Processing and characterization of Ti–B-based functionally graded materials produced by microwave-activated combustion synthesis

2002 ◽  
Vol 17 (11) ◽  
pp. 2823-2830 ◽  
Author(s):  
M. Cirakoglu ◽  
S. Bhaduri ◽  
S. B. Bhaduri
Keyword(s):  
Combustion Synthesis ◽  
Functionally Graded ◽  
X Ray Diffraction ◽  
Entire Cross Section ◽  
Graded Materials ◽  
X Ray ◽  
Conventional Combustion ◽  
Titanium Monoboride ◽  
Graded Layers

Single as well as graded compositions were fabricated in the Ti–B system using a microwave-activated combustion synthesis (MACS) process. When synergistically combined with microwave processing, combustion synthesis offers great potential for the fabrication of ceramic structures and composites. Combustion waves were triggered using a SiC susceptor to initially absorb microwaves. The effects of processing variables, such as thermal insulation, and atmosphere on the process were investigated. Examination of reacted samples by means of x-ray diffraction indicated the presence of titanium monoboride and diboride along with unreacted titanium. Compared with conventional combustion synthesized products, MACS resulted in smaller pores. However, the total amount of porosity remained almost the same. The microstructure of the graded layers and interfaces were examined using optical and scanning electron microscopy. Over the entire cross section, the interfaces were continuous and crack free.

Phase Contamination Characterization of Stepwise-Built Functionally Graded Hydroxyapatite/Titanium (HA/Ti) Sintered under Various Atmospheres

2017 ◽  
Vol 889 ◽  
pp. 90-95 ◽  
Author(s):  
Siti Nur Sakinah Jamaludin ◽  
Shahnor Basri ◽  
Faizal Mustapha ◽  
Dewan Muhammad Nuruzzaman ◽  
Muhammad Ihsan Abdul Latiff ◽  
...  
Keyword(s):  
Functionally Graded ◽  
Alkyl Halides ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
High Tendency ◽  
Sintering Atmosphere ◽  
X Ray ◽  
Constituent Element ◽  
Graded Material

Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD) test were utilized to detect the phase transformation of a HA/Ti Functionally Graded Material (FGM) prepared via Powder Metallurgy (PM) technique. The effects of oxygen (O2), nitrogen (N2), forming (N2+H2) and Argon (Ar) sintering atmospheres on the FGM specimens were examined by considering the gas flowing duration. It was found that the original metallurgical profile of pure Ti in HA/Ti FGM sintered under N2 atmosphere was almost preserved. However the carburization of the pure Ti was observed on the specimen. Medium alkyl halides (C-Br) and alkenes (-C=C-) stretches were detected, producing the dominant elements in the pure Ti layer of the specimen. The almost stable constituent element remains in the specimen sintered under flowing N2+H2 atmosphere as detected by XRD result. This proved the significance of controlling the sintering atmosphere during the entire sintering process. The results achieved reveal the high tendency of Ti and HA elements to react with the sintering environment, thus very precise furnace with controllable atmosphere is crucial for the fabrication of the HA/Ti FGM.

Functionally Graded TiC-Based Cermets via Combustion Synthesis and Quasi-Isostatic Pressing

2005 ◽  
Vol 492-493 ◽  
pp. 63-68 ◽  
Author(s):  
M. Martinez Pacheco ◽  
Marianne Stuivinga ◽  
Eric Carton ◽  
Laurens Katgerman
Keyword(s):  
Combustion Synthesis ◽  
Functionally Graded ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
Powder Mixtures ◽  
X Ray ◽  
High Temperature Synthesis ◽  
Graded Material ◽  
Granulate Medium ◽  
Scanning Electron

Experimental results on the preparation of functionally graded TiC-based cermets obtained by combustion synthesis (also known as Self-Propagating High-Temperature Synthesis, SHS) followed by quasi-isostatic (QIP) pressing in a granulate medium are presented. Pellets of TiC-Fe graded cermets are produced by stacking layers of Ti and C powder mixtures in which the content of a NiFe alloy (50 wt% Ni and 50 wt% Fe) is varied from 5 up to 25 vol %. X-ray diffraction showed that the NiFe alloy did not react with the TiC, thus preserving its special properties. Scanning electron microscopy results show a graded material with pores increasing in size towards the side with the highest ceramic fraction.

