High-strain-rate deformation and comminution of silicon carbide

Shih, Chun Kuang; Nesterenko, V. F.; Meyers, Marc A.

doi:10.1063/1.367252

Cited by 63 publications

(46 citation statements)

References 21 publications

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“…Shear localization under dynamic loading was observed in both prefractured and granular Al 2 O 3 [61,62] and SiC [63,64]. The micromechanism is dependent on particle size, and two principal mechanisms were identified: 1.…”

Section: Ceramicsmentioning

confidence: 99%

“…12(a) and (b) show this process for prefractured and granular SiC; a schematic representation is shown in Fig. 12(c) [63,64]. 2.…”

Section: Ceramicsmentioning

confidence: 99%

“…Small particles: when the size of particles is below a c , the critical flaw size, they no longer fracture under the imposed conditions. Shih et al [63,64] calculated the critical particle size for the change in regime. They used a Weibull distribution of flaws and a Griffith failure criterion.…”

Section: Ceramicsmentioning

confidence: 99%

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Shear localization in dynamic deformation of materials: microstructural evolution and self-organization

Meyers

Nesterenko

LaSalvia

et al. 2001

Materials Science and Engineering: A

333

117

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The plastic deformation of crystalline and non-crystalline solids incorporates microscopically localized deformation modes that can be precursors to shear localization. Shear localization has been found to be an important and sometimes dominant deformation and fracture mode in metals, fractured and granular ceramics, polymers, and metallic glasses at high strains and strain rates. Experiments involving the collapse of a thick walled cylinder enable controlled and reproducible application of plastic deformation at very high strain rates to specimens. These experiments were supplemented by hat-shaped specimens tested in a compression Hopkinson bar. The initiation and propagation of shear bands has been studied in metals (Ti, Ta, Ti-6Al-4V, and stainless steel), granular and prefractured ceramics (Al 2 O 3 and SiC), a polymer (teflon) and a metallic glass (Co 58 Ni 10 Fe 5 Si 11 B 16 ). The first aspect that was investigated is the microstructural evolution inside the shear bands. A fine recrystallized structure is observed in Ti, Cu, Al-Li, and Ta, and it is becoming clear that a recrystallization mechanism is operating. The fast deformation and short cooling times inhibit grain-boundary migration; it is shown, for the first time, that a rotational mechanism, presented in terms of dislocation energetics and grain-boundary reorientation, can operate within the time of the deformation process. In pre-fractured and granular ceramics, a process of comminution takes place when the particles are greater than a critical size a c . When they are smaller than a c , particle deformation takes place. For the granular SiC, a novel mechanism of shear-induced bonding was experimentally identified inside the shear bands. For all materials, shear bands exhibit a clear self-organization, with a characteristic spacing that is a function of a number of parameters. This self-organization is analyzed in terms of fundamental material parameters in the frame of Grady-Kipp (momentum diffusion), Wright-Ockendon, and Molinari (perturbation) models.

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Section: Ceramicsmentioning

confidence: 99%

“…12(a) and (b) show this process for prefractured and granular SiC; a schematic representation is shown in Fig. 12(c) [63,64]. 2.…”

Section: Ceramicsmentioning

confidence: 99%

See 1 more Smart Citation

Shear localization in dynamic deformation of materials: microstructural evolution and self-organization

Meyers

Nesterenko

LaSalvia

et al. 2001

Materials Science and Engineering: A

333

117

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“…Debonding of metal particles from the matrix and the fracture of matrix were two major meso-scale mechanisms for the failure of the specimen 15 . The relevant meso-scale mechanism of shear localization at low levels of strain is considered in 16 , examples of shear localization due to micro-fracture mechanisms leading to reaction in granular materials can be found in 17,18 . …”

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confidence: 99%

The influence of metallic particle size on the mechanical properties of polytetraflouroethylene-Al–W powder composites

