scholarly journals Towards Manufacturing of Ultrafine-Laminated Structures in Metallic Tubes by Accumulative Extrusion Bonding

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 389
Author(s):  
Matthew R. Standley ◽  
Marko Knezevic
Keyword(s):  
Solid State ◽  
Wall Thickness ◽  
Complex Geometry ◽  
Tube Wall ◽  
Film Theory ◽  
Radial Strain ◽  
Surface Preparation ◽  
Grain Structure ◽  
Outer Diameter ◽  
Laminated Structures

A severe plastic deformation process, termed accumulative extrusion bonding (AEB), is conceived to steady-state bond metals in the form of multilayered tubes. It is shown that AEB can facilitate bonding of metals in their solid-state, like the process of accumulative roll bonding (ARB). The AEB steps involve iterative extrusion, cutting, expanding, restacking, and annealing. As the process is iterated, the laminated structure layer thicknesses decrease within the tube wall, while the tube wall thickness and outer diameter remain constant. Multilayered bimetallic tubes with approximately 2 mm wall thickness and 25.25 mm outer diameter of copper-aluminum are produced at 52% radial strain per extrusion pass to contain eight layers. Furthermore, tubes of copper-copper are produced at 52% and 68% strain to contain two layers. The amount of bonding at the metal-to-metal interfaces and grain structure are measured using optical microscopy. After detailed examination, only the copper-copper bimetal deformed to 68% strain is found bonded. The yield strength of the copper-copper tube extruded at 68% improves from 83 MPa to 481 MPa; a 480% increase. Surface preparation, as described by the thin film theory, and the amount of deformation imposed per extrusion pass are identified and discussed as key contributors to enact successful metal-to-metal bonding at the interface. Unlike in ARB, bonding in AEB does not occur at ~50% strain revealing the significant role of more complex geometry of tubes relative to sheets in solid-state bonding.

Structural characterization of the fullerene nanotubes prepared by the liquid–liquid interfacial precipitation method

2005 ◽  
Vol 20 (3) ◽  
pp. 688-695 ◽  
Author(s):  
Kun'ichi Miyazawa ◽  
Jun-ichi Minato ◽  
Tetsuro Yoshii ◽  
Masahisa Fujino ◽  
Tadatomo Suga
Keyword(s):  
Linear Relationship ◽  
Wall Thickness ◽  
Structural Characterization ◽  
Tube Wall ◽  
Precipitation Method ◽  
Outer Diameter ◽  
Tubular Structures ◽  
Growth Axis ◽  
Inner Diameter

Fine tubular fibers composed of C60 and C70 fullerene molecules were successfully fabricated by the liquid–liquid interfacial precipitation method. The walls of the tubular fibers were crystalline, and the fullerene molecules were densely packed along the growth axis of tube wall. The tubular structures are called “fullerene nanotubes.” The inner diameter and the outer diameter of C70 tubes showed a linear relationship, suggesting a constant wall thickness of the tubes. The tubular structures composed of C70 molecules could be formed when their diameter was larger than about 240 nm. The fullerene tubes were successfully fabricated by using a C60-C70 soot as well. The formation of fullerene nanotubes can be understood by assuming a mechanism of core dissolution of the solvated fullerene nanowhiskers.

Numerical simulation of P91 pipe welding including the effects of solid-state phase transformation on residual stresses

2007 ◽  
Vol 221 (4) ◽  
pp. 213-224 ◽  
Author(s):  
A H Yaghi ◽  
T H Hyde ◽  
A A Becker ◽  
W Sun
Keyword(s):  
Phase Transformation ◽  
Solid State ◽  
Residual Stresses ◽  
Wall Thickness ◽  
Outer Diameter ◽  
Fe Method ◽  
P91 Steel ◽  
Weld Region ◽  
Solid State Phase Transformation ◽  
Hoop Stresses

The methodology of numerically simulating residual stresses in a welded P91 pipe section is described. The finite element (FE) method has been applied to simulate residual axial and hoop stresses generated in the weld region and heat affected zone (HAZ) of an axisymmetric 50-bead circumferentially butt-welded P91 steel pipe, with outer diameter of 145 mm and wall thickness of 50mm. The FE simulation consists of a thermal analysis which is followed by a sequentially-coupled structural analysis. Solid-state phase transformation (SSPT), which is characteristic of P91 steel during welding thermal cycles, has been modelled in the FE analysis by allowing for volumetric changes in steel and associated changes in yield stress due to austenitic and martensitic transformations. Phase transformation plasticity has also been taken into account. Preheat and interpass temperature control has been included in the modelling process. Thermally-obtained temperature contours indicate the size of the weld region, parent metal penetration, and HAZ. Residual axial and hoop stresses have been depicted through the pipe wall thickness as well as along the outer surface of the pipe. The results indicate the importance of including SSPT in the simulation of stresses during the welding of P91 steel.

