Effect of Cu Content on Ageing Behavior for AA3104-H19 Can Body Sheet

2020 ◽  
Vol 993 ◽  
pp. 358-364
Author(s):  
Yang Yang ◽  
Pi Zhi Zhao ◽  
Xiang Xiao ◽  
Xiao Bing Zheng

AA3104 ingots with different Cu content (0.1wt.%, 0.2wt.% and 0.3wt.%) were prepared by DC casting, and then the ingots were processed to 0.26mm sheets with the method of making AA3104 can be body sheet. The AA3104-H19 sheets were aged at 180°C and the aging strengthen effect were found in the 0.2wt.%Cu and 0.3wt.%Cu alloys. Optical micrograph (OM), X-ray diffraction, high resolution transmission electron microscope were used on the sheets after different ageing time. Rod like coherency precipitates with the length about 5-10nm and the thickness about 2-3nm which were parallel to the [111] plane of the matrix was precipitated at peak aging (180°C-2h). According to the result of the thermodynamic phase diagram calculation, the precipitates should be S-Al2CuMg phase, but the structure of the precipitates were different from the precipitates reported in 2XXX alloy.

2013 ◽  
Vol 591 ◽  
pp. 138-141
Author(s):  
Zhi Dong Han ◽  
Xin Ke Zhang ◽  
Yue Wang ◽  
Zheng Quan Jiang ◽  
Peng Wang

Mg-Al layered double hydroxide (LDH) was modified with sodium dodecyl sulfate (SDS) by regeneration method. The structure of modified LDH (SDS-LDH) was investigated by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The composites of SDS-LDH and polyethylene (PE) were prepared by melt blending and solution mixing method with maleated PE (PEgMA) as compatibilizer. The structure of the composites and the dispersion of SDS-LDH in the matrix were investigated by XRD and transmission electron microscopy (TEM), respectively. The results reveal that SDS was successfully intercalated into the interlayer space of LDH. SDS-LDH was hardly exfoliated in PE/PEgMA by melt blending. The nanocomposites of PE/(PEgMA/SDS-LDH) were successfully prepared by melt blending PE with SDS-LDH/PEgMA master-batch obtained by solution mixing. Homogeneous dispersion of SDS-LDH in the matrix was observed by TEM.


MRS Advances ◽  
2019 ◽  
Vol 4 (5-6) ◽  
pp. 277-284
Author(s):  
Nikolay A. Bert ◽  
Vladimir V. Chaldyshev ◽  
Nikolay A. Cherkashin ◽  
Vladimir N. Nevedomskiy ◽  
Valery V. Preobrazhenskii ◽  
...  

ABSTRACTWe studied the microstructure of Al0.28Ga0.72As0.972Sb0.028 metamaterials containing a developed array of AsSb nanoinclusions. The AlGaAsSb films were grown by low-temperature molecular-beam epitaxy followed by high-temperature annealing at 750°C. The process resulted in an array of self-organized AsSb nanonclusions with an average diameter of 15 nm. The volume filling factor was about 0.003. Using transmission electron microscopy and x-ray diffraction we showed that the nanoinclusions have A7-type rhombohedral atomic structure with the following orientation in the matrix (0003)p || {111}m and [-2110]p || 〈220〉m, where p and m indices indicate the AsSb precipitate and AlGaAsSb matrix, correspondingly. The nanoinclusions appeared to be strongly enriched by antimony (more than 90 atomic %), whereas the Sb content in the AlGaAsSb matrix was 2.8 atomic %. The strong enrichment of the inclusion with Sb resulted from the local thermodynamic equilibrium between the solid AlGaAsSb matrix and AsSb inclusions which became liquid at a formation temperature of 750°C.


1995 ◽  
Vol 398 ◽  
Author(s):  
A.D. Sequeira ◽  
H.A. Calderon ◽  
G. Kostorz

ABSTRACTThe influence of coherency strains produced by the γ-γ’ lattice mismatch, δ, on the decomposition process of Ni-Al-Mo alloys with a bimodal size distribution is presented. Samples with δ ranging from positive to negative, were investigated in a double-step aging procedure. The evolution of the microstructure and the kinetics of coarsening were studied using transmission electron microscopy (TEM). The lattice mismatch between the matrix and the different classes of precipitates was determined by high-resolution high-temperature x-ray diffraction. It is shown that the strain fields produced by the lattice mismatch can influence dramatically the decomposition of metallic alloys. It is suggested that the reduction of the coarsening rate of the large precipitates, the fast coarsening rate of the small precipitates and the distortions detected in the matrix are all direct consequences of the elastic fields produced by the γ-γ’ lattice mismatch.


