scholarly journals Review on different welding techniques of Titanium and its alloys

2020 ◽  
pp. 286-294
Author(s):  
Malis Krishna Prasad Reddy ◽  
Ramawath Prashanth Naik ◽  
Madhukar Samatham ◽  
Chelluboina Harish Kumar
Keyword(s):  
Creep Property ◽  
Notch Toughness ◽  
Aerospace Engineering ◽  
Dissimilar Metals ◽  
Nuclear Engineering ◽  
High Tendency ◽  
Atmospheric Air ◽  
Welding Defects ◽  
Good Biocompatibility ◽  
Very High

Titanium and its alloys are the most commonly and most widely used due to its significant properties like good biocompatibility , good tensile strength , low density , and good creep property up to 300 degrees centigrade .It is used in the major engineering fields like civil engineering , nuclear engineering , aerospace engineering etc., but the welding of titanium in industries has become a major challenging objective to the fabricators because, a lot of titanium alloys are found in the form of sheets , problem arises mainly while fabricating the space crafts , marine bodies , jet engine’s where the ends are need to be joined through welding with a similar or dissimilar metals and titanium possess to have a very high tendency to oxidize at higher temperatures .As Titanium becomes highly reactive to chemicals in its environment. In regular air, welding contaminates titanium with carbides, nitrides, and oxides that make the weld and HAZ (heat-affected zone) brittle, resulting in lower fatigue resistance and notch toughness. so, In order to get a perfect weld it is very important to avoid the molten metal to the exposure of atmospheric air , which will lead to porosity and results into a poor welding conditions or welding defects. This paper reviews the different methods of welding titanium and its alloys.

scholarly journals Critical review on different burnishing processes of Ti-6Al-4V Alloy

2020 ◽  
pp. 266-273
Author(s):  
Madhukar Samatham ◽  
Ashok Kumar U ◽  
Laxminarayana Pappula
Keyword(s):  
Surface Finish ◽  
Power Loss ◽  
Creep Property ◽  
Aerospace Engineering ◽  
Low Density ◽  
Nuclear Engineering ◽  
Cryogenic Burnishing ◽  
Lathe Machine ◽  
Titanium Material ◽  
Good Biocompatibility

Titanium and its alloys are the most commonly and most widely used due to its significant properties like good biocompatibility , good tensile strength , low density , and good creep property up to 300 degrees centigrade .It is used in the major engineering fields like civil engineering , nuclear engineering , aerospace engineering etc. Surface finish of the titanium material plays a prominent role in influencing its functional characteristics like wear resistance, fatigue strength, corrosion resistance and power loss due to friction. In normal machining methods like turning, milling or even classical grinding can’t meet the desired surface finish. To overcome this one of the method employed is burnishing, which is very simple and effective method for improvement in surface finish and can be carried out on lathe machine. The latest innovate technique used in the burnishing is the cryogenic burnishing in which the liquid nitrogen is supplied as the coolant. This work deals with study of different burnishing processes of titanium alloy Ti-6Al-4V.

USS STRUX

Alloy Digest ◽  
1960 ◽  
Vol 9 (7) ◽  
Keyword(s):  
United States ◽  
Tensile Strength ◽  
High Strength ◽  
Notch Toughness ◽  
United States Steel Corporation ◽  
Treated Condition ◽  
High Strength Level ◽  
Heat Treated ◽  
Heat Treated Condition ◽  
Very High

Abstract USS STRUX is an alloy steel designed for use in the heat treated condition at a minimum tensile strength of 280,000 psi. At this very high strength level the steel has adequate ductility and notch toughness for critical applications. This datasheet provides information on composition and tensile properties. Filing Code: SA-100. Producer or source: United States Steel Corporation.

scholarly journals Randomised trial on clinical performances and biocompatibility of four high-flux hemodialyzers in two mode treatments: hemodialysis vs post dilution hemodiafiltration

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Marion Morena ◽  
Caroline Creput ◽  
Mouloud Bouzernidj ◽  
Annie Rodriguez ◽  
Lotfi Chalabi ◽  
...  
Keyword(s):  
Primary Outcome ◽  
Randomised Trial ◽  
High Flux ◽  
Β2 Microglobulin ◽  
Inflammatory Parameters ◽  
Large Size ◽  
Significant Difference ◽  
Good Biocompatibility ◽  
Very High ◽  
Solute Clearance

