Minimization of the Thermal Impact in the Laser Welding of Dissimilar Stainless Steels

Laser welding of dissimilar stainless steels is of interest when mechanical, corrosion, or esthetical requirements impose the use of a high-performance stainless steels, while production-cost requirements prevent using expensive materials in all the parts of a given device. The compromise may lead to the use of the most expensive material in critical areas and the cheapest one in the remaining. Their union can be materialized by laser-pulsed welding. It has intrinsic difficulties derived from the different physical and chemical properties of the steels, and from the need of preserving the protective passive layer. The present work achieves a welded joint with minimum thermal impact by means of laser pulses, capable of preserving the corrosion resistance of the involved stainless steels. The influence of the parameters to define static and dynamic pulses on the material and on the welding regime, keyhole, or heat conduction, is studied. It is used to calculate the overlapping factor of the pulses on the basis of the real dimensions of the melted area. A continuous joint has been built with dynamic pulses. The corrosion resistance of it has been checked showing a similar behavior to the non-heated material. The microstructure of the optimized joint is associated with a reduced HAZ while its mechanical behavior is suitable for its real application.

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Effect of Co-Content on the Corrosion of High Performance Stainless Steels in Simulated Bio-Solutions

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.342-343.585 ◽

2007 ◽

Vol 342-343 ◽

pp. 585-588

Author(s):

Y.R. Yoo ◽

H.H. Cho ◽

S.G. Jang ◽

K.Y. Lee ◽

H.Y. Son ◽

...

Keyword(s):

Corrosion Resistance ◽

Stainless Steels ◽

High Performance ◽

316L Stainless Steel ◽

Impedance Measurement ◽

Cytotoxicity Test ◽

Polarization Test ◽

Acidic Chloride Solution ◽

Acidic Chloride ◽

Test Result

This work focused on the effect of Co content on the corrosion resistance of high pitting resistance equivalent (PRE), super ferritic, Ni-free stainless steels in simulated biosolutions. The effect of Co in Ni-free alloys was evaluated by cytotoxicity test. Anodic polarization test and AC impedance measurement were performed to evaluate the effect of Co on corrosion resistance of the alloys. The cytotoxicity test result for 4 experimental alloys shows non-cytotoxic but mild cytotoxic for 316L stainless steel due to relatively poor corrosion resistance. However, the effect of Co on the passivity was positive in bio-solution but it was negative in acidic chloride solution.

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Tribology of 2D Nanomaterials: A Review

10.20944/preprints202008.0683.v1 ◽

2020 ◽

Author(s):

Paul С. Uzoma ◽

Huan Hu ◽

Mahdi Khadem ◽

Oleksiy V. Penkov

Keyword(s):

High Performance ◽

2D Materials ◽

Chemical Properties ◽

Solid Lubricants ◽

Friction Behavior ◽

Comprehensive Overview ◽

Wear Rates ◽

Recent Developments ◽

Frictional Coefficients ◽

Physical And Chemical

The exfoliation of graphene has opened a new frontier in material science with a focus on 2D materials. The unique thermal, physical and chemical properties of these materials have made them one of the choicest candidates in novel mechanical and nano-electronic devices. Notably, 2D materials such as graphene, MoS2, WS2, h-BN, and Black Phosphorus have shown outstanding lowest frictional coefficients and wear rates, making them attractive materials for high-performance nano-lubricants and lubricating applications. The objective of this work is to provide a comprehensive overview of the most recent developments in the tribological potentials of 2D materials. At first, the essential physical, wear, and frictional characteristics of the 2D materials including their production techniques are discussed. Subsequently, the experimental explorations and theoretical simulations of the most common 2D materials are reviewed in regards to their tribological applications such as their use as solid lubricants and surface lubricant nano-additives. The effects of micro/nano textures on friction behavior are also reviewed. Finally, the current challenges in tribological applications of 2D materials and their prospects are discussed.

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Air

Elements of a Sustainable World ◽

10.1093/oso/9780198827832.003.0004 ◽

2020 ◽

pp. 139-177

Author(s):

John Evans

Keyword(s):

Carbon Capture ◽

High Performance ◽

Internal Combustion Engines ◽

Atmospheric Oxygen ◽

Carbon Capture And Storage ◽

Chemical Properties ◽

Energy Capture ◽

Physical And Chemical ◽

And Storage

The chemical properties of the volatile elements in groups 15 to 18 are outlined, showing how the the periodicicty of the properties of the elements shapes their chemistry. The manufacture of hydrogen and chlorine is described, showing how mercury-free methods have been developed for the latter. The effect of the formation of atmospheric CO2 on atmospheric oxygen content is explained in terms of dissolution in the oceans. Remediation of the exhaust gases from internal combustion engines by catalysts to remove CO2, NOx and carbonaceous particulates is explained. Options for carbon capture and storage by physical and chemical processes are evaluated, and examples provided of these processes in operation. Exploitation of the atmosphere for energy capture using wind turbines has been aided by the development of high performance magnets. The basis of these magnets and the role of rare earth elements is explained.

