Application of Eddy Currents in Processed Materials Structural Evaluation

2012 ◽  
Vol 730-732 ◽  
pp. 715-720
Author(s):  
Telmo G. Santos ◽  
João Faria ◽  
Pedro Vilaça ◽  
R.M. Miranda
Keyword(s):  
Electrical Conductivity ◽  
Solid State ◽  
Eddy Currents ◽  
Microstructural Analysis ◽  
Structural Features ◽  
Crystal Defects ◽  
Electrical Currents ◽  
Friction Stir ◽  
Characterization Technique ◽  
Physical Phenomena

Eddy currents are based on electromagnetic induction and analysis of electrical currents on conductive materials. This method is used for thickness measurements, corrosion and defects detection, electrical conductivity and magnetic permeability measurements. Recently, it has been exploited as a materials characterization technique, namely in solid state welding, since, compared to hardness, it is based in distinct physical phenomena. Electrical conductivity is controlled by electronic mobility, while hardness depends on crystal defects and thus a scale factor exists. This paper presents results of this characterization technique applied to multipass solid state friction stir processing (FSP) of AA1100 alloy. These results were compared to microstructural analysis and hardness measurements and show that eddy current is a feasibly, reliable and expedite technique to characterize processed materials. The electrical conductivity measured by eddy currents, maps more precisely structural features, while hardness does not. Measurement of electrical conductivity field suggests having potential to constitute an alternative and/or complement to hardness evaluation with the further advantage of being a non-destructive method.

A Non-Conventional Technique for Evaluating Welded Joints Based on the Electrical Conductivity

2014 ◽  
Vol 611-612 ◽  
pp. 671-676 ◽  
Author(s):  
Telmo G. Santos ◽  
Gonçalo Sorger ◽  
Pedro Vilaça ◽  
R.M. Miranda
Keyword(s):  
Electrical Conductivity ◽  
Solid State ◽  
Welded Joints ◽  
Conventional Technique ◽  
Carbon Steels ◽  
Fusion Welding ◽  
Friction Stir ◽  
Wide Range ◽  
Welding Processes ◽  
Non Destructive

Recent studies showed that electrical conductivity is a valuable technique to identify the different zones of solid-state welded joints with a good correlation with the microstructure and hardness. This is a relevant result since this technique is expedite and, in some cases, non destructive. The concept was applied to other welding processes as the ones involving fusion and to a wide range of materials. For this, a comprehensive study was performed using friction stir welding, tungsten inert gas (TIG) and gas metal arc (MAG) welding processes in either bead on plate or butt joints in: carbon steel, magnesium and titanium. Eddy current non-destructive testing (NDT) was used to measure the electrical conductivity at different depths in transverse sections of the processed materials. The obtained profiles were compared to the hardness profiles in the same sections. As a result, a good correlation was observed in most materials welded by solid state and by fusion processes. The variation of the electrical conductivity closely follows the one detected in the hardness. Another interesting conclusion is that, even for fusion welding of carbon steels, the technique has potential to complement the hardness measurements and microstructural observations, allowing to identify the distinct zones of welds in materials commonly used in industry.

Friction Stir Welding of Steel Structures - A Brief Review

2021 ◽  
Vol 890 ◽  
pp. 105-119
Author(s):  
Mihai Octavian Crăcănel ◽  
Eduard Laurențiu Niţu ◽  
Daniela Monica Iordache
Keyword(s):  
Friction Stir Welding ◽  
Solid State ◽  
Steel Structures ◽  
Scientific Work ◽  
Industrial Applications ◽  
Technological Parameters ◽  
Friction Stir ◽  
Full Development ◽  
Main Development ◽  
Physical Phenomena

Friction stir welding is a relatively new technique, developed in 1991, which, due to its advantages, has been continuously developed and applied to industrial applications. This process of joining materials in solid state is an extremely complex one because of the physical phenomena that occur during the process, which makes the research still in full development. The paper presents an analysis of recent scientific work on the use of the FSW process for the joining of steel structures. Thus, the types of steels and merged structures, the processes used and the technological parameters used are analyzed. On the basis of this analysis, the main conclusions of the studied works are summarized and the main development directions for research on the FSW process of steel structures are identified.

