scholarly journals A genetic algorithm modelling of temperature distributions in the AZ31B magnesium alloys with 7075 aluminium alloy friction welded joints

2019 ◽  
Vol 132 ◽  
pp. 01029
Author(s):  
Radosław Winiczenko ◽  
Andrzej Sibicki ◽  
Paweł Skoczylas ◽  
Jędrzej Trajer
Keyword(s):  
Genetic Algorithm ◽  
Aluminium Alloy ◽  
Magnesium Alloys ◽  
Welded Joints ◽  
Goodness Of Fit ◽  
Welding Process ◽  
Coefficient Of Determination ◽  
Maximum Temperature ◽  
Interface Temperature ◽  
Temperature Distributions

This paper presents a genetic algorithm modelling of temperature distribution during heating and cooling of AZ31B magnesium alloys with 7075 aluminium alloy friction welded joints. The temperature distributions estimated in the joints using K-type thermocouples with the accuracy of ±⚟0.1°C. The thermocouples were installed in 1.2 mm holes at the periphery joint - 5, 10, and 15 mm from the weld interface. Temperature reading was performed with a digital thermometer with the requisition frequency of 1000Hz during friction welding. Maximum temperature measurements in the half-radius of the analysed joints were equal to 305°C and 324°C, for the AZ31B magnesium alloy and 7075 aluminium alloy specimens, respectively. Both temperature and increasing temperature gradient at the axial specimens were higher than those at the half-radius and periphery of the joints. The empirical models for heating T=a/b+exp(ct) and cooling phases T=a-btc were formulated by the authors of this study. These models used to describe the temperature curves of welding process. The goodness of fit of tested mathematical models to the experimental data was evaluated with the coefficient of determination R2. A nonlinear regression analysis was conducted to fit the models by genetic algorithm (GA) using computer program MATLAB.

scholarly journals The impact of microstructural non-conformities on microhardness of EN AW 5754 aluminium alloy welded joints made with the use of the TIG method

2018 ◽  
Vol 48 (1) ◽  
pp. 253-262
Author(s):  
Piotr Woźny ◽  
Józef Błachnio
Keyword(s):  
Aluminium Alloy ◽  
Process Parameters ◽  
Welded Joints ◽  
Welded Joint ◽  
Welding Process ◽  
Strong Link ◽  
Tomographic Method ◽  
The Impact

Abstract The article presents the impact of welding non-conformities on microhardness of EN AW 5754 aluminium alloy welded joints made with the use of the TIG method. The results of microhardness tests of welded samples made with various process parameters. The impact of the welding non-conformities disclosed with the use of a tomographic method on the welded joint microhardness were analysed. The studies showed a strong link between the participation of welding non-conformities, welding process parameters and microhardness of welds.

Assessment of the Fatigue Behaviour of Friction Stir Welded Joints: Aluminium Alloy 6082-T6

2007 ◽  
Vol 348-349 ◽  
pp. 209-212 ◽  
Author(s):  
Pedro Miguel Guimarães Pires Moreira ◽  
A.M.P. de Jesus ◽  
A.S. Ribeiro ◽  
Paulo Manuel Salgado Tavares de Castro
Keyword(s):  
Aluminium Alloy ◽  
Welded Joints ◽  
Base Material ◽  
Welding Process ◽  
Growth Curves ◽  
Fatigue Behaviour ◽  
Fatigue Properties ◽  
Friction Stir ◽  
Crack Propagation Resistance ◽  
Strength And Ductility

A study on the fatigue behaviour of friction stir butt welds of 3mm thick 6082-T6 aluminium alloy was carried out. Monotonic tensile and cyclic tests of welded joints and base material were performed to understand the influence of the welding process on the static and fatigue properties. Microhardness profiles were measured and fatigue crack growth curves were determined for cracks growing in different locations of the weldments. Friction stir material exhibited lower strength and ductility properties than the base material. However, an enhanced crack propagation resistance is observed.

scholarly journals Mechanical Properties and Microstructural Characterization of Dissimilar Friction Stir Welded AA5083 and AA6061 Aluminium Alloys

Mechanika ◽  
2020 ◽  
Vol 26 (6) ◽  
pp. 545-552
Author(s):  
Sasi Lakshmikhanth RAJASEELAN ◽  
Subbaiah KUMARASAMY
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Welded Joints ◽  
Aluminium Alloys ◽  
Microstructural Analysis ◽  
Testing Machine ◽  
Welding Process ◽  
Fusion Welding ◽  
Friction Stir

