Microstructure and Tensile Properties Anisotropy of 7xxx Ultra-Thick Plate

2021 ◽  
Vol 1035 ◽  
pp. 134-142
Author(s):  
Ze Yu Zhou ◽  
Xiang Xiao ◽  
Wen Jing Zhang ◽  
Feng Chun Wang ◽  
Wei Cai Ren ◽  
...  

The microstructure,texture distribution and tensile property of 7xxx ultra-thick plate was investigated by optical microscopy (OM), scanning electron microscopy (SEM), electron back scattering diffraction (EBSD), transmission electron microscopy (TEM) and tensile tests. The results show that the microstructure, texture and tensile property were inhomogeneous along the thickness direction. A large number of sub-crystals remained on the surface of the thick plate and was accompanied by much recrystallization. Most of the structures were random texture, and the proportion of typical texture was low at the edge. For the center layer, there were also a lot of recrystallized grains and typical deformed texture along the β-fiber (Brass, S, and Copper) was observed. The 1/4 layer of the plate is a transition one, and had the lowest recrystallized fraction. From surface to center, precipitation phases within grains and grain boundaries gradually coarsen, mechanical properties reduced. At the same thickness, the tensile property showed appreciable anisotropy, the L direction was the highest and the S direction was the lowest.

2015 ◽  
Vol 55 (4) ◽  
pp. 282 ◽  
Author(s):  
Oleksandr Trudonoshyn ◽  
Maxim Puchnin ◽  
Kostiantyn Mykhalenkov

<p>The as-cast and heat-treated structure of permanent mould castings of AlMg<sub>5</sub>Si<sub>2</sub>Mn alloys with different contents of Ti has been investigated by differential scanning calorimetry, hardness and microhardness measurements, tensile tests and fractography analyses, scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray analysis. We have established that α-Al dendrites can be nucleated on an Al-Ti substrate, and also that primary Mg<sub>2</sub>Si crystals can be nucleated on oxides, including oxides of Al and Ti compounds. The dependence of the change in mechanical properties on ageing time, and on the amount of Ti in the alloys, is shown.</p>


2014 ◽  
Vol 1004-1005 ◽  
pp. 148-153
Author(s):  
Min Hao ◽  
Ji Gang Ru ◽  
Ming Liu ◽  
Kun Zhang ◽  
Liang Wang ◽  
...  

Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were utilized to study the microstructure and mechanical behavior of an Al-Cu-Mg alloy after tensile test at 125°C, 150°C, 175°C and 200 °C, respectively. The yield strength and ultimate tensile strength decreased with the increase of temperature, while the elongation increased firstly and then decreased. The S and S′ precipitate after tension at elevated temperatures. When the temperature was higher than 175°C, the precipitate coarsens rapidly. The alloys displayed a shear fracture features at elevated temperature. The larger S′ and S phase coarsened and dropped which forming crack in the grain boundaries and precipitate interfaces, resulting in the decrease of the elongation of the alloy.


2017 ◽  
Vol 54 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Maria Adina Vulcan ◽  
Celina Damian ◽  
Paul Octavian Stanescu ◽  
Eugeniu Vasile ◽  
Razvan Petre ◽  
...  

This paper deals with the synthesis of polyurea and its use as polymer matrix for nanocomposites reinforced with multi-walled carbon nanotubes (MWCNT). Two types of materials were obtained during this research, the first cathegory uses the polyurea as matrix and the second one uses a mixture between epoxy resin and polyurea. The nanocomposites were characterized by Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM) and Tensile Tests .The elastomeric features of nanocomposites were highlighted by the results which showed low value of Tg. Also higher thermal stability with ~40oC compared with commercial products (M20) were observed, but lower mechanical properties compared to neat polyurea.


Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3351 ◽  
Author(s):  
Wei Chen ◽  
Xiaoyong Zhang ◽  
YongCheng Lin ◽  
Kechao Zhou

Multi-pass hot rolling was performed on bi-modal Ti-55511 alloy with 50% rolling reduction at 700 °C. Mechanical properties were evaluated by tensile test, and microstructure evolution was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the Ti-55511 alloy with bi-modal microstructure exhibits good strength and high ductility (1102 MPa, 21.7%). Comparatively, after 50% hot rolling, an enhanced strength and decreased ductility were obtained. The refinement of α phases leads to the increased tensile strength, while the fragmentation of the equiaxed α phase results in a decreased ductility. The fragmentation process of equiaxed α phases followed the sequence of: elongation of α phases → formation of grooves and localized shear bands → the final fragmentation accomplished via deepening grooves.


2019 ◽  
Vol 54 (8) ◽  
pp. 1119-1126
Author(s):  
Mohammad Mokhles ◽  
Morteza Hosseini ◽  
Habib Danesh-Manesh ◽  
Seyed Mojtaba Zebarjad

This research studies the structure and mechanical properties of Ni/Ti multilayered composites produced from commercial pure Ni and Ti foils by accumulative roll-bonding technique. To investigate these properties, scanning electron microscopy, Vickers microhardness, and uniaxial tensile tests were conducted at different processing cycles. Studies showed that in terms of structure, Ni and Ti layers maintain their continuity even up to 10 cycles of accumulative roll-bonding. Moreover, the energy-dispersive spectroscopy in scanning electron microscopy detected no deformation induced diffusion or reactive interfacial zones. It was found that by increasing the accumulative roll-bonding cycles, tensile and yield strengths as well as the hardness of the composite enhance and the total elongation reduces continuously.


Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1048 ◽  
Author(s):  
Huibin Jiao ◽  
Kanghua Chen ◽  
Songyi Chen ◽  
Zhen Yang ◽  
Peng Xie ◽  
...  

In the present work, the influence of Cu content on microstructure, mechanical properties and exfoliation corrosion behaviors of Al-Zn-Mg-xCu alloy extrusions has been investigated in longitudinal-transverse (L-T) and short-longitudinal (S-L) directions by means of mechanical tensile and exfoliation corrosion testing combined with optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that a higher Cu content significantly decreased the fracture toughness and ductility of the alloy in S-L direction compared with L-T direction. Concomitant with the increase in Cu content, a transition in fracture mode was observed from transgranular dimpled rupture to intergranular rupture in S-L direction. Moreover, the exfoliation corrosion (EXCO) resistance of the alloy decreased as the Cu content increased and the exfoliation corrosion resistance of the alloy in short-transverse (S-T) direction was better than that of L-T direction. These results were mainly associated with the large number of coarse intermetallics caused by high Cu content in the L-T direction of alloy.


Clay Minerals ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 643-656 ◽  
Author(s):  
Zhi-Lin Cheng ◽  
Xing-Yu Chang ◽  
Zan Liu ◽  
Dun-Zhong Qin

ABSTRACTIn order to improve the dispersibility of halloysite nanotubes (HNTs) in polytetrafluoroethylene (PTFE), the modification of HNT surfaces was studied with three types of modifiers (polymethyl methacrylate [PMMA], sodium dodecyl sulfate [SDS] and carboxylic acid). The modified HNTs were characterized by Fourier-transform infrared (FTIR) spectrometry, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and contact angle measurements. The HNTs were used to reinforce the mechanical properties of PTFE. The mechanical results indicated that the tensile strength of the modified HNT-filled PTFE nanocomposites (F-HNT/PTFE) improved to an acceptable degree and Young's modulus increased significantly. The tribological results showed that the wear rate of F-HNT/PTFE decreased by 21–82 and 9–40 times compared to pure PTFE and the pristine F-HNT/PTFE, respectively.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Srihanum Adnan ◽  
Tuan Noor Maznee Tuan Ismail ◽  
Norhayati Mohd Noor ◽  
Nik Siti Mariam Nek Mat Din ◽  
Nurul ‘Ain Hanzah ◽  
...  

This study examined the effect of organoclay montmorillonite (OMMT) on the mechanical properties and morphology of flexible polyurethane/OMMT nanocomposite (PU/OMMT) foams prepared from petroleum- and palm olein-based polyols. Palm-based PU foams exhibited inferior mechanical strength as compared to neat petroleum PU foams. However, addition of OMMT significantly improved the foams strength of flexible polyurethane/OMMT nanocomposite foams prepared from palm olein-based polyol (PU bionanocomposite foam). The morphology analysed by scanning electron microscopy (SEM) showed that the cell size of the foam decreased with increasing OMMT content. PU bionanocomposite foam with 5 wt% of OMMT had the most improved tensile (63%) and tear (48%) strengths compared to its neat counterpart. Transmission electron microscopy (TEM) revealed the exfoliated structure of the respective foam. It was concluded that OMMT improved mechanical properties and morphology of PU foams.


2018 ◽  
Vol 913 ◽  
pp. 270-276
Author(s):  
Hong Xiang Yin ◽  
Yi Wu ◽  
Ai Min Zhao ◽  
Zheng Zhi Zhao ◽  
Qiu Qin Fu

The effects of annealing temperature on microstructure, mechanical properties, formability, and texture evolution were analyzed in the article. The microstructure of the steel obtained through different annealing processes were investigated by means of transmission electron microscopy; The micro texture of steel was measured by using electron back scattering diffraction analysis; The relationship between Cu precipitates and matrix was analyzed by using the selected area diffraction technology. The results show that when annealing temperature was 700 ~ 850 °C, the yield strength and tensile strength first decreased slightly and then increased, while the elongation accordingly first increased then decreased slightly. The best mechanical property and formability were obtained at 800 °C. Cu precipitates reduced with the increase of annealing temperature and it accorded with K - S relationship with matrix. The grains near the {111} < 112 > orientation grew up selectively. The higher the temperature, the more the γ fiber texture content. But at higher temperature (850 °C), γ texture was damaged and the content was reduced.


2008 ◽  
Vol 575-578 ◽  
pp. 941-946
Author(s):  
Hong Yan Tang ◽  
Ji Hui Wang ◽  
Guo Qiang Gao ◽  
Wen Xing Chen

Fiberglass continuous strand mat(CSM)/poly(urethane-isocyanurate) composites were formed by SRIM process, treated under different conditions and then characterized based on dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) ,transmission electron microscopy (TEM) and the mechanical property tests. The results show that the mechanical properties of the composites could be increased with improving the degree of microphase separation. At a given temperature (120°C), the degree of microphase separation is the highest for 4h and decreases gradually with prolonging treatment time. For a given time (4h), the well microphase-separated morphology is obtained and the degree of microphase mixing is increased at 120°C and 140°C treatments, respectively. The degree of microphase separation of the composites decreases with enhancing the temperature to 140°C.


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