scholarly journals Microstructural and spectrophotometric analysis system for metal welding processes

2019 ◽  
Author(s):  
Roberto Filippo ◽  
Pier Paolo Capra ◽  
Manuel Lai ◽  
Maria Giulia Faga
Keyword(s):  
Process Parameters ◽  
Production Systems ◽  
Microstructural Analysis ◽  
Welding Process ◽  
Spectrophotometric Analysis ◽  
Optical Systems ◽  
Source Power ◽  
Analysis System ◽  
Metal Welding ◽  
Welding Processes

We describe an analysis system for some of the most important methods of metal welding, based on the acquisition, study and comparison of the atomic emission spectra (in the range from 250 nm to 830 nm), hyperspectral imaging between 600 nm and 950 nm wavelengths and microstructural analysis. The radiometric measurement system acquires information while the welding process is in progress and acquired data are then compared with those resulting from the subsequent microstructural analysis. It is known that the process parameters like, for example, the source power or its speed over the parts during welding, significantly affect the mechanical properties and quality of the resulting junction like hardness, porosity, presence of cracks or other damages and so on. On the other hand, these properties and, above all, the changes in the joint features due to unwanted variations in the process parameters or in the materials being welded, can be inferred by studying the microstructure. In this sense, a proper correlation between the in situ spectral analysis and the microstructural properties is of paramount importance for controlling and adjusting the parameters during the process. In line with the requirements of Industry 4.0, the system described is a study of the application of metrology in a production line, designed to increase information about the production parameters of mechanical industry without increasing costs and limiting the complexity of additional installations. In this paper we report a series of experiments performed using LASER and TIG welding systems applied to different metals. The comparison between the welding conditions acquired by the optical systems and the methods of structural analysis are the basis of a project to improve production systems and their automation.

scholarly journals Optimisation of process parameters for M.A.G welding of API X70m material to predict tensile strength using Taguchi method

2021 ◽  
Vol 39 (4) ◽  
pp. 1100-1107
Author(s):  
N.S. Akonyi ◽  
O.A. Olugboji ◽  
E.A.P. Egbe ◽  
O. Adedipe ◽  
S.A. Lawal
Keyword(s):  
Tensile Strength ◽  
Process Parameters ◽  
Welding Process ◽  
Statistical Technique ◽  
Engineering Software ◽  
Area Of Interest ◽  
Girth Welding ◽  
Welding Processes ◽  
Selection Of ◽  
Welding Technique

Girth welded replica of API X70M material have been produced on NG-GMAW welding technique. The particular area of interest is to develop suitable girth welding process parameter using NGGMAW. The major aim of the work was to replicate welds having tensile strength between 650 and 680 MPa. Design of Experiment (DoE) method by Taguchi design, using some selected welding processes was adopted. Two process parameters (factors) – arc voltage and wire feed rate, (the variables), and three levels were used. The resultant joint property on tensile strength of X70M pipeline was examined. The targeted mechanical property was achieved by selecting the best process parameters. Their effects on ultimate tensile strength – UTS was analysed using statistical technique – analysis of variance - ANOVA and Signal to Noise - S/N ratio with ‘thebigger-the–better’ value. Validation was done using MIDAS NFX (an FEA) mechanical engineering software. In conclusion, process parameters that affects or influences the girth welded properties of API X70M under field conditions were identified. Guidance for the specifications and selection of processes that could be used in field-welding for optimum performance has been recommended. Keywords: Optimization, Girth-Weld, Process Parameters, Tensile Strength, NG-GMAW

scholarly journals Weldability Investigation and Optimization of Process Variables for TIG-Welded Aluminium Alloy (AA 8006)

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
T. Sathish ◽  
S. Tharmalingam ◽  
V. Mohanavel ◽  
K. S. Ashraff Ali ◽  
Alagar Karthick ◽  
...  
Keyword(s):  
Experimental Design ◽  
Aluminium Alloy ◽  
Process Parameters ◽  
Surface Hardness ◽  
Weight Ratio ◽  
Welding Process ◽  
Tig Welding ◽  
Low Weight ◽  
Superior Corrosion Resistance ◽  
Welding Processes

Aluminium and its alloys play a significant role in engineering material applications due to its low weight ratio and superior corrosion resistance. The welding of aluminium alloy is challenging for the normal conventional arc welding processes. This research tries to resolve those issues by the Tungsten Inert Gas welding process. The TIG welding method is an easy, friendly process to perform welding. The widely applicable wrought aluminium AA8006 alloy, which was not considered for TIG welding in earlier studies, is considered in this investigation. For optimizing the number of experiments, the Taguchi experimental design of L9 orthogonal array type experimental design/plan was employed by considering major influencing process parameters like welding speed, base current, and peak current at three levels. The welded samples are included to investigate mechanical characterizations like surface hardness and strengths for standing tensile and impact loading. The results of the investigation on mechanical characterization of permanent joint of aluminium AA8006 alloy TIG welding were statistically analyzed and discussed. The 3D profilometric images of tensile-tested specimens were investigated, and they suggested optimized process parameters based on the result investigations.

