scholarly journals Microstructures of Three In-Situ Reinforcements and the Effect on the Tensile Strengths of an Al-Si-Cu-Mg-Ni Alloy

2018 ◽  
Vol 8 (9) ◽  
pp. 1523 ◽  
Author(s):  
Lusha Tian ◽  
Yongchun Guo ◽  
Jianping Li ◽  
Feng Xia ◽  
Minxian Liang ◽  
...  

In the present paper, the microstructures of three kinds of in-situ reinforcements Al-Ti-C, Al-Ti-B, and Al-Ti-B-C-Ce were deeply investigated using a combination of scanning electron microscopy, X-ray diffraction spectroscopy, and transmission electron microscopy. The effect of in-situ reinforcements on the room temperature and elevated temperature (350 °C) tensile strengths of Al-13Si-4Cu-1Mg-2Ni alloy were analyzed. It is found that doping with trace amounts of B and Ce, the size of the Al3Ti phase in the in-situ reinforced alloy changed from 80 µm (un-reinforced) to about 10 µm, with the simultaneous formation of the AlTiCe phase. The Al-Ti-B-C-Ce reinforcement which is rapid solidified, was more effective and superior to enhance the tensile strengths of the Al-13Si-4Cu-1Mg-2Ni alloy, both at room and high temperatures than those of addition other reinforcements. The room temperature (RT) strength increased by 19.0%, and the 350 °C-strength increased by 18.4%.

2013 ◽  
Vol 457-458 ◽  
pp. 244-247
Author(s):  
Min Li ◽  
Li Guang Xiao ◽  
Hong Kai Zhao

Polyethylene/montmorillonite (PE/MMT) nanocomposites were prepared by in situ polymerization. The morphology of MMT/MgCl2/TiCl4 catalyst and PE/MMT nanocomposites was investigated by scanning electron microscopy (SEM). It can be seen that MMT/MgCl2/TiCl4 catalyst remained the original MMT sheet structures and many holes were found in MMT and the morphology of PE/MMT nanocomposites is part of the sheet in the form of existence, as most of the petal structure. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were carried out to characterize all the samples. XRD results reveal that the original basal reflection peak of PEI1 and PEI2 disappears completely and that of PEI3 become very weak. MMT/MgCl2/TiCl4 catalyst was finely dispersed in the PE matrix. Instead of being individually dispersed, most layers were found in thin stacks comprising several swollen layers.


NANO ◽  
2016 ◽  
Vol 11 (07) ◽  
pp. 1650079 ◽  
Author(s):  
Wenjun Yan ◽  
Ming Hu ◽  
Jiran Liang ◽  
Dengfeng Wang ◽  
Yulong Wei ◽  
...  

A novel composite of Au-functionalized porous silicon (PS)/V2O5 nanorods (PS/V2O5:Au) was prepared to detect NO2 gas. PS/V2O5 nanorods were synthesized by a heating process of pure vanadium film on PS, and then the obtained PS/V2O5 nanorods were functionalized with dispersed Au nanoparticles. Various analytical techniques, such as field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), have been employed to investigate the properties of PS/V2O5:Au. Herein, the PS/V2O5:Au sample exhibited improved NO2-sensing performances in response, stability and selectivity at room temperature (25[Formula: see text]C), compared with the pure PS/V2O5 nanorods. These phenomena were closely related to not only the dispersed Au nanoparticles acting as a catalyst but also the p-n heterojunctions between PS and V2O5 nanorods. Whereas, more Au nanoparticles suppressed the improvement of response to NO2 gas.


2012 ◽  
Vol 717-720 ◽  
pp. 845-848 ◽  
Author(s):  
Alexia Drevin-Bazin ◽  
Jean François Barbot ◽  
Thierry Cabioc’h ◽  
Marie France Beaufort

In this study, investigations on MAX phase Ti3SiC2 formation to n-type 4H-SiC substrates and its ohmic-behaved are reported. Ti-Al layers were deposited onto SiC substrates at room temperature by magnetron sputtering in high vacuum system. Thermal annealing at 1000°C in Ar atmosphere were performed to allow interdiffusion processes. X-ray diffraction and High Resolution Transmission Electron Microscopy reveal that a Ti3SiC2 contact, in perfect epitaxy with 4H-SiC substrate, is so-obtained. In situ annealing experiment underlines the evolution of Ti-Al contact microstructure versus temperature. The evolution of contact system from Schottky to Ohmic behaved is observed by I-V measurements for annealing temperatures larger than 700°C.


2010 ◽  
Vol 8 (2) ◽  
pp. 434-439 ◽  
Author(s):  
Junhao Zhang ◽  
Ling Yang ◽  
Xiaofang Cheng ◽  
Jinmeng Zhang ◽  
Fucai Li

AbstractHierarchical nickel microwires with nanothorns were fabricated through a reduction of nickelous salt with hydrazine in diethanolamine. The product was characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). The growth mechanism of the nickel microwires with nanothorns is proposed, based on the evolution of the structures and morphologies, which could be ascribed to the cooperative effect of the complexant of diethanolamine and inherent magnetic interactions. Magnetic properties of the product were measured at room temperature and compared with other shaped counterparts.


2012 ◽  
Vol 535-537 ◽  
pp. 481-485 ◽  
Author(s):  
Mang Jiang ◽  
Jun Hong Duan ◽  
Zhiang Liu

The authors present the results of hetero-epitaxial growth of ultrafine SnO2nanowires on ZnS nanobelt substrates by a simple thermal evaporation method. ZnS/SnO2hetero-nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), transmission electron microscopy (TEM) to obtain the morphology and structural information. Comparing with ZnS nanobelts and SnO2nanowires respectively, the optical properties of ZnS/SnO2hetero-nanostructures are studied by Raman scattering and photoluminescence (PL) spectroscopy at room temperature.


2011 ◽  
Vol 121-126 ◽  
pp. 65-69
Author(s):  
Li Peng Zhang ◽  
Xian Jin Yu ◽  
Zhi Wei Ge ◽  
Yun Hui Dong ◽  
Dang Gang Li

Al-Ni Alloys were obtained from NiCl2-AlCl3-1-ethyl-3-methylimidazolium bromide ([EMIM]Br) ionic liquid at room temperature. The analysis of Al-Ni alloys that co-deposited at different potentials for 2h were performed using Scanning Electron Microscopy (SEM) and X-ray diffraction analysis (XRD). It appears that Ni has been rapidly solidified in the alloys and homogeneous Al-Ni alloys can be obtained at room temperature. As increasing the overpotential, the amount of Ni in the alloys was decreased whereas the amount of Al was increased. The chloride pitting potentials of alloys with the molar ratio of NiCl2/AlCl3/[EMIM]Br 0.03:2:1 was approximately 0.3 V more than pure Al.


2008 ◽  
Vol 55-57 ◽  
pp. 809-812 ◽  
Author(s):  
V. Kosalathip ◽  
T. Kumpeerapun ◽  
S. Migot ◽  
B. Lenoir ◽  
A. Dauscher

Nanopowders of n-type (Bi0.95Sb0.05)2(Te0.95Se0.05)3 and p-type (Bi0.2Sb0.8)2Te3 have been synthesized by laser fracture of micron-sized powders in water. These alloys are the best conventional thermoelectric materials for use in room temperature applications. The nanopowders have been characterized by x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The nanopowders have been mechanically mixed in different ratios with the micron sized powders. These mixtures have then been cold pressed in order to perform thermoelectric characterization and to see the influence of nano-particle inclusions on the transport properties.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.


Sign in / Sign up

Export Citation Format

Share Document