scholarly journals Application of X-Ray Microtomography to the Microstructural Characterization of Al-Based Functionally Graded Materials

2006 ◽  
Vol 45 ◽  
pp. 1109-1116 ◽  
Author(s):  
Alexandre Velhinho ◽  
Francisco Manuel Braz Fernandes ◽  
S.C. Ferreira ◽  
L.A. Rocha ◽  
Gerard Vignoles ◽  
...  
Keyword(s):  
Functionally Graded Materials ◽  
Metal Matrix ◽  
Microstructural Characterization ◽  
Functionally Graded ◽  
Graded Materials ◽  
X Ray ◽  
Computed Microtomography ◽  
X Ray Computed

This paper provides a brief overview of the possibilities offered by X-ray computed microtomography, and particularly synchrotron radiation X-ray microtomography, regarding metal matrix composite characterization, emphasis being placed in the case of Al-based functionally graded materials. Examples are provided concerning the characterization of the reinforcement population, interfacial properties, in-situ transformation and damage evolution. The specific needs of the technique and limitations to its widespread use are mentioned.

Synthesis and Characterization of YAG:Ce Phosphor by Microwave Induced Combustion Synthesis with Different Fuel Sources

2020 ◽  
Vol 301 ◽  
pp. 69-76
Author(s):  
Khai Shenn Lau ◽  
Zainuriah Hassan ◽  
Way Foong Lim ◽  
Hock Jin Quah ◽  
Naser Mahmoud Ahmed ◽  
...  
Keyword(s):  
Combustion Synthesis ◽  
Luminescent Properties ◽  
Yttrium Aluminium Garnet ◽  
X Ray Diffraction ◽  
Mixed Fuel ◽  
X Ray ◽  
White Leds ◽  
Yttrium Aluminium ◽  
Cie Chromaticity

White LEDs (WLEDs) have been produced from the combination of blue LED chips and phosphor converter. In the present work, considerable amount of yttrium aluminium garnet (YAG) phosphor powders doped with 0.3 mol% of cerium (Ce) have been synthesized via Microwave Induced Combustion Synthesis (MICS) method with different fuel sources such as urea and mixed fuel of urea and glycine. The effects of different fuel sources on the crystallinity, structure, luminescent properties and Commision International de L’Eclairage (CIE) chromaticity was characterized and studied using high resolution X-ray diffraction (HR XRD), field emission-scanning electron microscopy (FE SEM), energy dispersive X-ray spectroscopy (EDX), electroluminescence (EL) and standard CIE 1931 chromaticity diagram, respectively. The highest EL intensity can be observed from the sample prepared by mixed fuel technique. In contrast, the experimental enhancement in the aforementioned properties was demonstrated by the WLED synthesized using mixed fuel technique. Keywords: White LEDs, phosphor converter, microwave induced combustion, mixed fuel technique.

Characterization of Sub-Surface Structures by Double Crystal X-Ray Diffraction

1986 ◽  
Vol 82 ◽  
Author(s):  
D.K. Bowen ◽  
M.J. Hill ◽  
B.K. Tanner
Keyword(s):  
Vapour Phase ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Vapour Phase Epitaxy ◽  
X Ray ◽  
Glancing Angle ◽  
Graded Layers ◽  
Superlattice Structures

ABSTRACTThe application of double crystal X-ray diffractometry and computer simulation to the characterization of lattice parameter variations through the thickness of heteroepitaxial layers is reviewed. The sensitivity is demonstrated in studies of graded layers grown by vapour phase epitaxy. Capping layers significantly affect rocking curves from superlattice structures. The use of glancing angle diffraction to characterize thin, low period multilayers is examined.

scholarly journals Characterization of High Ge Content SiGe Heterostructures and Graded Alloy Layers Using Spectroscopic Ellipsometry

1994 ◽  
Vol 358 ◽  
Author(s):  
A. R. Heyd ◽  
S. A. Alterovitz ◽  
E. T. Croke
Keyword(s):  
Spectroscopic Ellipsometry ◽  
Alloy Composition ◽  
Compressive Strain ◽  
Energy Shift ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
X Ray ◽  
Si Substrates ◽  
Graded Layers