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Tribology of 2D Nanomaterials: A Review

Coatings ◽

10.3390/coatings10090897 ◽

2020 ◽

Vol 10 (9) ◽

pp. 897

Author(s):

Paul C. Uzoma ◽

Huan Hu ◽

Mahdi Khadem ◽

Oleksiy V. Penkov

Keyword(s):

High Performance ◽

2D Materials ◽

Chemical Properties ◽

Solid Lubricants ◽

Friction Behavior ◽

Comprehensive Overview ◽

Wear Rates ◽

Recent Developments ◽

Frictional Coefficients ◽

Physical And Chemical

The exfoliation of graphene has opened a new frontier in material science with a focus on 2D materials. The unique thermal, physical and chemical properties of these materials have made them one of the choicest candidates in novel mechanical and nano-electronic devices. Notably, 2D materials such as graphene, MoS2, WS2, h-BN and black phosphorus have shown outstanding lowest frictional coefficients and wear rates, making them attractive materials for high-performance nano-lubricants and lubricating applications. The objective of this work is to provide a comprehensive overview of the most recent developments in the tribological potentials of 2D materials. At first, the essential physical, wear and frictional characteristics of the 2D materials including their production techniques are discussed. Subsequently, the experimental explorations and theoretical simulations of the most common 2D materials are reviewed in regards to their tribological applications such as their use as solid lubricants and surface lubricant nano-additives. The effects of micro/nano textures on friction behavior are also reviewed. Finally, the current challenges in tribological applications of 2D materials and their prospects are discussed.

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Carbonaceous Nanomaterials Employed in the Development of Electrochemical Sensors Based on Screen-Printing Technique—A Review

Catalysts ◽

10.3390/catal10060680 ◽

2020 ◽

Vol 10 (6) ◽

pp. 680 ◽

Cited By ~ 5

Author(s):

Alexandra Virginia Bounegru ◽

Constantin Apetrei

Keyword(s):

High Performance ◽

Screen Printing ◽

Electrochemical Sensors ◽

Chemical Properties ◽

Structural Features ◽

Screen Printing Technique ◽

Printing Technique ◽

Carbon Based Nanomaterials ◽

Physical And Chemical ◽

Carbon Based

This paper aims to revise research on carbonaceous nanomaterials used in developing sensors. In general, nanomaterials are known to be useful in developing high-performance sensors due to their unique physical and chemical properties. Thus, descriptions were made for various structural features, properties, and manner of functionalization of carbon-based nanomaterials used in electrochemical sensors. Of the commonly used technologies in manufacturing electrochemical sensors, the screen-printing technique was described, highlighting the advantages of this type of device. In addition, an analysis was performed in point of the various applications of carbon-based nanomaterial sensors to detect analytes of interest in different sample types.

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Effect of Doping of Fe into TiO2 Layer in Fe2O3/TiO2/FTO System for High Performance of Water Splitting

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.93.82 ◽

2014 ◽

Vol 93 ◽

pp. 82-89 ◽

Cited By ~ 3

Author(s):

Aryan Azad ◽

Eul Noh ◽

Kang Seop Yun ◽

Hee June Jeong ◽

Sang Chul Jung ◽

...

Keyword(s):

Metal Oxides ◽

Water Splitting ◽

High Performance ◽

Chemical Properties ◽

Layer By Layer ◽

Energy Problem ◽

Dipping Process ◽

Promising Solution ◽

Physical And Chemical ◽

And Chemical Properties

Hydrogen has unique physical and chemical properties which present benefits and challenges to its successful widespread adoption as a fuel. The photoelectrochemical (PEC) water splitting process with semiconductor metal oxides can be a promising solution to the global energy problem. Although amongst metal oxides Fe2O3 by 2.2 eV bang gap energy is more applicable, for reducing the recombination of electron and hole, Fe was doped into TiO2. In this study Fe2O3/Fe doped TiO2 photocatalysts were compared with Fe-doped TiO2 and TiO2 structures by using layer by layer-self-assemble (LBL-SA) method and dipping process on FTO glass. According to our results the Fe2O3 coated on Fe doped TiO2 /FTO has had best results.

