Ductile–brittle transition in micropillar compression of GaAs at room temperature

Östlund, Fredrik; Howie, Philip R.; Ghisleni, R.; Korte, Sandra; Leifer, Klaus; Clegg, William; Michler, Johann

doi:10.1080/14786435.2010.509286

Cited by 120 publications

(89 citation statements)

References 27 publications

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“…The fact that micropillar compression of LiF [111] yields plastic deformation and not fracture is an indication that the small size suppressed cracking, as shown elsewhere (Ostlund et al, 2011), and highlights the benefit of using micropillar compression to study plasticity in brittle materials without the need of using complex tests, like compression under confining pressure. The measured flow stress of R±500 MPa leads to an estimation of the critical resolved shear stresses for the hard slip system of the order of 250 MPa, which is reasonable for bulk LiF (Gilman, 1959), although the exact value is very sensitive to impurities and dislocation density.…”

Section: Compressive Behavior Of As-grown Micropiuarsmentioning

confidence: 99%

Micropillar compression of LiF [111] single crystals: Effect of size, ion irradiation and misorientation

Soler

Molina-Aldareguia

Segurado

et al. 2012

International Journal of Plasticity

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The mechanical response under compression of LiF single crystal micropillars oriented in the [111] direction was studied. Micropillars of different diameter (in the range 1-5 u.m) were obtained by etching the matrix in directionally-solidified NaCl-LiF and KCl-LiF eutectic compounds. Selected micropillars were exposed to high-energy Ga + ions to ascertain the effect of ion irradiation on the mechanical response. Ion irradiation led to an increase of approximately 30% in the yield strength and the maximum compressive strength but no effect of the micropillar diameter on flow stress was found in either the as-grown or the ion irradiated pillars. The dominant deformation micromechanisms were analyzed by means of crystal plasticity finite element simulations of the compression test, which explained the strong effect of micropillar misorientation on the mechanical response. Finally, the lack of size effect on the flow stress was discussed to the light of previous studies in LiF and other materials which show high lattice resistance to dislocation motion.

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Section: Compressive Behavior Of As-grown Micropiuarsmentioning

confidence: 99%

Micropillar compression of LiF [111] single crystals: Effect of size, ion irradiation and misorientation

Soler

Molina-Aldareguia

Segurado

et al. 2012

International Journal of Plasticity

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“…[2,[21][22][23][24][25][26][27][28][29][30][31][32] A selection of materials thus studied in terms of their plasticity is shown in Fig. 2, while Figs.…”

Section: Investigating Plasticity In Hard Crystalsmentioning

confidence: 99%

“…Among the systems, which have been studied to date by research groups around the globe are Cu-Sn phases (solders), carbides and nitrides, MAX phases, binary nickel and iron aluminides, metallic and silicate glasses, high entropy alloys and quasicrystals, [2,[21][22][23][24][25][26][27][28][29][30][31][32]36,[44][45][46][47][48] see also Fig. 2.…”

Section: Investigating Plasticity In Hard Crystalsmentioning

confidence: 99%

“…Most prominent is microcompression, which helps overcome the fundamental challenge of studying plasticity in materials, which suffer from extreme brittleness in conventional testing. [1,2] Their plastic properties may, at first glance, appear to be of only academic interest: aiming to deduce fundamental relationships of crystal plasticity and structure to enable knowledge-guided search and data mining for new structural materials. However, they are in fact essential to performance at the microstructural scale of many advanced and highly alloyed materials and to understanding the effects of alloying strategies aimed at inducing deformability as baseline or reference information.…”

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confidence: 99%

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Microcompression of brittle and anisotropic crystals: recent advances and current challenges in studying plasticity in hard materials

