Dissimilar Aluminum Alloys Research Articles

Effects of filler on the microstructure and corrosion of similar and dissimilar gas inert tungsten arc welding aluminum alloys joints

Welding of dissimilar aluminum alloys has been widely used in many industrial applications. However, the selection of filler type still attracts significant interest in the welding research area. The present work concerns the effect of filler metal on the microstructure and corrosion of weld joints of dissimilar aluminum alloys. AA 5083 and AA 6082 alloys were welded by tungsten inert gas welding (GTAW) using filler metals ER 4043 and ER 5356. The microstructure observations and the corrosion test of the weld joints were carried out. Solidification cracks were observed in the ER 4043 weld zone, whereas defect-free joints were obtained using a mix filler welding process. A galvanic corrosion was observed on the boundary between the filler rod ER 4043 weld zone and AA 5083 base alloy. From the corrosion standpoint of view, the using of ER 4043 electrodes is not preferred for welding 5000 series aluminum alloys, whereas ER 5356 filler electrode is more favorable than ER 4043 filler electrode either for dissimilar welding of AA 5083 and AA 6082 alloys or individual welding of both aluminum alloys. No galvanic corrosion is observed between ER 4043 fillers and AA 6082 base alloy.

Influence of dissimilar plate thickness on temperature during friction stir welding between AA5083 and AA6061 aluminium alloy grades

This paper investigates the influence of dissimilar plate thickness on the temperature profile of AA5083 and AA6061 aluminium alloy. Plates of dissimilar aluminium alloy grades are welded in a butt joint configuration by using a milling machine and a custom FSW tool made of H13 tool. Datalogger and type K thermocouples embedded in the workpieces at different distances from the weld line are used to collect the temperature data during the experiment. One thermocouple is placed at each side of the advancing side and retreating side at equally distance from the center line except for Joint 1, 2 and 3. The results show the range of temperature measurement during the experiment is between 300°C and 600°C. FSW process between similar plate thickness produces the highest value of peak temperature and better surface appearance than dissimilar plate thickness. The thermocouples located near the weld line contributed the higher temperature since the heat source comes from the rotating tool. Besides, higher temperatures were recorded at 5 mm thickness of AA6061 aluminium alloy plate located on the advancing side than the retreating side.

An experimental method for choosing the tool pin profile and shoulder size to join dissimilar aluminum alloys AA7075-T651 and AA6061-T6 joints

Many military and light weight aircraft designs call for joints between two different grades of aluminium alloy. This present study looked at the effect of tool shoulder diameter and tool pin profile on the tensile strength properties of dissimilar aluminium alloy AA6061-T6 and AA7075-T651 joints created by friction stir welding. The joints were fabricated utilizing three distinct tool shoulder diameters 15 mm, 20 mm and 25 mm along with two distinct tool pin profiles namely taper and square. The microstructure and microhardness of weld stir zone (WSZ) were examined and linked with the strength parameters of the joints. Adequate frictional heat generation from 20 mm shoulder diameter and pulsating stirring action of square pin revealed the formation of very fine grains in the weld nugget zone (WNZ). Due to enhanced material flow and the production of a defect-free stir zone, the joint created using a tool with a 20 mm shoulder diameter and square pin profile had the maximum hardness of 117 HV and the highest tensile strength of 284 MPa. The ductile mechanism of fracture is revealed by the presence of fine dimples accumulating in the tensile fractured surface of the joint fabricated by 20 mm tool shoulder diameter and square pin.

Microstructural and Mechanical Characterization of the Dissimilar AA7075 and AA2024 Aluminum Alloys Reinforced with Different Carbide Particles Welded by Friction Stir Welding

In the present study, AA7075 and AA2024 aluminum alloys were reinforced with ZrC, and the particles of WC were joined using the friction stir welding (FSW) method. The microstructural and mechanical properties of the welds were investigated using SEM, EDS, and tensile tests. The FSW process resulted in high-quality welds with fine grain structure; the stirred zone has 666% smaller grain size than AA7075 and AA2024 aluminum alloys. The tensile test showed strong and ductile welds. The fracture test showed ductile and less brittle composite joints of AA2024 and AA7075 alloys reinforced with WC and ZrC. The processing parameters in the FSW process significantly affect tensile strength (UTS); therefore, the improvement of UTS with tool speed is much greater than with welding speed. Increasing the tool speed from 400 to 560 rpm increased UTS by 7.1%, and from 560 to 700 rpm by 5.4%. The tensile test results showed that the welds exhibited considerable strength and ductility. Fracture analysis showed that the composite joints made of different AA2024 and AA7075 alloys and reinforced with WC and ZrC were ductile and less brittle. This study showed that FSW can efficiently fuse different aluminum alloys reinforced with ceramic particles.

