The combined effect of grain size and strain rate on the dislocation substructures and mechanical properties in pure aluminum

1993 ◽  
Vol 24 (5) ◽  
pp. 1153-1161 ◽  
Author(s):  
Deepak Sil ◽  
S. K. Varma
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Strain Rate ◽  
Pure Aluminum ◽  
Combined Effect

The Combined Effect of Grain Size and Strain Rate on the Mechanical Behavior in Ultra-High Purity Aluminum

2011 ◽  
Vol 179-180 ◽  
pp. 662-667
Author(s):  
Yong Gang Wang ◽  
Chun Lei Wang ◽  
Hong Wei Liu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Flow Stress ◽  
Strain Rate ◽  
Pure Aluminum ◽  
Testing Machine ◽  
Tensile Tests ◽  
Hydraulic Testing ◽  
Petch Relation ◽  
Split Hopkinson

The effect of grain size on the mechanical properties in ultra-high pure aluminum had been investigated as a function of strain rate. Specimens with average grain diameter sizes of 243, 678 and 1070 m were compressed and elongated at quasi-static and high strain rates by a computer controlled servo-hydraulic testing machine and a Split Hopkinson Pressure (Tension) Bar (SHPB and SHTB). The mechanical properties were found to vary significantly with grain size, and strain rate. The relationship between flow stress and grain size can be expressed by a Hall - Petch relation with the different slope for both compressive tests and tensile tests. The influence of strain rate on the slope of the Hall - Petch relation is such that in compression, the slope does not change much, but in tension, there is an increase in the slope value. The strain hardening rate was seen to increase with increasing strain rate. The strain rate dependence of flow stress is obvious, and is seen to be more significant for the smallest grain size specimens. The 3D fractographs illustrated that the numbers of the dimples decrease with the increase of the grain size.

Grain refinement of C-Mn steel through thermo-mechanical processing

2015 ◽  
Vol 13 (2) ◽  
pp. 282-297
Author(s):  
Archana Rethinam ◽  
Vinoo D. Shivakumar ◽  
L. Harish ◽  
M.B. Abhishek ◽  
G.V. Ramana ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Strain Rate ◽  
Cooling Rate ◽  
Hot Rolling ◽  
New Technologies ◽  
Processing Parameter ◽  
Coiling Temperature ◽  
Content Type ◽  
Plant Processing

Purpose – The application of new technologies requires, however, modern rolling mills. Indeed, in manufacturing plants of older types, strict compliance with the developed rolling regimes is not always feasible. Improving the mechanical properties in such cases is possible only by means of cooling. Compressive deformation behavior of carbon–manganese (C-Mn) grade has been investigated at temperatures ranging from 800-900°C and strain rate from 0.01-50 s−1 on Gleeble-3800, a thermo-mechanical simulator. Simulation studies have been conducted mainly to observe the microstructural changes for various strain rate and deformation temperatures at a constant strain of 0.5 and a cooling rate of 20°C s−1. Design/methodology/approach – The project begins with simulation of a hot rolling condition using the thermo-mechanical simulator; this was followed by microstructural examination and identification of phases present by using an optical microscope for hot-rolled coil and simulated samples; grain size measurement and size distribution studies; and optimization of finishing temperature, coiling temperature and cooling rate by mimicking plant processing parameters to improve the mechanical properties. Findings – As the strain rate and temperature increase, pearlite banding decreases gradually and finally gets completely eliminated, thereby improving the mechanical properties. True stress–strain curves were plotted to extrapolate the effect of strain-hardening and strain rate sensitivity on austenite (γ) and austenite–ferrite (γ-a) regions. To validate the effect of strain rate and temperature over the grain size, the hardness of simulated samples was measured using the universal hardness tester and the corresponding tensile strength was found from the standard hardness chart. Practical implications – The results of the study carried out have projected a new technology of thermo-mechanical simulation for the studied C-Mn grade. These results were used to optimize the plant processing parameter like finishing and coiling temperature and finishing stands strain rate. Originality/value – By controlling the hot rolling conditions like finishing, coiling temperature and cooling rate, structures differing in mechanical properties can be obtained for the same material. Accurate understanding of a structure being formed when different temperatures are applied enables the control of the process that assures intended structures and mechanical properties are achieved.

scholarly journals Investigation on grain size effect in high strain rate ductility of 1100 pure aluminum

2017 ◽  
Author(s):  
N. Bonora ◽  
N. Bourne ◽  
A. Ruggiero ◽  
G. Iannitti ◽  
G. Testa
Keyword(s):  
Grain Size ◽  
Size Effect ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Pure Aluminum ◽  
Grain Size Effect