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Stainless Steels for the Citrus Processing Industry

ASME 1960 Citrus Engineering Conference ◽

10.1115/cec1960-0606 ◽

1960 ◽

Author(s):

William T. Tiffin

Keyword(s):

Stainless Steels ◽

Nickel Alloys ◽

Chemical Properties ◽

Operating Conditions ◽

Physical And Chemical Properties ◽

Processing Industry ◽

Corrosion Resistant ◽

Physical And Chemical ◽

And Chemical Properties

A previous paper presented at this Conference in 1955 was concerned principally with corrosion resistant materials for processing citrus products. Although this paper considered several different materials, each of which might prove satisfactory for certain operating conditions, the citrus processing industry has been able to satisfy most of its requirements with a relatively few alloys. These alloys are principally the chromium and the chromium-nickel alloys that are generally classified as stainless steels. This series of steels lends itself to certain basic treatments that have a very significant effect upon the mechanical, physical, and chemical properties. This paper will be concerned principally with these basic treatments and with certain specific treatments for special requirements. Paper published with permission.

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SURFACE STATE EFFECT OF WELDED STAINLESS STEELS ON CORROSION BEHAVIOR

Acta Metallurgica Slovaca ◽

10.12776/ams.v22i1.627 ◽

2016 ◽

Vol 22 (1) ◽

pp. 44 ◽

Cited By ~ 1

Author(s):

Tatiana Liptáková ◽

Martin Lovíšek ◽

Ayman Alaskari ◽

Branislav Hadzima

Keyword(s):

Stainless Steel ◽

Corrosion Resistance ◽

Stainless Steels ◽

Passive Layer ◽

Argon Atmosphere ◽

Oxidation Products ◽

Surface Finishing ◽

Font Size ◽

Steel Aisi ◽

Stainless Steel Aisi

Welding joints of stainless steels are in practice very sensitive places attacked by local corrosion, such as pitting and crevice corrosion, mostly in chloride containing oxidizing environments. It is caused by different oxidation products created on the surface by welding. Corrosion resistance of stainless steels is affected by quality of passive layer (Cr2O3) which created at normal conditions on air. After welding the steels are heated and on the surface are originated different types of oxides which do not have the same protective properties. Resistance to intergranular and pitting corrosion of the welded stainless steels with different surface finishing was tested. Experimental materials are the austenitic stainless steel AISI 316L (welded by the TIG method in inert argon atmosphere with filler) and the ferritic stainless steel AISI CA6-NM (welded by the WPS method in inert argon atmosphere with filler and after welding heat treated). Character of the surface after welding and after finishing by grinding and pickling was evaluated by SEM microscopy, EDX analysis. Corrosion resistance to local forms of corrosion was investigated by electrochemical potentiodynamic test and by exposure tests in chloride solutions. The steel AISI CA6-NM was tested in fluvial water to simulate real operation environment. The evaluation is supported by microscopic analysis. Susceptibility to intergranular corrosion was tested too and results detect the dangerous localities for corrosion attack and show increasing of corrosion resistance by surface treatment.

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High performance graphene embedded rubber composites

RSC Advances ◽

10.1039/c5ra16446j ◽

2015 ◽

Vol 5 (99) ◽

pp. 81707-81712 ◽

Cited By ~ 25

Author(s):

Sung Ho Song ◽

Jung Mo Kim ◽

Kwang Hyun Park ◽

Dong Ju Lee ◽

O.-Seok Kwon ◽

...

Keyword(s):

High Performance ◽

Chemical Properties ◽

Physical And Chemical Properties ◽

Rubber Composites ◽

Synergy Effects ◽

Physical And Chemical ◽

And Chemical Properties

Nano-fillers have provided a big advantage for enhancing the performance of rubber composites through leading the synergy effects in the physical and chemical properties.

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The Evaluation of Different Types of Welding in the Orthodontic Expanders

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1111.56 ◽

2015 ◽

Vol 1111 ◽

pp. 56-61

Author(s):

Camelia Szuhanek ◽

Traian Fleșer

Keyword(s):

Laser Welding ◽

Mechanical Testing ◽

Chemical Properties ◽

Physical And Chemical Properties ◽

Different Types ◽

Laboratory Procedures ◽

Physical And Chemical ◽

And Chemical Properties

The purpose of our paper was to evaluate the effect of different methods of welding in the laboratory procedures of orthodontic expanders. The results of flame, ultrasound, resistance and laser welding methods were evaluated by means of mechanical testing. Metallographic investigations were also used in order to compare the results of different welding testing. A combination of techniques which offer optimum mechanical, biological, physical and chemical properties must be selected. New results are presented in comparison to previous research with published results.

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