Microstructure and mechanical properties of tungsten inert gas welded dissimilar aluminum alloys joint subjected to normal multi-pass friction stir process

This work investigated the effect of multi-pass friction stir processing on the tungsten inert gas welded joints of AA6082/AA8011. The friction stir processing approach is broadly used in the marine, automotive, and aerospace engineering sectors. The flow of plasticized material seems to be significant in the mixed flow region, which causes an erratic intercalation pattern. By using a stirring tool action, deformation was induced in situ extrusions of dissimilar alloys. The plasticized material was moved layer by layer to generate a lamellae structure. Theparent materials AA6082 and AA8011 were seen to be penetrating and vigorously mixing in this zone. After the fourth pass friction stir processing, the tungsten inert gas weldment's ultimate tensile strength and % strain dramatically increased. The defects that had been present before friction stir processing were eliminated when the coarse grain structure of the tungsten inert gas weldments was changed into a refined grain structure from 18.09 to 8.92 µm. The microstructure study shows the linear relationship between friction stir processing passes and grain size. The increases in friction stir processing pass resulted in a decrease in grain size. The maximum ultimate tensile strength (89.60) was observed in tungsten inert gas + 4 pass friction stir processing compared to the other joints.

Optimization of friction stir spot welding parameters for joining dissimilar AZ31B magnesium alloy and AA6061 aluminium alloy using response surface methodology

Optimization of friction stir spot welding parameters for joining dissimilar AZ31B magnesium alloy and AA6061 aluminium alloy using response surface methodology

Multi-objective optimization using Taguchi based grey relational analysis in friction stir welding for dissimilar aluminium alloy

Multi-objective optimization using Taguchi based grey relational analysis in friction stir welding for dissimilar aluminium alloy

Multi-response Optimization of Friction Stir Welded Reinforced Joints of Dissimilar Aluminum Alloys

Multi-response Optimization of Friction Stir Welded Reinforced Joints of Dissimilar Aluminum Alloys

Joining of dissimilar aluminum alloys AA5154 and AA2024 by cold roll bonding

Joining of dissimilar aluminum alloys AA5154 and AA2024 by cold roll bonding

Prediction of Axial Force on Dissimilar Aluminum Alloys Friction Stir Welding Using Design of Experiment

Friction stir welding (FSW) has become very popular for joining similar or dissimilar aluminum alloys. The heat used for this welding process is caused by friction between the welding tool and the workpiece which the axial force, the main parameter for heat generation, plays a very important role. Insufficient heat during welding will result in defective workpieces. This research is aimed to predict the axial force from the relevant factors of the FSW of dissimilar materials (aluminum alloys AA2024-T3 and AA6061-T6). The 23 full factorial design with center point was used for this experiment that consisted of 3 main factors: 1) rotation speed (rpm), 2) welding speed (mm/min), and 3) pin geometry each factor has 2 levels and 2 replications with the total of 20 experiments. The axial force data of each experiment were collected using a stationary dynamometer which obtained the data acquisition every 0.1 seconds (frequency of 10 Hz). The results from the design of experiment were analyzed by statistical method at the significance level of α = 0.05 which found that the significance and the optimum value of the main factors were rotation speed of 1500 rpm, welding speed of 35 mm/min, pin geometry of tri flat threaded, and the 2-way interaction between rotation speed and pin geometry. Furthermore, the prediction of the average axial force value on dissimilar aluminum alloys obtained from the specified parameters equals 478.91 N.

Effects of Stacking Number on Microstructure and Mechanical Properties for Cold Roll Bonding Process of Dissimilar Aluminum Alloy Sheets

A cold roll-bonding (CRB) process is applied to study the effects of stacking number on the microstructure and mechanical properties of roll-bonded and age-treated Al sheets. Commercial AA1050 and AA6061 sheets with a thickness of 2 mm were stacked alternately on each other to two and four layers, and roll-bonded by multi-pass cold rolling. The roll-bonded Al sheets were then subjected to natural aging (T4) and artificial aging (T6) treatments. The as roll-bonded Al sheets showed a typical deformation structure, where the grains are elongated in the rolling direction regardless of the stacking number. However, after the T4 and T6 aging treatments, the Al sheets had a recrystallization structure consisting of coarse grains in both the AA5052 and AA6061 regions with different grain sizes in each. In addition, the sheets showed an inhomogeneous hardness distribution in the thickness direction, with higher hardness in AA6061 than in AA1050 after the T4 and T6 age treatments. The tensile strength of the T6-treated specimen was higher than that of the T4-treated one for both the 2 and 4-layer CRBs. In addition, both the tensile strength and elongation of the specimens processed by the 4-layer stack CRB were higher than those of the 2-layer stack CRB for all experimental conditions.