Process Monitoring in Ultrasonic Metal Welding of Lithium Batteries by Power Signals

2021 ◽  
pp. 1-22
Author(s):  
Xinhua Shi ◽  
Lin Li ◽  
Suiran Yu ◽  
Lingxiang Yun
Keyword(s):  
Electric Power ◽  
Process Monitoring ◽  
Lithium Batteries ◽  
Welding Process ◽  
Ultrasonic Metal Welding ◽  
Isometric Transformation ◽  
Welding Defects ◽  
Different Types ◽  
Metal Welding ◽  
Welding Processes

Abstract Ultrasonic metal welding is one of the key technologies in manufacturing lithium batteries, and the welding quality directly determines the battery performance. Therefore, an online welding process monitoring system is critical in identifying abnormal welding processes, detecting defects, and improving battery quality. Traditionally, the peak welding power is used to indicate abnormal process signals in welding process monitoring systems. However, since various factors have complex impacts on the electric power signals of ultrasonic welding processes, the peak power is inadequate to detect different types of welding defects. Therefore, a signal pattern matching method is proposed in this study, which is based on the electric power signal during the entire welding process and thus is capable of identifying abnormal welding processes in various conditions. The proposed method adopts isometric transformation and homogenization as signal pretreatment methods, and Euclidean distance is used to calculate the similarity metric for signal matching. The effectiveness and robustness of the proposed method are experimentally validated under different abnormal welding conditions.

On-Line Detection of Friction Stir Welded Joints by High Temperature Phased Array Ultrasonic Inspection and Control of Weld Process Parameters

2017 ◽  
Author(s):  
Daniel Huggett ◽  
Muhammad Wahab ◽  
T. W. Liao ◽  
Ayman Okeil
Keyword(s):  
High Temperature ◽  
Process Parameters ◽  
Welded Joints ◽  
Phased Array ◽  
Welding Process ◽  
Inspection System ◽  
Friction Stir ◽  
On Line ◽  
And Control ◽  
Welding Processes

Non-Destructive Evaluation (NDE) of welded structures is essential in industry and manufacturing sectors. However, NDE techniques are limited when applied at high temperatures, which prevents usefulness for on-line real time inspection of welded joints. In this work, a high temperature (HT) inspection system was created utilizing Phased Array Ultrasonic Testing (PAUT), and tested on Friction Stir (FS) welded aluminum alloy joints. The system created in this work proves HT-PAUT is capable of determining defects during the welding process. Supplementing this work, a custom defect detection software was created to analyze S-Scan data to interpret when and where a defect occurs to provide defect indicator signals. These defect signals can be utilized for controlling the FSW process parameters to automatically correct if a defect is observed. The technology developed can be utilized as a platform for future automated welding processes and control for creating the next generation weld-NDE systems.

Empirical Dynamic Modeling of Friction Stir Welding Processes

2007 ◽  
Author(s):  
Xin Zhao ◽  
Prabhanjana Kalya ◽  
Robert G. Landers ◽  
K. Krishnamurthy
Keyword(s):  
Steady State ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Dynamic Models ◽  
Welding Process ◽  
Recursive Least Squares ◽  
Finite Difference Schemes ◽  
Power Relationship ◽  
Friction Stir ◽  
Welding Processes

Current Friction Stir Welding (FSW) process modeling research is concerned with the detailed analysis of local effects such as material flow, heat generation, etc. These detailed thermo-mechanical models are typically solved using finite element or finite difference schemes and require substantial computational effort to determine temperature, forces, etc. at a single point in time. Dynamic models describing the total forces acting on the tool throughout the entire welding process are required for the design of feedback control strategies and improved process planning and analysis. In this paper, empirical models relating the process parameters (i.e., plunge depth, traverse rate, and rotation speed) to the process variables (i.e., axial, traverse, and lateral forces) are developed to understand their dynamic relationship. First, the steady-state relationship between the process parameters and variables is constructed, and the relative importance of each process parameter on each process variable is determined. Next, the dynamic process response characteristics are determined using Recursive Least-Squares. The results indicate that the steady-state relationship between the process parameters and variables is well characterized by a nonlinear power relationship, and the dynamic responses are well characterized by low-order linear equations. Experiments are conducted that validate the developed FSW dynamic models.