Solidification is one of the major issues that was faced during the fusion welding of dissimilar non-heat treatable and heat treatable aluminium alloys. To overcome this issue Friction Stir Welding played a very vital role, since it is a solid state welding process. In the current study, dissimilar friction stir welding was carried out between non heat-treatable aluminium alloy AA5083-H111 and heat-treatable aluminium alloy AA6061-T6. The microstructural analysis and the mechanical properties of the dissimilar friction stir welded aluminium alloy AA5083-H111 and AA6061-T6 have been investigated. Both optical microscopy and scanning electron microscopy was used to evaluate the microstructural features. The elemental analysis was carried out using SEM-EDX. The tensile properties are studied using Universal Testing Machine. Hardness at various zones of the welded joints was measured using Vicker’s Hardness Testing Machine. The mechanical properties of the friction stir welded joints were correlated with the microstructure of the dissimilar welded joints.

scholarly journals Managing the influence of microstructure defects on the strength of EN AW 5754 aluminium alloy welded joints executed with the TIG method

2018 ◽  
Vol 182 ◽  
pp. 02025
Author(s):  
Piotr Woźny ◽  
Józef Błachnio
Keyword(s):  
Aluminium Alloy ◽  
Process Parameters ◽  
Welded Joints ◽  
Welding Process ◽  
Inert Gases ◽  
Weld Strength ◽  
Tungsten Electrode ◽  
Welding Defects ◽  
Strong Relation ◽  
The Impact

The paper concerns the issue of the impact of welding defects on the strength of EN AW 5754 aluminium alloy welded joints, executed with the TIG welding method (tungsten inert gas, i.e., a method of welding with a non-consumable tungsten electrode shielded with inert gases). The article presents examples of operating damage to welded joints and discusses the factors impacting the weld quality. The strength test results of welding samples taken under different process parameters were presented. The impact of welding defects and non-conformities identified with a CAT test on the weld joint impact was analysed. The studies showed a strong relation between the presence of welding defects, welding process parameters and weld strength.

scholarly journals Prediction of Transient Temperature Distributions for Laser Welding of Dissimilar Metals

2021 ◽  
Vol 11 (13) ◽  
pp. 5829
Author(s):  
Partha Sarathi Ghosh ◽  
Abhishek Sen ◽  
Somnath Chattopadhyaya ◽  
Shubham Sharma ◽  
Jujhar Singh ◽  
...  
Keyword(s):  
Heat Source ◽  
Laser Welding ◽  
Thin Sheet ◽  
Weld Line ◽  
Welding Process ◽  
Radiant Heat ◽  
Butt Joint ◽  
Maximum Temperature ◽  
Transient Temperature ◽  
Temperature Distributions

Distribution of temperature during the welding process is essential for predicting and realizing some important welding features such as microstructure of the welds, heat-affected zone (HAZ), residual stresses, and their effects. In this paper, a numerical model was developed using COMSOL Multiphysics of dissimilar laser welding (butt joint) of AISI 316L and Ti6Al4V thin sheet of 2.5 mm thickness. A continuous mode (CW) fiber laser heat source of 300W laser power was used for the present study. A time-dependent prediction of temperature distributions was attempted. The heat source was assumed as a Hermit–Gaussian analytical function with a moving velocity of 120 mm/min. Both convective and radiant heat loss and phase change of the materials were considered for the analysis. In addition, variation of temperature-dependent material properties was also considered. The maximum and minimum temperature for the two materials at different times and the temperature in the different penetration depths were also predicted. It was found that the average temperature that can be achieved in the bottom-most surface near the weld line was more than 2400K, which justifies the penetration. Averages of maximum temperatures on the weld line at different times at the laser spot irradiation were identified near 3000K.The temperature fluctuation near the weld line was minimal and decreased more in the traverse direction. Scanning with a displaced laser relative to the interface toward the Ti6Al4V side reduces the maximum temperature at the interface and the HAZ of the 316L side. All of these predictions agree well with the experimental results reported in current literature studies.