Influence of Mg Content, Grain Size and Strain Rate on Mechanical Properties and DSA Behavior of Al-Mg Alloys Processed by ECAP and Annealing

2014 ◽  
Vol 794-796 ◽  
pp. 870-875 ◽  
Author(s):  
Min Zha ◽  
Yan Jun Li ◽  
Ragnvald H. Mathiesen ◽  
Christine Baumgart ◽  
Hans J. Roven
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Strain Rate ◽  
Room Temperature ◽  
Uniform Elongation ◽  
Mg Alloys ◽  
Lower Strain Rate ◽  
Lower Strain ◽  
Mg Content ◽  
Al Mg Alloys

Ultrafine-grained (UFG) binary Al-xMg (x=1, 5 and 7 wt %) alloys were processed by equal channel angular pressing (ECAP) at room temperature via route Bccombined with inter-pass annealing. The effects of Mg content, grain size and strain rate on mechanical properties and dynamic strain aging (DSA) behaviour of the Al-Mg alloys upon tensile testing at room temperature were studied. An increase in Mg content from 5 to 7 wt % leads to a pronounced increase in strength and uniform elongation in both the as-homogenized and as-ECAP Al-Mg alloys. Thereby, the Al-7Mg alloy, either prior to or after ECAP processing, possess significantly higher strength and comparable or even higher uniform elongation than the more dilute Al-Mg alloys. However, the as-ECAP Al-Mg alloys exhibit significantly higher strength but little work hardening and hence rather limited uniform elongation. In general, decreasing grain size leads to significant increase in strength while dramatic decrease in ductility. Moreover, DSA serration amplitudes increase with reducing grain size in the micrometer range. However, the UFG Al-Mg alloys exhibit much less DSA effect than the micrometer scaled grain size counterparts, i.e. probably due to the high dislocation densities and special grain boundary features in the UFG materials. Also, the Al-Mg alloys, especially those with a UFG structure, exhibit higher strength and ductility at lower strain rate than at higher strain rate, due mainly to enhanced DSA effect and hence work hardening at a lower strain rate.

Effects of grain size, temperature and strain rate on the mechanical properties of polycrystalline graphene – A molecular dynamics study

Carbon ◽  
2015 ◽  
Vol 85 ◽  
pp. 135-146 ◽  
Author(s):  
M.Q. Chen ◽  
S.S. Quek ◽  
Z.D. Sha ◽  
C.H. Chiu ◽  
Q.X. Pei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Grain Size ◽  
Strain Rate

Simulation of Thermomechanical Control Processing of Steels through the Use of Experimental Planning and FEM

2013 ◽  
Vol 762 ◽  
pp. 289-294
Author(s):  
G.E. Kodzhaspirov ◽  
A.I. Rudskoy
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Strain Rate ◽  
Cross Section ◽  
Computer Modelling ◽  
Planning Method ◽  
Combined Effect ◽  
Experimental Planning ◽  
Temperature Strain

The experimental planning method has been used for the examination of the combined effect of the temperature, strain, strain rate and time elapsed from the end of deformation to the start of quenching parameters of the Thermomechanical Control Processing on the structure and mechanical properties. Simulation of Thermomechanical Control Processing for the definite cross-section of profile by Finite Element Method on the base of the data obtained by the experimental planning method allowed to predict structure and mechanical properties and to develop computer modelling for the different cross-section of rolling profile.

FABRICATION OF NANOSTRUCTURED TUBE BY A NOVEL SPD PROCESS: ACCUMULATIVE SPIN-BONDING (ASB)

2012 ◽  
Vol 05 ◽  
pp. 342-349
Author(s):  
M. S. MOHEBBI ◽  
A. AKBARZADEH
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Optical Microscopy ◽  
Grain Refinement ◽  
Pure Aluminum ◽  
High Strength ◽  
Commercially Pure ◽  
Tension Tests ◽  
Average Grain Size

A novel SPD process for manufacturing high strength tubes and cylinders titled as accumulative spin-bonding (ASB) is proposed. This process is applied to a commercially pure aluminum up to four cycles and its effects on the microstructure and mechanical properties are examined by optical microscopy, TEM, microhardness and tension tests. The results show that ultra-fine grains are developed during the process leading to a nanostructure with average grain size in order of 150 nm. Mechanical properties indicate that while the hardness of outer layers is more than inner ones, the hardness and its homogeneity is increased by increasing the ASB cycles. As a result of grain refinement and the scheme of hardness development, the yield and tensile strength of material are increased significantly up to the values of 194 and 235 MPa, respectively.

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