AbstractThis prospective multicenter randomized comparative cross-over trial aimed at evaluating the influence of hemodialysis vs post-dilution hemodiafiltration with high-flux dialyzers in solute clearance and biocompatibility profile. 32 patients were sequentially dialyzed with Leoceed-21HX, Polypure-22S+, Rexsys-27H and VIE-21A. Primary outcome was β2-microglobulin removal. Secondary outcomes were (i) extraction of other uremic solutes (ii) parameters of inflammation and nutrition and (iii) comparative quantification of perdialytic albumin losses (using total ‘TDC’ vs partial ‘PDC’ collection of dialysate). Significant increases in removal rates of β2-microglobulin (84.7 ± 0.8 vs 71.6 ± 0.8 mg/L), myoglobin (65.9 ± 1.3 vs 38.6 ± 1.3 µg/L), free immunoglobulin light chains Kappa (74.9 ± 0.8 vs 55.6 ± 0.8 mg/L), β-trace protein (54.8 ± 1.3 vs 26.8 ± 1.4 mg/L) and orosomucoid (11.0 ± 1.1 vs 6.0 ± 1.1 g/L) but not myostatin (14.8 ± 1.5 vs 13.0 ± 1.5 ng/mL) were observed in HDF compared to HD when pooling all dialyzers. Rexsys and VIE-A use in both HD and HDF subgroups was associated to a better removal of middle/large-size molecules compared to Leoceed and Polypure, except β2-microglobulin for Rexsys. Inflammatory parameters were unchanged between dialyzers without any interaction with dialysis modality. Mean dialysate albumin loss was comparable between TDC and PDC (1.855 vs 1.826 g/session for TDC and PDC respectively). In addition, a significant difference in albumin loss was observed between dialyzers with the highest value (4.5 g/session) observed using Rexsys. Use of all dialyzers was associated with good removals of the large spectrum of uremic toxins tested and good biocompatibility profiles, with an additional gain in removal performances with HDF. Larger surface area, thinner wall and resultant very high ultrafiltration coefficient of Rexsys should be taken into account in its clear performance advantages.

scholarly journals THE IMPACT OF COVID-19 QUARANTINE MEASURES ON THE LEVEL OF AIR POLLUTION IN THE SHCHUCHINSK-BOROVSKAYA RESORT AREA

2021 ◽  
Author(s):  
Maikanov Balgabay ◽  
Auteleeva Laura
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Sulfur Dioxide ◽  
Maximum Permissible Concentration ◽  
Atmospheric Air ◽  
Standard Index ◽  
High Degree ◽  
The Impact ◽  
Very High

In this study, changes in air quality were quantified before and during the introduction of COVID-19 quarantine measures in the Shchuchinsk-Borovskaya resort area. During 2020, there were only 49 resolutions "On strengthening restrictive quarantine measures in the territory of the Akmola region"on the territory of the resort zone. The maximum permissible concentration of sulfur dioxide in the atmospheric air has been exceeded. We have revealed that in the entire territory of the resort area for 2018-2019. atmospheric air pollution, according to the standard index, was elevated and high (3.38 to 6.4), according to the highest frequency (16.6 to 100%), there was a very high degree of pollution, and in 2020, the indicators of the standard index and the highest frequency were within the norm.

scholarly journals Mechanical Properties of Additively Manufactured Thermoplastic Polyurethane (TPU) Material Affected by Various Processing Parameters

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3010
Author(s):  
Tao Xu ◽  
Wei Shen ◽  
Xiaoshan Lin ◽  
Yi Min Xie
Keyword(s):  
Mechanical Properties ◽  
Medical Devices ◽  
Thermoplastic Polyurethane ◽  
Critical Factor ◽  
Processing Parameters ◽  
Aerospace Engineering ◽  
Post Processing ◽  
Build Orientation ◽  
Good Biocompatibility ◽  
Material Tests

Thermoplastic polyurethane (TPU) is a polymer material that has high ductility, good biocompatibility and excellent abrasion resistance. These properties open a pathway to manufacturing functional TPU parts for applications in various fields such as aerospace engineering, medical devices and sports equipment. This study aims to investigate the mechanical properties of additively manufactured TPU material affected by three different processing parameters, including build orientation, mix ratio of the new and reused powders and post-processing. A series of material tests are conducted on TPU dumb-bell specimens. It is found that the mix ratio of the new powder is the most critical factor in improving the mechanical properties of the printed TPU parts. Compared to reused powder, new powder has better particle quality and thermal properties. Besides, build orientation is also a very important factor. TPU parts printed in flat and on-edge orientations show better tensile strength and deformability than those printed in upright orientation. In addition, post-processing is found to significantly enhance the deformability of TPU parts.

