Effect of As-Rolled Microstructure on Static Recrystallization Characteristics and Texture Evolution during Annealing

2016 ◽  
Vol 879 ◽  
pp. 1876-1881
Author(s):  
Jing Su ◽  
Abu S.H. Kabir ◽  
Steve Yue

Magnesium AZ31 alloy sheets were rolled at 100 °C at a high rolling speed of 1000 m/min. After 30% reduction, the microstructure was heavily twinned and shear banded, while a partially dynamically recrystallized and twinned microstructure was seen at the reduction of 49%. The as-rolled specimens were then annealed at 500 °C for increasing times. Microstructure and texture were characterized by optical microscopy, electron backscattered diffraction (EBSD) and X-ray diffraction (XRD). Texture weakening was found during annealing of the specimens at both reductions. However, the texture weakening was more effective in the fully twinned and shear banded specimen than the partially DRXed and twinned specimen. Effects of as-rolled microstructure on static recrystallization characteristics and texture evolution during annealing were studied.

2009 ◽  
Vol 1170 ◽  
Author(s):  
Lei Guan ◽  
Guoyi Tang

AbstractThe effect of the electropulsing on recrystallized microstructure and on texture evolution of a cold rolling (CR) AZ31 strip was studied with the help of light microscopy and X-ray diffraction technique. It was exciting that the completed recrystallization state of sample subjected to the electropulsing treatment (EPT) could be obtained rapidly in ˜7s with the basal texture weakened. The favoring mechanism of static recrystallization (SRX) of MPT could be attributed to the coupled action of the thermal and athermal effects, thereinto, the latter one activated dislocation climb effectively.


2015 ◽  
Vol 828-829 ◽  
pp. 239-243
Author(s):  
Jing Su ◽  
Mehdi Sanjari ◽  
Abu Syed Kabir ◽  
In Ho Jung ◽  
Steve Yue

Microstructure evolution and static recrystallization kinetics of a magnesium AZ31 alloy during annealing have been investigated. The Mg alloy sheets were rolled at 100°C at a low rolling speed of 15m/min and a high rolling speed of 1000m/min to reductions of 8%, 23% and 30%. Annealing was then conducted on the as-rolled specimens at 200°C for different times. The microstructure was characterized by optical microscopy and recrystallization kinetics were evaluated by means of Johnson-Mehl-Avrami-Kolmogorov (JMAK) model. The softening behavior was found to be divided into two annealing stages. The first stage was related to the recrystallization on high stored energy regions, such as shear bands and twins, while the second stage was associated to the recrystallization of low stored energy areas.


2020 ◽  
Author(s):  
Chi-Toan Nguyen ◽  
Alistair Garner ◽  
Javier Romero ◽  
Antoine Ambard ◽  
Michael Preuss ◽  
...  

2010 ◽  
Vol 428-429 ◽  
pp. 126-131
Author(s):  
Wei Zhong Lu ◽  
Chun Wei ◽  
Qui Shan Gao

Polymethylene bis(p-hydroxybenzoates) were prepared from methyl p-hydroxybenzoate and different diols by melted transesterification reaction. Three liquid crystalline polyesters were synthesized from terephthaloyl dichloride and polymethylene bis(p-hydroxybenzoates). Its structure, morphology and properties were characterized by Ubbelohde viscometer, Fourier transform infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC), polarized optical microscopy (POM) with a hot stage, and wide-angle X-ray diffraction (WAXD). Results indicated that the intrinsic viscosities were between 0.088 and 0.210 dL/g. Optical microscopy showed that the TLCP has a highly threaded liquid crystalline texture and a high birefringent schlieren texture character of nematic phase and has wider mesophase temperature ranges for all polyesters. DSC analysis were found that the melting point (Tm), isotropic temperature (Ti) of TLCPs decreased and the temperature range of the liquid crystalline phase became wider with increased number of methylene spacers in the polyester. The WAXD results showed that TLCPs owned two strong diffraction peaks at 2θ near 19° and 23°.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Juanping Xu ◽  
Jinxu Li ◽  
Zheng Wang ◽  
Hao Fu ◽  
Ming Wu

