Effects of Cathode-Mandrel Surface Irregularities on the Mechanical Properties and Structure of Electroformed Iron Foil

1980 ◽  
Vol 22 (2) ◽  
pp. 49-54 ◽  
Author(s):  
W. A. Crichton ◽  
J. A. McGeough ◽  
J. R. Thomson

Iron foil, of thicknesses between 003 and 0.15 mm has been electroformed at a current density of 30 A/dm2 and an electrolyte temperature of 100°C upon cathodes of surface roughness ranging from 0.04 to 4.4 μm Ra. The surface roughnesses of the face of the foil formed adjacent to the cathode, and of that electrode, are similar. The roughness of the reverse anodic face increases with increasing foil thickness, due to the increase in size of the crystal growth sites. The hardness of the cathodic face of the foil is unaffected by either cathode surface roughness or foil thickness. The hardness of the anodic face increases with both increasing cathode surface roughness and decreasing foil thickness, due to corresponding changes in grain size. A slight net decrease in tensile properties with increasing cathode surface roughness is attributed to the greater amount of stress concentration borne by the rougher foils. Young's modulus for the foil is not affected by cathode surface roughness. The electroforming of foil upon a mandrel surface carrying an isolated V-shaped scratch, 0.14 mm deep and 0.28 mm wide, has also been studied by numerical and experimental methods. The cathodic surface of foil is found to adopt the shape of the scratch whilst its upper side becomes level. The effect upon the geometric configuration of the foil depends upon the relationship between current efficiency and current density for the electrolyte, and on the polarisation (overpotential) characteristics at the mandrel surface.

Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 313
Author(s):  
Simona Mrkonjić Zajkoska ◽  
Edmund Dobročka ◽  
Selma Hansal ◽  
Rudolf Mann ◽  
Wolfgang E. G. Hansal ◽  
...  

Magnetic properties of the sustainable Fe–Sn alloys are already known. However, there is lack of information in the field of Fe–Sn electrodeposition. In the present study, a novel Fe(III)–Sn(II) electrolyte with tartaric acid as a single complexing agent is introduced. The influence of the pH and the current density on the structural properties of the Fe–Sn deposit was studied. The stability of the electrolytes as a main attribute of sustainability was tested. The ferromagnetic phases Fe5Sn3 and Fe3Sn were electrodeposited for the first time, and it was found that the mechanism of the Fe–Sn deposition changes from normal to anomalous at a pH value 3.0 and a current density of approximately 30 mA/cm2. A possible reason for the anomalous deposition of Fe–Sn is the formation of Fe-hydroxides on the cathode surface. Two electrolyte stability windows exist: The first stability window is around a pH value of 1.8 where bimetallic Fe–Sn tartrate complexes were formed, and second one is around a pH value of 3.5 where most of the Sn ions were present in the form of [Sn(tart)2]2− and Fe in the form of [Fe(tart)]+ complexes.


Author(s):  
I-Fei Tsu ◽  
D.L. Kaiser ◽  
S.E. Babcock

A current theme in the study of the critical current density behavior of YBa2Cu3O7-δ (YBCO) grain boundaries is that their electromagnetic properties are heterogeneous on various length scales ranging from 10s of microns to ˜ 1 Å. Recently, combined electromagnetic and TEM studies on four flux-grown bicrystals have demonstrated a direct correlation between the length scale of the boundaries’ saw-tooth facet configurations and the apparent length scale of the electrical heterogeneity. In that work, enhanced critical current densities are observed at applied fields where the facet period is commensurate with the spacing of the Abrikosov flux vortices which must be pinned if higher critical current density values are recorded. To understand the microstructural origin of the flux pinning, the grain boundary topography and grain boundary dislocation (GBD) network structure of [001] tilt YBCO bicrystals were studied by TEM and HRTEM.


2021 ◽  
Author(s):  
Minmin Wang ◽  
Mengke Zhang ◽  
Wenwu Song ◽  
Weiting Zhong ◽  
Xunyue Wang ◽  
...  

A CoMo2S4/Ni3S2 heterojunction is prepared with an overpotential of only 51 mV to drive a current density of 10 mA cm−2 in 1 M KOH solution and ∼100% of the potential remains in the ∼50 h chronopotentiometric curve at 10 mA cm−2.