2015 ◽  
Vol 35 (6) ◽  
pp. 597-603 ◽  
Author(s):  
Mohsen Khademian ◽  
Hossein Eisazadeh

Abstract Emulsion nanoparticles of polyaniline (PANI) were synthesized in the aqueous media by using hydroxylpropylcellulose (HPC) as a stabilizer and ammonium persulfate as an oxidant in the presence of TiO2 with nanometer size. New poly(vinyl acetate) (PVAc) coating over carbon steel was prepared by addition of emulsion nanoparticles in different concentrations (1%, 2% and 1.5%) in PVAc as the major matrix. The Tafel plot records were used for the definition of potential and corrosion current (Icorr). Nanoparticles were characterized and compared by X-ray diffraction (XRD), thermal gravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). By adding TiO2, the thermal stability of the nanocomposite increased. A small size of colloidal particles prevented the precipitation of conducting polymer particles and led to better dispersion of nanocomposites in the matrix of the PVAc binder; therefore, the paint was homogeneous and anticorrosion properties of the coating increased. According to the results, 1.5% of PANI-TiO2 nanocomposite in PVAc has a much lower Icorr in NaCl aqueous solution and 2% of PANI-TiO2 nanocomposite in PVAc has the best corrosion protection in HCl.


2016 ◽  
Vol 16 (4) ◽  
pp. 3744-3748 ◽  
Author(s):  
Yuan Gao ◽  
Yuebo Hu ◽  
Dacheng Zhou ◽  
Jianbei Qiu

Transparent oxyflouride glass ceramics composed of SiO2–Al2O3–Na2O–NaF–YF3 tri-coped with Nd3+/Yb3+/Ho3+ were prepared by thermal treatment. Segregation of NaYF4 nanocrystals in the matrix was confirmed from structural analysis by means of X-ray diffraction and transmission electron microscopy. Compared with glass samples, very strong green upconversion (UC) luminescence due to the Ho3+:(4F5, 5S2)→5I8 transition was observed in the glass ceramics under 808 nm excitation. It was found that upconversion intensity of Ho3+ strongly depends on the Nd3+ concentration, and the energy transfer process from Nd3+ to Ho3+ via Yb3+ was proposed.


2007 ◽  
Vol 336-338 ◽  
pp. 1270-1273 ◽  
Author(s):  
Wan Chang Sun ◽  
He Jun Li ◽  
Shou Yang Zhang ◽  
Yong Huang

The morphologies and textures of the pyrolytic carbon matrix in 2D-C/C composites after graphitization were investigated by means of polarized light microscope (PLM) and high resolution transmission electron microscope (HRTEM). The microstructure parameters of the pyrolytic carbon matrix before and after graphitization were characterized with X-ray diffraction (XRD) technology. It was found that the interplanar distance of (002) planes (d002) of pyrolytic carbon matrix decreases, and the microcrystalline stack height (LC) increases after graphitization. Graphitization treatment resulted in a coarsening of the surface texture and in the formation of circumferential cracks within the matrix. The lattice fringes of the pyrolytic carbon matrix are continuous and longer in each domain and the (002) peak spot is smaller and more intense after graphitization.


Author(s):  
A. Hakamy ◽  
F. U. A. Shaikh ◽  
I. M. Low

influence of calcined nanoclay (CNC) on the porosity and fracture toughness of treated hemp fabric-reinforced cement nanocomposites is presented in this paper. Characterisation of microstructure is investigated using Quantitative X-ray Diffraction Analysis (QXDA) and High Resolution Transmission Electron Microscopy (HRTEM). An optimum replacement of ordinary Portland cement with 1 wt% CNC is observed through reduced porosity and increased fracture toughness of treated hemp fabric-reinforced nanocomposite. The microstructural analysis indicates that the CNC affect not only as a filler to improve the microstructure, but also as the activator to support the pozzolanic reaction and thus improved the adhesion between the treated hemp fabric and the matrix. Cost-benefit analysis indicates the benefit of such cement eco-nanocomposites to develop new environmentally friendly nanomaterials and it can be used for various construction applications such as, ceilings and roofs.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Chern Chiet Eng ◽  
Nor Azowa Ibrahim ◽  
Norhazlin Zainuddin ◽  
Hidayah Ariffin ◽  
Wan Md. Zin Wan Yunus ◽  
...  