Considerations for Requiring Intermediate Stress Relief (ISR) for All Weld Types on 2 1/4 Cr-1 Mo-V Reactors

2010 ◽  
Author(s):  
Cathleen Shargay ◽  
Karly Moore ◽  
Timothy D. Breig ◽  
Les P. Antalffy ◽  
Michael M. Basic
Keyword(s):  
Heat Treatment ◽  
Postweld Heat Treatment ◽  
Stress Relief ◽  
Welding Defects ◽  
Before And After ◽  
Asme Code ◽  
Brittle Fractures ◽  
The Cost ◽  
Postweld Heat ◽  
Very High

As an industry consensus, API 934-A is an excellent recommended practice on the materials and fabrication requirements for Cr-Mo reactors. However, it is cautious and somewhat vague on the topic of Intermediate Stress Relief (ISR) versus Dehydrogenation Heat Treatment (DHT) for the different types of welds — which reflects the industry’s varying practices. For the advanced steels, API 934-A states that DHT should only be used with Purchaser approval, and that it should not be used on restrained welds such as nozzle welds. As a result, it is common for a DHT to be permitted on longitudinal and circumferential seams to achieve the cost and schedule savings, and ISR is used for nozzle welds. There are risks to the fabricator however, as the welds remain extremely brittle after DHT (the toughness is restored after postweld heat treatment {PWHT}, and at intermediate levels after ISR), and welding defects that are acceptable per ASME Code criterias can lead to brittle fractures during subsequent fabrication steps. The costs of the repairs and delays can then be very high, especially if the cracking is not detected until after PWHT. This paper shows the risks of acceptable defects causing brittle fractures by fracture mechanics calculations, and presents some case histories of cracking. The relative costs of ISR versus DHT, versus repairs before and after PWHT are also reviewed.

scholarly journals Forensic Engineering Analysis Of Copper/Brass Contacts

2001 ◽  
Vol 18 (2) ◽  
Author(s):  
Roger L. Owens
Keyword(s):  
High Resistance ◽  
Ignition Temperature ◽  
Progressive Failure ◽  
Dissimilar Metals ◽  
Light Weight ◽  
Engineering Analysis ◽  
Contact Points ◽  
Forensic Engineering ◽  
Electrical Connections ◽  
Very High

A Great Many Articles Have Been Written About The Phenomena Of High Resistance Electrical Connections. These Articles Both Suggest And Acknowledge That In The Presence Of Combustible Materials, Inferior Electrical Connections Can Cause A Fire. In An Attempt To Explain The Mechanics Of A Failure At An Electrical Connection, The Authors Discuss Loose Connections, Dissimilar Metals At The Connection, Oxidation At The Contact Points And A Host Of Other Variables. A Thorough Review Of Forensic Publications Provides Very Little Information About Copper To Brass Failures Even Though Failures Involving Connections Between Other Conductive Metals Are Discussed In Great Detail. Copper And Brass Have A Very High Conductivity, Are Ductile, Resist Oxidation, And Are Generally More Resistive To Progressive Failure As Compared To Other Conductors When The Mechanical Connection Is Inferior. Further, The Characteristics Of Copper And Brass Make It Difficult To Reproduce Connection Failures In The Laboratory. This Paper Presents Data From Laboratory Experimentation Where Localized Temperatures At Brass To Copper Connections Escalated Above The Ignition Temperature Of Light Weight Combustibles. Copper To Brass Connections Can Fail And The Result Can Result In A Fire.

scholarly journals Interaction of Th(IV), Pu(IV) and Fe(III) with ferritin protein: how similar?

2022 ◽  
Vol 29 (1) ◽  
Author(s):  
Cyril Zurita ◽  
Satoru Tsushima ◽  
Pier Lorenzo Solari ◽  
Aurélie Jeanson ◽  
Gaëlle Creff ◽  
...  
Keyword(s):  
Oxidation State ◽  
Experimental Conditions ◽  
Ionic Radii ◽  
High Tendency ◽  
Ferric Oxyhydroxide ◽  
Main Protein ◽  
Horse Spleen Ferritin ◽  
Fe Storage ◽  
Very High ◽  
Actinide Elements

Ferritin is the main protein of Fe storage in eukaryote and prokaryote cells. It is a large multifunctional, multi-subunit protein consisting of heavy H and light L subunits. In the field of nuclear toxicology, it has been suggested that some actinide elements, such as thorium and plutonium at oxidation state +IV, have a comparable `biochemistry' to iron at oxidation state +III owing to their very high tendency for hydrolysis and somewhat comparable ionic radii. Therefore, the possible mechanisms of interaction of such actinide elements with the Fe storage protein is a fundamental question of bio-actinidic chemistry. We recently described the complexation of Pu(IV) and Th(IV) with horse spleen ferritin (composed mainly of L subunits). In this article, we bring another viewpoint to this question by further combining modeling with our previous EXAFS data for Pu(IV) and Th(IV). As a result, the interaction between the L subunits and both actinides appears to be non-specific but driven only by the density of the presence of Asp and Glu residues on the protein shell. The formation of an oxyhydroxide Th or Pu core has not been observed under the experimental conditions here, nor the interaction of Th or Pu with the ferric oxyhydroxide core.

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