Crystallographic Peculiarities of β-α Transformation in Brass Induced by Hot Extrusion

2020 ◽  
Vol 299 ◽  
pp. 541-545
Author(s):  
Mikhail L. Lobanov ◽  
S.V. Danilov ◽  
Vladimir I. Pastukhov
Keyword(s):  
Coincident Site Lattice ◽  
Hot Extrusion ◽  
Air Cooling ◽  
Orientation Microscopy ◽  
Β Phase ◽  
Α Phase ◽  
Orientation Relations ◽  
Main Components ◽  
Relationship Of ◽  
Significant Concentration

Structure-texture states in brass rods after hot extrusion and air-cooling have been investigated with the orientation microscopy (EBSD). In the examined samples, a significant concentration of β-phase with the lattice, close to bcc and fcc α-phase, has been detected. The β-phase texture consisted of the main components: two close to {110}<110> and {001}<110>. The α-phase texture consisted of the main components: close to {001}<100> and two close {110}<111>. The analysis of crystallographic relationship of the texture components of β-and α-phases demonstrates that they may all be obtained, in accordance with the orientation relations, which are intermediate between the Kurdjumov-Sachs and Nishiyama-Wasserman types It is assumed that β-α transformation began in β-phase at coincident site lattice Σ3 and Σ33a boundaries.

Effects of Heat Treatment on Microstructures and Mechanical Properties of Ti-38644 Alloy for Aerospace Fasteners

2018 ◽  
Vol 913 ◽  
pp. 109-117 ◽  
Author(s):  
Qing Yun Zhao ◽  
Si Rui Cheng ◽  
Li Dong Wang ◽  
Li Min Dong ◽  
Feng Lei Liu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Tensile Strength ◽  
Solution Temperature ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Air Cooling ◽  
Β Phase ◽  
Α Phase

The effects of heat treatment on microstructure and mechanical properties of Ti-38644 alloy were investigated by scanning electron microscope (SEM) and transmission electron microscopy (TEM) as well as uniaxial tensile test. The results show that when the solution temperature is lower than 845°C, the microstructure of Ti-38644 alloy is equiaxed β phase with the grain size of 20μm, and the tensile strength is about 960MPa. As raising solution temperature to 860°C, the grain size of Ti-38644 alloy increases to 100μm and the tensile strength decreased to 870MPa. There are a large number of secondary α phase precipitated from the grain boundaries and within grain of β phase undergoing aging treatment. Secondary α phase coarsens with increasing the aging temperature, leading to the decrease of tensile strength. After solution treatment at 815°C for 1.5h, water quenching plus aging at 520°C for 10h, air cooling, Ti-38644 alloy shows a better mechanical property with the tensile strength 1330MPa, elongation and reduction of area 10% and 45% respectively.

scholarly journals Influence of microtexture on ultrasonic reflection in Ti-6Al-4V alloy hot-forged in α+β region

2020 ◽  
Vol 321 ◽  
pp. 11021
Author(s):  
Yoshinori Ito ◽  
Hiroyuki Takamatsu ◽  
Shogo Saeki ◽  
Nobuhiro Tsuji
Keyword(s):  
Elastic Modulus ◽  
Inclination Angle ◽  
Radial Direction ◽  
Axial Direction ◽  
Phase Region ◽  
Ultrasonic Measurement ◽  
Air Cooling ◽  
Β Phase ◽  
Α Phase ◽  
Crystallographic Orientations

Morphological change in regions with microtexture, i.e., macrozones, in Ti-6Al-4V alloy after hot-forging in α+β phase region was analyzed using SEM/EBSD technique, and then the correlation with ultrasonic reflection was investigated. Starting material had colony-type microstructure consisting of lamellar-α with the same crystallographic orientation. Forging (cogging and upsetting) was conducted in α+β phase region to produce a cylindrical material with smaller cross section, followed by air cooling. Thus, resulting microstructure consisted of granular-α. To estimate local change in elastic modulus within the materials, we analyzed crystallographic orientations of α-phase using SEM/EBSD in terms of an inclination angle of c-axis. The regions having the nearly common crystallographic orientations of α-phase were found. Shapes of such regions with microtexture were elongated along the axial direction, which formed quasi-periodic variation of the inclination angle, i.e., elastic modulus, of α-phase along the radial direction of the forged material. Ultrasonic measurement was conducted at a frequency of 5 MHz along the radial direction and the axial direction. Relationship between the morphology of regions having microtexture and the amplitude of backscattered noises was evaluated. It was considered that the quasi-periodicity of the inclination angle correlated with the amplitude of backscattered noises in ultrasonic measurement.

