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A Comparative Study on Ballistic Behaviour of MWCNT / Graphene Reinforced AL6061 Surface Composites Fabricated Via Friction Stir Processing

Magarajan U., Suresh Kumar S.

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

541--550

EN

In this work, a comparative study on the ballistic behaviour of friction stir processed AL6061 targets had been made. Base Metal AL6061 (BM) plates with 25 mm thickness were friction stir processed by adding Multi Walled Carbon Nano Tubes (MWCNT) and Graphene (G), producing AL6061-MWCNT and AL6061-G surface composites. Optical microscopy and microhardness test on BM, AL6061-MWCNT and AL6061-G samples were performed as per the standard procedure. It was noticed that uniform dispersion of ceramic particles and refined grains were obtained for the friction stir processed surface composites. From the microhardness test, it was perceived that friction stir processing had induced strengthening of surface composites, hence increasing the microhardness of AL6061-MWCNT and AL6061-G by ~60.3% and ~73.6% respectively. Also, ballistic experiments were conducted at 680±10 m/s by impacting Ø7.62×51 mm projectiles. AL6063 backing plates were placed to compare the ballistic behaviours AL6061-MWCNT and AL6061-G targets by depth of penetration. It was noted that the depth of penetration of AL6061-MWCNT and AL6061-G targets were 37.81% and 65.84% lesser than the BM target. Further, from the results of Post ballistic microscopy it was observed that the microstructure near and away from the penetration channel edge looks unchanged in BM target. However, the AL6061-MWCNT and AL6061-G targets showed considerable change in their morphology, by forming Adiabatic Shear Bands.

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Effect of SiO2 flux on the depth of penetration, microstructure, texture and mechanical behavior of AA6063 T6 aluminum alloy using activated TIG welding

Kumar Rajiv, Vettivel S. C., Kumar Kansal Harmesh

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 1

art. no. e136215

EN

Activated tungsten inert gas (ATIG) welding has a good depth of penetration (DOP) as compared to the conventional tungsten inert gas (TIG) welding. This paper is mainly focused on ATIG characterization and mechanical behavior of aluminum alloy (AA) 6063-T6 using SiO2 flux. The characterization of the base material (BM), fusion zone (FZ), heat affected zone (HAZ) and, partially melted zone is carried out using the suitable characterization methods. The weld quality is characterized using ultrasonic-assisted non-destructive evaluation. A-scan result confirms that the ATIG welded samples have more DOP and less bead width as compared to conventional TIG. The recorded tensile strength of ATIG with SiO2 is better than the conventional TIG welding. The failure mode is ductile for ATIG welding with larger fracture edges and is brittle in the case of conventional TIG welding.

3

Estimation of the depth of penetration in a plunging hollow jet using artificial intelligence techniques

Bodana D., Tiwari N. M., Ranjan S., Ghanekar U.

Archives of Materials Science and Engineering

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2020

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Vol. 103, nr 2

49--61

EN

Purpose: Experimental investigations assessment and comparison of different classical models and machine learning models employed with Gaussian process regression (GPR) and artificial neural network (ANN) in the estimation of the depth of penetration (Hp) of plunging hollow jets. Design/methodology/approach: In this analysis, a set of data of 72 observations is derived from laboratory tests of plunging hollow jets which impinges into the water pool of tank. The jets parameters like jet length, discharge per unit water depth and volumetric oxygen transfer coefficient (Kla20) are varied corresponding to the depth of penetration (Hp) are estimated. The digital image processing techniques is used to estimate the depth of penetration. The Multiple nonlinear regression is used to establish an empirical relation representing the depth of penetration in terms of jet parameters of the plunging hollow jets which is further compared with the classical equations used in the previous research. The efficiency of MNLR and classical models is compared with the machine learning models (ANN and GPR). Models generated from the training data set (48 observations) are validated on the testing data set (24 observations) for the efficiency comparison. Sensitivity assessment is carried out to evaluate the impact of jet variables on the depth of penetration of the plunging hollow jet. Findings: The experimental performance of machine learning models is far better than classical models however, MNLR for predicting the depth of penetration of the hollow jets. Jet length is the most influential jet variable which affects the Hp. Research limitations/implications: The outcomes of the models efficiency are based on actual laboratory conditions and the evaluation capability of the regression models may vary beyond the availability of the existing data range. Practical implications: The depth of penetration of plunging hollow jets can be used in the industries as well as in environmental situations like pouring and filling containers with liquids (e.g. molten glass, molten plastics, molten metals, paints etc.), chemical and floatation process, wastewater treatment processes and gas absorption in gas liquid reactors. Originality/value: The comprehensive analyses of the depth of penetration through the plunging hollow jet using machine learning and classical models is carried out in this study. In past research, researchers were used the predictive modelling techniques to simulate the depth of penetration for the plunging solid jets only whereas this research simulate the depth of penetration for the plunging hollow jets with different jet variables.

