Effects of grain size and dislocation density on strain hardening behavior of ultrafine grained AA1050 processed by accumulative roll bonding

Recently, the accumulative roll bonding (ARB) technique has made significant progress in the production of various ultrafine-grained (UFG) metals and alloys. In this work, a UFG copper sheet was produced by ARB and subsequent annealing at 300 °C for 60 min to optimize strength and ductility. It was found that homogeneous lamellar UFG materials with a thickness of 200–300 nm were formed after six ARB passes. The microhardness and tensile strength of as-ARBed Cu increased, while the ductility and strain hardening decreased with the cumulative deformation strain. The as-ARBed specimens fractured in a macroscopically brittle and microscopically ductile way. After annealing, discontinuous recrystallization occurred in the neighboring interface with high strain energy, which was prior to that in the matrix. The recrystallization rate was enhanced by increasing the cumulative strain. UFG Cu ARBed for six passes after annealing manifested a completely recrystallized microstructure with grain sizes approximately ranging from 5 to 10 μm. Annealing treatment reduced the microhardness and tensile strength but improved the ductility and strain hardening of UFG Cu. As-annealed UFG-Cu fractured in a ductile mode with dominant dimples and shear zones. Our work advances the industrial-scale production of UFG Cu by exploring a simple and low-cost fabrication technique.

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Effect of Grain Size on the Microstructure and Strain Hardening Behavior of Solution Heat-Treated Low-C High-Mn Steel

Materials ◽

10.3390/ma13071489 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1489 ◽

Cited By ~ 1

Author(s):

Marek Opiela ◽

Gabriela Fojt-Dymara ◽

Adam Grajcar ◽

Wojciech Borek

Keyword(s):

Grain Size ◽

Strain Hardening ◽

Strengthening Mechanism ◽

Strength Properties ◽

Low Carbon ◽

Premature Failure ◽

Hardening Behavior ◽

Heat Treated ◽

Strain Hardening Behavior ◽

Grain Diameter

The low-carbon high-Mn austenitic steel microalloyed with titanium was investigated in this work. The steel was solution heat-treated at different temperatures in a range from 900 to 1200 °C. The aim was to receive a different grain size before the static tensile test performed at room temperature. The samples of different grain sizes showed the different strain hardening behavior and resulting mechanical properties. The size of grain diameter below 19 μm was stable up to 1000 °C. Above this temperature, the very enhanced grain growth took place with the grain diameter higher than 220 μm at 1200 °C. This huge grain size at the highest temperature resulted in the premature failure of the sample showing the lowest strength properties at the same time. Correlations between the grain size, the major strengthening mechanism, and fracture behavior were addressed. The relationships were assessed based on microstructural investigations and fractography tests performed for the deformed samples. The best combination of strength and ductility was found for the samples treated at 1000–1100 °C.

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Correlation of microstructure and strain hardening behavior in the ultrafine-grained Nb-bearing dual phase steels

Materials Science and Engineering A ◽

10.1016/j.msea.2016.09.108 ◽

2016 ◽

Vol 678 ◽

pp. 215-226 ◽

Cited By ~ 24

Author(s):

A. Ghatei Kalashami ◽

A. Kermanpur ◽

E. Ghassemali ◽

A. Najafizadeh ◽

Y. Mazaheri

Keyword(s):

Strain Hardening ◽

Dual Phase ◽

Dual Phase Steels ◽

Hardening Behavior ◽

Ultrafine Grained ◽

Strain Hardening Behavior

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The Effect of Grain Size on the Strain Hardening Behavior for Extruded ZK61 Magnesium Alloy

Journal of Materials Engineering and Performance ◽

10.1007/s11665-017-3023-x ◽

2017 ◽

Vol 26 (12) ◽

pp. 6013-6021 ◽

Cited By ~ 5

Author(s):

Lixin Zhang ◽

Wencong Zhang ◽

Wenzhen Chen ◽

Junpeng Duan ◽

Wenke Wang ◽

...

Keyword(s):

Grain Size ◽

Magnesium Alloy ◽

Strain Hardening ◽

Hardening Behavior ◽

Strain Hardening Behavior

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Bond Strength of Ultrafine Grained Zr Fabricated by Accumulative Roll Bonding

Materials Science Forum ◽

10.4028/www.scientific.net/msf.584-586.243 ◽

2008 ◽

Vol 584-586 ◽

pp. 243-248 ◽

Cited By ~ 2

Author(s):

Ling Jiang ◽

Maria Teresa Pérez-Prado ◽

Oscar A. Ruano ◽

M.E. Kassner

Keyword(s):

Grain Size ◽

Shear Strength ◽

Bond Strength ◽

Fracture Strength ◽

Accumulative Roll Bonding ◽

Shear Fracture ◽

High Ductility ◽

Roll Bonding ◽

Ultrafine Grained

The bond strength of ultrafine grained Zr with a grain size of 0.4 µm, fabricated by accumulative roll bonding (ARB), was assessed. The shear strength of the bond was estimated to be about 20% of the shear fracture strength of the as processed metal, a ratio significantly higher than that found in other materials processed by similar methods. The favorable degree of bonding achieved is attributed to the high ductility of Zr as well as to the high reductions used during the ARB process.

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Influence of Precipitation and Dislocation Density on Flow Stress Characteristics Under Compression Deformation of Heat-Treated 17-4 PH Stainless Steel Alloy

Volume 12: Advanced Materials: Design, Processing, Characterization, and Applications ◽

10.1115/imece2019-11201 ◽

2019 ◽

Author(s):

Athul Sathyanath ◽

Anil Meena

Keyword(s):

Stainless Steel ◽

Flow Stress ◽

Dislocation Density ◽

Strain Hardening ◽

Steel Alloy ◽

Hardening Behavior ◽

Compression Deformation ◽

Heat Treated ◽

Strain Hardening Behavior ◽

The Impact

Abstract The strengthening mechanism of 17-4 PH stainless steel is mainly due to the precipitation of copper particles in the martensitic lath matrix. The renowned steel grade possesses an exceptional combination of high strength and excellent corrosion resistance and hence is widely employed in high stress environments. In that case, under external loading, the movement and accumulation of dislocations are influenced by the nature of precipitation. Hence, the present study is based on the impact of precipitation on the dislocation induced hardening during compression of the heat-treated 17-4 PH stainless steel. Room temperature uniaxial compression test was used to evaluate the direct effect of precipitates and the dislocation interaction on the flow stress and strain-hardening behavior under the different heat-treated regime. Microstructural evolution during deformation and its influence on the strain-hardening mechanism were analyzed by optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). A semi-empirical model was adopted to quantify the role of precipitate nature on the strain-hardening rate. The evaluated normalized microstrain and dislocation density from the XRD analyses were used to explain the observed variation in the mechanical property. Coarse particle precipitation was found to greatly affect the strain-hardening behavior of the steel alloy during compression deformation.

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