TEM studies of solid-state reactions in sputter-deposited Nb/Al multilayer thin films

1996 ◽  
Vol 54 ◽  
pp. 1020-1021
Author(s):  
F. Ma ◽  
S. Vivekanand ◽  
K. Barmak ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Stoichiometric Composition ◽  
Analytical Electron Microscopy ◽  
Grain Structure ◽  
Solid State Reactions ◽  
Multilayer Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sputter Deposited

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.

Full Well Corrosion Insight – Case Studies in the Added Value of Electromagnetic Thickness Measurements During Well Interventions

2021 ◽  
Author(s):  
Andrew Imrie ◽  
Maciej Kozlowski ◽  
Omar Torky ◽  
Aditya Arie Wijaya
Keyword(s):  
Case Studies ◽  
Wall Thickness ◽  
Added Value ◽  
Metal Loss ◽  
Outer Diameter ◽  
Metal Thickness ◽  
True Condition ◽  
Pass Through ◽  
External Corrosion ◽  
The Individual

AbstractMonitoring pipe corrosion is one of the critical aspects in the well intervention. Such analysis is used to evaluate and justify any remedial actions, to prolong the longevity of the well. Typical corrosion evaluation methods of tubulars consist of multifinger caliper tools that provide high-resolution measurements of the internal condition of the pipe. Routinely, this data is then analyzed and interpreted with respect to the manufacture's nominal specification for each tubular. However, this requires assumptions on the outer diameter of the tubular may add uncertainty, and incorrectly calculate the true metal thicknesses. This paper will highlight cases where the integration of such tool and electromagnetic (EM) thickness data adds value in discovering the true condition of both the first tubular and outer casings.These case studies demonstrate the use of a multireceiver, multitransmitter electromagnetic (EM) metal thickness tool operating at multiple simultaneous frequencies. It is used to measure the individual wall thickness across multiple strings (up to five) and operates continuously, making measurements in the frequency domain. This tool was combined with a multifinger caliper to provide a complete and efficient single-trip diagnosis of the tubing and casing integrity. The combination of multifinger caliper and EM metal thickness tool results gives both internal and external corrosion as well as metal thickness of first and outer tubular strings.The paper highlights multiple case studies including; i) successfully detecting several areas of metal loss (up to greater than 32%) on the outer string, which correlated to areas of the mobile salt formation, ii) overlapping defects in two tubulars and, iii) cases where a multifinger caliper alone doesn't provide an accurate indication of the true wall thickness. The final case highlights the advantages of integrating multiple tubular integrity tools when determining the condition of the casing wall.Metal thickness tools operating on EM principles benefit from a slim outer diameter design that allows the tools to pass through restrictions which typically would prevent ultrasonic scanning thickness tools. Additionally, EM tools are unaffected by the type of fluid in the wellbore and not affected by any non-ferrous scale buildup that may present in the inside of the tubular wall. Combinability between complementary multifinger caliper technology and EM thickness results in two independent sensors to provide a complete assessment of the well architecture.

Structural Integrity Assessment of Steam Generator Tubes Using a New EPRI Statistical Approach

2002 ◽  
Author(s):  
Carlos Alexandre de Jesus Miranda ◽  
Miguel Mattar Neto
Keyword(s):  
Steam Generator ◽  
Wall Thickness ◽  
Nuclear Power ◽  
Structural Integrity ◽  
Tube Wall ◽  
New Approach ◽  
Inconel 600 ◽  
Integrity Assessment ◽  
Tube Wall Thickness ◽  
Uniform Tube

A fundamental step in tube plugging management of a Steam Generator (SG), in a Nuclear Power Plant (NPP), is the tube structural integrity evaluation. The degradation of SG tubes may be considered one of the most serious problems found in PWRs operation, mainly when the tube material is the Inconel 600. The first repair criterion was based on the degradation mode where a uniform tube wall thickness corrosion thinning occurred. Thus, a requirement of a maximum depth of 40% of the tube wall thickness was imposed for any type of tube damage. A new approach considers different defects arising from different degradation modes, which comes from the in-service inspections (NDE) and how to consider the involved uncertainties. It is based on experimental results, using statistics to consider the involved uncertainties, to assess structural limits of PWR SG tubes. In any case, the obtained results, critical defect dimensions, are within the regulatory limits. In this paper this new approach will be discussed and it will be applied to two cases (two defects) using typical data of SG tubes of one Westinghouse NPP. The obtained results are compared with ‘historical’ approaches and some comments are addressed from the results and their comparison.