ABSTRACTSixGe1–x heterostructures on Si substrates have been widely studied due to the maturity of Si technology. However, work on SixGe1–x heterostructures on Ge substrates has not received much attention. A SixGe1–x: layer on a Si substrate is under compressive strain while SixGe1–x on Ge is under tensile strain; thus the critical points will behave differently. In order to accurately characterize high Ge content SixGe1–x layers the energy shift algorithm, which is used to calculate alloy compositions, has been modified. These results have been used along with variable angle spectroscopic ellipsometry (VASE) measurements to characterize SixGe1–x/Ge superlattices grown on Ge substrates. The results are found to agree closely with high resolution x-ray diffraction measurements made on the same samples.The modified energy shift algorithm also allows the VASE analysis to be upgraded in order to characterize linearly graded layers. In this work VASE has been used to characterize graded SixGe1–x layers in terms of the total thickness, and the start and end alloy composition. Results are presented for a 1 µm SixGe1–x layer linearly graded in the range 0.5 ≤ x ≤ 1.0.

scholarly journals SINTESIS BAHAN UBAHAN GRADUAL ALUMINUM TITANAT/KORUNDUM DARI ALUMINA TRANSISI DENGAN PENAMBAHAN MgO

2012 ◽  
Vol 13 (2) ◽  
pp. 80-86
Author(s):  
Achmad Sulhan Fauzi ◽  
Suminar Pratapa ◽  
Mohammad Herman Eko Santoso
Keyword(s):  
Functionally Graded ◽  
Holding Time ◽  
Phase Identification ◽  
Metal Powders ◽  
Aluminum Titanate ◽  
X Ray Diffraction ◽  
Graded Materials ◽  
Transition Alumina ◽  
X Ray ◽  
Graded Material

This article describes the results of research on the use of transition alumina for improving the performance of ceramics. Synthesis has been made of gradual changes materials (Functionally Graded Materials, FGM) aluminum titanate (AT) / corundum based on transition alumina powders with the addition of MgO as a stabilizer of AT as much as 2 wt.%. Samples without the addition of MgO was also made for comparison. Transition alumina with and without the addition of MgO were calcined at a temperature of 1100C for 1 hour to become ?-alumina. The powder mixture was compacted at a pressure of 49.3 MPa and then prasintered at a temperature of 1100C for 1 hour, then repeatedly infiltrated with infiltrator TiCl3 solution (20%) which prepared by dissolving the Ti metal powders into HCl. Furthermore, the material sintered at temperatures of 1500C with a holding time for 3 hours. Physical character of materials showed an increase in density and decrease in porosity of the material due to the addition of MgO. Phase identification results obtained from the content of AT and corundum phases which gradual in depth, indicating that FGM has been formed. These results were supported by analysis of x-ray diffraction pattern showing the formation of a solid solution Al2 (1-x) + MgxTi1 xO5 which marked by the shifting of the peak of AT phase in FGM samples with the addition of MgO.   Tulisan ini menjelaskan hasil penelitian tentang penggunaan alumina transisi untuk meningkatkan performa keramik. Telah dilakukan sintesis bahan ubahan gradual (Functionally Graded Material, FGM) aluminum titanat (AT)/korundum berbahan dasar serbuk alumina transisi dengan penambahan MgO sebagai penstabil AT sebanyak 2 wt.%. Sampel tanpa tambahan MgO juga dibuat sebagai pembanding. Alumina transisi dengan dan tanpa penambahan MgO dikalsinasi pada temperatur 1100C selama 1 jam sehingga menjadi ?-alumina. Serbuk campuran dikompaksi pada tekanan 49,3 MPa lalu diprasinter pada temperatur 1100C selama 1 jam, kemudian diinfiltrasi secara berulang dengan infiltran larutan TiCl3 (20%) yang dibuat dengan cara melarutkan serbuk logam Ti ke dalam HCl. Selanjutnya bahan disinter pada temperatur 1500C dengan holding time selama 3 jam. Karakterisasi fisik bahan memperlihatkan adanya kenaikan densitas dan penurunan porositas bahan akibat penambahan MgO. Dari hasil identifikasi fasa didapatkan kandungan fasa AT dan korundum yang gradual terhadap kedalaman, menunjukkan bahwa FGM telah terbentuk. Hasil ini didukung dengan analisis pada pola difraksi sinar-x yang memperlihatkan terbentuknya larutan padat Al2(1-x)MgxTi1+xO5 yang ditandai terjadinya pergeseran puncak fasa AT pada sampel FGM dengan penambahan MgO.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

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.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

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