2017 ◽  
Vol 10 (2) ◽  
pp. 197-216
Author(s):  
Sarah Irving-Stonebraker

Through an examination of the extensive papers, manuscripts and correspondence of American physician Benjamin Rush and his friends, this article argues that it is possible to map a network of Scottish-trained physicians in the late eighteenth and early nineteenth-century Atlantic world. These physicians, whose members included Benjamin Rush, John Redman, John Morgan, Adam Kuhn, and others, not only brought the Edinburgh model for medical pedagogy across the Atlantic, but also disseminated Scottish stadial theories of development, which they applied to their study of the natural history and medical practices of Native Americans and slaves. In doing so, these physicians developed theories about the relationship between civilization, historical progress and the practice of medicine. Exploring this network deepens our understanding of the transnational intellectual geography of the eighteenth and early nineteenth century British World. This article develops, in relation to Scotland, a current strand of scholarship that maps the colonial and global contexts of Enlightenment thought.


2013 ◽  
Vol 4 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Zs. Kun ◽  
I. G. Gyurika

Abstract The stone products with different sizes, geometries and materials — like machine tool's bench, measuring machine's board or sculptures, floor tiles — can be produced automatically while the manufacturing engineer uses objective function similar to metal cutting. This function can minimise the manufacturing time or the manufacturing cost, in other cases it can maximise of the tool's life. To use several functions, manufacturing engineers need an overall theoretical background knowledge, which can give useful information about the choosing of technological parameters (e.g. feed rate, depth of cut, or cutting speed), the choosing of applicable tools or especially the choosing of the optimum motion path. A similarly important customer's requirement is the appropriate surface roughness of the machined (cut, sawn or milled) stone product. This paper's first part is about a five-month-long literature review, which summarizes in short the studies (researches and results) considered the most important by the authors. These works are about the investigation of the surface roughness of stone products in stone machining. In the second part of this paper the authors try to determine research possibilities and trends, which can help to specify the relation between the surface roughness and technological parameters. Most of the suggestions of this paper are about stone milling, which is the least investigated machining method in the world.


2011 ◽  
Vol 5 (2) ◽  
pp. 297-332
Author(s):  
Kate Zebiri

This article aims to explore the Shaykh-mur?d (disciple) or teacher-pupil relationship as portrayed in Western Sufi life writing in recent decades, observing elements of continuity and discontinuity with classical Sufism. Additionally, it traces the influence on the texts of certain developments in religiosity in contemporary Western societies, especially New Age understandings of religious authority. Studying these works will provide an insight into the diversity of expressions of contemporary Sufism, while shedding light on a phenomenon which seems to fly in the face of contemporary social and religious trends which deemphasize external authority and promote the authority of the self or individual autonomy.


2010 ◽  
Vol 4 (1) ◽  
pp. 85-93
Author(s):  
Timothy Beal

This article reads between two recent explorations of the relationship between religion, chaos, and the monstrous: Catherine Keller’s Face of the Deep and Author's Religion and Its Monsters. Both are oriented toward the edge of chaos and order; both see the primordial and chaotic as generative; both pursue monstrous mythological figures as divine personifications of primordial chaos; both find a deep theological ambivalences in Christian and Jewish tradition with regard to the monstrous, chaotic divine; both are critical of theological and cultural tendencies to demonize chaos and the monstrous; and finally, both read the divine speech from the whirlwind in the book of Job as a revelation of divine chaos. But whereas one sees it as a call for laughter, a chaotic life-affirming laughter with Leviathan in the face of the deep, the other sees it as an incarnation of theological horror, leaving Job and the reader overwhelmed and out-monstered by God. Must it be one way or the other? Can laughter and horror coincide in the face of the deep?


2020 ◽  
Vol 2 (8) ◽  
pp. 101-110
Author(s):  
N. N. ILYSHEVA ◽  
◽  
E. V. KARANINA ◽  
G. P. LEDKOV ◽  
E. V. BALDESKU ◽  
...  

The article deals with the problem of achieving sustainable development. The purpose of this study is to reveal the relationship between the components of sustainable development, taking into account the involvement of indigenous peoples in nature conservation. Climate change makes achieving sustainable development more difficult. Indigenous peoples are the first to feel the effects of climate change and play an important role in the environmental monitoring of their places of residence. The natural environment is the basis of life for indigenous peoples, and biological resources are the main source of food security. In the future, the importance of bioresources will increase, which is why economic development cannot be considered independently. It is assumed that the components of resilience are interrelated and influence each other. To identify this relationship, a model for the correlation of sustainable development components was developed. The model is based on the methods of correlation analysis and allows to determine the tightness of the relationship between economic development and its ecological footprint in the face of climate change. The correlation model was tested on the statistical materials of state reports on the environmental situation in the Khanty-Mansiysk Autonomous Okrug – Yugra. The approbation revealed a strong positive relationship between two components of sustainable development of the region: economy and ecology.


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