Microstructural characterization of AIN sintered with Y2O3

1988 ◽  
Vol 46 ◽  
pp. 578-579
Author(s):  
S-K. Chiang
Keyword(s):  
Microstructural Analysis ◽  
Microstructural Characterization ◽  
Packaging Material ◽  
Oxygen Impurity ◽  
Microstructural Investigation ◽  
Intergranular Phase ◽  
Processing History ◽  
Triple Points ◽  
Standard Techniques

Aluminum nitride's high thermal but low electrical conductivity make it a potential ceramic packaging material. Processing history, however, can have significant effects on these properties and studies aimed at correlating them to the processing and microstructure are sparse.Pure AIN cannot be readily sintered without additives. Addition of Y2O3 significantly improves its densification behavior and the results presented here concern microstructural analysis of AIN sintered with Y2O3.High-purity AIN powder (containing 1.24% oxygen impurity) with 3 or 9 weight% Y2O3 added was sintered in N2 at 1850°C for 1 hour followed by a further 3 hours at 1900°C. Samples made using this treatment were >95% dense. Specimens for microstructural investigation were prepared using standard techniques and examined using a JEOL 200 CX AEM.The general microstructure of all specimens consists of AIN grains with pockets of intergranular phase(s) located at triple points and some grain boundaries (FIG. 1).

Synthesis and Microstructural Analysis of Si3N4 Nanorods

2002 ◽  
Vol 8 (1) ◽  
pp. 5-10 ◽  
Author(s):  
Y.H. Gao ◽  
Y. Bando ◽  
K. Kurashima ◽  
T. Sato
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Activated Carbon ◽  
Carbothermal Reduction ◽  
Microstructural Analysis ◽  
Microstructural Characterization ◽  
X Ray ◽  
Transmission Electron ◽  
Closest Packing

α-Si3N4 nanorods with 20–80 nm width were synthesized by carbothermal reduction of SiO with amorphous activated carbon (AAC) as a reductant. Microstructural characterization of the synthesized nanorods was carried out by high resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray analysis. Many Si3N4 nanorods were found to be twisted. Each twisted nanorod contained several straight Si3N4 parts. The straight parts had the rod axes orientated along the 〈1010〉 direction, which is the closest packing direction of α-Si3N4. There were two kinds of joints between the two adjacent straight Si3N4 parts. Formation mechanism of the Si3N4 nanorods is discussed.

Mechanical and microstructural characterization of poly(N-isopropylacrylamide) hydrogels and its nanocomposites

2021 ◽  
pp. 146442072098830
Author(s):  
Necmi Dusunceli ◽  
Catalina Gabriela Sanporean ◽  
Aleksey D Drozdov ◽  
Jesper de Claville Christiansen ◽  
Florina-Elena Comanici
Keyword(s):  
Mechanical Behavior ◽  
Microstructural Analysis ◽  
Compressive Loading ◽  
Microstructural Characterization ◽  
Ammonium Persulfate ◽  
Mechanical Responses ◽  
Highly Nonlinear ◽  
Nonlinear Mechanical ◽  
The Mathematical Model

Mechanical behavior dependency of the poly(N-isopropylacrylamide) hydrogel related to the amount of initiator, crosslinker, and nanoparticles was investigated. An experimental approach has been undertaken to observe these dependencies and assess the amount of initiator (ammonium persulfate), crosslinker (N, N′-methylene-bisacrylamide), and nanoparticles (graphene oxide) on the macroscopic responses of poly(N-isopropylacrylamide). Different amounts of initiator, crosslinker, and nanoparticle were used to manufacture specimens for the compression test. The specimens were subjected to compressive loading up to breakage to investigate the breaking behavior of poly(N-isopropylacrylamide). The responses of these specimens indicated that the mechanical behavior of poly(N-isopropylacrylamide) was highly nonlinear and depends on these ingredients. The mechanical responses of poly(N-isopropylacrylamide) were simulated using the ideal network model. The simulation results of the mathematical model substantially complied with the experimental data of poly(N-isopropylacrylamide). In addition, a more in-depth microstructural analysis was performed on these specimens. The analysis results allowed us to correlate the dependent amounts of the ingredients on the nonlinear, mechanical behavior of poly(N-isopropylacrylamide).

