Correlation of the Crystal Structural and Microstructural Effects of the Interfacial Processes Between Gold and GaAs

1981 ◽  
Vol 10 ◽  
Author(s):  
Xian-Fu Zeng ◽  
D. D. L. Chung
Keyword(s):  
Solid Solution ◽  
Terminal Solid Solution ◽  
Small Surface ◽  
Interfacial Processes ◽  
Β Phase ◽  
Α Phase ◽  
Microstructural Effects ◽  
Crystal Structural ◽  
High Cooling Rates ◽  
Sharp Corners

The solid state interfacial reaction between gold and GaAs, was found to result in small surface microstructural changes, whereas melting of the reaction product (tentatively identified as AuGa) and subsequent solidification to form the β phase resulted in aligned rectangular protrusions with sharp corners. The rectangular protrusions were found to be much finer in scale after heating in a vacuum than after heating in argon at 1 atm. High cooling rates (e.g. 40°C min−1) during solidification resulted in the formation of both rectangular protrusions and irregularly shaped protrusions with jagged boundaries and topography. The irregular protrusions were associated with a phase tentatively identified as Au2Ga. Rapid cooling at about 600°C min−1 during solidification resulted in the formation of the gold-rich terminal solid solution (α phase) which appeared as aligned rectangular protrusions with rounded corners.

Effect of the Solid-Solution Treatment on the Die-Casting Structures and Properties of Commercial RE-AZ91D Mg Alloy

2014 ◽  
Vol 1061-1062 ◽  
pp. 13-16
Author(s):  
Zhi Chao Liu ◽  
Yao Li ◽  
Jun Jie Yang
Keyword(s):  
Solid Solution ◽  
Tensile Strength ◽  
Die Casting ◽  
Solution Treatment ◽  
Treatment Temperature ◽  
Elongation Ratio ◽  
Β Phase ◽  
Solid Solution Treatment ◽  
Α Phase ◽  
Structures And Properties

Effect of the solid-solution treatment on the structures and properties of the die-casting AZ91D alloy with mixed rare-earth elements was explored.The results show that the the tensile strength and the elongation ratio δ have been improved by solid-solution treatment.The higher the treatment temperature was,the better the improvement were.With the increase of the temperature,the content of β phase was lower when those of M-RE compound and the refinement α phase were higher.The tensile strength can reach 304.74Mpa and the elongation ratio can reach 11% after the solid-solution treatment of 370°C×16h.

Structure and properties of Al–Mg mechanical alloys

2003 ◽  
Vol 18 (8) ◽  
pp. 1827-1836 ◽  
Author(s):  
Mirko Schoenitz ◽  
Edward L. Dreizin
Keyword(s):  
Solid Solution ◽  
Energetic Materials ◽  
Amorphous Material ◽  
Bulk Composition ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Β Phase ◽  
Α Phase ◽  
Diffraction Microscopy

Mechanically alloys in the Al–Mg binary system in the range of 5–50 at.% Mg were produced for prospective use as metallic additives for propellants and explosives. Structure and composition of the alloys were characterized by x-ray diffraction microscopy (XRD) and scanning electron microscopy. The mechanical alloys consisted of a supersaturated solid solution of Mg in the α aluminum phase, γ phase (Al12Mg17), and additional amorphous material. The strongest supersaturation of Mg in the α phase (20.8%) was observed for bulk Mg concentrations up to 40%. At 30% Mg, the γ phase formed in quantities detectable by XRD; it became the dominating phase for higher Mg concentrations. No β phase (Al3Mg2) was detected in the mechanical alloys. The observed Al solid solution generally had a lower Mg concentration than the bulk composition. Thermal stability and structural transitions were investigated by differential scanning calorimetry. Several exothermic transitions, attributed to the crystallization of β and γ phases were observed. The present work provides the experimental basis for the development of detailed combustion and ignition models for these novel energetic materials.

Effect of Heat Treatments on the Bio-Corrosion Resistance of Magnesium Alloy Mg-8.0Al-1.0Zn-xGd

2011 ◽  
Vol 213 ◽  
pp. 497-501
Author(s):  
Lei Li ◽  
Rui He ◽  
Guo Jie Huang ◽  
Shui Sheng Xie
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Annealing Treatment ◽  
Microstructure Analysis ◽  
Β Phase ◽  
Α Phase ◽  
Treatment Procedures ◽  
Human Fluid

In order to improve the bio-corrosion resistance of magnesium alloy Mg-8.0Al-1.0Zn-xGd in the simulated human fluid, different heat treatment procedures were studied. Results showed that annealing treatment lowered the alloy’s corrosion resistance and hardness, while T6 treatment (solid solution+ aging) improved the alloy’s corrosion resistance and hardness. Microstructure analysis showed that the β phase dissolved into α phase after the annealing treatment. Hence, annealing treatment decreased the alloy’s corrosion resistance. However, lots of β-phases were precipitated in the T6 heat treatment, and they impeded the corrosion extending.

