A Strengthening Model of Cu-Cr In Situ Fibrous Composites Produced by Equal Channel Angular Pressing

2013 ◽  
Vol 745-746 ◽  
pp. 321-326 ◽  
Author(s):  
Wei Wei ◽  
Kun Xia Wei ◽  
Igor V. Alexandrov ◽  
Fei Wang ◽  
Jing Hu

The composite filament structure was produced in the Cu-5.7%Cr and Cu-12.4%Cr as-cast alloy ingots by using equal channel angular pressing (ECAP) at room temperature. Optical and TEM microstructure, micro-hardness, tensile strength and electrical conductivity of ECAPed samples were investigated. The rotation and spreading of Cr particles took place during ECAP, and resulted in long thin in-situ filaments. The tensile strength increased with the number of the ECAP passes. A strengthening model was recommended to predict the enhancement of the tensile strength in Cu-Cr in situ fibrous composites.

2010 ◽  
Vol 667-669 ◽  
pp. 541-546 ◽  
Author(s):  
Wei Wei ◽  
Fei Wang ◽  
Kun Xia Wei ◽  
Igor V. Alexandrov ◽  
Jing Hu

The composite filament structure was produced in Cu-5.7%Cr as-cast alloy ingots, subjected to equal channel angular pressing (ECAP) and cold rolling (CR) at room temperature. Microstructure, tensile properties and electrical conductivity before and after the severe plastic deformation (SPD) processing have been investigated here. The results point out that the rotation and spreading of Cr particles took place during ECAP and the additional rolling resulting in long thin in situ filaments. The average grain size of a Cu phase is equal to about 200 nm after eight ECAP passes. The formation of finer equiaxed grains of the Cu phase has been revealed after the additional CR. The tensile strength 403 MPa and 507 MPa have been achieved after one and eight ECAP passes respectively and increased up to 517 MPa and 607 MPa after the subsequent CR deformation. The enhancement of the tensile strength and the deterioration of the electrical conductivity have been explained by the microstructure evolution of Cu matrix and the dendritic Cr phase.


2006 ◽  
Vol 114 ◽  
pp. 91-96 ◽  
Author(s):  
Maxim Yu. Murashkin ◽  
M.V. Markushev ◽  
Julia Ivanisenko ◽  
Ruslan Valiev

The effects of equal channel angular pressing (ECAP), further heat treatment and rolling on the structure and room temperature mechanical properties of the commercial aluminum alloys 6061 (Al-0.9Mg-0.7Si) and 1560 (Al-6.5Mg-0.6Mn) were investigated. It has been shown that the strength of the alloys after ECAP is higher than that achieved after conventional processing. Prior ECAP solution treatment and post-ECAP ageing can additionally increase the strength of the 6061 alloy. Under optimal ageing conditions a yield strength (YS) of 434 MPa and am ultimate tensile strength (UTS) of 470 MPa were obtained for the alloy. Additional cold rolling leads to a YS and UTS of 475 and 500 MPa with 8% elongation. It was found that the post-ECAP isothermal rolling of the 1560 alloy resulted in the formation of a nano-fibred structure and a tensile strength (YS = 540 MPa and UTS = 635 MPa) that has never previously been observed in commercial non-heat treatable alloys.


2010 ◽  
Vol 667-669 ◽  
pp. 421-426 ◽  
Author(s):  
M.X. Yang ◽  
Gang Yang ◽  
Zheng Dong Liu ◽  
Cun Yu Wang ◽  
C.X. Huang

An 18Ni (C-250) maraging steel was successfully processed by equal channel angular pressing (ECAP) for a single pass at room temperature. Microstructural observations showed that the martensite laths of 18Ni maraging steel were elongated to more narrow bands with a width of 100-200 nm after ECAP deformation. After ageing treatment, many nano-sized precipitates distributed uniformly within the refined martensite lathes. In comparison with the tensile strength (1940 MPa) of general used steel (solution + aging treatment), the tensile strength of the sample processed by ECAP and subsequent aging treatment was enhanced for more than 100 MPa (above 2050 MPa). The enhancement of tensile properties was attributed to microstructural refinement and uniformly distributed nano-precipitates.


2012 ◽  
Vol 629 ◽  
pp. 198-202 ◽  
Author(s):  
Ping Yang ◽  
Kai Huai Yang

Three groups of commercial 1050 Al alloy were subjected to equal channel angular pressing (ECAP) at room temperature using route A, route C and route Bc, respectively. Mechanical properties and fracture modes of as-annealed and ECAPed samples were investigated. The microhardness of 1050 Al fabricated by ECAP increases by a factor of about 1.5 compared to the as-annealed state. The ultimate tensile strength (UTS) increases significantly after ECAP, while the elongation decreases. But they are strongly dependence on the number of ECAP passes and the pressing route. The UTS and elongation of the samples processed by route Bc are best, consequently, the static toughness U of the samples is enhanced. Besides, all specimens subjected to ECAP deformation failed in a ductile manner.