Human behaviour capturing in manual tungsten inert gas welding for intelligent automation

2015 ◽  
Vol 231 (9) ◽  
pp. 1619-1627 ◽  
Author(s):  
Prasad Manorathna ◽  
Sundar Marimuthu ◽  
Laura Justham ◽  
Michael Jackson
Keyword(s):  
Process Parameters ◽  
Welding Process ◽  
Visual Observation ◽  
Inert Gas ◽  
Process Variables ◽  
Tungsten Inert Gas Welding ◽  
Aerospace Applications ◽  
Level Of Automation ◽  
Welding Processes ◽  
Part Variation

Tungsten inert gas welding is extensively used in aerospace applications due to its unique ability to produce higher quality welds compared to other conventional arc welding processes. However, most tungsten inert gas welding is performed manually, and it has not achieved the required level of automation. This is mostly attributed to the lack of process knowledge and adaptability to complexities, such as mismatches due to part fit-up and thermal deformations associated with the tungsten inert gas welding process. This article presents a novel study on quantifying manual tungsten inert gas welding, which will ultimately help intelligent automation of tungsten inert gas welding. Through tungsten inert gas welding experimentation, the study identifies the key process variables, critical tasks and strategies adapted by manual welders. Controllability of welding process parameters and human actions in challenging welding situations were studied both qualitatively and quantitatively. Results show that welders with better process awareness can successfully adapt to variations in the geometry and the tungsten inert gas welding process variables. Critical decisions taken to achieve such adaptations are mostly based on visual observation of the weld pool. Results also reveal that skilled welders prioritise a small number of process parameters to simplify the dynamic nature of tungsten inert gas welding process so that part variation can be accommodated.

Dynamics of Battery Tabs Under Ultrasonic Welding

2013 ◽  
Author(s):  
Bongsu Kang ◽  
Wayne Cai ◽  
Chin-An Tan
Keyword(s):  
Longitudinal Vibration ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Point Of View ◽  
Structural Vibration ◽  
Kinetic Properties ◽  
Weld Quality ◽  
Ultrasonic Metal Welding ◽  
Metal Welding ◽  
Welding Processes

Ultrasonic metal welding for battery tabs must be performed with 100% reliability in battery pack manufacturing as the failure of a single weld essentially results in a battery that is inoperative or cannot deliver the required power due to the electrical short caused by the failed weld. In ultrasonic metal welding processes, high-frequency ultrasonic energy is used to generate an oscillating shear force (sonotrode force) at the interface between a sonotrode and few metal sheets to produce solid-state bonds between the sheets clamped under a normal force. These forces, which influence the power needed to produce the weld and the weld quality, strongly depend on the mechanical and structural properties of the weld parts and fixtures in addition to various welding process parameters such as weld frequencies and amplitudes. In this work, the effect of structural vibration of the battery tab on the required sonotrode force during ultrasonic welding is studied by applying a longitudinal vibration model for the battery tab. It is found that the sonotrode force is greatly influenced by the kinetic properties, quantified by the equivalent mass and equivalent stiffness, of the battery tab and cell pouch interface. This study provides a fundamental understanding of battery tab dynamics during ultrasonic welding and its effects on weld quality, and thus provides useful guidelines for design and welding of battery tabs from tab dynamics point of view.

scholarly journals Analysis of Mechanical, Microstructural Properties and Weld Morphology of A-TIG Welded AH-36 Marine-Grade Steels with Oxide and Duplex Flux Coating

2021 ◽  
Vol 18 (3) ◽  
pp. 9101-9112
Author(s):  
Vijaya Kumar K. ◽  
N. Ramanaiah ◽  
N. Bhargava Rama Mohan Rao
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Heat Input ◽  
Welding Process ◽  
Marangoni Effect ◽  
Tig Welding ◽  
Inert Gas ◽  
Width Ratio ◽  
Tungsten Inert Gas Welding ◽  
Welding Processes