scholarly journals Fabrication, Structure and Mechanical and Ultrasonic Properties of Medical Ti6Al4V Alloys Part I: Microstructure and Mechanical Properties of Ti6Al4V Alloys Suitable for Ultrasonic Scalpel

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 478
Author(s):  
Zheyu He ◽  
Hao He ◽  
Jia Lou ◽  
Yimin Li ◽  
Dongyang Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Elastic Modulus ◽  
Solution Treatment ◽  
Phase Content ◽  
Ultrasonic Scalpel ◽  
Ultrasonic Properties ◽  
Β Phase ◽  
Α Phase ◽  
Microstructure And Mechanical Properties

Ti6Al4V alloy has been considered as a key component used in ultrasonic scalpels. In this series of papers, the fabrication, structure, and mechanical and ultrasonic properties of medical Ti6Al4V alloys suitable for ultrasonic scalpel are studied systemically. These alloys with low elastic modulus and present a typical bimodal microstructure with relatively high β phase content (~40%) and lamellar α thickness of ≤ 0.9 µm. In the first paper, the relationship between the microstructure and mechanical properties of hot-rolled Ti6Al4V alloys treated by heating treatment is discussed. In the second paper, the dependence of the ultrasonic properties on the microstructure of the heat-treated Ti6Al4V alloys is reported. With increasing solid solution temperature, the content and size of the primary α phase decrease. In contrast, the content and size of the lamellar α phase increase. Additionally, the β phase content first increases and then decreases. The microstructure of Ti6Al4V alloys could be slightly changed by aging treatment. When the solid solution treatment temperature increases to 980 °C from 960 °C, the average size of the lamellar α phase in the alloys increases by 1.1 µm. This results in a decrease in the average yield strength (93 MPa). The elastic modulus of alloys is mainly controlled by the β phase content. The microstructure of alloys by solution-treatment at 960 °C shows the highest β phase content and lowest average elastic modulus of 99.69 GPa, resulting in the minimum resonant frequency (55.06 kHz) and the highest average amplitude (21.48 µm) of the alloys at the length of 41.25 mm.

Uptake, Internalization and Degradation of the Novel Plasminogen Activator Reteplase (BM 06.022) in the Rat

1995 ◽  
Vol 74 (06) ◽  
pp. 1501-1510 ◽  
Author(s):  
J Kuiper ◽  
H van de Bilt ◽  
U Martin ◽  
Th J C van Berkel
Keyword(s):  
Plasminogen Activator ◽  
Liver Cells ◽  
The Novel ◽  
Uptake Mechanism ◽  
Liver Uptake ◽  
Lysosomal Compartment ◽  
Β Phase ◽  
Α Phase ◽  
Parenchymal Liver

SummaryThe catabolism of the novel plasminogen activator reteplase (BM 06.022) was described. For this purpose BM 06.022 was radiolabelled with l25I or with the accumulating label l25I-tyramine cellobiose (l25I-TC).BM 06.022 was injected at a pharmacological dose of 380 μg/kg b.w. and it was cleared from the plasma in a biphasic manner with a half-life of about 1 min in the α-phase and t1/2of 20-28 min in the β-phase. 28% and 72% of the injected dose was cleared in the α-phase and β-phase, respectively. Initially liver, kidneys, skin, bones, lungs, spleen, and muscles contributed mainly to the plasma clearance. Only liver and the kidneys, however, were responsible for the uptake and subsequent degradation of BM 06.022 and contributed for 75% to the catabolism of BM 06.022. BM 06.022 was degraded in the lysosomal compartment of both organs. Parenchymal liver cells were responsible for 70% of the liver uptake of BM 06.022. BM 06.022 associated rapidly to isolated rat parenchymal liver cells and was subsequently degraded in the lysosomal compartment of these cells. BM 06.022 bound with low-affinity to the parenchymal liver cells (550 nM) and the binding of BM 06.022 could be displaced by t-PA (IC50 5.6 nM), indicating that the low-density lipoprotein receptor-related protein (LRP) could be involved in the binding of BM 06.022. GST-RAP, which is an inhibitor of LRP, could in vivo significantly inhibit the uptake of BM 06.022 in the liver.It is concluded that BM 06.022 is metabolized primarily in the liver and the kidneys. These organs take up and degrade BM 06.022 in the lysosomes. The uptake mechanism of BM 06.022 in the kidneys is unknown, while LRP is responsible for a low-affinity binding and uptake of BM 06.022 in parenchymal liver cells.