Effect of Parawood Ash on Drying Shrinkage, Compressive Strength and Microstructural Characterization of Metakaolin-Based Geopolymer Mortar

2013 ◽  
Vol 594-595 ◽  
pp. 411-415 ◽  
Author(s):  
Danupon Tonnayopas ◽  
Abideng Hawa ◽  
Woraphot Prachasaree ◽  
Pichai Taneerananon
Keyword(s):  
Compressive Strength ◽  
Microstructural Analysis ◽  
Drying Shrinkage ◽  
Microstructural Characterization ◽  
Partial Replacement ◽  
X Ray Diffraction ◽  
Microscopy Techniques ◽  
Metakaolin Geopolymer ◽  
Test Result

Drying shrinkage, compressive strength and microstructural analysis of metakaolin based geopolymers partial replacement with Parawood ash was investigated. It was involved different SiO2/Al2O3 and CaO/SiO2 ratios. Characterization of geopolymer mortar was determined on drying shrinkage, compressive strength, mineral phases and microstructure was analysed by X-ray diffraction and scanning electron microscopy techniques. Test result of highest compressive strength was about 71 MPa at 6-h (4-h in oven at 80oC and 2-h ambient temperature). Voids-cement ratio is the most effect on the unconfined compressive strength of this metakaolin geopolymer mortar.

Microstructural Characterization of Clay-Based Ceramics with the Addition of Granite Residues

2019 ◽  
Vol 958 ◽  
pp. 123-128
Author(s):  
Monica Castoldi Borlini Gadioli ◽  
Mariane Costalonga de Aguiar ◽  
Carlos Maurício Fontes Vieira ◽  
Fabio da Costa Garcia Filho ◽  
Sergio Neves Monteiro
Keyword(s):  
Microstructural Analysis ◽  
High Capacity ◽  
Microstructural Characterization ◽  
Ceramic Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ornamental Stones ◽  
Lower Porosity ◽  
Scanning Electron

Million tons of ornamental stones residues are produced every year. Most of this residue is disposed without any kind of processing or treatment. Moreover, disposal occurs without a prospective of reuse or recycling. The incorporation into ceramics is a possible alternative for part of this residue. Clay-based ceramics have high capacity of incorporation of industrial residues. This work aimed to conduct a microstructural characterization of clay-based ceramics with incorporation of granite residues in the composition of the ceramic matrix. Specimens were produced with the addition of 0, 10, 20 and 30 wt. % of granite residues. The specimens were prepared by uniaxial pressing and sintered at temperatures of 1050 and 1200°C. For the microstructural analysis were carried out by scanning electron microscopy and X-ray diffraction. The results indicated that the incorporated ceramics sintered at 1200oC presented higher densification and lower porosity as compared with those sintered at 1050oC.

Microstructure of silicon implanted with MeV gold ions

1991 ◽  
Vol 49 ◽  
pp. 876-877
Author(s):  
M.J. Kim ◽  
M. Catalano ◽  
T.P. Sjoreen ◽  
R.W. Carpenter
Keyword(s):  
Single Crystal ◽  
Ion Irradiation ◽  
Microstructural Characterization ◽  
High Energy ◽  
Ion Milling ◽  
Cross Sectional ◽  
Microstructural Investigation ◽  
Annealing Behavior ◽  
Different Doses