scholarly journals Effect of Third-Stage Heat Treatments on Microstructure and Properties of Dual-Phase Titanium Alloy

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2776
Author(s):  
Xiqin Mao ◽  
Meigui Ou ◽  
Desong Chen ◽  
Ming Yang ◽  
Wei Long
Keyword(s):  
Tensile Strength ◽  
Titanium Alloy ◽  
Aging Treatment ◽  
Air Cooling ◽  
Phase Zone ◽  
Two Phase ◽  
Β Phase ◽  
Solution Treated ◽  
Α Phase ◽  
Third Stage

Two-phase TC21 titanium alloy samples were solution-treated at 990 °C (β phase zone) and cooled by furnace cooling (FC), air cooling (AC), and water quenching (WQ), respectively. The second solution stage treatment was carried out at 900 °C (α + β phase zone), then aging treatment was performed at 590 °C. The influence of the size and quantity of the α phase on the properties of the sample were studied. The experimental results showed as the cooling rate increased after the first solution stage treatment, wherein the thickness of primary layer α gradually decreased, and the tensile strength and yield strength gradually increased. After the second solution stage treatment, the tensile properties of samples increased due to the quantity of layers α increased. The aging treatment promoted the precipitation of the dispersed α phase and further improved the tensile strength. After the third solution stage treatments, the FC samples with more β-phase had the best comprehensive mechanical properties.

Effect of Heat Treatment on the Microstructure Evolution of Ti-6Al-3Sn-3Zr-3Mo-3Nb-1W-0.2Si Titanium Alloy

2016 ◽  
Vol 879 ◽  
pp. 1828-1833 ◽  
Author(s):  
Xiao Yun Song ◽  
Wen Jing Zhang ◽  
Teng Ma ◽  
Wen Jun Ye ◽  
Song Xiao Hui
Keyword(s):  
Heat Treatment ◽  
Titanium Alloy ◽  
Microstructure Evolution ◽  
Solution Treatment ◽  
Treatment Temperature ◽  
Water Quenching ◽  
Air Cooling ◽  
Two Phase ◽  
Β Phase ◽  
Α Phase

Ti-6Al-3Sn-3Zr-3Mo-3Nb-1W-0.2Si (BTi-6431S) alloy is a novel two-phase high temperature titanium alloy for short-term using in aerospace industry up to 700°C. The effects of heat treatment on the microstructure evolution of BTi-6431S alloy bar were investigated through optical microscopy (OM), X-ray diffraction (XRD), electron probe microanalysis (EPMA) and transmission electron microscopy (TEM). The results show that solution treatment in β region at 1010°C followed by water quenching results in the formation of orthorhombic martensite α′′ phase, while air cooling leads to the formation of hexagonal martensite α′ phase. When solution-treated in α+β phase field at temperatures from 900°C to 980°C following by water quenching, the content of primary α phase decreases with the increase of heat treatment temperature. For the alloy subjected to identical heat treatment, the content of Al in α phase is much higher than that in β phase, while the contents of Nb, Mo and W elements in α phase are much less than those in β phase.

Brass H62 Hot Extrusion of Micro Gear

2011 ◽  
Vol 704-705 ◽  
pp. 236-239
Author(s):  
Xiang Ru Liu ◽  
Xu Dong Zhou
Keyword(s):  
Hot Extrusion ◽  
Extrusion Process ◽  
Optical Microscope ◽  
Flow Lines ◽  
Β Phase ◽  
Α Phase ◽  
Internal Part ◽  
Anisotropic Mechanical Properties ◽  
Mems Technology ◽  
Circle Diameter

Gears are very important and widely used driving components in mechanical instruments, and the demands of micro-gears are increasing more and more active as the MEMS technology develops in recent years. In this paper, a brass micro gear, which modulus m = 0.125 mm, pressure angle α = 20°, number of teeth z = 6, addendum circle diameter d = 1 mm, hot extruded from brass H62 billet with size Φ3×3 mm at 650°C was studied by experimental method. The microstructure of the micro gear was observed by scanning electron microscope and optical microscope, and the conclusions are as follows: the fiber flow lines within the micro-gear were formed by the extrusion, so that the anisotropic mechanical properties of the micro-gear was happened; The tissue distribution of micro-gear was that, the surface of the gear is almost entirely α-phase, while the internal part of the gear was the mixture of α-phase and β-phase, because the α-phase with lower hardness flowing outward to the surface of the gear during the extrusion process.

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.

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