Spray Forming of Al-Fe-Cr-Ti and Al-Si-Li Alloys

2007 ◽  
Vol 561-565 ◽  
pp. 1075-1078 ◽  
Author(s):  
Chaiyasit Banjongprasert ◽  
S.C. Hogg ◽  
I.G. Palmer ◽  
N. Grennan-Heaven ◽  
I.C. Stone ◽  
...  

This work presents an investigation of the spray forming and downstream processing of Al alloys that are difficult to produce in bulk by conventional solidification processing: Al-Fe-Cr-Ti alloys for intermediate temperature applications and Al-Si-Li alloys for high stiffness, low density applications in fast moving machinery. For the Al-Fe-Cr-Ti alloys, spray forming is being investigated to allow the scale-up of alloy compositions previously explored only as ribbons or powders in traditional rapid solidification routes. For Al-Si-Li alloys, spray forming is used to provide globular primary AlLiSi in a fully divorced AlLiSi/α-Al eutectic structure. For both alloys, the as spray formed and downstream processed microstructure of 20kg billets has been investigated by scanning electron microscopy, electron probe microanalysis, and X-ray diffractometry. Preliminary mechanical properties have also been investigated.

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 256 ◽  
Author(s):  
Zicheng Ling ◽  
Weiping Chen ◽  
Weiye Xu ◽  
Xianman Zhang ◽  
Tiwen Lu ◽  
...  

The influence of a Mo addition on the interfacial morphologies and corrosion resistances of novel Fe-Cr-B alloys in molten aluminum at 750 °C was systematically investigated using scanning electron microscopy, X-ray diffractometer, electron probe microanalysis, and transmission electron microscopy. The results indicated that Mo could not only strengthen the matrix but also facilitate the formation of borides. Furthermore, the microstructures of Mo-rich M2B boride changed from a local eutectic net-like structure to a typical coarse dendritic structure and a blocky hypereutectic structure with increasing Mo addition. This was true of the blocky Mo-rich M2B boride, rod-like Cr-rich M2B boride and the corrosion products, which had a synergistic effect on retarding of the diffusion of molten aluminum. Notably, the corrosion resistance of the Fe-Cr-B-Mo alloy, with an 8.3 wt.% Mo addition, was 3.8 times higher than that of H13 steel.


2012 ◽  
Vol 508 ◽  
pp. 178-182
Author(s):  
Jian Zhang ◽  
Guo Qiang Luo ◽  
Mei Juan Li ◽  
Qiang Shen ◽  
Lian Meng Zhang

Mo and Cu Were Bonded Successfully by Means of Vacuum Diffusion Bonding. The Interfacial Structure of the Joints Was Studied by Scanning Electron Microscopy (SEM), Electron Probe Microanalysis (EPMA), Energy Dispersive X-Ray Spectrometer (EDS) and X-Ray Diffraction (XRD), the Mechanical Property Is Tested by Tensile Strength Measurement. The Results Showed that the Differentatoms Diffused to each other in the Bonding Process. A Mo-Cu Solid Solution Was Formed in the Joint and with No Intermetallic Compounds. The Tensile Strength of the Joint Increased with the Increasing of Temperature, however, while the Holding Time Increased, the Strength Increased in the First Stages and then Decreases. It Were Observed that the Fracture Mode of the Joints Was a Brittle Fracture.


1988 ◽  
Vol 33 (6) ◽  
pp. 12576J ◽  
Author(s):  
Noriaki Ikeda ◽  
Goutaro Watanabe ◽  
Akira Harada ◽  
Tsuneo Suzuki

2005 ◽  
Vol 20 (9) ◽  
pp. 2340-2347 ◽  
Author(s):  
H. Wei ◽  
X.F. Sun ◽  
Q. Zheng ◽  
H.R. Guan ◽  
Z.Q. Hu ◽  
...  

The pseudo NiAl binary phase was formed in a nickel-based superalloy by pack cementation. Scanning electron microscopy, transmission electron microscopy, x-ray diffraction, electron probe microanalysis, and positron annihilation technique were used to characterize the pseudo NiAl binary phase. Based on reasonable assumptions, the chemical interdiffusivities of the pseudo NiAl binary phase were then assessed by means of the modified Wagner’s method. The results showed that the chemical interdiffusivities of the pseudo NiAl binary phase were about two orders of magnitude lower than those reported by others. The analysis indicated that the change in thermodynamic properties due to the additions of the microalloying atoms originally present in a superalloy could be responsible mainly for a decrease in chemical interdiffusivities.


1998 ◽  
Vol 13 (5) ◽  
pp. 1327-1334 ◽  
Author(s):  
Srečo Škapin ◽  
Drago Kolar ◽  
Danilo Suvorov ◽  
Zoran Samardžija

Subsolidus phase relations in the BaTiO3–La2TiO5–TiO2 part of the ternary BaO–La2O3–TiO2 system at 1300 °C in air were determined. The phases were characterized by x-ray diffraction, scanning electron microscopy, and electron probe wavelength dispersive spectroscopic microanalysis. A combination of techniques was employed because of insensitivity in detecting secondary phases by x-ray diffraction. The location and extent of Ba6−xLa8+2x/3Ti18O54 ternary solid solution 0.2(1) ⩽ x ⩽ 2.3(1) and Ba1−yLayTi1−y/4 (VTi)y/4O3 binary solid solution 0 ⩽ y ⩽ 0.3 at 1300 °C was established. Tie lines between various barium polytitanates with a sequence of Ba6−xLa8+2x/3Ti18O54 solid solution regions were determined.