Mechanical Alloying Behavior in the Nb-Si, Ta-Si, and Nb-Ta-Si Systems

1988 ◽  
Vol 133 ◽  
Author(s):  
K. S. Kumar ◽  
S. K. Mannan
Keyword(s):  
High Temperature ◽  
Mechanical Alloying ◽  
Mechanical Milling ◽  
Room Temperature ◽  
Crystalline Compound ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Α Phase

ABSTRACTThe mechanical alloying behavior of elemental powders in the Nb-Si, Ta-Si, and Nb-Ta-Si systems was examined via X-ray diffraction. The line compounds NbSi2 and TaSi2 form as crystalline compounds rather than amorphous products, but Nb5Si3 and Ta5Si3, although chemically analogous, respond very differently to mechanical milling. The Ta5Si3 composition goes directly from elemental powders to an amorphous product, whereas Nb5Si3 forms as a crystalline compound. The Nb5Si3 compound consists of both the tetragonal room-temperature α phase (c/a = 1.8) and the tetragonal high-temperature β phase (c/a = 0.5). Substituting increasing amounts of Ta for Nb in Nb5Si3 initially stabilizes the α-Nb5Si3 structure preferentially, and subsequently inhibits the formation of a crystalline compound.

scholarly journals Synthesis of naked vanadium pentoxide nanoparticles

2021 ◽  
Author(s):  
Patrick Taylor ◽  
Matthew Kusper ◽  
Tina Hesabizadeh ◽  
Luke D. Geoffrion ◽  
Fumiya Watanabe ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Vanadium Pentoxide ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Energy Bandgap ◽  
Β Phase ◽  
Α Phase ◽  
Laser Ablation In Liquids

Vanadium pentoxide α-phase and β-phase synthesized by Pulsed Laser Ablation in Liquids, exhibiting a 2.50 eV and 3.65 eV energy bandgap.

scholarly journals X-Ray Investigations of the Low-Temperature Phases of the Organic Metals α- and β-(BEDT-TTF)2I3

1986 ◽  
Vol 41 (11) ◽  
pp. 1319-1324 ◽  
Author(s):  
H. Endres ◽  
H. J. Keller ◽  
R. Swietlik ◽  
D. Schweitzer ◽  
K. Angermund ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Room Temperature ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
Slight Variation ◽  
X Ray ◽  
Organic Metals ◽  
Β Phase ◽  
Α Phase

The structure of single crystals of the organic metals α- and β-(BEDT-TTF)2I3* was determined at 100 K, well below the phase transitions indicated by resistivity and thermopower measurements as well as by differential thermal analysis. In the α-phase no unusual change of the room temperature unit cell but a slight variation in the triiodide network and especially a more pronounced dimerization in one of the two donor stacks have been found. The β-phase develops a superstructure with a unit cell volume three times as large as that at room temperature and with pronounced distortions of the I3--ions.

Fabrication of Piezoelectric Polyvinylidene Fluoride (PVDF) Polymer-Based Tactile Sensor Using Electrospinning Method

2016 ◽  
Vol 12 ◽  
pp. 42-50 ◽  
Author(s):  
N. Manikandan ◽  
S. Muruganand ◽  
K. Sriram ◽  
P. Balakrishnan ◽  
A. Suresh Kumar
Keyword(s):  
Polyvinylidene Fluoride ◽  
Biomedical Application ◽  
Electric Pulse ◽  
High Sensitivity ◽  
Tactile Sensor ◽  
Main Role ◽  
Nano Structure ◽  
Sem Image ◽  
Β Phase ◽  
Α Phase

The polyvinylidene fluoride (PVDF) nanofiber has widely investigated as a sensor and transducer material, because of its high piezo and Ferro electric properties. The novel nano structure of PVDF has attracted considerable interest in the bio sensing and biomedical application. This paper deals with PVDF Tactile sensor. Basically The PVDF acts as piezoelectric effect which convert load into electrical signals. The tactile sensor has a main role for visual handicap and robotics. Any physical activities of robotic in all industrial the tactile sensor is a crucible role, whether it can left the object or handling glass parts pressure of object is main. The Sandwich type PVDF base tactile sensor has been fabricated using nanofiber. Using electro spinning method, the PVDF based nanofiber coated over coper the electrodes. In normal, the PVDF has α-phase and while applying electric pulse the PVDF polymer would be changed from α-phase into β-phase. Only in β-phase, the PVDF act as piezo electrics sensor and measure the piezoelectricity simultaneously measure pressure and temperature in real time. The pressure was monitored from the change in the electrical resistance via the piezo resistance of the material. The enhancement of PVDF properties has been carried by using SEM. The SEM image result showed that the size of nanofiber, the size of nanofiber is varied in the range of (180 nm-400 nm) with smooth surface. The X-Ray diffraction has shown that the PVDF was aggregated with the β-phase crystalline nature. Due to β-phase it was act as a piezo electric prosperity’s and its results are very high sensitivity.

Sign in / Sign up

Export Citation Format

Share Document