact mechanics based on Hertz's theory, the results during scratching can be related to the friction between the surface and the tip. Moreover, Hertz's model suggests that dislocations nucleate firstly at the surface and then propagate inside the bulk. The dislocation nucleation process explains the pop-in event which is characterized by a sudden extension of the indenter inside the surface during loading.

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Section: Discussionmentioning

confidence: 99%

Analysis of onset of dislocation nucleation during nanoindentation and nanoscratching of InP

et al. 2011

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“…13). According to the scratching analytical model developed by Ahn et al [47], shear stress and compressive stress are distributed in the front and beneath the moving indentation, respectively. The former part is mainly responsible for governing the nucleation and propagations of the SFs and twinning, while under the influence of lateral stress a tensile stress was generated perpendicular to the compressive stress as proposed in Ref.…”

Section: The Mechanism Of Brittle To Ductile Transitionmentioning

confidence: 99%

Experimental investigation on the surface and subsurface damages characteristics and formation mechanisms in ultra-precision grinding of SiC

Zhang

et al. 2017

Int J Adv Manuf Technol

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Surface and subsurface damages appear inevitably in the grinding process, which will influence the performance and lifetime of the machined components. In this paper, ultraprecision grinding experiments were performed on reactionbonded silicon carbide (RB-SiC) ceramics to investigate surface and subsurface damages characteristics and formation mechanisms in atomic scale. The surface and subsurface damages were measured by a combination of scanning electron microscopy (SEM), atomic force microscopy (AFM), raman spectroscopy, and transmission electron microscope (TEM) techniques. Ductile-regime removal mode is achieved below critical cutting depth, exhibiting with obvious plow stripes and pile-up. The brittle fracture behavior is noticeably influenced by the microstructures of RB-SiC such as impurities, phase boundary, and grain boundary. It was found that subsurface damages in plastic zone mainly consist of stacking faults (SFs), twins, and limited dislocations. No amorphous structure can be observed in both 6H-SiC and Si particles in RB-SiC ceramics. Additionally, with the aid of high-resolution TEM analysis, SFs and twins were found within the 6H-SiC closed packed plane, i.e., (0001). At last, based on the SiC structure characteristic, the formation mechanisms of SFs and twins were discussed, and a schematic model was proposed to clarify the relationship between plastic deformation-induced defects and brittle fractures.

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“…3) often represent the most detrimental grinding damage. Therefore, in the present investigation, we focused on this category of chipping defects caused by the intersection of lateral and radial cracks (Ahn et al, 1998;Lawn et al, 1980;Lawn, 1997;Marshall et al, 1982;Wasmer et al, 2005Wasmer et al, , 2008aWasmer et al, , 2013.…”

Section: Analysis Of Grinding Defectsmentioning

confidence: 99%

Parametric experimental study and design of experiment modelling of sapphire grinding

Wasmer

Pochon

Sage

et al. 2017

Journal of Cleaner Production

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a b s t r a c tThis study investigates and models the grinding process of single crystal sapphire. Five parameters: the wheel speed, the feed speed, the vertical feed, the ultrasonic assistance and the crystallographic direction were considered via a design of experiments (DoE) approach. The responses were multiple but can be divided in three groups: the process, the machine and the grinding quality. DoE results revealed that the parameters interact in a complex manner and depends on the responses. Therefore, to gain a better understanding of the grinding process of sapphire, the interactions between parameters have also to be taken into consideration. It was found that three main parameters have the largest influences on the tangential grinding forces: the wheel speed, the feed speed and the vertical feed. In contrast, the median defect area is mainly impacted by the quadratic effects of the wheel speed and vertical feed followed by various interactions. After an optimization procedure, the second optimum for the tangential forces was found to be very close to the best optimum for the median defect area. The optimum solution is: a wheel speed of 7 0 500 rpm, a feed speed of 60 mm/min, a vertical feed of 12.5 mm/pass, no ultrasonic assistance and grinding along the c-axis. This set of parameters was validated with additional and repeated tests on both Verneuil and Kyropouloas sapphire. Finally, it came out that the optimum solution has also a very good productivity.

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Sliding microindentation fracture of brittle materials: Role of elastic stress fields

Cited by 124 publications

References 9 publications

Analysis of onset of dislocation nucleation during nanoindentation and nanoscratching of InP

Analysis of onset of dislocation nucleation during nanoindentation and nanoscratching of InP

Experimental investigation on the surface and subsurface damages characteristics and formation mechanisms in ultra-precision grinding of SiC

Parametric experimental study and design of experiment modelling of sapphire grinding

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