scholarly journals Recent Advances in Hollow Cathode Technology for Plasma-Enhanced ALD—Plasma Surface Modifications for Aluminum and Stainless-Steel Cathodes

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1506
Author(s):  
Kenneth Scott Alexander Butcher ◽  
Vasil Georgiev ◽  
Dimka Georgieva
Keyword(s):  
Stainless Steel ◽  
Surface Modification ◽  
Hollow Cathode ◽  
Atomic Layer ◽  
Plasma Surface ◽  
Metal Work Function ◽  
Gas Plasma ◽  
Lower Oxygen ◽  
Order Of Magnitude ◽  
Langmuir Probe Measurements

Recent designs have allowed hollow cathode gas plasma sources to be adopted for use in plasma-enhanced atomic layer deposition with the benefit of lower oxygen contamination for non-oxide films (a brief review of this is provided). From a design perspective, the cathode metal is of particular interest since—for a given set of conditions—the metal work function should determine the density of electron emission that drives the hollow cathode effect. However, we found that relatively rapid surface modification of the metal cathodes in the first hour or more of operation has a stronger influence. Langmuir probe measurements and hollow cathode electrical characteristics were used to study nitrogen and oxygen plasma surface modification of aluminum and stainless-steel hollow cathodes. It was found that the nitridation and oxidation of these metal cathodes resulted in higher plasma densities, in some cases by more than an order of magnitude, and a wider range of pressure operation. Moreover, it was initially thought that the use of aluminum cathodes would not be practical for gas plasma applications, as aluminum is extremely soft and susceptible to sputtering; however, it was found that oxide and nitride modification of the surface could protect the cathodes from such problems, possibly making them viable.

Combined plasma surface modification of austenitic stainless steel for bipolar plates

2017 ◽  
Vol 328 ◽  
pp. 142-151 ◽  
Author(s):  
K. Nikolov ◽  
K. Bunk ◽  
A. Jung ◽  
J.W. Gerlach ◽  
P. Kaestner ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Surface Modification ◽  
Austenitic Stainless Steel ◽  
Bipolar Plates ◽  
Plasma Surface Modification ◽  
Plasma Surface

scholarly journals On the Microstructures and Fatigue Behaviors of 316L Stainless Steel Metal Injection Molded with Gas- and Water-Atomized Powders

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 893 ◽  
Author(s):  
Yongyun Zhang ◽  
Ensheng Feng ◽  
Wei Mo ◽  
Yonghu Lv ◽  
Rui Ma ◽  
...  
Keyword(s):  
Stainless Steel ◽  
316L Stainless Steel ◽  
Fatigue Cracks ◽  
Selective Laser Sintering ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Metal Injection Molding ◽  
Strengthening Effect ◽  
Lower Oxygen ◽  
Order Of Magnitude

316L stainless steel samples are fabricated by metal injection molding using water-atomized and gas-atomized powder with different oxygen contents. The influences of oxygen on the microstructural evolution and fatigue properties of the samples are investigated. The oxygen tends to react with Mn and Si to form oxide particles during sintering. The oxides hamper the densification process and result in decreased sintered density. Moreover, their existence reduces the Mn and Si dissolving into the base metal and compromises the solution strengthening effect. The oxides lead to stress concentration in the tensile and fatigue tests and become the initiation sites of fatigue cracks. After sintering, the samples made from the gas-atomized powder have a much lower oxygen content compared to those made from the water-atomized powder, therefore, exhibiting much better mechanical properties. The tensile strength, yield strength and the elongation of the samples made from the gas-atomized powder are 560 MPa, 205 MPa, and 58%, respectively. Their fatigue lives are about one order of magnitude longer than the samples made from water-atomized powder, and also longer than those fabricated by powder metallurgy and selective laser sintering which were reported in other studies.

Finite Element Simulation on the Distribution of Discharge Gas in Hollow Cathode Plasma

2016 ◽  
Vol 693 ◽  
pp. 1054-1060
Author(s):  
Yi Fang Wen ◽  
Yan Nian Rui ◽  
Hong Wei Wang
Keyword(s):  
Thin Film ◽  
Finite Element ◽  
Surface Modification ◽  
Hollow Cathode ◽  
Fluid Distribution ◽  
Large Area ◽  
Cathode Plasma ◽  
Plasma Surface Modification ◽  
Plasma Surface ◽  
Discharge Gas

The graft polymerization in radio frequency hollow cathode plasma (RFHCP) is suitable for the surface modification of large-area thin film materials. The homogeneity of plasma surface modification of large-area thin film materials has always been paid close attention, and it is also the key factor affecting the industrialized applications of the technique. However, the homogeneity of plasma surface modification is thought to depend greatly on the distribution of discharge gas. In this paper, a finite element model is proposed to discuss the flow of discharge gas in hollow cathode plasma. The concentration distribution of the discharge gas has been discussed by the combination of numerical simulation of fluid distribution and pipe flow theory based on the investigation of the transport property of gas under vacuum. Comparisons between available experiments have also been performed to validate the applicability and practicability of the proposed model.

The Study about the Effect of Work-Piece Space on Copper-Cerium Alloy Case Thickness and Component

2013 ◽  
Vol 803 ◽  
pp. 285-288
Author(s):  
Bo Gao ◽  
Jin Yong Xu ◽  
Wen Yao Luo ◽  
Yi Guang Wang ◽  
Cheng Gao
Keyword(s):  
Stainless Steel ◽  
Hollow Cathode ◽  
Case Depth ◽  
Work Piece ◽  
Plasma Surface ◽  
Glow Plasma

In this paper, the author uses double glow plasma surface metallurgy technology, prepares antibacterial stainless steel with copper-cerium case on its surface, does some research on how work-piece space affects Copper-cerium case thickness and component in the case. According to experiment, we find in the range of 10 mm to 25 mm, copper-cerium case depth firstly increase and then decrease with the distance expands; copper-cerium component first rises and then falls with the work-piece space .When the distance is 15mm, hollow cathode effect forms between two plates, we can obtain ideal copper-cerium alley case.

scholarly journals Influence of Surface Modification on Properties of Stainless Steel Used for Implants / Wpływ Modyfikacji Powierzchni Na Właściwości Stali Nierdzewnej Stosowanej Na Implanty

2015 ◽  
Vol 60 (4) ◽  
pp. 2965-2970 ◽  
Author(s):  
M. Basiaga ◽  
R. Jendruś ◽  
W. Walke ◽  
Z. Paszenda ◽  
M. Kaczmarek ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Surface Modification ◽  
Surface Treatment ◽  
Functional Properties ◽  
Atomic Layer ◽  
Scratch Test ◽  
Mechanical Polishing ◽  
Layer Deposition ◽  
Chemical Passivation ◽  
Stainless Steel 316

The aim of the study was assessment of the influence of stainless steel 316 LVM surface modification on its functional properties. The analyzed steel undergone a surface treatment consisting of the following processes: mechanical polishing, chemical passivation and deposition of Al2O3 layers by Atomic Layer Deposition method. The proposed variant of surface treatment will undoubtedly contribute to improving the functional properties of stainless steel intended for implants. In order to assess functional properties of the steel, electrochemical studies, adhesion (scratch test), wetting angle tests and topography of surface (AFM method) were performed. The obtained results of the study showed clearly that the proposed by the authors way of surface treatment including: mechanical polishing, chemical passivation and deposition of Al2O3 layer by means of the ALD method effectively improves the corrosion resistance of stainless steel.

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