Stress induced phase transitions in silicon

Budnitzki, Michael; Kuna, Meinhard

doi:10.1016/j.jmps.2016.03.017

Cited by 30 publications

(20 citation statements)

References 143 publications

(147 reference statements)

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“…9,10 re-measured the phase diagram of zirconium using synchrotron x-ray diffraction and time-of-flight neutron scattering techniques, and a negative dT / dP slope of approximately 15.5 K/GPa was obtained along the ω-β phase boundary near the triple point, which was contrary to the earlier results. Similar controversies were also found in many other substances 13,19,24–27 . Although some studies were devoted to explain these controversies 20,21 , their understanding remains an open issue.…”

Section: Introductionsupporting

confidence: 75%

Understanding controversies in the α-ω and ω-β phase transformations of zirconium from nonhydrostatic thermodynamics

Zhang

Gu³

et al. 2019

Sci Rep

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Significant debate has been noted in the α-ω and ω-β phase transformations of zirconium. The initial pressure of the α-to-ω transformation at room temperature has been reported to vary from 0.25 to 7.0 GPa, while the hydrostatic transformation is believed to occur at approximately 2.2 GPa. Shear stress is commonly considered as a key factor leading to the discrepancy. However, the principal mechanisms previously proposed concluded that the phase transformation pressure would be decreased in the presence of shear stress. The experimental results of the α-ω transformation in zirconium are contrary to this conclusion. In the ω-β phase diagram of zirconium, the dT/dP along the phase boundary near the α-ω-β triple-point was reported to be either positive or negative, but no theoretical explanation, especially a quantitative one, has been proposed. This article aimed to quantitatively investigate and explain the controversies reported in the α-ω and ω-β phase transformations of zirconium by applying a new nonhydrostatic thermodynamic formalism for solid medium, which has recently been proposed and is capable of quantitatively estimating the impact of shear stress on phase transformations in solids.

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Section: Introductionsupporting

confidence: 75%

Understanding controversies in the α-ω and ω-β phase transformations of zirconium from nonhydrostatic thermodynamics

Zhang

Gu³

et al. 2019

Sci Rep

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“…Thus, the fulfillment of the SC criterion and extremum principle (41) is not sufficient for the occurrence of SC, and only the extremum principle (Eq. (44) or (45))-called the global SC criterion-offers the final solution. Application of stability analysis to straininduced nucleation at a shear-band intersection can be found in [264] and in Section 14 and in [172] and in Section 19.2 for competition between PT and fracture.…”

Section: Global Criterion For Structural Changes Based On Stability Analysesmentioning

confidence: 99%

Phase transformations, fracture, and other structural changes in inelastic materials

Levitas

2021

International Journal of Plasticity

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“…Stresses play a major role in the plastic response of the Si phase in which amorphous transformation can be initiated, even at extremely low temperature of liquid nitrogen boiling point (-195 o C) [23]. Some previous studies show that plastic deformation of amorphously transformed Si can be initiated when indented at hydrostatic pressure greater than 11-13 GPa [6,24]. Since diamond abrasives have a higher wear resistance than SiC, their sharpness was retained during the process.…”

Section: Wear Mechanisms During Diamond Disk Polishingmentioning

confidence: 99%

“…However, RB-SiC is a two-phase material consisting of a Si matrix surrounding the SiC grains, so that its responses to stresses are distinctively different. It is noted that the SiC grains are brittle and experience no phase transition during a polishing process, whereas the Si matrix is not only softer than the SiC grains, but also transformable by stresses to an amorphous phase which is plastic deformable under stresses [6]. An abrasive that can engage into the Si matrix may engage at a lower depth or not engaged at all with the hard SiC grains.…”

Section: Introductionmentioning

confidence: 99%

The wear mechanisms of reaction bonded silicon carbide under abrasive polishing and slurry jet impact conditions

Nguyen

Liu

Thongkaew

et al. 2018

Wear

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A study of the wear mechanism on a reaction bonded silicon carbide (RB-SiC) subjected to fixed abrasive polishing and loose abrasive waterjet (AWJ) impact conditions is presented. It is found that the wear of the material is characterised by different mechanisms in its silicon and silicon carbide constituents. The surface polished by diamond abrasives appears with brittle fractures on the silicon carbide phase, while the silicon phase is found to be plastically deformed and embedded onto the surface of the fractured silicon carbide. Submicrometre surface finish can be obtained by polishing using silicon carbide abrasives, and the process is initiated through the penetration of abrasive tips into the softer silicon matrix.Since the progressive wear flattens the tips of abrasives, the penetration depth of abrasives into the material gradually decreases. When the penetration depth is below a critical value, ductile material removal mode becomes dominant in the removal process. When abrasives that are softer than the silicon carbide grains are sufficiently introduced onto the material surface by a slurry jet, wear can occur even at a pressure below the critical value for phase transformation of the silicon constituent. Wear takes place mainly through weakening the Si bond by erosion and wedging, which eventually releases the SiC grain from the material structure. It is feasible to use a relatively low-pressure alumina slurry jet to machine RB-SiC without causing any surface damage and the processed surface quality depends mainly on the material structure.

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Stress induced phase transitions in silicon

Cited by 30 publications

References 143 publications

Understanding controversies in the α-ω and ω-β phase transformations of zirconium from nonhydrostatic thermodynamics

Understanding controversies in the α-ω and ω-β phase transformations of zirconium from nonhydrostatic thermodynamics

Phase transformations, fracture, and other structural changes in inelastic materials

The wear mechanisms of reaction bonded silicon carbide under abrasive polishing and slurry jet impact conditions

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