High-energy implantation of silicon is of great interest in recent years for microelectronics due to the formation of a buried damage or dopant layer away from the active region of the device. The damage nucleation and growth behavior is known to vary significantly along the ion's track for MeV irradiation. In this paper, a detailed characterization of the damage morphology produced by MeV gold ions for different doses into single crystal Si, as well as the associated annealing behavior, is presented.Single crystal n-type Czochralski silicon {001} wafers were implanted with Au++ ions from doses of 1x1015 to 3x1016 cm-2 at 2-3 MeV. Specimen temperatures for all implantations were 20 or 300°C. A measurement with an infrared pyrometer of the implanted surface indicated a slight temperature rise during ion irradiation. The compositional and damage profiles were determined by Rutherford backscattering/channeling spectroscopy (RBS). Cross-sectional TEM samples for microstructural characterization were prepared by mechanical polishing and ion milling. A Philips 400ST/FEG analytical microscope was used for nanoprobe experiments, at 100 kV. Microstructural investigation was performed using ISI-002B and JEM-2000FX microscopes, at 200 kV.

Processing and Microstructural Characterization of TiB2 Liquid Phase Sintered with Ni and Ni3Al

1983 ◽  
Vol 24 ◽  
Author(s):  
P. Angelini ◽  
P. F. Becher ◽  
J. Bentley ◽  
C. B. Finch ◽  
P. S. Sklad
Keyword(s):  
Analytical Electron Microscopy ◽  
Phase Diagram Data ◽  
Microstructural Characterization ◽  
Convergent Beam Electron Diffraction ◽  
Intergranular Phase ◽  
X Ray ◽  
Analytical Electron ◽  
Convergent Beam ◽  
Electron Energy Loss

ABSTRACTAn Analytical Electron Microscopy investigation of TiB2 hot-pressed and pressureless sintered with Ni revealed the presence of Ni3B and tau intergranular phase, respectively. Convergent Beam Electron Diffraction (CBED) was used for crystal structure determination and compositions were determined by quantitative x-ray Energy Dispersive Spectroscopy (EDS) and Electron Energy Loss Spectroscopy (EELS). The phase analyses were compared with phase diagram data. An evaluation was also made of TiB2 hot pressed with Ni3Al. Quantitative EDS and EELS microanalysis indicated a Ni,Al type boride tau (Cr23C6 type) intergranular phase.

Microstructural characterization of CoPtCr/Cr thin film disks by cross-section TEM and elongated probe micro-diffraction

1991 ◽  
Vol 49 ◽  
pp. 762-763
Author(s):  
M.A. Parker ◽  
K.E. Johnson ◽  
C. Hwang ◽  
A. Bermea
Keyword(s):  
Magnetic Recording ◽  
Electron Probe ◽  
Microstructural Characterization ◽  
Crystallographic Structure ◽  
Recording Media ◽  
Layer By Layer ◽  
Cross Sectional ◽  
New Techniques ◽  
Polished Side

We have reported the dependence of the magnetic and recording properties of CoPtCr recording media on the thickness of the Cr underlayer. It was inferred from XRD data that grain-to-grain epitaxy of the Cr with the CoPtCr was responsible for the interaction observed between these layers. However, no cross-sectional TEM (XTEM) work was performed to confirm this inference. In this paper, we report the application of new techniques for preparing XTEM specimens from actual magnetic recording disks, and for layer-by-layer micro-diffraction with an electron probe elongated parallel to the surface of the deposited structure which elucidate the effect of the crystallographic structure of the Cr on that of the CoPtCr.XTEM specimens were prepared from magnetic recording disks by modifying a technique used to prepare semiconductor specimens. After 3mm disks were prepared per the standard XTEM procedure, these disks were then lapped using a tripod polishing device. A grid with a single 1mmx2mm hole was then glued with M-bond 610 to the polished side of the disk.

