Morphological features of the copper surface layer under sliding with high density electric current

2015 ◽  
Author(s):  
V. V. Fadin ◽  
M. I. Aleutdinova ◽  
V. Ye. Rubtsov ◽  
V. A. Aleutdinova
Keyword(s):  
Surface Layer ◽  
Electric Current ◽  
Copper Surface ◽  
Morphological Features ◽  
High Density

The basis of quality of sheep pelts and fur products is morphological features of the skin of sheep

2020 ◽  
pp. 50-57
Author(s):  
I. Dmitrik ◽  
G. Zavgorodnyaya
Keyword(s):  
Mechanical Strength ◽  
Breaking Load ◽  
Hair Follicles ◽  
Morphological Features ◽  
High Density ◽  
Fat Cells ◽  
High Quality ◽  
Histological Features ◽  
Weakened Zone

The morphological and histological features of the skin and wool cover of sheep as the basis for the quality of fur sheep pelts have been studied. The most important properties of sheep pelts (uniformity, thinness and density of wool) are provide the possibility of producing high-quality fur semi-finished products from them. However, the features of the histostructure of fine-wool sheep determine the low mechanical strength of the “facial” layer of skin. As a result, the “front” layer during processing often cracks to the upper border of the reticular layer or even peels off from the latter, making the sheep pelt unsuitable for use on fur products. These defects in fur practice are called “cracking” and “peeling” of the facial layer. They are mainly peculiar to sheep pelts of fine-wooled sheep. In these animals due to the high density and tone of the coat, the roots and hair follicles, root vaginas, secretory departments, excretory ducts of the glands and other structures occupy a significant share of the volume in the thickness of the Pilar layer (up to 25–30 %). The share of fibrous structures remains less volume, and these structures themselves are relatively weakly developed, located loosely and loosely intertwined with each other. The accumulations of fat cells that occur here also cannot be attributed to skin-strengthening elements. In fine-fleece sheep the pilar layer is on average 60 % of the thickness of the dermis. Therefore, more than half of its thickness is a weakened zone. The strength of the “front” layer is not the same in different fine-wool breeds of sheep and in different animals within the breed. For example, the average breaking load for cod of the “front” layer in Soviet Merino pelts is 1,25 kg, and in Precoce is 2,49 kg.

scholarly journals Effect of High Density Electric Current Pulse on Solidification of Cu-37.4 wt.%Pb Monotectic Alloy Melt

2019 ◽  
Vol 26 (1) ◽  
pp. 34-40
Author(s):  
Teng MA ◽  
Guihong GENG ◽  
Xiaosi SUN ◽  
Xi HAO ◽  
Weixin HAO
Keyword(s):  
Wear Resistance ◽  
Electric Current ◽  
Current Pulse ◽  
Metal Cluster ◽  
High Density ◽  
Formation Mechanisms ◽  
Electric Current Pulse ◽  
Monotectic Alloy ◽  
Scanning Calorimetry ◽  
Cluster Theory

The effect of high-density electric current pulse (ECP) on the solidification of Cu-37.4 wt.%Pb monotectic alloy melt was investigated. The microstructure formation mechanisms of ECP were clarified according to liquid metal cluster theory. The results demonstrated that with ECP treatment, the microstructure of Cu-Pb monotectic alloy became finer, the distribution of Pb phase in the matrix was more even and the solute trapping was significantly apparent. Based on the metal liquid cluster theory under ECP, the solid solubility increase result might be due to the salvation clusters increase under the action of pulse current, leading to the binding force increase among solute atoms and solvent atoms. Simultaneously, the aforementioned results were verified through the Differential Scanning Calorimetry (DSC) curve analysis. The results of hardness test, anti-friction test and wear- resistance test show that the ECP can enhance the hardness, improve the properties of anti-friction and wear-resistance of the alloy.

Transient Electrochemical Measurements During Copper Chemical Mechanical Polishing

2003 ◽  
Vol 767 ◽  
Author(s):  
Seung-Mahn Lee ◽  
Wonseop Choi ◽  
Valentin Craciun ◽  
Rajiv K. Singh
Keyword(s):  
Surface Layer ◽  
Reaction Kinetics ◽  
Chemical Mechanical Polishing ◽  
Copper Surface ◽  
Mechanical Polishing ◽  
Electrochemical Measurements ◽  
Chemically Modified ◽  
Modified Surface ◽  
Selection Of ◽  
Modified Surface Layer

AbstractChronoamperometry was used to investigate the reaction/passivation kinetics and thickness of the chemically modified surface layer on the copper during chemical mechanical polishing (CMP). The result showed that the reaction/passivation kinetics and the thickness of the chemically modified surface layer are strongly dependent on the chemistry of CMP slurry in the chemical aspect of CMP and play critical keys in the selection of the chemistry and its concentration. BTA and H2O2 enhanced the passivation kinetics, resulting in thinner layer on the copper surface. In addition, the reaction kinetics increased as pH decreased.

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