2018 ◽  
Vol 913 ◽  
pp. 77-82 ◽  
Author(s):  
Ting Biao Guo ◽  
Qi Li ◽  
Chen Wang ◽  
Shi Ru Wei ◽  
Yi Bo Wu

The evolution of microstructure of ZL205A alloy during equal channel angular pressing (ECAP) by route A at room temperature was investigated by OM, SEM and XRD, and the hardness of cast and heat treatment alloy from different strain were tested. The results showed that the grain of cast alloy were obviously refined, the massive q phase along the grain boundary were crushed, and prompts the distribution of q streamline after one pass through ECAP. After two passes of ECAP, the distribution of q phase is more uniform. After heat treatment through ECAP, the grains were also obviously refined, and elongated in axial direction, which also prompts the distribution of q streamline. The hardness was significantly improved after ECAP. The hardness of cast alloy increases from 65HV to 132HV after two passes, and that of heat treatment alloy increases from 112HV to 198HV. With the increase of extrusion passes, the number of dimples gradually increased and evenly distributed, the depth of dimples was of a similar level, and the distribution of precipitated phase is more uniform.


2011 ◽  
Vol 194-196 ◽  
pp. 1720-1723 ◽  
Author(s):  
Li Ping Bian ◽  
Wei Liang ◽  
Wen Li Zhang

Microstructure and mechanical property of a hypoeutectic Al-Mg2Si composite processed by equal channel angular pressing up to eight passes in a combined route 2A+4BA+2A were investigated. The results show that the initial developed eutectic Mg2Si was significantly refined into submicrometer-scale particles and distributed homogeneously in the Al matrix, which together with the refinement of Al matrix leads to a much higher ductility with the elongation to failure up to 24% and a significantly enhanced ultimate tensile strength of 284MPa in the processed composite, increased by 2300% and 70%, respectively, compared to those in its as-cast counterpart.


2014 ◽  
Vol 783-786 ◽  
pp. 2611-2616 ◽  
Author(s):  
Sergey V. Dobatkin ◽  
Werner Skrotzki ◽  
Vladimir Terent’ev ◽  
Olga Rybalchenko ◽  
Andrey Belyakov ◽  
...  

After equal channel angular pressing (ECAP) at room temperature in 08%C-18%Cr-10%Ni-Ti steel grain-subgrain structure with the size of structural elements of 100-250 nm, volume of high angle boundaries (HAB) about 59% and 38% of martensite is formed. ECAP at 400°C results in fully austenitic structure with the structural element size of 100-400 nm and volume of HAB ~54%. ECAP increases the ultimate tensile strength of 08%C-18%Cr-10%Ni-Ti steel by 1.5 - 2 times, the yield stress by 3.8 - 5.2 times, the fatigue limit - by 1.4 - 1.7 times, however the ductility is reduced. Fatigue strength is enhanced by the refinement of the structure and twinning in the austenite during ECAP and due to intensive dynamic twinning, partial martensitic transformation and increasing of the volume of HAB during cyclic deformation.


2005 ◽  
Vol 488-489 ◽  
pp. 177-180
Author(s):  
T. Liu ◽  
Yan Dong Wang ◽  
Shi Ding Wu ◽  
Shou Xin Li ◽  
Ru Lin Peng ◽  
...  

The room temperature tensile strength and ductility of Mg-3.3%Li alloy were improved simultaneously by two kinds of different equal channel angular pressing (ECAP) treatments. Microstructural analyses showed that grain refinement and texture modification are the principal reasons for the improvement of mechanical properties.


Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 607
Author(s):  
A. I. Alateyah ◽  
Mohamed M. Z. Ahmed ◽  
Yasser Zedan ◽  
H. Abd El-Hafez ◽  
Majed O. Alawad ◽  
...  

The current study presents a detailed investigation for the equal channel angular pressing of pure copper through two regimes. The first was equal channel angular pressing (ECAP) processing at room temperature and the second was ECAP processing at 200 °C for up to 4-passes of route Bc. The grain structure and texture was investigated using electron back scattering diffraction (EBSD) across the whole sample cross-section and also the hardness and the tensile properties. The microstructure obtained after 1-pass at room temperature revealed finer equiaxed grains of about 3.89 µm down to submicrons with a high density of twin compared to the starting material. Additionally, a notable increase in the low angle grain boundaries (LAGBs) density was observed. This microstructure was found to be homogenous through the sample cross section. Further straining up to 2-passes showed a significant reduction of the average grain size to 2.97 µm with observable heterogeneous distribution of grains size. On the other hand, increasing the strain up to 4-passes enhanced the homogeneity of grain size distribution. The texture after 4-passes resembled the simple shear texture with about 7 times random. Conducting the ECAP processing at 200 °C resulted in a severely deformed microstructure with the highest fraction of submicron grains and high density of substructures was also observed. ECAP processing through 4-passes at room temperature experienced a significant increase in both hardness and tensile strength up to 180% and 124%, respectively.


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