Microstructural Characterization of Au-Ge-Ni based ohmic contacts to GaAs/AlGaAs modfet device

1987 ◽  
Vol 45 ◽  
pp. 326-327
Author(s):  
A.K. Rai ◽  
A.K. Petford-Long ◽  
A. Ezis ◽  
D.W. Langer
Keyword(s):  
Contact Resistance ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Microstructural Characterization ◽  
Almost Everywhere ◽  
Spacer Layer ◽  
Good Contact ◽  
The Relationship ◽  
Lower Contact

Considerable amount of work has been done in studying the relationship between the contact resistance and the microstructure of the Au-Ge-Ni based ohmic contacts to n-GaAs. It has been found that the lower contact resistivity is due to the presence of Ge rich and Au free regions (good contact area) in contact with GaAs. Thus in order to obtain an ohmic contact with lower contact resistance one should obtain a uniformly alloyed region of good contact areas almost everywhere. This can possibly be accomplished by utilizing various alloying schemes. In this work microstructural characterization, employing TEM techniques, of the sequentially deposited Au-Ge-Ni based ohmic contact to the MODFET device is presented.The substrate used in the present work consists of 1 μm thick buffer layer of GaAs grown on a semi-insulating GaAs substrate followed by a 25 Å spacer layer of undoped AlGaAs.

Microstructural characterization of a cast RENi5-based alloy

1993 ◽  
Vol 51 ◽  
pp. 1176-1177
Author(s):  
G. M. Micha ◽  
L. Zhang
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Microstructural Characterization ◽  
Binary Compound ◽  
Nickel Metal ◽  
Cast Material ◽  
Nickel Metal Hydride ◽  
Transmission Electron ◽  
Cast Condition

RENi5 (RE: rare earth) based alloys have been extensively evaluated for use as an electrode material for nickel-metal hydride batteries. A variety of alloys have been developed from the prototype intermetallic compound LaNi5. The use of mischmetal as a source of rare earth combined with transition metal and Al substitutions for Ni has caused the evolution of the alloy from a binary compound to one containing eight or more elements. This study evaluated the microstructural features of a complex commercial RENi5 based alloy using scanning and transmission electron microscopy.The alloy was evaluated in the as-cast condition. Its chemistry in at. pct. determined by bulk techniques was 12.1 La, 3.2 Ce, 1.5 Pr, 4.9 Nd, 50.2 Ni, 10.4 Co, 5.3 Mn and 2.0 Al. The as-cast material was of low strength, very brittle and contained a multitude of internal cracks. TEM foils could only be prepared by first embedding pieces of the alloy in epoxy.

Applications of ultramicrotomy for materials characterization

1993 ◽  
Vol 51 ◽  
pp. 232-233
Author(s):  
R.T. Blackham ◽  
J.J. Haugh ◽  
C.W. Hughes ◽  
M.G. Burke
Keyword(s):  
Materials Science ◽  
Microstructural Analysis ◽  
Analytical Electron Microscopy ◽  
Austenitic Stainless Steels ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Thermally Induced ◽  
Radiation Induced ◽  
Characterization Of Materials

Essential to the characterization of materials using analytical electron microscopy (AEM) techniques is the specimen itself. Without suitable samples, detailed microstructural analysis is not possible. Ultramicrotomy, or diamond knife sectioning, is a well-known mechanical specimen preparation technique which has been gaining attention in the materials science area. Malis and co-workers and Glanvill have demonstrated the usefulness and applicability of this technique to the study of a wide variety of materials including Al alloys, composites, and semiconductors. Ultramicrotomed specimens have uniform thickness with relatively large electron-transparent areas which are suitable for AEM anaysis.Interface Analysis in Type 316 Austenitic Stainless Steel: STEM-EDS microanalysis of grain boundaries in austenitic stainless steels provides important information concerning the development of Cr-depleted zones which accompany M23C6 precipitation, and documentation of radiation induced segregation (RIS). Conventional methods of TEM sample preparation are suitable for the evaluation of thermally induced segregation, but neutron irradiated samples present a variety of problems in both the preparation and in the AEM analysis, in addition to the handling hazard.

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