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•Relative radiance of keyhole tungsten inert gas welding scene is measured by camera.•Pulse triggered imaging is introduced to capture high-dynamic range images of keyhole tungsten ...inert gas welding.•The correlation between the front features of the weld zone and the weld penetration was found.•Two deep learning models are established to realize the weld penetration prediction in keyhole tungsten inert gas welding.
The strong light generated during welding process covers most details inside the weld zone, making it difficult to monitor the weld quality from the front of the weld with visual sensor. Therefore, a weld penetration prediction model based on high-dynamic range imaging is developed in order to record the shape change of keyhole and weld pool and predict the weld penetration. First, the relative radiance distribution of the weld zone is measured and a pulse-triggered imaging technology is introduced to capture the well-exposure images of keyhole zone and weld pool zone. Next, by extracting six feature parameters from weld zone, the relationship between weld penetration and weld zone features are analyzed. Finally, a Softmax model and a multi-SVM model are established to describe this relation, with the extracted features as input and the weld penetration as output. The results show that the Softmax penetration prediction model based on high-dynamic range imaging technology has a good weld penetration predicting effect with accuracy of 92.71 % and the Softmax model has an average time cost of 0.73μs for every weld penetration prediction.
Comprehensive research was conducted to assess the feasibility of repairing CuZn37 brass products using the Tungsten Inert Gas (TIG) welding process. Standard welding wires designed for copper and ...its alloys (4 wire grades) were used as filler materials. The research on the macro- and microstructure of the weld joints revealed that the recrystallization region did not exceed 2 mm. The single-phase α-solid solution structure was characteristic of the welds made with CuSn4Zn3 filler wire. Microhardness measurements of the welds and the heat-affected zone showed significant softening up to 22-25 mm from the weld axis due to the thermal influence of the welding process on cold-rolled brass.
As a result of the comprehensive research, a fundamental technology for repairing CuZn37 brass products using TIG welding with CuSn4Zn3 filler wire was developed. This approach ensures high-quality defect-free weld joints, dense welds with satisfactory mechanical properties, and a minimal zone of softening.
•Studied the weldability of 304 CMT additive manufacturing stainless steel successfully.•Welding along the traveling direction can obtain welded joints with better performance.•Welding along the ...traveling direction, ∂1 = 0.919, ∂2 = 0.869, and the elongation is 37.7 % after welding.
In this study, 304 stainless steel thin-wall component were obtained by wire arc additive manufacturing (WAAM) as one of the methods of additive manufacturing. In view of the limits that the WAAM technology can not produce large and complex components at one time, TIG welding was chosen during secondary processing to achieve the effectively connection. Weldability, microstructure, texture strength and mechanical properties were particularly investigated when welding along the traveling and building direction. The results show that welding along the traveling direction gained better performance weld joints than building direction including higher tensile and yield strength, greater elongation and lower texture strength. Besides, the grain orientation changed from 001 before welding to 111 after welding in both traveling and building direction.
The present investigations aims to improve weld characteristics of Aluminum (Al-6001) plate using a pulsed TIG welding. The welding speed of the current study has been controlled by PUG machine ...coupled with TIG machine for automatic operation. The similar welding of the of Al-6001 plate have been performed by varying welding process parameters for full depth of penetration. Single side welding of Al-6001 plate has been studied. The influence of welding current & welding speed on the weld characteristics of the welded joint have been studied. The weld zone features have been analyzed with the microstructure images using Optical Microscopic and SEM (Scanning electron microscope) and on the other hand different phases have been characterized using XRD (X-ray diffraction) analysis. The hardness variation across the weld zone has also been quantified to study the change in mechanical property of the welded zone.
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•Quantitative relationships between eutectic and tensile properties of PMZ were proposed.•Constitutive behavior and damage mechanism of individual phases were determined.•A ...microstructure-based model was developed to predict the tensile behavior.