Multi objective Optimizations of friction stir welding process parameters for reinforcement of copper particles in aluminum alloy using Taguchi based grey relational analysis (GRA) and ANOVA.

In this paper, optimize process parameters of friction stir welding for reinforcement of copper particulate in between aluminum alloys. It is to boost the thermal conductivity and mechanical properties of base metals. Two dissimilar aluminum alloys with different mechanical properties .AA6061-AA6063. successfully joined. In addition, the introducing copper particles of 325 mesh size in between aluminum alloy 6061 and 6063. It is a direct application of rotating non-consumable friction stir welding tool plunged for reinforcement. Introduction of a copper particle in between aluminum alloy is a unique system in the solid-state welding process. Taguchi method as an optimization tool used to design process parameters. Afterward, welding samples were cut in the desired size and progressed for a further test such as tensile and hardness test. Finally, it is observed to have improved mechanical strength in minimum spindle speed i.e.1000 rpm and welding speed 20 mm/min. Study also shows feasibility of GRA, Hypothesis .Z-test. test and ANOVA with Taguchi technique.

Experimental Analysis on Ultrasonic Resistance Spot Welding of Aluminum Alloys

A recently developed hybrid joining process known as ultrasonic resistance spot welding (URW) was used on various pairs of similar and dissimilar aluminum (Al) alloys with different thicknesses, including AA5182–AA5182, AA6111–AA6111, AA7075–AA6111, and AA7075–AA5182, and comprehensively studied. Compared to conventional resistance spot welding (RSW), URW of the alloys showed consistently enhanced mechanical behavior in lap shear and crosstension tests. This can be attributed to the multiple perspectives on microstructure improvements. For different stacks of Al alloys and welding conditions, nugget formation was promoted with a larger nugget size in URW. In the nugget center, ultrasonically assisted (UA) vibration facilitated the formation of an equiaxed crystal zone. At the nugget boundary, URW showed a narrower coarse columnar zone and partially melted zone, which are associatedwith the lowest hardness in the weld. Specifically in dissimilar Al welds, UA vibration moved the nugget more centered toward the weld interface. These microstructure improvements indicated UA vibration can homogenize temperature and elemental distribution, which modifies solidification behavior.

Microstructure and mechanical behavior of similar and dissimilar AA2114 and AA7075 aluminium alloy joints using fusion welds

Joining of aluminium and its alloys are always a major challenge to welding community because of high thermal conductivity, coefficient of linear expansion, affinity to combine with oxygen and sensitive to hot cracking. Ample of researches carried out to address above issues. The selected investigation aimed at one such attempt to combine AA2114 and AA 7075(AA2XXX and AA7XXX series promises a lot in aircraft applications) in all possible ways i.e. similar and dissimilar by adopting TIG (Tungsten Inert Gas) and CMT (Cold Metal Transfer) welding. After series of trials, all the combinations welded successfully and tensile specimen as per ASTM E8 machined. While performing mechanical testing, all specimens failed along the interface of weld zone and AA2114 side irrespective of TIG/ CMT dissimilar welding. This is accounted to softening in the heat affected zone of selected heat treated alloys i.e. AA2114 and AA7075. Among all the fabricated weld joints AA 2114-AA7075 specimen showed highest ultimate tensile strength of 247 MPa using filler ER 4043 alloy with CMT welding. Yielding of above outcome may be due to segregation of alloying elements (acts barrier to dislocation motion) and low concentrated heat input (favoring maximum extent of finer dendritic equiaxed grains).XRD-report revealed the presence of Zn, Cu, Mg elements in the intermetallic to have strength in CMT dissimilar CMT weldment. SEM analysis report on dissimilar joints of both TIG and CMT exemplifies the presence both dimples and flakes, which led to the ductile–brittle mixed mode nature of failure.

An experimental investigation on mechanical characteristics and wear behaviour of TIG welded dissimilar aluminum alloys

The present research aims to investigate the combined influence of arc current and travel speed in terms of heat input during tungsten inert gas (TIG) welding and examine it through microstructural, mechanical, and wear characterizations. An automated welding setup was employed to fabricate the dissimilar AA6061-T6 and AA7075-T6 aluminum joints in a butt configuration. Macro and micrographic inspections were also conducted and investigated the changes across the weld cross-section with respect to heat input. Tensile, Charpy impact, residual stress, and wear tests were performed to examine the quality and strength of the joint. The results revealed that the joints with increased heat input displayed higher ultimate tensile strength, impact toughness, residual stress, and wear resistance. The consistent distribution of intermetallic phases and the fine equiaxed grains with minimal porosity development are probably responsible for it. However, excessive heat input caused reversion phenomena, coarser grains, and significant porosities, which reduced the tensile strength, impact toughness, and wear resistance of the joint. The welded sample S-3, having a welding current of 145 A, a travel speed of 78 mm/min, and a heat input of 1.67 kJ/mm, exhibited the highest ultimate tensile strength of 178 MPa, the largest elongation of 12.6%, the highest impact toughness of 13 J, and the lowest wear rate of 34 µm, along with a compressive residual stress of 60 MPa at the weld centre. The analysis of tensile and impact-fractured surfaces using SEM and EDS analyses validated the experimental results.