Effects of tool pin profile on tensile and wear behaviour of friction stir welded AA6101-T6 and AA1350 alloys

2020 ◽  
Vol 117 (5) ◽  
pp. 503
Author(s):  
R. Ashok kumar ◽  
R. Muneeswaran ◽  
M. Saravana Mohan ◽  
Sathish Rengarajan ◽  
G.R. Raghav ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Friction Stir Welding ◽  
Solid State ◽  
Frictional Heat ◽  
Wear Behaviour ◽  
Base Metals ◽  
High Electrical Conductivity ◽  
Wear Properties ◽  
Friction Stir ◽  
Tool Pin

In Friction Stir Welding (FSW) technique, hard rotating tool with specially profiled pin is plunged into base metals and traversed along the interface of the plates, generating the frictional heat and plasticizing the base metals. This leads to flow of materials and makes solid state joint. AA6101-T6 and AA1350 alloys are widely applied in electrical bus bars, because of their high electrical conductivity. In this present work, these two alloys are joined by varying the pin profile of the tools as circular, triangular, square and hexagonal. Of these four joints, the joint fabricated by circular pin profiled tool exhibits poor tensile and wear properties whereas hexagonal pin profiled tool exhibits better tensile and wear properties. This is due to the volume defects and grain refinement at stirred zone.

Microstructure, mechanical properties, and electrical conductivity of the solid-state recycled pure copper machining chips

2020 ◽  
pp. 146442072095736
Author(s):  
Reza Abdi Behnagh ◽  
Hadi Abdollahi ◽  
Mohsen Agha Mohammad Pour ◽  
Bahman Shahbazi
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Solid State ◽  
Pure Copper ◽  
Economic Value ◽  
Consolidation Process ◽  
Friction Stir ◽  
New Methods ◽  
Recycling Technique ◽  
State Form

The demand for new methods to reduce CO2 emission by reusing metal scrap has increased recently. This study deals with a new recycling technique utilizing a friction stir consolidation process. In this work, copper was directly recycled from machining chips in the solid-state form without any remelting to reduce environmental pollution and to increase the economic value of the waste material. During the process, copper chips were loaded into the chamber; then, a rotating tool was plunged into the chips at a specified rotational speed and feed rate. Due to the huge amount of heat generated, the softened material was compressed and synthesized to form a consolidated part. Microstructure, mechanical properties, and electrical conductivity of the finished samples were evaluated and compared with as-received material. Also, a numerical model was implemented to predict the evolution of the main field variables, including temperature, density, and strain.

Synthesis of New Chalcogenide Materials. The Novel One-Dimensional Semiconductor K4 Ti3 S14

1987 ◽  
Vol 97 ◽  
Author(s):  
Steven A. Sunshine ◽  
Doris Kang ◽  
James A. Ibers
Keyword(s):  
Electrical Conductivity ◽  
Solid State ◽  
Alkali Metal ◽  
The Novel ◽  
Conductivity Measurements ◽  
One Dimensional ◽  
General Utility ◽  
Solid State Materials ◽  
Chalcogenide Materials

ABSTRACTThe use of A2 Q/Q melts (A - alkali metal, Q - S or Se) for the synthesis of new one-dimensional solid-state materials is found to be of general utility and is illustrated here for the synthesis of K4 Ti3 SI4. Reaction of Ti metal with a K2 S/S melt at 375°C for 50 h affords K4 Ti3 SI4. The structure possesses one-dimensional chains of seven and eightcoordinate Ti atoms with each chain isolated from all others by surrounding K atoms. There are six S-S pairs (dave - 2.069(3) Å) so that the compound is one of TiIV and may be described as K4 [Ti3 (S)2 (S2)6]. Electrical conductivity measurements indicate that this material is a semiconductor.