Cai

Nesterenko

Vecchio

et al. 2008

Applied Physics Letters

Self Cite

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The dynamic mechanical properties of reactive materials (e.g., high density mixtures of polytetraflouroethylene (PTFE), aluminum (Al) and tungsten (W) powders) can be tailored by changing the morphology of the particles and porosity. Cold isostatically pressed PTFE-Al-W powder composites with fine metallic particles and a higher porosity exhibited higher ultimate compressive strength than less porous composites having equivalent mass ratios with coarse W particles. The mesoscale force chains between the fine metallic particles are responsible for this unusual phenomenon. We observed macrocracks below the critical failure strain for the matrix and a competition between densification and fracture in some porous samples in dynamic tests. 2Mixtures containing polytetrafluoroethylene (PTFE) and aluminum (Al) are known to be energetic under dynamic and/or thermal loading [1][2][3][4][5][6] . They are similar in composition to thermites 7 , a subgroup of the class of pyrotechnics, and are formulated to generate a large quantity of heat during the reaction driven by mechanical deformation in the bulk material. This paper describes the mechanical behavior of the PTFE-Al-W composites with varying W particle size and porosity. Varying cold isostatic pressing conditions introduces different porosities and component configurations within the samples. The quasi-static and dynamic ultimate compressive strength of the composites were measured to identify influence of their mesostructure on mechanical properties and fracture. The unusual phenomenon of increased strength of porous composites with reducing size of metallic particles was observed. A two-dimensional Eulerian hydrocode is used to numerically model the composite systems to explain experimental phenomenon.Tailoring the mechanical and chemical properties of reactive materials is important for various applications. For example, varying particle size and morphology in pressed explosives (HNS) 8 or layer thicknesses in laminate 9 can be used for tailoring of shocksensitivity and the rate of energy release. The stress/force chain formation in granular energetic materials can be related to ignition sites within composite energetic materials under a compressive load 10 . Bardenhagen, Brackbill 11 and Roessig, Foster, and Bardenhagen 12 examined the localized stress propagation due to force chains and effects of binder in two dimensional particle bed under static and dynamic loading.Cold Isostatic Pressing (CIPing) was used to prepare specimens from a mixture of 17.5 wt% PTFE, 5.5 wt% Al, and 77 wt% W powders with different porosities. The initial powders had the following average sizes: Al: 2 μm (Valimet H-2); coarse W powder: < 44 μm (Teledyne, -325 mesh) and fine W powder with particle sizes < 1μm 3 (Alfa-Aesar); PTFE: 100 nm (DuPont, PTFE 9002-84-0, type MP 1500J). The mixed powders were ball milled in the SPEX 800 mill for 2-10 minutes using alumina balls with a 1:5 mass ratio of balls to powder to break down the agglomeration of powders. Table I shows the density of vari...

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“…There exists a vast literature on the subject Cadoni et al 2001;Camacho and Ortiz 1996;Deshpande and Evans 2008;Doyoyo 2002;Ferri et al 2010;Forquin et al 2008;Frank et al 2012;Gailly and Espinosa 2002;Gatuingt and Pijaudier-Cabot 2002;Grady 1982;Grady 1998;Grady and Kipp 1979;Grady and Kipp 1995;Grady 1990;Kožar and Ožbolt 2010;Mescall and Weiss 1984;Mott 1947;Ožbolt et al 2011;Shih et al 1998;Wei et al 2009) and many aspects are well understood, including the micro-mechanics of dynamic propagation and branching of individual cracks (Freund 1990). …”

Section: Introductionmentioning

confidence: 99%

Viscous energy dissipation of kinetic energy of particles comminuted by high-rate shearing in projectile penetration, with potential ramification to gas shale

Bažant

Zhao

et al. 2015

Int J Fract

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While dynamic comminution is of interest to many processes and situations, this work is focused on the projectile impact onto concrete walls, in which predictions have been hampered by the problem of the so-called 'dynamic overstress'. Recently, in analogy with turbulence, Bažant and Caner modeled the overstress as an additional viscous stress generated by apparent viscosity that accounts for the energy dissipation due to kinetic comminution of concrete into small particles at very high shear strain rate. Their viscosity estimation, however, was approximate since it did not satisfy the energy balance exactly. Here their model is extended and refined by ensuring that the drop of local kinetic energy of high shear strain rate of form- ing particles must be exactly equal to the energy dissipated by interface fracture of these particles. The basic hypothesis is that the interface fracture occurs instantly, as soon as the energy balance is satisfied. Like in the preceding work, this additional apparent viscosity is a power function of the rate of the deviatoric strain invariant. But here the power exponent is different, equal to −7/3, and the apparent viscosity is found to be proportional also to the time derivative of the rate of that invariant, i.e., to the second derivative of the shear strain. It is assumed that the interface fracture that comminutes the material into small particles occurs instantly, as soon as the local kinetic energy of shear strain rate in the forming particles becomes equal to the energy required to form interface fractures. The post-comminution behavior, including subsequent further comminution and clustering into bigger particle groups to release the kinetic energy that is being dissipated by inter-group friction, is discussed and modeled. The present formulation makes it possible to eliminate the artificial damping of all types, which is normally embedded in commercial finite element codes but is not predictive since it is not justified physically. With the aforementioned improvements, and after implementation into the new microplane model M7 for fracturing damage in concrete (which includes the quasi-static rate effects), the finite element predictions give superior agreement with the measured exit velocities of steel projectiles penetrating concrete walls of different thicknesses and with the measured depths of penetration into concrete blocks by projectiles of different veloci-123 78 Y. Su et al. ties. Finally it is pointed out that the theory presented may also be used to predict proximate fragmentation and permeability enhancement of gas shale by powerful electric pulsed-arc explosions in the borehole.

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High-strain-rate deformation and comminution of silicon carbide

Cited by 63 publications

References 21 publications

Shear localization in dynamic deformation of materials: microstructural evolution and self-organization

Shear localization in dynamic deformation of materials: microstructural evolution and self-organization

The influence of metallic particle size on the mechanical properties of polytetraflouroethylene-Al–W powder composites

Viscous energy dissipation of kinetic energy of particles comminuted by high-rate shearing in projectile penetration, with potential ramification to gas shale

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