Analysing the Influence of Tool Pin on Mechanical Properties of Friction Stir Welded Dissimilar Aluminium Alloys AA6082 & AA5052

Analysing the Influence of Tool Pin on Mechanical Properties of Friction Stir Welded Dissimilar Aluminium Alloys AA6082 & AA5052

Experimental investigations on the position of plates in friction stir welding of dissimilar alloys

Friction Stir Welding (FSW) is a solid-state welding procedure that involves heating and stirring the surfaces of two metal components to cause them to fuse together. The paper aims to present the influence of the plate position in friction stir welding of dissimilar aluminum alloys, of the same family. Friction stir welding experiments are conducted on AA6061 and AA6082 for different plate positions. The results of mechanical and microstructural characterization reveal that AA6082 on the advancing side provides better strength due to the material properties, temperature developed, and distribution along and across the weldments.

Genetic-neural optimization approach for gas metal arc welding of dissimilar aluminium alloys of AA5083-O/AA6061-T6

Distinct alloys have different chemical and thermal characteristics, making it difficult to weld together. For the purpose of maximizing tensile strength and weld hardness of the joint, the gas metal arc (GMA) welding process for the dissimilar aluminium alloys AA5083-O and AA6061-T6 was modelled and optimized in the current study. A genetic-neural approach was attempted, in which optimal artificial neural network (ANN) was applied to model the process and genetic algorithm (GA) approach was extended to optimize the parameters. The proposed genetic-neural (GA-ANN) approach was also compared to the traditional response surface methodology (RSM). In predicting the reactions of a GMA welded joint made of two different alloys, AA5083-O and AA6061-T6, the suggested optimum ANN model was shown to be more accurate (error 6%). The genetic-neural optimization technique has less inaccuracy (approximately 5% error) than the RSM optimization approach, however the more computational time was required to select GA-ANN parameters.

The role of filler wire and scanning strategy in laser welding of difficult-to-weld aluminum alloys

AbstractLaser welding of dissimilar aluminum alloys has gained interest over recent years, especially for the production of lightweight components. Pore and crack formation is one of the most critical factors to be taken into consideration for such applications, in particular when one or more parts are produced by die casting or additive manufacturing (AM). Current laser systems offer several methods for defect reduction and process control, while optimized process strategies must be correlated to key factors influencing welding outcomes. In light of these aspects, the current paper investigates the welding of AA6082 sheets with AlSi10Mg parts produced by AM in a lap-joint configuration typical of battery housings in the e-mobility industry. Both laser welding with and without filler wire are investigated, along with the potential advantages of using a wobbling scanning strategy, in order to understand the impact of process strategies on weld bead quality. The importance of process parameter optimization is highlighted for all of the employed strategies, with special emphasis on defects, weld bead chemical composition, joint morphology, and dilution between the materials involved. The findings demonstrate that by introducing filler wire and employing active wobbling, highly reflective alloys can be welded correctly (porosity below 1%, equivalent ultimate strength up to 204 MPa) with good tolerance to variations in process parameters, while filler wire can be excluded in high-productivity welding where linear scanning is employed and detailed optimization of process parameters is performed (porosity below 2%, equivalent ultimate strength up to 190 MPa).

Investigation of the Microstructure and Mechanical Properties in Friction Stir Welded Dissimilar Aluminium Alloy Joints via Sampling Direction

This research study investigates the influence of sampling direction on the microstructure and mechanical properties of dissimilar joints formed by friction stir welding (FSW). The specimens were cut in two directions: perpendicular (transverse) and parallel (longitudinal) to the FSW joint. The tests conducted included X-ray diffraction (XRD), macrostructure, microstructure, tensile, microhardness, and fractography analysis. Different phases were noted in the XRD patterns and explained, with the aluminum phase being the dominating one. The results further showed that the transverse dissimilar joint exhibited higher microhardness compared to the longitudinal dissimilar joint, which is consistent with the respective grain sizes. Moreover, the ultimate tensile strength of the longitudinal joint exceeded that of the transverse joints, showing a substantial 47% increase. Similarly, the elongation of the joints followed a similar trend, with the longitudinal joint displaying a significant 41% increase in elongation compared to the transverse joint. Fractographic analysis revealed ductile fracture behaviour in all joints.