The effects of hydrophilic nanoclay, Nanomer PGV, on mechanical properties of Polylactic Acid (PLA)/Polycaprolactone (PCL) blends were investigated and compared with hydrophobic clay, Montmorillonite K10. The PLA/PCL/clay composites were prepared by melt intercalation technique and the composites were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). FTIR spectra indicated that formation of hydrogen bond between hydrophilic clay with the matrix. XRD results show that shifting of basal spacing when clay incorporated into polymer matrix. TEM micrographs reveal the formation of agglomerate in the composites. Based on mechanical properties results, addition of clay Nanomer PGV significantly enhances the flexibility of PLA/PCL blends about 136.26%. TGA showed that the presence of clay improve thermal stability of blends. DMA show the addition of clay increase storage modulus and the presence of clay Nanomer PGV slightly shift two Tg of blends become closer suggest that the presence of clay slightly compatibilizer the PLA/PCL blends. SEM micrographs revealed that presence of Nanomer PGV in blends influence the miscibility of the blends. The PLA/PCL blends become more homogeneous and consist of single phase morphology.


1981 ◽  
Vol 7 ◽  
Author(s):  
A. Perez ◽  
M. Treilleux ◽  
P. Thevenard ◽  
G. Abouchacra ◽  
G. Marest ◽  
...  

ABSTRACTMgO single crystals implanted with alkali ions (Li+, Na+, K+ and Rb+),Fe+, In+ and Au+ ions have been studied after implantation with doses up to 1017 ions.cm−2 and after annealing at temperatures up to 1100°C.In order to characterize defects and precipitated phases, several techniques have been associated depending on the implanted ions : optical absorption, transmission electron microscopy, Rutherford backscattering spectrometry, conversion electron Mössbauer spectroscopy and X-ray diffraction at oblique incidence. Directly after implantation the intrinsic defects in the anionic sublattice (F, F+, F2-centers) and in the cationic sublattice (V−-centers) are observed. As to the implanted species, two precipitation processes are observed : (i) the implanted ions precipitate independently of the matrix elements. This is the case of alkali ions which form alkali metal precipitates. (ii) the implanted species precipitate with those of the matrix to form compounds. This is observed with iron which forms oxide precipitates and spinel ferrite. In the case of indium and gold, the precipitation process occurs with the cations of the matrix to form binary alloys : Mg3In and Au3Mg.


Author(s):  
Łukasz Rakoczy ◽  
Małgorzata Grudzień-Rakoczy ◽  
Fabian Hanning ◽  
Grzegorz Cempura ◽  
Rafał Cygan ◽  
...  

AbstractThe equiaxed Ni-based superalloy René 108 was subjected to short-term annealing at five temperatures between 900 °C and 1100 °C. The phase composition, phase lattice parameters, microstructure, stereological parameters, and chemical composition of γ′ precipitates were investigated by thermodynamic simulations, X-ray diffraction, scanning and transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Analysis of the γ and γ′ lattice parameters using the Nelson-Riley extrapolation function showed that the misfit parameter for temperatures 900 °C to 1050 °C is positive (decreasing from 0.32 to 0.11 pct). At 1100 °C, the parameter becomes negative, δ = − 0.18 pct. During the short-term annealing, γ′ precipitates dissolution occurred progressing more rapidly with increasing temperatures. The surface fraction of γ′ precipitates decreased with increasing temperature from 0.52 to 0.34. The dissolution of γ′ precipitates did not only proceed through uninterrupted thinning of each individual precipitate, but also included more complex mechanisms, including splitting. Based on transmission electron microscopy, it was shown that after γ′ precipitates dissolution, the matrix close to the γ/γ′ interface is strongly enriched in Co and Cr and depleted in Al.


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