scholarly journals Characteristics of Short-circuiting Transfer in High-speed Oscillating MAG process-Development of Automatic MAG Welding Machine with Arc Sensor for Field Welding of Gas Pipelines (Report 1)-

2005 ◽  
Vol 23 (2) ◽  
pp. 252-258 ◽  
Author(s):  
Shinji KODAMA ◽  
Yasutomo ICHIYAMA ◽  
Yasuyuki IKUNO ◽  
Norimitsu BABA
Keyword(s):  
High Speed ◽  
Process Development ◽  
Mag Welding ◽  
Gas Pipelines ◽  
Welding Machine ◽  
Arc Sensor

Study on Arc and Drop Transfer Behaviors of DCEN MAG Welding

2014 ◽  
Vol 887-888 ◽  
pp. 1290-1293
Author(s):  
Xu Ming Wang ◽  
Qing Xia Bi
Keyword(s):  
Direct Current ◽  
High Speed ◽  
Welding Process ◽  
Mag Welding ◽  
High Speed Camera ◽  
High Current ◽  
Current Electrode ◽  
The Stability

By means of the high speed camera, the arc and drop transfer behaviours of direct current electrode negative MAG welding process are researched. The influences of luminous arc ball on the stability of MAG welding process are analyzed. On this basis, the process interval of DCEN MAG welding is determined. And the influences of wire polarity on wire melting coefficient are compared. By using the shield gas 98%Ar + 2%O2, the stable drop transfer manner can be divided into two kinds: dropwise transfer with low current, and streaming transfer with high current.

Influences of Obstacles Installed in the Container on the Superheated Liquid Boiling

2012 ◽  
Vol 429 ◽  
pp. 62-66 ◽  
Author(s):  
Si Ning Chen
Keyword(s):  
Storage Tank ◽  
High Speed ◽  
Process Development ◽  
Control Measures ◽  
Movement Speed ◽  
Superheated Liquid ◽  
Two Phase ◽  
Microscopic Mechanism ◽  
Boiling Process ◽  
And Control

During the accident mechanism investigation of Boiling Liquid Expanding Vapor Explosion (BLEVE), numerous dada shows that overheated liquid explosive boiling is the main reason and driving force to cause accidents. Research on the micro-process of overheated liquid instant boiling in BLEVE as well as the microscopic mechanism to influence this process development under different device conditions is favorable to seek the preventive and control measures for this accident. In this paper, regarding the mesh obstacle provided inside the storage tank, high-speed camera technology has been utilized to shoot the boiling process during continuous leakage of the storage tank, and the influence of the obstacle on the overheated liquid boiling has been tested and analyzed. It is found out that the boiling process of overheated liquid has been delayed. When the bubbles are rising, the growth process has been suppressed, after passing the obstacle, the movement speed and volume has been decreased, and the upward expansion speed of two-phase flow has also been decreased.

Introduction of new surface geometry to join Ti-6Al-4V and SS304L by friction welding

2020 ◽  
Vol 16 (5) ◽  
pp. 1233-1244
Author(s):  
M. Balasubramanian ◽  
R. Kumar
Keyword(s):  
Friction Welding ◽  
High Speed ◽  
Joint Strength ◽  
Ti Alloy ◽  
Surface Geometry ◽  
Dissimilar Joints ◽  
Content Type ◽  
Welding Machine ◽  
More Care ◽  
Copper Coin

PurposeIn friction welding of dissimilar joint method, few material compositions are not possible to weld effectively. For better dissimilar metal joining in friction welding, the interlayer techniques are used by the third metal to increase the diffusion for suitable metal bonding. The interlayer metals are popularly held by coating, foils, sheet and solid rod form. The coating method needs more care for surface preparation with special coating equipment with high workmanship. In case of foil as intermediate metal, more care is neededfor holding between the metal; most of the time this technique has the possibility of failure by peeling off from the contact surface during high speed rotation with pressure during friction generation.Design/methodology/approachIn this investigation, a copper coin was machined to a suitable size (transition fit) to suit the recess inside the SS rod. The mating surfaces of Cu coin, SS rod and Ti alloy were machined, polished to mirror finish and handled in friction welding machine. The purpose of the transition fit between the coin and SS rod is for holding the same intact before the beginning of the process.FindingsSuccessful joint was achieved with good joint strength at less time. Empirical models were established to fin out the joint strength at any given parameter within the range of investigationResearch limitations/implicationsThe models developed can be used only within the range of investigation considered for experimentation.Practical implicationsThe paper includes implications for the development of a method of joining any dissimilar jointsOriginality/valueIn this investigation, a copper coin was machined to a suitable size (transition fit) to suit the recess inside the SS rod. The mating surfaces of Cu coin, SS rod and Ti alloy were machined, polished to mirror finish and handled in friction welding machine. The purpose of the transition fit between the coin and SS rod is for holding the same intact before the beginning of the process.

