Advanced Scaling Techniques for the Modeling of Materials Processing

2009 ◽  
Author(s):  
Karem Tello ◽  
Ustun Duman ◽  
Patricio Mendez
Keyword(s):  
Weld Pool ◽  
Arc Welding ◽  
Maximum Temperature ◽  
Scaling Analysis ◽  
Weld Penetration ◽  
Friction Stir ◽  
Gas Tungsten Arc ◽  
Pool Surface ◽  
Scaling Models ◽  
Welding Processes

The present work presents how scaling analysis can be applied into multiphysics and multicoupled problems related to welding processes. The formation of the weld pool surface depression in high current and velocity Gas Tungsten Arc Welding (GTAW) is dominated by the gas shear acting on the weld pool. Considering this dominant force the weld penetration was estimated and compared to experimental results. Plastic deformation and heat flow are coupled phenomena in Friction Stir Welding (FSW), the maximum temperature was estimated using scaling analysis and compared with experimental and numerical results reported in the literature. Although the simplicity of the scaling models, they are capable of capturing correct trends and order of magnitudes of the unknown estimations in a problem. Moreover, they are capable of determining the dominant forces that act on the process studied.

A study on sustainability assessment of welding processes

2019 ◽  
Vol 234 (3) ◽  
pp. 501-512 ◽  
Author(s):  
Jaber Jamal ◽  
Basil Darras ◽  
Hossam Kishawy
Keyword(s):  
Arc Welding ◽  
Social Impact ◽  
Sustainability Assessment ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Friction Stir ◽  
Gas Tungsten Arc ◽  
Metal Arc Welding ◽  
Sustainability Assessments ◽  
Welding Processes

The concept of “sustainability” has recently risen to take the old concept of going “green” further. This article presents general methodologies for sustainability assessments. These were then adapted to measure and assess the sustainability of welding processes through building a complete framework, to determine the best welding process for a particular application. To apply this methodology, data about the welding processes would be collected and segregated into four categories: environmental impact, economic impact, social impact, and physical performance. The performance of each category would then be aggregated into a single sustainability score. To demonstrate the capability of this methodology, case studies of three different welding processes were performed. Friction stir welding obtained the highest overall sustainability score compared to gas tungsten arc welding and gas metal arc welding.

Influences of Sign of Surface Tension Coefficient on Turbulent Weld Pool Convection in a Gas Tungsten Arc Welding (GTAW) Process: A Comparative Study

2005 ◽  
Vol 127 (8) ◽  
pp. 848-862 ◽  
Author(s):  
Nilanjan Chakraborty ◽  
Suman Chakraborty
Keyword(s):  
Surface Tension ◽  
Weld Pool ◽  
Arc Welding ◽  
Surface Tension Coefficient ◽  
Scaling Analysis ◽  
Gas Tungsten Arc ◽  
Gtaw Process ◽  
Order Of Magnitude ◽  
Negative Surface ◽  
Surface Tension Coefficients

The effects of positive and negative surface tension coefficients (∂σsur∕∂T) on both laminar and turbulent weld pool convection are numerically studied for a typical gas tungsten arc welding (GTAW) process. Three-dimensional turbulent weld pool convection in a pool is simulated using a suitably modified high Reynolds number k‐ε model in order to account for the morphology of an evolving solid-liquid interface. Key effects of the sign of surface tension coefficient (∂σsur∕∂T) on the turbulent transport in a GTAW process are highlighted by comparing the turbulent simulation results with the corresponding ones from a laminar model, keeping all other process parameters unaltered. A scaling analysis is also performed in order to obtain order-of-magnitude estimates of weld pool penetration for both positive and negative surface tension coefficients. The scaling analysis predictions are in good agreement with the numerical results, in an order-of-magnitude sense.

Friction Stir and Gas Tungsten Arc Welding of ZM21 Magnesium Alloy

2014 ◽  
Vol 909 ◽  
pp. 77-82
Author(s):  
Hari Krishna Kallipudi ◽  
Rama Koteswara Rao Sajja ◽  
Venkata Subba Rao Veera
Keyword(s):  
Friction Stir Welding ◽  
Magnesium Alloy ◽  
Arc Welding ◽  
Welding Process ◽  
Gas Tungsten Arc Welding ◽  
Friction Stir ◽  
Friction Stir Welding Process ◽  
Gas Tungsten Arc ◽  
Gas Tungsten ◽  
Welding Processes

Magnesium alloy ZM21 plates were welded using friction stir welding, a solid state process and gas tungsten arc welding which is a fusion welding process. Defect free, full penetration welds were obtained after several trials using different process parameters. The effect of welding processes on mechanical properties of Mg-Zn-Mn joints were evaluated using tensile tests, bend test, vickers micro hardness measurements and optical microscopy. Welds produced by Friction stir welding process exhibited superior tensile properties compared to Gas Tungsten Arc Welding process. Hardness reduction in the weld metals were observed for both the welding techniques. Friction stir welds showed finer grains in the weld nugget and in the heat affected zone. Both types of welds exhibited good bend ductility comparable to that of the base material. It has been concluded that both the processes are well suited to obtain sound welds of the magnesium alloy ZM21 and Friction stir welding process offers stronger welds.

Nonlinear Dynamic Modelling of Weld Penetration in Gas Tungsten Arc Welding Process

2013 ◽  
Vol 658 ◽  
pp. 292-297 ◽  
Author(s):  
Yu Kang Liu ◽  
Shu Jun Chen ◽  
Wei Jie Zhang ◽  
Yu Ming Zhang
Keyword(s):  
Linear Model ◽  
Weld Pool ◽  
Nonlinear Dynamic ◽  
Arc Welding ◽  
Welding Process ◽  
Gas Tungsten Arc Welding ◽  
Weld Penetration ◽  
Inference System ◽  
Gas Tungsten Arc ◽  
Gas Tungsten

Skilled welders can estimate and control the weld penetration based on weld pool observation. This implies that an advanced control system could be developed to control the penetration by emulating the decision making process of the human welder. In this paper a nonlinear dynamic model is established to correlate the process inputs (welding current and traveling speed) and weld penetration in Gas Tungsten Arc Welding (GTAW). An innovative 3D vision sensing system capable of measuring the weld pool characteristic parameters in real-time is utilized. Dynamic experiments are conducted under various welding conditions. Dynamic linear model is first constructed and the results are analyzed. The linear model is then improved by incorporating a nonlinear operating point modeled by Adaptive Neuro Fuzzy Inference System (ANFIS). It is found that the penetration state can be better modeled by the proposed ANFIS model.

Review the Effect of Welding Processes on the Comprehensive Mechanical Properties of Magnesium Alloy Joints

2014 ◽  
Vol 716-717 ◽  
pp. 184-187
Author(s):  
Zhi Jun Zhang ◽  
Bo Lin He ◽  
Zong Min Lv ◽  
Kang Wei
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Arc Welding ◽  
Mechanical Performance ◽  
Laser Beam Welding ◽  
Pulsed Current ◽  
Friction Stir ◽  
Gas Tungsten Arc ◽  
Comprehensive Properties ◽  
Welding Processes

In this paper, the effect of welding processes such as friction stir welding (FSW), laser beam welding (LBW) and pulsed current gas tungsten arc welding (PCGTAW) on comprehensive mechanical properties of AZ31B magnesium alloy was reviewed. Among the three different welding processes, the LBW joints showed superior comprehensive properties to FSW and PCGTAW joints. The formation of very fine grains in weld region, higher fusion zone hardness, uniformly distributed finer precipitates were the main reasons for superior comprehensive mechanical performance of LBW joints compared to PCGTAW and FSW joints.

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