Effect of thermal annealing on mechanical properties of a nanostructured copper prepared by means of dynamic plastic deformation

2008 ◽  
Vol 59 (4) ◽  
pp. 475-478 ◽  
Author(s):  
Y LI ◽  
Y ZHANG ◽  
N TAO ◽  
K LU
2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Xiurong Fang ◽  
Jiang Wu ◽  
Xue Ou ◽  
Fuqiang Yang

Dynamic plastic deformation (DPD) achieved by multipass hammer forging is one of the most important metal forming operations to create the excellent materials properties. By using the integrated approaches of optical microscope and scanning electron microscope, the forging temperature effects on the multipass hammer forging process and the forged properties of Ti-6Al-4V alloy were evaluated and the forging samples were controlled with a total height reduction of 50% by multipass strikes from 925°C to 1025°C. The results indicate that the forging temperature has a significant effect on morphology and the volume fraction of primary α phase, and the microstructural homogeneity is enhanced after multipass hammer forging. The alloy slip possibility and strain rates could be improved by multipass strikes, but the marginal efficiency decreases with the increased forging temperature. Besides, a forging process with an initial forging temperature a bit above β transformation and finishing the forging a little below the β transformation is suggested to balance the forging deformation resistance and forged mechanical properties.


Wear ◽  
2011 ◽  
Vol 271 (9-10) ◽  
pp. 1609-1616 ◽  
Author(s):  
B. Yao ◽  
Z. Han ◽  
Y.S. Li ◽  
N.R. Tao ◽  
K. Lu

2010 ◽  
Vol 667-669 ◽  
pp. 337-342 ◽  
Author(s):  
Jing Li Sun ◽  
Jing Tao Wang

Dynamic plastic deformation of commercially pure titanium in the temperature range of -100-18°C at the strain rates of 3.0×102-2.5×103, as well as at quasi-static compression were carried out by a Split Hopkinson Pressure Bar technique and conventional compression testing machine respectively. The formation of deformation twins plays a key role on the accommodation of a large amount of strain produced by plastic deformation. Grain orientation has a great influence on the formation of twins. Temperature has smaller effects than strain rate on the evolutions of the microstructures and mechanical properties. The area fraction of twins and their intersections increase with the increasing strain rate and the deformation strain, resulting in refined microstructures and higher hardness values. Strain rate also leads to the change of twin shape (type). While more lenticular twins are observed in samples after quasi-static deformation, there are lots of needle-like twins with straight and long boundaries in samples processed via dynamic plastic deformation. This may imply that different twin systems operate at different strain rate. For the needle-like twins in samples after dynamic plastic deformation, the twin area fraction approaches saturation beyond the true strain of about 0.13, which is significant turning point for twinning rate. This saturated trend is not observed in quasi-static deformation.


2018 ◽  
Vol 1 (1) ◽  
pp. 77-90
Author(s):  
Walaa Abdelaziem ◽  
Atef Hamada ◽  
Mohsen A. Hassan

Severe plastic deformation is an effective method for improving the mechanical properties of metallic alloys through promoting the grain structure. In the present work, simple cyclic extrusion compression technique (SCEC) has been developed for producing a fine structure of cast Al-1 wt. % Cu alloy and consequently enhancing the mechanical properties of the studied alloy. It was found that the grain structure was significantly reduced from 1500 µm to 100 µm after two passes of cyclic extrusion. The ultimate tensile strength and elongation to failure of the as-cast alloy were 110 MPa and 12 %, respectively. However, the corresponding mechanical properties of the two pass CEC deformed alloy are 275 MPa and 35%, respectively. These findings ensure that a significant improvement in the grain structure has been achieved. Also, cyclic extrusion deformation increased the surface hardness of the alloy by 49 % after two passes. FE-simulation model was adopted to simulate the deformation behavior of the material during the cyclic extrusion process using DEFORMTM-3D Ver11.0. The FE-results revealed that SCEC technique was able to impose severe plastic strains with the number of passes. The model was able to predict the damage, punch load, back pressure, and deformation behavior.


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