Purpose The purpose of this paper is to investigate the effect of the soft annealing time on the microstructure and hydrogen embrittlement (HE) of Fe-0.22C-11.54Mn-2.05Al steels. Design/methodology/approach Steels A and B with different morphologies were prepared by cold rolling after warm rolling, long/short softening annealing and finally annealing at 700 °C for 30 min. Uncharged and charged samples were subjected to tensile, and HE behavior was studied by electron backscattered diffraction, scanning electron microscopy and X-ray diffraction. Findings The two samples exhibited similar tensile strengths. The homogeneous equiaxed microstructure of steel B was found to be more conducive to relieve its HE sensitivity. Steel A exhibited bimodal-grained microstructures – blocky and lath. The formation of crack in the blocky grains of steel A resulted in a significant reduction in its plasticity and tensile strength. Originality/value The high HE susceptibility of steel A is mainly connected with the inhomogeneity of martensite transformation.


Mineralogia ◽  
2013 ◽  
Vol 44 (1-2) ◽  
pp. 3-12 ◽  
Author(s):  
Kamaleldin M. Hassan ◽  
Julius Dekan

AbstractOlivine basalts from southern Egypt were studied by 57Fe Mössbauer spectroscopy at 297 and 77 K, and by optical microscopy and X-ray diffraction. The 57Fe Mössbauer spectra show three-magnetic sextets, three doublets of ferrous (Fe2+), and a weak ferric (Fe3+) doublet that is attributable to a nanophase oxide (npOx). The magnetic sextets relate to titanomagnetite and the Fe2+ doublets to olivine, pyroxene, and ulvöspinel. Variations in the hyperfine parameters of the various Fe components are attributed to changes in the local crystal chemistry. The intensity of oxidation (Fe3+/ΣFe) in the rocks varies from 20-27% with the oxidized iron largely residing in the titanomagnetite.


2009 ◽  
Vol 41 (1) ◽  
pp. 27-33 ◽  
Author(s):  
I.R. Ziganshin ◽  
S.E. Porozova ◽  
A.E. Stolina ◽  
M.F. Torsunov

Impact of mechanochemical activation (MCA) in aqueous medium with various organic additives on commercial titania powder and products made of it has been investigated by X-ray diffraction, optical microscopy and Raman spectroscopy. Agar-agar additive has been shown to offer promise for activation of titania powders used in obtaining both dense and porous materials.


Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1278
Author(s):  
Chao Voon Samuel Lim ◽  
Yang Liu ◽  
Chen Ding ◽  
Aijun Huang

There is increasing usage of high strength Beta Ti alloy in aerospace components. However, one of the major challenges is to obtain homogeneous refined microstructures via the thermo-mechanical processing. To overcome this issue, an understanding of the hot deformation conditions effect on the microstructure, prior to and after annealing, is needed. In this work, the effect of strain levels, which is more precise than percentage of reduction, and strain rate under supra-transus deformation temperature on beta annealing are studied using a double cone sample. The Electron Backscattered Diffraction (EBSD) is used to determine the deformed microstructure and texture evolution, as well as the static recrystallized grains evolution using the ex situ annealing approach. This work provides evidence that the mechanisms of dynamic recovery and recrystallization, along with texture evolution, are affected by the deformation conditions, which in turn affected the subsequent static recrystallization during annealing. It will also be shown that high levels of strain do not necessarily lead to an increase in the rate of recrystallization. Finally, the results obtained provided several examples of guidance in designing the TMP processes for obtaining not only a refine microstructure, but a more homogeneous beta microstructure during the beta processing of Beta Ti alloy.


Fuel ◽  
1983 ◽  
Vol 62 (3) ◽  
pp. 274-278 ◽  
Author(s):  
Asao Ōya ◽  
Zhanfen Qian ◽  
Harry Marsh

2016 ◽  
Vol 881 ◽  
pp. 422-426
Author(s):  
Carlos Maurício Fontes Vieira ◽  
Regina Maria Pinheiro ◽  
Sergio Neves Monteiro

This work has for objective to evaluate the microstructure of clayey ceramic incorporated with a waste in the form of sludge generated during treatment of effluent of a paper making industry. The microstructure of ceramics incorporated with 0 and 10 wt.% of waste, and then fired at 600°C, was evaluated by optical microscopy, scanning electron microscopy and X-ray diffraction. The results showed that the waste changes the microstructure of the clayey ceramic increasing the porosity, as well as forming new crystalline phases, mainly with calcium compounds.


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