2007 ◽  
Vol 336-338 ◽  
pp. 1829-1832 ◽  
Author(s):  
Qing Bo Tian ◽  
Yue Wang ◽  
Xue Tao Yue ◽  
Yan Sheng Yin ◽  
Su Hua Fan

The phase-separation and the crystallization of SiO2-MgO-Al2O3-K2O-Fe2O3-F glass were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe of microanalyzers (EPMA). The results reveal that the varieties and the morphology of crystalline phases formed depend sensitively on the thermal treatment schedules. During the isothermal treatments, the crystalline phases of mica, mica and iron oxide (FeFeO4), and FeFeO4 as major crystals are precipitated in the glass samples heat-treated at 900, 1000 and 1050°C respectively. However, the two-step heat treatment beginning at 900°C for 1h and subsequently followed at 1050°C for 1h leads to the precipitation of mica crystal and no any signs of FeFeO4 crystalline phase is observed. Also the morphology of sample is different from that of the isothermally treated glass at 1050°C, but is similar from that of sample at 900°C. A “worm”-shaped phase-separation is observed in the sample heated at 800°C for 0.5h, which exhibits different morphology from that of droplet- or globule-shape conventionally discerned. EPMA results show that the incorporation of Fe2O3 accelerates accumulation of fluorine element, promoting the phase-separation and the crystallization of the present glass.


2006 ◽  
Vol 12 (5) ◽  
pp. 406-415 ◽  
Author(s):  
Marco Alvisi ◽  
Markus Blome ◽  
Michael Griepentrog ◽  
Vasile-Dan Hodoroaba ◽  
Peter Karduck ◽  
...  

A calibration procedure for the detection efficiency of energy dispersive X-ray spectrometers (EDS) used in combination with scanning electron microscopy (SEM) for standardless electron probe microanalysis (EPMA) is presented. The procedure is based on the comparison of X-ray spectra from a reference material (RM) measured with the EDS to be calibrated and a reference EDS. The RM is certified by the line intensities in the X-ray spectrum recorded with a reference EDS and by its composition. The calibration of the reference EDS is performed using synchrotron radiation at the radiometry laboratory of the Physikalisch-Technische Bundesanstalt. Measurement of RM spectra and comparison of the specified line intensities enables a rapid efficiency calibration on most SEMs. The article reports on studies to prepare such a RM and on EDS calibration and proposes a methodology that could be implemented in current spectrometer software to enable the calibration with a minimum of operator assistance.


2011 ◽  
Vol 284-286 ◽  
pp. 1317-1320
Author(s):  
Quan Shui Chen ◽  
Xiao Dong Liu ◽  
Guang Yuan Ren ◽  
Pan Yi Liang ◽  
Hui Ma

Yttrium Aluminium Garnet (YAG) has a extensive applications in many fields because of its excellent properties. In this study the products synthesized by co-precipitation method is regular, and the reaction is complete, the YAG ceramic obtained is white, its density is 2.42g/cm3 and shrinkage is 7.78%. The YAG ceramic tablets were investigated by Field emission scanning electron microscopy (FE-SEM), Electron probe microanalysis (EPMA) and X-ray diffractometer (XRD). The results show that the structure of YAG ceramic is loose with spherical grain size of 0.2-0.3μm. The main mineral phase of YAG ceramic is composed of polycrystalline Al5Y3O12 with good crystallinity, and containing very small amount of unreacted alumina and other impurities.


2019 ◽  
Vol 3 (2) ◽  
pp. 10-17
Author(s):  
Andromeda Dwi Laksono ◽  
Rifqi Aulia Tanjung

Bulk Metallic Glass (BMG) memiliki sifat mekanik, magnetik, kimia dan fisik yang berbeda dengan paduan polikristalin karena susunan internal atomnya yang tidak teratur. Sehingga, BMG memiliki kekuatan mekanik yang baik, kekerasan yang tinggi, ketahanan terhadap aus dan korosi yang tinggi, dan kehalusan permukaan yang baik. Berdasarkan sifat tersebut, BMG memiliki kelayakan yang menjanjikan di bidang industry. Dalam penelitian ini, metode pengecoran cetakan di tembaga digunakan untuk menyiapkan BMG paduan Cu45Zr45Al5Ag5. Paduan dileburkan ulang dengan pendinginan super cepat menggunakan mesin pendingin di bawah temperatur -25 oC. Dengan metode pengecoran cetakan di tembaga, sampel ukuran besar berbentuk batang dipotong dengan diameter 2 mm hingga 4 mm dan panjang 30 mm. Batang kemudian dipotong lagi menjadi spesimen berbentuk cakram. Untuk memastikan apakah sampel adalah BMG atau tidak, sampel dievaluasi dengan Scanning Electron Microscopy (SEM), Energy Dispersion Spectrometer (EDS), Differential Scanning Calorimetry (DSC), Electron Probe X-ray Micro Analyzer (EPMA), dan X -ray Difraction (XRD). Hasilnya dibahas dalam penelitian ini. Kata Kunci: Bulk Metallic Glasses, Cu45Zr45Al5Ag5, Pengecoran Cetakan di Tembaga.


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