Equilibrium and Kinetic Properties of Minerals

1998 ◽  
Vol 62 (5) ◽  
pp. 581-583
Author(s):  
Simon A. T. Redfern
Keyword(s):  
Solid State ◽  
Statistical Mechanics ◽  
Structural Features ◽  
Atomic Scale ◽  
Kinetic Properties ◽  
Computational Power ◽  
Equilibrium Thermodynamics ◽  
Bulk Properties ◽  
Scale Characteristics ◽  
Number Of Publications

How can the equilibrium and non-equilibrium thermodynamics of minerals be understood from their atomic-scale structural features? How can they be predicted, simply from models for the forces between atoms? Advances in analytical theory, statistical mechanics, experimental solid-state science, computational power, and the sophistication of a mineralogical approach that brings all of these together, means that these questions, once imponderable, are now realistically tractable. These questions have been exercising the minds of mineralogists over the last decade or so, and have motivated many developments in the science. Acting as way-markers along the path, there are a number of publications which have followed from meetings where these questions have been addressed. It is now twelve years since the publication of Microscopic to Macroscopic, an edition of Reviews in Mineralogy (Kieffer and Navrotsky, 1985) that sought to identify the fundamental controls on the bulk properties of minerals in terms of their atomic-scale characteristics.

scholarly journals Redox-State Dependent Spectroscopic Properties of Porous Organic Polymers Containing Furan, Thiophene, and Selenophene

2017 ◽  
Vol 70 (11) ◽  
pp. 1227 ◽  
Author(s):  
Carol Hua ◽  
Stone Woo ◽  
Aditya Rawal ◽  
Floriana Tuna ◽  
James M. Hook ◽  
...  
Keyword(s):  
Solid State ◽  
Redox State ◽  
Spectroscopic Properties ◽  
Structural Features ◽  
Organic Polymers ◽  
Stimuli Responsive ◽  
Porous Organic Polymers ◽  
Paramagnetic Resonance ◽  
Responsive Materials ◽  
State Dependent

A series of electroactive triarylamine porous organic polymers (POPs) with furan, thiophene, and selenophene (POP-O, POP-S, and POP-Se) linkers have been synthesised and their electronic and spectroscopic properties investigated as a function of redox state. Solid state NMR provided insight into the structural features of the POPs, while in situ solid state Vis-NIR and electron paramagnetic resonance spectroelectrochemistry showed that the distinct redox states in POP-S could be reversibly accessed. The development of redox-active porous organic polymers with heterocyclic linkers affords their potential application as stimuli responsive materials in gas storage, catalysis, and as electrochromic materials.

A State-of-the-Art Review on Solid-State Metal Joining

2018 ◽  
Author(s):  
Wayne Cai ◽  
Glenn Daehn ◽  
Anupam Vivek ◽  
Jingjing Li ◽  
Haris Khan ◽  
...  
Keyword(s):  
Solid State ◽  
State Of The Art ◽  
Dissimilar Materials ◽  
Process Conditions ◽  
Discussion Section ◽  
Friction Stir ◽  
Process Characterization ◽  
Rotary Friction Welding ◽  
Impact Welding ◽  
Solid State Joining

This paper aims at providing a state-of-the-art review of an increasingly important class of joining technologies called solid-state welding. Among many other advantages such as low heat input, solid-state processes are particularly suitable for dissimilar materials joining. In this paper, major solid-state joining technologies such as the linear and rotary friction welding, friction stir welding, ultrasonic welding, impact welding, are reviewed, as well as diffusion and roll bonding. For each technology, the joining process is first depicted, followed by the process characterization, modeling and simulation, monitoring/diagnostics/NDE, and ended with concluding remarks. A discussion section is provided after reviewing all the technologies on the common critical factors that affect the solid-state processes such as the joining mechanisms, chemical and materials compatibility, surface properties, and process conditions. Finally, the future outlook is presented.

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