The Influence of Section Thickness on Microstructure of Elektron 21 and QE22 Magnesium Alloys

2012 ◽  
Vol 191 ◽  
pp. 145-150 ◽  
Author(s):  
Michał Stopyra ◽  
Robert Jarosz ◽  
Andrzej Kiełbus
Keyword(s):  
Solid Solution ◽  
Grain Size ◽  
Magnesium Alloys ◽  
Statistical Methods ◽  
Wall Thickness ◽  
Light Microscope ◽  
Volume Fraction ◽  
Grain Structure ◽  
Section Thickness ◽  
Gating System

The paper presents analysis of section thickness’ influence on microstructure of Elektron 21 and QE22 magnesium alloys in the form of a stepped casting test. Solid solution grain size and volume fraction of eutectic areas were measured using light microscope and sterological methods. The results showed the significant increase of grain size caused by wall thickness and its slight decrease connected with the distance beetwen analysed section and the gating system. This relationship was confirmed using statistical methods. QE22 alloy demonstrated finer grain structure than Elektron 21 alloy as well as lesser susceptibility of grain size to solidification conditions

scholarly journals Manufacture of Water Pipe From Clampshell Powder Materials

2018 ◽  
Vol 2 (2) ◽  
pp. 73
Author(s):  
Abdul Rahmansyah ◽  
Zulfikar Zulfikar ◽  
Bobby Umroh
Keyword(s):  
Wall Thickness ◽  
Unsaturated Polyester ◽  
Polymer Composite Material ◽  
Raw Material ◽  
Household Waste ◽  
Thickness Variation ◽  
Powder Materials ◽  
Outer Diameter ◽  
Water Pipe ◽  
Water Pipes

<h1>In general, household waste water pipelines use plastic pipes of PVC type that are not environmentally friendly and are relatively expensive. Therefore, this research will design molds and manufacture of composite pipes using raw materials of clampshell powder. The raw material used is clampshell powder with the composition of MgO and CaO compounds which is about 22.28% and 66.70%. The mixture of materials used consisted of clampshell powder with a size of 40 mesh, catalyst, and unsaturated polyester resin as a matrix. The objective of this study is manufacture of water pipes made from polymer composites reinforced by clampshell powder. Composite pipe manufacturing is carried out using the casting method. Pipe molds are made of stainless steel with a diameter of 40.46 mm (1.6 in) and an outer diameter of 50.8 mm (2 in). This mold size follows SNI 06-0084-2002 standards. The results of the study, water pipes from polymer composite material reinforced by clampshell powder with an inner diameter size of 40.64 mm and varying outside diameter. This variation depends on the composition of the clampshell powder in composite materials. The greater the clampshell powder composition, the more easily the maximum pipe wall thickness can be obtained. The average wall thickness variation is 3.35 mm. This variation is still included in the polymer water pipe requirements, which is a minimum of 2 mm.</h1>

Abstract 11093: Layer-specific Quantification of Myocardial Deformation by Strain Echocardiography May Reveal the Mechanism of Preserved Left Ventricular Ejection Fraction in Patients With Hypertrophic Cardiomyopathy

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Jing Ping Sun ◽  
Xianda Ni ◽  
Tingyan Xu ◽  
Min Xu ◽  
Xing Sheng Yang ◽  
...  
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Ejection Fraction ◽  
Wall Thickness ◽  
Radial Strain ◽  
Left Ventricular ◽  
Relative Wall Thickness ◽  
Left Ventricular Ejection ◽  
Compensatory Mechanisms ◽  
Ventricular Ejection Fraction ◽  
Bull's Eye