4

Response surface methodology assisted multi-objectiveoptimization of TIG process for 15CDV6 steel

Skariya P. D., Satheesh D. M., Dhas J. E., Chandrasekar G.

Control and Cybernetics

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2018

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Vol. 47, no. 4

465--496

EN

Welding is a way of heating pieces of metal usingelectricity or flame so that they melt and stick together. There aremany kinds of welding processes, such as, for instance, MIG/MAGand MMA welding. However, such welding schemes require moreelectrodes during the process of welding. Hence, this paper intendsto analyse the alternative tungsten inert gas (TIG) welding tech-nology using Response Surface Methodology (RSM), and to identifythe effect of TIG welding process parameters on the weld bead pro-file of 15CDV6 high strength low alloy (HSLA) steel. Moreover, themethodology applied allows for identification of the optimal weld-ing conditions by means of multi-objective optimization using RSMto increase the depth of penetration (DOP) and reduce BW (beadwidth) and heat-affected zone (HAZ) width. The variables takenfor the model-based investigations are: welding current (Wc), torchspeed (Ts), gas flow rate (Gr), torch angle (Ta) and arc gap (Ag).Moreover, the responses taken are DOP, BW and HAZ width. Fur-ther, the results from the proposed model optimisation can be seenas highly beneficial for the rocket-motor hardware program, indus-tries and fabrication of pressure vessels, which are using 15CDV6steel.

5

Visualization of magnetotelluric data with apparent velocity method

Miecznik J., Klityński W.

Geologia / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie

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2010

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T. 36, z. 2

187-202

EN

Magnetotelluric (MT) field data are usually presented as plots of amplitude and phase MT sounding data vs frequency. Visualization of resistivity changes of geoelectric complexes with the use of apparent resistivity and phase curves give qualitative results only. Quantitative interpretation of MT sounding curves is needed to get geoelectric parameters. For a 1D horizontally layered earth, amplitude curves (apparent resistivity curves) and phase curves can be transformed into apparent velocity curves versus depth of EM field penetration into the conducting earth. Apparent velocity curves can be approximated by straight-line segments corresponding to homogeneous geoelectric layer complexes. Each segment of the apparent velocity curve (with a given angle of inclination) is related with the resistivity and thickness of individual geoelectric complexes. For heterogeneous earth (2D or 3D) vertical component of the magnetic field is directly connected with boundary of geo-electric complexes. It can be used to express components of vectors of apparent velocity. For a 1D horizontally layered earth, a vector of apparent velocity has only the vertical component. For heterogeneous earth horizontal components of apparent velocity also are inducted. The angle of inclination of the total vector of velocity and its value depend on the geometry of studied structure.

PL

Podstawową wielkością prezentującą zmiany przewodnictwa elektrycznego górotworu z głębokością jest oporność pozorna jako funkcja częstotliwości pola magnetotellurycznego. Wizualizacja tych zmian, jak również granic struktur geologicznych, przez oporność pozorną ma charakter jedynie jakościowy, dalece przybliżony. Parametry przekroju geoelektrycznego uzyskujemy jedynie przez interpretację ilościową danych pomiarowych. W przypadku przekrojów geoelektrycznych 1D krzywe sondowań magnetotellurycznych możemy przetransformować w krzywe prędkości pozornej jako funkcje głębokości wnikania pola elektromagnetycznego w głąb badanego ośrodka. Krzywe te możemy aproksymować odcinkami linii prostych, a kąty nachylenia poszczególnych odcinków względem osi głębokości i ich punkty przecięcia są ściśle związane z opornościami i miąższościami poszczególnych warstw geoelektrycznych. W przypadku ośrodków niejednorodnych 2D i 3D wielkością bezpośrednio związaną z granicami kompleksów geoelektrycznych jest pionowa składowa pola magnetycznego. Przez tę wielkość możemy wyrazić składowe wektora prędkości pozornej. W obszarach 1D wektor prędkości redukuje się do składowej pionowej, natomiast w obszarach niejednorodnych generują się również składowe poziome. Kąt nachylenia całkowitego wektora prędkości do poziomu i jego długość są ściśle związane z geometrią badanej struktury.

