scholarly journals Effect of thermo-mechanical treatment on ridging behavior and cube-oriented grain formation process in 6111 aluminum alloy

2014 ◽  
Vol 64 (8) ◽  
pp. 353-360 ◽  
Author(s):  
Ken-ichi Ikeda ◽  
Yukimasa Miyata ◽  
Takahiro Yoshihara ◽  
Naoki Takata ◽  
Hideharu Nakashima
2020 ◽  
Vol 326 ◽  
pp. 05004
Author(s):  
Zhiguo Chen ◽  
Chenghua Lu ◽  
Jing Peng ◽  
Zhengui Yuan

The comprehensive performance of Al-Zn-Mg-Cu alloy can be significantly improved by a proposed novel thermo-mechanical treatment (NTMT). The influence of the NTMT on the properties and microstructure was investigated by tensile test, corrosion resistance test, X-ray diffraction (XRD), and transmission electron microscopy (TEM). Results show that Al-Zn-Mg-Cu alloy treated by the NTMT can obtain an excellent combination of strength and ductility. The highest yield strength and ultimate tensile strength reached 643 MPa and 664 MPa respectively, and the elongation was 9.7%. Meanwhile, electrochemical corrosion resistance and intergranular corrosion resistance in the aluminum alloy can be improved after the NTMT. The mechanism of the excellent combination of strength and ductility is thought to be the synergistic effect of dislocations substructures, texture configuration, and nanoprecipitates. The improvement of intergranular corrosion resistance of the aluminum alloy is caused by changes in the micro-morphology of grain boundary precipitates after the NTMT, which can block anodic dissolution channels along grain boundaries to reduce the rate of anodic dissolution and avoid hydrogen embrittlement.


Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1496 ◽  
Author(s):  
Lei Liu ◽  
Yunxin Wu ◽  
Hai Gong

To explore the effective way of grain refinement for 2219 aluminum alloy, the approach of ‘thermal compression tests + solid solution treatment experiments’ was applied to simulate the process of intermediate thermo-mechanical treatment. The effects of deformation parameters (i.e., temperature, strain, and strain rate) on microstructural evolution were also studied. The results show that the main softening mechanism of 2219 aluminum alloy during warm deformation process is dynamic recovery, during which the distribution of CuAl2 phase changes and the substructure content increases. Moreover, the storage energy is found to be decreased with the increase in temperature and/or the decrease in strain rate. In addition, complete static recrystallization occurs and substructures almost disappear during the solid solution treatment process. The average grain size obtained decreases with the decrease in deforming temperature, the increase in strain rate, and/or the increase in strain. The grain refinement mechanism is related to the amount of storage energy and the distribution of precipitated particles in the whole process of intermediate thermal-mechanical treatment. The previously existing dispersed fine precipitates are all redissolved into the matrix, however, the remaining precipitates exist mainly by the form of polymerization.


2007 ◽  
Vol 546-549 ◽  
pp. 1027-1032
Author(s):  
Gao Yong Lin ◽  
Zhen Feng Zhang ◽  
Qi Quan Lin ◽  
Da Shu Peng

A procedure of thermo-mechanical treatment (TMT) was carried out to 2519 aluminum alloy to improve its properties. The influences of cold deformation ratio, ageing temperature and ageing time of the TMT on the mechanical properties and electrochemical corrosion resistance of this alloy were investigated. The results show that after TMT the tensile strength of 2519 aluminum alloy can be improved obviously but its electrochemical corrosion resistance decreases slightly. The optimum processing parameters of the TMT for 2519 aluminum alloy can be described as: solid solution at 530°Cfor 0.5h, then cold deform with a ratio of 15% followed by aging at 150°C for 10h.


2015 ◽  
Vol 24 (10) ◽  
pp. 3905-3911 ◽  
Author(s):  
Xifeng Li ◽  
Kun Lei ◽  
Peng Song ◽  
Xinqin Liu ◽  
Fei Zhang ◽  
...  

Author(s):  
L.E. Murr

Ledges in grain boundaries can be identified by their characteristic contrast features (straight, black-white lines) distinct from those of lattice dislocations, for example1,2 [see Fig. 1(a) and (b)]. Simple contrast rules as pointed out by Murr and Venkatesh2, can be established so that ledges may be recognized with come confidence, and the number of ledges per unit length of grain boundary (referred to as the ledge density, m) measured by direct observations in the transmission electron microscope. Such measurements can then give rise to quantitative data which can be used to provide evidence for the influence of ledges on the physical and mechanical properties of materials.It has been shown that ledge density can be systematically altered in some metals by thermo-mechanical treatment3,4.


2013 ◽  
Vol 577-578 ◽  
pp. 593-596 ◽  
Author(s):  
Václav Mentl

The steam turbine rotors represent large components both in radial and axial directions. Their local properties generally differ from one forging to another, or if we compare head and bottom parts of the original ingot, or central and circumferential localities of one rotor body respectively, or if we compare the properties of separate discs e.g. in the case of welded rotors. These differences stem from both even slight changes in the chemical composition (of separate heats or even within one ingot) and thermo-mechanical treatment and in the differences in technology with respect to the real shape and size of the forgings in question. In the paper, the consequences of the differences in fracture toughness characteristics in various rotor localities are discussed with respect to the rotors operational safety taking into account the existence of cracks and material degradation.


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