Purpose: We aimed to evaluate compensatory mechanisms in hypertrophic cardiomyopathy (HCM) patients (pts) with preserved left-ventricular (LV) ejection fraction (EF). Methods: Speckle-tracking echocardiography (Vivid E9, GE) was performed in 50 HCM with preserved LV EF (38 m; 49± 14 y, all LV EF > 55%) and 50 age, gender matched controls (38 m; 49±12 y). The global and segmental longitudinal (LS), circumferential (CS) and radial strain (RS) strains of endocardia (End), mid-wall and epicardia layers were analyzed using a novel layer-specific TTE. The ratio of End to epicardia strain (End/Epi) was calculated. Results: The LV EF were similar in pts and controls (64±8 vs 64±7 %, p=0.95). The diastolic function was significantly impaired in HCM pts compared with controls (E/E’:18.4±8.4 vs 8.6 ±2.4, p<0.0001). The absolute value of LS and CS was reserved at apical End layers (-34±7 vs -35±6, p=0.44); the remaining segments and LV global LS and CS of three layers were significantly smaller (LS,-16±5 vs -22±3; CS -24±8 vs -33±7; p<0.0001), and LS and CS End/Epi (1.7±0.3 vs 1.3±0.1, 3.4±1.1 vs 1.7±0.2 respectively, P <0.0001) was significantly higher in HCM pts than in controls. The RS and LV twist were preserved in all LV segments (27±10 vs 24±12, p=0.19; 20±8 vs 18±5, p=0.33; respectively). In HCM pts, the LV LS value at basal and middle levels revealed significant negative correlations with LV relative wall thickness (r=–0.65, –0.59 and –0.60, –0.54, respectively , p< 0.0001); and mild negative correlations (r=-0.33,-0.29, p<0.0001). The LV CS value at all levels revealed mild correlations with relative wall thickness (r=-0.22, p<0.05) . The LS were significantly reduced at the hypertrophic segments (Figure). Conclusions: In HCM patients with preserved LVEF, LV GLS was impaired, but apical End LS and basal End CS, LV RS as well as LV twist were maintained as the compensation for reduction LV LS and CS. The Bull’s eye of LS may help us to localize the lesion segments and define the type of HCM.

The Formation of Tracheae and Tracheoles in Rhodnius prolixus

1958 ◽  
Vol s3-99 (45) ◽  
pp. 29-46
Author(s):  
M. LOCKE
Keyword(s):  
Axial Compression ◽  
Wall Thickness ◽  
Tube Wall ◽  
Rhodnius Prolixus ◽  
Axial Orientation ◽  
Tube Wall Thickness ◽  
Walled Cylinder ◽  
Tangential Orientation

The formation of tracheae in Rhodnius is described by the hypothesis of expansion and buckling. The cuticulin lining is at first a smooth-walled cylinder. Later it expands equally in each direction, increasing in diameter but buckling in the axis. An engineering expression describing symmetrical buckling in a cylinder under uniform axial compression has been applied to this process. Agreement was obtained between the expected and observed values for buckling frequency and tube-wall thickness. The taenidia are formed within the buckles, their amplitude being proportional to the increase in diameter. The axial orientation of the chitin micelles in the lining membrane and the tangential orientation in the taenidia are consistent with their being oriented by the stresses expected during expansion and buckling. The formation of tracheoles may also be described by the expansion and buckling hypothesis.

Fractal Geometry and Properties of Doped BaTiO3 Ceramics

2010 ◽  
Vol 67 ◽  
pp. 42-48 ◽  
Author(s):  
V.V. Mitic ◽  
V.B. Pavlovic ◽  
L. Kocic ◽  
V. Paunovic ◽  
L. Zivkovic
Keyword(s):  
Fractal Dimension ◽  
Solid State ◽  
Fractal Geometry ◽  
Grain Shape ◽  
Grain Structure ◽  
Fractal Method ◽  
Ceramic Structure ◽  
New Approach ◽  
Fractal Modeling ◽  
Dielectrical Properties

Taking into account that the complex grain structure is difficult to describe by using traditional analytical methods, in this study, in order to establish ceramic grain shapes of sintered BaTiO3, new approach on correlation between microstructure and properties of doped BaTiO3 ceramics based on fractal geometry has been developed. BaTiO3 ceramics doped with various dopants (MnCO3, Er2O3, Yb2O3) were prepared using conventional solid state procedure, and were sintered at 1350oC for four hours. The microstructure of sintered specimens was investigated by SEM-5300. Using method of fractal modeling a reconstruction of microstructure configurations, like grains shapes, or intergranular contacts has been successfully done. Furthermore, the area of grains surface was calculated using fractal correction that expresses the irregularity of grains surface through fractal dimension. The presented results, indicate that fractal method for ceramics structure analysis provides a new approach for describing, predicting and modeling the grain shape and relations between the BaTiO3-ceramic structure and dielectrical properties.

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