6

Określanie głębokości elementów podziemnych metodą georadarową

Sołtys M.

Geodezja / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie

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2005

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T. 11, z. 1/1

175--182

PL

W pracy podano zasadnicze elementy kształtujące zakres pomiaru głębokości georadarem z uwzględnieniem uwarunkowań obejmujących czynniki instrumentalne i wybrane parametry penetrowanego ośrodka. Wzajemne zależności pomiędzy czynnikami instrumentalnymi i parametrami pomiaru dotyczyły: częstotliwości anteny, rozmiaru i głębokości lokalizowanego obiektu, częstotliwości próbkowania, doboru okna czasowego, prędkości rozchodzenia się fal elektromagnetycznych w badanym ośrodku. Przedstawiono geometryczne zasady określania głębokości obiektów oraz dokonano oceny dokładności przetworzonych radargramów

EN

The paper discusses essential factors influencing the range of depth determination with GPR, including instrument features and chosen parameters of penetrated medium. Interrelations between instrument factors and measurement parameters pertained to: antenna frequency, size and depth of the object to be located, sampling frequency, time window selection and velocity of electromagnetic waves in the penetrated ground. Geometric principles of depth determination are presented and accuracy of processed radargrams is assessed

7

Perspektywy badań magnetotellurycznych w Polsce

Miecznik J., Pepel A.

Geologia / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie

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2003

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T. 29, z. 3--4

219-232

PL

Pięćdziesiąt lat stosowania metody magnetotellurycznej do rozwiązywania różnorodnych zagadnień geologicznych potwierdziło jej prospekcyjną efektywność. Najczęściej magnetotelluryka jest wykorzystywana w zagadnieniach geologii strukturalnej, zwłaszcza w aspekcie poszukiwań złóż węglowodorów, oraz w badaniach podstawowych do oceny własności fizycznych skorupy ziemskiej i jej struktury. Rejestracja niskich częstotliwości wariacji pola elektromagnetycznego umożliwia uzyskanie informacji o własnościach górotworu na znacznych głębokościach. Dlatego też celowe jest włączenie badań magnetotellurycznych do programów sejsmicznych POLONAISE'97 i CELEBRATION'2000. Rejestrując wysokie częstotliwości, możemy metodą magnetotelluryczną kartować przypowierzchniowe struktury i anomalie opornościowe. Do tych celów stosuje się odmianę magnetotelluryki zwaną Controlled Source Audio Frequency Magnetotellurics (CSAMT). Wymagania w zakresie dokładności odtworzenia fizycznych i geometrycznych parametrów górotworu implikują rozwój nowych metod inwersji danych pomiarowych. Można tu wskazać na metodę sieci neuronowych ANN (Artificial Neural Networks).

EN

The effectiveness of the magnetotelluric metod in solving geological problems has been proven for fifty years of its applications. Most often, the magnetotelluric method is applied in structural geology, particularly in hydrocarbon prospecting, and in the basic researches to determine physical properties and the structure of the Earth's crust. Measurement of MT field components over a low-frequency range gives information on the geology at great depth. Therefore, it seems justified to include the magnetotelluric investigations to projects POLONAISE'97 and CELEBRATION'2000. The magnetotelluric measurements over a high-frequency range can be successfully applied to map resistivity anomalies from near-surface geological structures. The Controlled Source Audio Frequency Magnetotellurics (CSAMT) is advantageous in such studies. The needs for high-accuracy reproduction of physical and geometrical parameters of the earth gave risk to the development of new methods of data inversion such as the Artificial Neural Networks (ANN).