Multifactor mathematical model of criticality of welding process of products from aluminum- magnesium alloys

2020 ◽  
pp. 12-18
Author(s):  
F.A. Urazbahtin ◽  
A.YU. Urazbahtina
Keyword(s):  
Mathematical Model ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Welding Process ◽  
Welding Equipment ◽  
Equipment Operation ◽  
Aluminum Magnesium Alloys ◽  
Aluminum Magnesium Alloy ◽  
Welding Materials

A multifactor mathematical model of the welding process of products from aluminum-magnesium alloys, consisting of 71 indicators that assess the quality of the weld, the welding process, costs, equipment operation and quality of the welded material. The model can be used to control and optimize the welding process of products from aluminum-magnesium alloys. Keywords welding, products, aluminum-magnesium alloy, indicators, process parameters, welding equipment, welding materials, electrode sharpening, lining [email protected]

scholarly journals Evaluation of NASA POWER Reanalysis Products to Estimate Daily Weather Variables in a Hot Summer Mediterranean Climate

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1207
Author(s):  
Gonçalo C. Rodrigues ◽  
Ricardo P. Braga
Keyword(s):  
Wind Speed ◽  
Bias Correction ◽  
Goodness Of Fit ◽  
Mediterranean Climate ◽  
Weather Data ◽  
Coefficient Of Determination ◽  
Mean Bias Error ◽  
Bias Error ◽  
Weather Variables ◽  
Weather Stations

This study aims to evaluate NASA POWER reanalysis products for daily surface maximum (Tmax) and minimum (Tmin) temperatures, solar radiation (Rs), relative humidity (RH) and wind speed (Ws) when compared with observed data from 14 distributed weather stations across Alentejo Region, Southern Portugal, with a hot summer Mediterranean climate. Results showed that there is good agreement between NASA POWER reanalysis and observed data for all parameters, except for wind speed, with coefficient of determination (R2) higher than 0.82, with normalized root mean square error (NRMSE) varying, from 8 to 20%, and a normalized mean bias error (NMBE) ranging from –9 to 26%, for those variables. Based on these results, and in order to improve the accuracy of the NASA POWER dataset, two bias corrections were performed to all weather variables: one for the Alentejo Region as a whole; another, for each location individually. Results improved significantly, especially when a local bias correction is performed, with Tmax and Tmin presenting an improvement of the mean NRMSE of 6.6 °C (from 8.0 °C) and 16.1 °C (from 20.5 °C), respectively, while a mean NMBE decreased from 10.65 to 0.2%. Rs results also show a very high goodness of fit with a mean NRMSE of 11.2% and mean NMBE equal to 0.1%. Additionally, bias corrected RH data performed acceptably with an NRMSE lower than 12.1% and an NMBE below 2.1%. However, even when a bias correction is performed, Ws lacks the performance showed by the remaining weather variables, with an NRMSE never lower than 19.6%. Results show that NASA POWER can be useful for the generation of weather data sets where ground weather stations data is of missing or unavailable.

Vibratory weld conditioning during gas tungsten arc welding of al 5052 alloy on the mechanical and micro-structural behavior

2020 ◽  
Vol 17 (6) ◽  
pp. 831-836
Author(s):  
M. Vykunta Rao ◽  
Srinivasa Rao P. ◽  
B. Surendra Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Great Influence ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Content Type ◽  
Average Grain Size

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.

Numerical Analysis of Residual Stresses and Distortions in Aluminium Alloy Welded Joints

2015 ◽  
Vol 809-810 ◽  
pp. 443-448 ◽  
Author(s):  
Tomasz Kik ◽  
Marek Slovacek ◽  
Jaromir Moravec ◽  
Mojmir Vanek
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Aluminium Alloy ◽  
Thermal Cycle ◽  
Technology Development ◽  
Welding Process ◽  
Simulation Software ◽  
Structure Knowledge ◽  
Welding Processes ◽  
Element Method

Simulation software based on a finite element method have significantly changed the possibilities of determining welding strains and stresses at early stages of product design and welding technology development. But the numerical simulation of welding processes is one of the more complicated issues in analyses carried out using the Finite Element Method. A welding process thermal cycle directly affects the thermal and mechanical behaviour of a structure during the process. High temperature and subsequent cooling of welded elements generate undesirable strains and stresses in the structure. Knowledge about the material behaviour subjected to the welding thermal cycle is most important to understand process phenomena and proper steering of the process. The study presented involved the SYSWELD software-based analysis of MIG welded butt joints made of 1.0 mm thickness, 5xxx series aluminium alloy sheets. The analysis of strains and the distribution of stresses were carried out for several different cases of fixing and releasing of welded elements.

Sign in / Sign up

Export Citation Format

Share Document