Korte‐Kerzel

2017

MRS Communications

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Recent years have seen an increased application of small-scale uniaxial testing-microcompression-to the study of plasticity in macroscopically brittle materials. By suppressing fast fracture, new insights into deformation mechanisms of more complex crystals have become available, which had previously been out of reach of experiments. Structurally complex intermetallics, metallic compounds, or oxides are commonly brittle, but in some cases extraordinary, though currently mostly unpredictable, mechanical properties are found. This paper aims to give a survey of current advances, outstanding challenges, and practical considerations in testing such hard, brittle, and anisotropic crystals.While the origin of mechanical strength, toughness, and creep resistance is well studied in most metals, much less is known about the properties of more complex crystal structuresdespite their wide use as reinforcement phases and the undiscovered potential in their sheer number and variability. A major challenge in plasticity research of the next years will therefore be to close this gap in knowledge. Small-scale testing techniques have been demonstrated as a key enabling technique for such studies. Most prominent is microcompression, which helps overcome the fundamental challenge of studying plasticity in materials, which suffer from extreme brittleness in conventional testing. [1,2] Their plastic properties may, at first glance, appear to be of only academic interest: aiming to deduce fundamental relationships of crystal plasticity and structure to enable knowledge-guided search and data mining for new structural materials. However, they are in fact essential to performance at the microstructural scale of many advanced and highly alloyed materials and to understanding the effects of alloying strategies aimed at inducing deformability as baseline or reference information. Investigating plasticity in hard crystalsA deep understanding of plasticity and dislocation motion exists in most metallic crystals and strategies to engineer different aspects, for example by adjustment of the stacking fault energy, have been very successful. [3,4] These are being applied-with great effect-to hexagonal metals [3] which in spite of their closely related atomic packing show strongly anisotropic deformation and are therefore much more difficult to deform at low temperatures. In BCC metals, fundamental aspects of dislocation core structure, stress tensor dependence, and resulting non-Schmid behavior, are also still under investigation. [5,6] However, in all of these materials, the availability of large-grained or single crystals with sufficient purity has scarcely been a problem, nor has the ability to deform such samples under carefully controlled conditions. Suitable investigations by conventional, analytical and high-resolution microscopy techniques have also been carried out whenever new methods have allowed researchers to dive deeper into the physics of their plastic deformation.In intermetallics, ceramics, and compounds we face challeng...

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“…In some cases, the geometry promotes the plastic flow of otherwise brittle materials, 18,19 and in others splitting is observed where cracks propagate through the sample. 20 Although much microcantilever bending work has been carried out, it is almost exclusively reported at room temperature. In many engineering systems of interest, from aerospace to nuclear, the performance of the materials at temperature close to or above service conditions is vital to allow safe engineering design.…”

Section: Introductionmentioning

confidence: 99%

Bend Testing of Silicon Microcantilevers from 21°C to 770°C

Armstrong

Tarleton

2015

JOM

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The measurement of mechanical properties at the microscale is of interest across a wide range of engineering applications. Much recent work has demonstrated that micropillar compression can be used to measure changes in flow properties at temperatures up to 600°C. In this work, we demonstrate that an alternative microscale bend testing geometry can be used to measure elastic, plastic, and fracture behavior up to 770°C in silicon. We measure a Young's modulus value of 130 GPa at room temperature, which is seen to drop with increasing temperature to %125 GPa. Below 500°C, no failure is seen up to elastic strains of 3%. At 530°C, the microcantilever fractures in a brittle fashion. At temperatures of 600°C and above plastic deformation is seen before brittle fracture. The yield stresses at these temperatures are in good agreement with literature values measured using micropillar compression.

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Ductile–brittle transition in micropillar compression of GaAs at room temperature

Cited by 120 publications

References 27 publications

Micropillar compression of LiF [111] single crystals: Effect of size, ion irradiation and misorientation

Micropillar compression of LiF [111] single crystals: Effect of size, ion irradiation and misorientation

Microcompression of brittle and anisotropic crystals: recent advances and current challenges in studying plasticity in hard materials

Bend Testing of Silicon Microcantilevers from 21°C to 770°C

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