Dislocation Damping in Aluminum at High Strain Rates

Ferguson, W. G.; Kumar, Avinash; Dorn, J.E.

doi:10.1063/1.1709772

Cited by 95 publications

(17 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[4][5][6][7][8] In general, the results show that, to a greater or lesser extent, most non-metallic and composite materials exhibit a significant change in mechanical properties when deformed under different strain rates and temperatures. Several mechanisms have been proposed to account for the change in mechanical properties prompted by high velocity deformation, including dislocation damping, 9) thermally-activated mechanisms, 10) and so on. However, to obtain a broader understanding of the effects of the deformation temperature and strain rate on the mechanical response of engineering materials, a comprehensive temperature-dependent analysis is required.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Impact Response of Inconel 718 Alloy under Low and High Temperatures

Lee

Lin

Chen³

et al. 2011

Mater. Trans.

View full text Add to dashboard Cite

Dynamic impact response of Inconel 718 alloy is studied at temperatures ranging from À150 to 550 C and strain rates in the range of 1000 to 5000 s À1 using a compressive split Hopkinson pressure bar. It is found that the flow stress increases with increasing strain rate, but decreases with increasing temperature. The highest work hardening rate is observed in the specimen at the lowest temperature (À150 C) and the highest strain rate (5000 s À1 ). However, the work hardening rate is weakened by the deformation-induced temperature rise under high strain and strain rate conditions. The strain rate sensitivity increases with increasing strain rate, but decreases with increasing temperature. The activation energy varies as a function of the strain rate and temperature, and has a maximum value of 40 kJ/mol. The greatest thermal softening effect occurs at the highest strain rate of 5000 s À1 and temperatures in the range À150$25 C. The microstructural observations confirm that the mechanical response of the Inconel 718 specimens is directly related to the effects of the strain rate and temperature on the evolution of the impacted microstructure.

show abstract

Section: Introductionmentioning

confidence: 99%

Dynamic Impact Response of Inconel 718 Alloy under Low and High Temperatures

Lee

Lin

Chen³

et al. 2011

Mater. Trans.

View full text Add to dashboard Cite

show abstract

“…Above the transition strain rate, the flow stress is assumed to be drag controlled [23]. Stress and strain rate in this regime is linear and expressed by Eq.…”

Section: Discussionmentioning

confidence: 99%

“…Tirupataiah [22] has further constructed the transition strain rates for a number of metals and showed that the transition strain rate for common metals and alloys lies between 102 and 104 s À1 . Before the transition strain rate, it is usually assumed that the deformation is controlled by the thermally activated deformation mechanism [23] and a logarithmic relation between stress and strain rate is usually found in this regime as,…”

Section: Discussionmentioning

confidence: 99%

Simulation of the strain rate sensitive flow behavior of SiC-particulate reinforced aluminum metal matrix composites

Tirtom

Güden

Yıldız

2008

Computational Materials Science

View full text Add to dashboard Cite

Strain rate dependent compression mechanical behavior of an SiC-particulate reinforced Al (2024-O) metal matrix composite (MMC) with different particle volume fractions was numerically investigated at various strain rates. Calculations were performed using axisymmetric finite element unit cell model, in which an elastic SiC particle was embedded inside a strain rate sensitive viscoplastic Al matrix. Stress-strain curves of Al matrix material were derived from Split Hopkinson Pressure Bar experiments at various strain rates and used as inputs in the FEM model. Numerically computed stress-strain curves and strain rate sensitivity were compared with those of experiments for a 15% SiC-particulate reinforced MMC. Computed strain rate sensitivity of the MMC was found to be higher than that of the matrix alloy and increased with increasing strain contrary to the strain independent matrix strain rate sensitivity. The strain rate sensitivity of the MMC was also found to increase with increasing particle volume fraction at the same particle size. Finally, several possible reasons including assumptions used in the model, adiabatic heating, microstructural variations between the composite matrix and matrix alloy, particle shape and distribution and damage accumulation for the small discrepancy found between computed and experimental stress-strain curves and strain rate sensitivity of the composite were discussed.

show abstract

“…1113) Several mechanisms have been proposed to account for the change in mechanical properties prompted by high velocity deformation, including dislocation damping, 14) thermal activation 15) and dislocation generation. 16) Many studies have shown that high strain rate loading induces microstructural evolution and phase transformation, and therefore has a significant effect on the material properties.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Properties and Dislocation Substructure of 6061-T6 Aluminum Alloy Impacted at Cryogenic Temperatures

Lee

Huang

2016

Mater. Trans.

View full text Add to dashboard Cite

The mechanical properties and dislocation substructure of 6061-T6 aluminum alloy deformed at temperatures of 0°C, ¹100°C and ¹196°C and strain rates of 1000 s ¹1 , 3000 s ¹1 and 5000 s ¹1 are investigated using a compressive split-Hopkinson pressure bar. It is found that the flow stress and strain rate sensitivity increase with increasing strain rate, but decrease with increasing temperature. In addition, the work hardening rate decreases with increasing strain rate and temperature. The flow stress corresponding to a true strain of 0.6 is modelled using a power law expression with an activation energy of 1.7 kJ/mol and an average strain rate sensitivity of 0.154. The dislocation density increases with increasing strain rate and decreasing temperature, and leads to a greater flow stress. A greater multiplication and tangling of the dislocations occurs at higher strain rates and lower temperatures. The flow stress and square root of the dislocation density are linearly related via the BaileyHirsch type relation · ¼ · 0 þ ¡ 1 Gb ffiffiffi µ p , where ¡ 1 has a value of 0.46 for the current 6061-T6 aluminum alloy.

show abstract

Dislocation Damping in Aluminum at High Strain Rates

Cited by 95 publications

References 23 publications

Dynamic Impact Response of Inconel 718 Alloy under Low and High Temperatures

Dynamic Impact Response of Inconel 718 Alloy under Low and High Temperatures

Simulation of the strain rate sensitive flow behavior of SiC-particulate reinforced aluminum metal matrix composites

Mechanical Properties and Dislocation Substructure of 6061-T6 Aluminum Alloy Impacted at Cryogenic Temperatures

Contact Info

Product

Resources

About