The current study investigates the metallurgical, mechanical properties and weld morphology of AH36 marine grade steel (with a thickness of 8 mm) by activated-tungsten inert gas  (A-TIG) butt joints, with the application of different fluxes (MoO3, V2O5, and duplex of MoO3 and V2O5) at various process parameters. The welding speed was kept constant at 120 mm/min, and current varied from 160 A to 220 A uniformly to optimise process parameters to achieve desired mechanical properties, weld morphology, and lowest possible heat input. The study also focused on comparing tensile strength, impact strength, and microhardness, heat input during welding, weld bead depth and width between conventional TIG welding and activated flux TIG welding processes at various operation parameters. Tensile results reported that fracture occurs at the base region in ordinary TIG welding and the activated tungsten inert gas welding process. It was noticed that a higher depth to width ratio attained MoO3 and V2O5 duplex flux coated weldments. There is evidence that the depth of weld joints is enhanced because of stable arc, Marangoni effect, and arc constriction. Microhardness results reported that the fusion zone has a higher microhardness in the activated tungsten inert gas welding than the ordinary TIG welding. It was concluded that out of all fluxes, MoO3 and V2O5 duplex flux coating produce better butt welds of AH36 steel.

Estimation and Comparison of Welding Performances Using MRA and GMDH in P-GMAW for SS 316L Material

2018 ◽  
Author(s):  
Rudreshi Addamani ◽  
Ravindra Holalu Venkatadas ◽  
Ugrasen Gonchikar ◽  
Y. D. Chethan
Keyword(s):  
Process Parameters ◽  
Arc Welding ◽  
Gas Flow ◽  
Gas Metal Arc Welding ◽  
Thin Sheet ◽  
Welding Process ◽  
Industrial Applications ◽  
Metal Arc Welding ◽  
Welding Processes ◽  
Gmaw Welding

The Pulsed Gas Metal Arc Welding (P-GMAW) process is used in high-technology industrial applications and it is one of the most significant arc welding processes. The quality, productivity and cost of welding will be affected by the P-GMAW welding input process parameters and are considered to the most important factors. It is necessary to determine the input and output relationship of the welding processes in order to understand and control the P-GMAW welding process parameters. P-GMAW is widely used process, especially in thin sheet metal industries. It offers an improvement in quality and productivity over regular Gas Metal Arc Welding (GMAW). The process enables stable spray transfer with low mean current and low net heat input. This paper describes the estimation and comparison of welding process parameters viz., current, gas flow rate and wire feed rate on ultimate tensile strength, yield strength, percentage of elongation and hardness. Experiments have been performed based on Taguchi’s L27 standard orthogonal array. Estimation of welding performances have been carried out using sophisticated mathematical models viz., MRA and GMDH, and, compared. The GMDH algorithm is designed to learn the process by training the algorithm with the experimental data. Three different criterion functions, viz., regularity, unbiased and combined criterions were considered for estimation in GMDH. Different GMDH models can be obtained by varying the percentage of data in the training set and the best model can be selected from these, viz., 50%, 62.5% and 75%. Estimation and comparison of welding performances were carried out using MRA and GMDH techniques.

scholarly journals Numerical and Experimental Validation of Gas Metal Arc Welding on AISI 441 Ferritic Stainless Steel Through Mechanical and Microstructural Analysis

2022 ◽  
Author(s):  
SERAFINO CARUSO ◽  
DOMENICO UMBRELLO
Keyword(s):  
Grain Size ◽  
Residual Stresses ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Microstructural Analysis ◽  
Welding Process ◽  
Production Costs ◽  
Metal Arc Welding ◽  
Residual Stresses And Strains ◽  
Welding Processes

Abstract Residual stresses and strains, distortion, heat affected zone (HAZ), grain size changes and hardness variation during gas metal arc welding (GMAW), are fundamental aspects to study and control during welding processes. For this reason, numerical simulations of the welding processes represent the more frequently used tool to better analyse the several aspects characterizing this joining process with the aim to reduce lead time and production costs. In the present study an uncoupled 3D thermo-mechanical analysis was carried out by two commercial finite element method (FEM) software to model an experimental single bead GMAW of AISI 441 at different process set-up. The experimental HAZ and measured temperatures were used to calibrate the heat source of both the used numerical codes, then a validation procedure was done to test the robustness of the two developed analytical procedures. One software was used to predict the residual stresses and strains and the distortions of the welded components, while in the second software a user routine was implemented, including a physical based model and the Hall-Petch (H-P) equation, to predict grain size change and hardness evolution respectively. The results demonstrate that the predicted mechanical and microstructural aspects agree with those experimentally found showing the reliability of the two codes in predicting the thermal phenomena characterizing the HAZ during the analysed welding process.

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