Partially melted zone (PMZ) is generally the weak region in 2219-T8 aluminum alloy TIG welding joint. In this work, a microstructure-based numerical simulation was performed to analyze the tensile behavior of PMZ. The constitutive behavior and damage mechanism of eutectic structure and Al matrix were determined. Stress–strain distribution and fracture behavior in tensile process were analyzed. Quantitative relationships between eutectic structure and tensile properties of PMZ were proposed. The results showed that the maximum area and clustering of eutectic particles have significant effects on the tensile strength and elongation. Plastic strain mainly concentrated in matrix, and stress concentration occurred in larger eutectic. The tensile cracks initiated from eutectic structure and then propagated into matrix and resulted in the final fracture.
•TIG welding is an improved technique used for manufacturing different components.•The conceptual model can increase the property and lowers error values in welding.•The optimization is undergone by ...neural networking which is an efficient process.•The Taguchi method and ANOVA is utilized for finding the best optimized value.•Thus the above criteria forms most appropriate method for TIG welding of materials.
The main criteria discussed in this paper concern the welding optimization parameters and tensile strength of duplex stainless steel 2205 by tungsten inert gas welding based on Taguchi method and analysis of variance. Taguchi method of orthogonal L9 design experiment is carried out using orthogonal array for defining the problem occur on welding process and to reduce the error occurred in the neural network for the prediction of output. The neural network is a mathematical prediction model for the optimization process using back propagation algorithm. Analysis of variance (ANOVA) is a decision tool for detecting the variation of process parameters, it is a statistical technique for find out the optimal level of factors for the verification of the optimal design parameters through confirmation experiments. The purpose of this paper to increase the tensile strength, hardness and depth of weld by varying the parameters such as current, time, speed, variation of oxide fluxes, electrode diameter and gas flow rate. The Mat lab software is used for analyzing results and it shows that neural network coupled with Taguchi method and Anova is an effective method for optimizing the weld quality of material.
This research article addresses about the joining of 4mm thick plates of Inconel 718 and ferritic stainless steel (S.S) 316L by Tungsten Inert Gas (TIG) welding process without using the activated ...flux. Trial experiments were conducted to find the influence of welding current on the depth of penetration and depth to width (D/W) ratio. The studies proved that a complete penetration could be achieved in multi pass. Microstructure examination using optical and Scanning Electron Microscope (SEM) clearly exposed the development of unmixed zone and also the Heat Affected Zone (HAZ) of Inconel 718. The chemical components of the Inconel 718 and SS316L were determined using Energy Dispersive Analysis (EDAX). Tensile and bend failures were observed at the parent metal of Inconel 718, SS316L and Inconel 718 & SS316L dissimilar joints. It was indicated from the notch tensile studies that the notch strength ratio was better than unity, which established that the weldments were ductile in all circumstances. The corrosion studies were carried out in the Nacl solution and it was found that Inconel 718 and SS316L dissimilar joint possess less corrosion resistance than similar SS316L weldment. It was inferred from the current study that the ultimate tensile strength of dissimilar weldments was better compared to similar weldments and the failure was observed in the parent metal for all the cases. Bend test results portrayed that dissimilar weldments possess better strength compared to SS316L weldments.
In the present study, the hybrid laser – TIG welding parameters for welding of 316LN austenitic stainless steel have been investigated by combining a pulsed laser beam with a TIG welding heat source ...at the weld pool. Laser power, pulse frequency, pulse duration, TIG current were presumed as the welding process parameters whereas weld bead width, weld cross-sectional area and depth of penetration (DOP) were considered as the process responses. Central composite design was used to complete the design matrix and welding experiments were conducted based on the design matrix. Weld bead measurements were then carried out to generate the dataset. Multiple regression models correlating the process parameters with the responses have been developed. The accuracy of the models were found to be good. Then, the desirability approach optimization technique was employed for determining the optimum process parameters to obtain the desired weld bead profile. Validation experiments were then carried out from the determined optimum process parameters. There was good agreement between the predicted and measured values.
•Hybrid laser – TIG welding (custom made) of 316 LN stainless steel.•Process optimization using RSM.•Maximum depth of penetration.•Experimental validation.