scholarly journals A Comprehensive Review of Integrated Hall Effects in Macro-, Micro-, Nanoscales, and Quantum Devices

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4163
Author(s):  
Avi Karsenty
Keyword(s):  
Hall Effect ◽  
High Speed ◽  
Review Paper ◽  
Process Development ◽  
Analytical Models ◽  
Nanoscale Devices ◽  
Comprehensive Review ◽  
Complex Design ◽  
Hall Effects

A comprehensive review of the main existing devices, based on the classic and new related Hall Effects is hereby presented. The review is divided into sub-categories presenting existing macro-, micro-, nanoscales, and quantum-based components and circuitry applications. Since Hall Effect-based devices use current and magnetic field as an input and voltage as output. researchers and engineers looked for decades to take advantage and integrate these devices into tiny circuitry, aiming to enable new functions such as high-speed switches, in particular at the nanoscale technology. This review paper presents not only an historical overview of past endeavors, but also the remaining challenges to overcome. As part of these trials, one can mention complex design, fabrication, and characterization of smart nanoscale devices such as sensors and amplifiers, towards the next generations of circuitry and modules in nanotechnology. When compared to previous domain-limited text books, specialized technical manuals and focused scientific reviews, all published several decades ago, this up-to-date review paper presents important advantages and novelties: Large coverage of all domains and applications, clear orientation to the nanoscale dimensions, extended bibliography of almost one hundred fifty recent references, review of selected analytical models, summary tables and phenomena schematics. Moreover, the review includes a lateral examination of the integrated Hall Effect per sub-classification of subjects. Among others, the following sub-reviews are presented: Main existing macro/micro/nanoscale devices, materials and elements used for the fabrication, analytical models, numerical complementary models and tools used for simulations, and technological challenges to overcome in order to implement the effect in nanotechnology. Such an up-to-date review may serve the scientific community as a basis for novel research oriented to new nanoscale devices, modules, and Process Development Kit (PDK) markets.

A Scientific Approach to the Process Development Bonded Attachments for High-Speed Rotor Application

2000 ◽  
Vol 124 (1) ◽  
pp. 190-195
Author(s):  
R. R. Cairo ◽  
K. A. Sargent
Keyword(s):  
High Speed ◽  
Process Development ◽  
Dead Load ◽  
Stress Concentrations ◽  
Blade Loading ◽  
Pressure Profiles ◽  
Scientific Approach ◽  
Deformable Bodies ◽  
Bond Plane ◽  
Tool Stresses

The quest for increased work per stage of compression to reduce overall gas turbine engine system cost has placed extreme demands on the high-pressure turbine (HPT) system. As an example, the HPT is required to operate at unprecedented levels of AN2 (the product of turbine annulus area and mechanical speed squared) to enable compressor performance goals to be met. The typical approach of mechanically attaching blades via firtree or dovetail configured mechanical attachments, limits rotor speed because of the life limiting broach slots (stress concentrators) in the disk rim. Exacerbating this problem is the fact that the disk lugs, which react the blade loading, impose a dead load. Higher disk speed results in higher blade loading requiring a deeper or wider lug to support the blade. This in turn results in a wider disk bore to support the deeper, dead load lug region. The dilemma is that higher speed results in larger stress concentrations at the rim and a wider disk bore to support the added parasitic rim load. The answer to this dilemma lies in creating an integrally bladed rotor (IBR) in which the blades are integral with the disk. Since typically, for an HPT, the blades are single crystal and the disk equiaxed nickel alloys, the IBR design suggested precludes absolute machining as the fabrication approach. A solution lies in metallurgically bonding the blades to the disk rim. Bonded airfoil attachments have the potential to increase AN2 and component life by 9–10 percent by eliminating broach induced stress concentrations as noted. Moreover, bonded attachments can reduce external rim loading by upward of 15 percent with a corresponding reduction in disk weight. The key to the solution is a controlled, economical process to concurrently join a full complement of HPT blades in a repeatable manner. This paper discusses how a scientific approach and creative design practice can lead to such a process. Three alternative tooling concepts, and one universal tool that allows independent use of two of these concepts, were developed. Tool stresses and deflections, tool load paths, and bond pressure profiles were all quantified through ANSYS finite element analyses and closed-form analytical solutions. Prior experience has shown that joint strength is sensitive to the bond pressure level. Therefore, the tool materials and geometry were iterated upon until the pressure applied to the blade bond plane was as uniform as possible. Since absolute uniformity is elusive when deformable bodies are part of the bond load train, accurately determining the maximum and minimum bond plane pressure is absolutely essential for subsequent joint characterization and design allowable determination. This allows localized working stresses in the designed attachment to be compared to specific, bond pressure driven, allowable strengths rather than an average strength. This paper will show how applying a scientific approach to the development of a critical technology process can reduce both the cost and risk of process development.

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