Dynamic recrystallization of tungsten in a shaped charge liner

Guo, Wei; Li, S.K.; Wang, F.C.; Wang, M.

doi:10.1016/j.scriptamat.2008.10.028

Cited by 40 publications

(19 citation statements)

References 14 publications

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“…In this condition, increased dislocation density (as shown in Figure B) is a warranty for extremely plastic deformation, and the dislocation drag controlled plasticity is the only possible mechanism. These fragmented subgrains eventually form small, recrystallized grains, which help in the further flow of the material . Figure C provides evidence that the well refined DRX grains with clear grain boundaries appear in the centre of DRX zone of steel target.…”

Section: Resultsmentioning

confidence: 94%

Dynamic response and microstructure evolution of the finite steel target subjected to high velocity impact by copper explosively formed projectile

Liu

Long

et al. 2017

Fatigue Fract Eng Mat Struct

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The dynamic deformation of the finite steel target subjected to high velocity impact of copper explosively formed projectile is investigated by optical, scanning, and transmission electron microscopy. Morphology analysis of fracture surfaces indicates that the copper remainder plated to the crater wall shows extremely plastic deformation, which consists of elongated parabolic dimples, and the mild carbon steel target exhibits excellent brittle features that material fails mainly along the cleavage facets on the rear surface of target under strong impact of explosively formed projectile. In the surface of crater, the whole part of copper remainder and partial material of steel target undergoes completely dynamic recrystallization. The layer thickness of dynamic recrystallization zone, which displays an extreme plastic flow in solid state, is about 21.3 μm in steel target, and the average size of the refined grains significantly decreases to approximately 200 nm. Theoretically calculated results indicate that the temperature increase is associated with shock wave and plastic deformation of steel target and can reach 1352 K, which is 0.75Tm (where Tm is the melting temperature of steel target). The change in microhardness from the crater wall to the matrix of target is consistent with micro‐deformation of grains, and maximum microhardness is observed on the interface between dynamic recrystallization and severe plastic deformation zones of steel target.

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Section: Resultsmentioning

confidence: 94%

Dynamic response and microstructure evolution of the finite steel target subjected to high velocity impact by copper explosively formed projectile

Liu

Long

et al. 2017

Fatigue Fract Eng Mat Struct

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“…In the main body of EFP, the matrix grains start fragmenting, recombination and growing under high shock wave pressure and the dislocation mechanism plays a key role in this dynamic process. These fragmented parts eventually form small, recrystallized grains, which help in the further flow of the material [Guo et al, 2009].…”

Section: Microstructural Evolution Of the Copper Linermentioning

confidence: 99%

Dynamic Response and Microstructure Evolution of Oxygen-Free High-Conductivity Copper Liner in Explosively Formed Projectile

Liu

Long

et al. 2017

Lat. Am. j. solids struct.

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The dynamic response and microstructure evolution of oxygen-free high-conductivity copper in a shaped charge liner are investigated through microstructural examination of a soft-recovery EFP. Adiabatic shear bands and voids which is the failure original of copper EFP can be observed in the rear part of the projectile. Numerical simulation results illustrate that the highest plastic strain reaches about 2.9 which can fully accommodate the grains deformation of copper EFP during the formation process at strain rates of the order of 10 4 s −1 . Theoretical calculation results indicate that the highest temperature increase of EFP caused by shock wave and plastic deformation can reach 747K, which is 0.55Tm (where Tm is the melting temperature of copper). The main body of the EFP undergoes completely dynamic recrystallisation, and the average size of the refined grains significantly decreases to approximately 10µm. A slight increase in grain size occurs mainly away from the center and extends towards the head and rear sections of the EFP. During the DRX process, the dislocation movement is believed to be the controlling mechanism significantly refining the microstructure.

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“…Although the resultant microstructure is controlled by the degree of deformation [1], it is influenced majorly by the strain/strain rate as well as the deformation temperature (itself a function of the nature of load on the liner) which varies along the jet length [5,6]. This variation, result in segments of the ending (slug) microstructure having higher deformation with apparently more refined microstructure than others [7]. Guo et al observed that, in spite of the small equiaxed microstructure observed in recovered Tungsten slugs, significant variations in grain size were recorded at the centre, 0.5 and 1 mm away [7].…”

Section: Introductionmentioning

confidence: 99%

“…This variation, result in segments of the ending (slug) microstructure having higher deformation with apparently more refined microstructure than others [7]. Guo et al observed that, in spite of the small equiaxed microstructure observed in recovered Tungsten slugs, significant variations in grain size were recorded at the centre, 0.5 and 1 mm away [7]. In short, the grain size of the slug appeared to change linearly outward with the smallest grains at the centre and the largest in the outer regions.…”

Section: Introductionmentioning

confidence: 99%

“…In addition to the starting liner microstructure, other factors such as the liner material properties, particularly; thermal conductivity and heat capacity as well as processing route have been reported to have a significant influence on the ending microstructure [7]. As an example, Murr et al, [9] observed that the grain size ratio between the starting and ending microstructure of Tantalum differs widely from that of Copper (by a ratio of 10:1.5), something the authors attributed to inherent liner material properties.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Comparison of the Microstructure of Machined and Laser Sintered Shaped Charge Liner in the Hydrodynamic Regime

Agu

Hameed

Appleby-Thomas

2019

J. dynamic behavior mater.

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To gain further insight into the mechanisms underlying jet formation and elongation of laser sintered shaped charge liners under high strain rate deformation, Cu-Cr-Zr alloy liners fabricated by selective laser sintering process were deformed by explosive detonation. Their as-manufactured (liner) and resultant (slug) microstructure have been investigated in comparison with those of traditional machined liners employing both optical and scanning electron microscopy. The resultant slug microstructure of both machined and laser sintered liners revealed a smaller refined equiaxed grain size consistent with traditionally fabricated liners, characteristic of dynamic recrystallization. The disappearance of the (originally present) pores in the post-shot/recovered material microstructure was observed for laser-sintered liners. Comparison of the forward and rear region of the slug revealed variations in liner deformation, a result attributed to temperature variation across the slug. In contrast with the machined liner, a unique feature of precipitation, observed in the ending (slug) microstructure of the laser sintered liner is indicative of the associated extreme high strain and strain rate liner deformation which occurred during slug formation. The precipitates are likely compounds of Chromium and Zirconium which are constituents of the laser sintered copper alloy-the first time this observation is reported. This study provides a link between post charge evolution microstructure and liner manufacturing processes, potentially providing a new route to help optimise jet formation and effectiveness.

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Dynamic recrystallization of tungsten in a shaped charge liner

Cited by 40 publications

References 14 publications

Dynamic response and microstructure evolution of the finite steel target subjected to high velocity impact by copper explosively formed projectile

Dynamic response and microstructure evolution of the finite steel target subjected to high velocity impact by copper explosively formed projectile

Dynamic Response and Microstructure Evolution of Oxygen-Free High-Conductivity Copper Liner in Explosively Formed Projectile

Comparison of the Microstructure of Machined and Laser Sintered Shaped Charge Liner in the Hydrodynamic Regime

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