Aluminum Stainless Steel Research Articles

Fatigue crack growth behavior in SS304-Al5083 dissimilar friction stir welded joints

Aluminum-stainless steel joints are desirable for weight reduction in applications such as aerospace and automotive. Such joints are unavoidably exposed to cyclic loading, thus requiring a study of fatigue crack propagation in joints. A Friction stir welding (FSW) exhibited potential for fabrication of dissimilar joints. This work aims to explore the fatigue crack propagation behavior of SS304-Al5083 dissimilar weld prepared using friction stir welding. The SS304 and Al5083 sheets (250 mm × 80 mm × 3 mm) are friction stir welded, using a tool made of tungsten carbide featuring 16.5 mm shoulder diameter and cylindrical pin with 2.7 mm height 4 mm diameter. Tensile tests and fatigue crack growth rate (FCGR) assessments are conducted on both the base materials and the welded joints. Notably, the yield strength of the FSW joints align closely with that of Al5083. Two initial notch cases, notch at interface and at 3 mm offset from the interface towards Al5083, are considered for the welded joints. In the FSW joint, higher fatigue crack growth rate along Al-SS interface crack is observed to that of both individual base materials. For offset notch, crack growth rate is lower compared to the Al5083. Fractography of FCGR specimens revealed a brittle failure of the interface crack in welded joints which leads to a higher crack growth rate.

Comparative study of the effects of galvanic corrosion on the strength and the failure of aluminium and stainless steel bolted joints

This paper investigates the effects of bimetallic insert on corrosion, material degradation, loading capacity, stress distribution, strain distribution and failure of aluminium-stainless steel lap shear bolted assemblies. The single bolt lap shear assemblies of aluminium and stainless steel plates were performed in two settings in one of them a bimetallic insert was used. Considering that the aluminium plays the role of sacrificial anode in the aluminium-stainless steel galvanic couple, a single bolt lap shear assembly joining two aluminium plates is also considered as a reference. The experimental measurements were determined by tensile-shear testing method for three different conditions: dry condition and two corrosion states corresponding to 6 weeks and 16 weeks of accelerated corrosion tests. To support understanding of the effects of preload and friction changes due to the formation of corrosion products, finite element simulations were performed with varying preloads and friction coefficients. The study demonstrated significant effects of corrosion on loading capacity, bolt rotation and failure mode. The tensile-shear forces measured for the aluminium-aluminium assembly and aluminium-stainless steel assembly after 6 weeks of accelerated corrosion tests increased compared to the tensile-shear forces measured in dry condition. The increase in tensile-shear forces was related to the formation of corrosion products, affecting the preload and the frictional behaviour of the contacting surfaces. In agreement with experimental observations, finite element simulations demonstrated an increase in the tensile-shear force with the increase of frictional forces. The application of bimetallic inserts considerably reduces the effect of corrosion on the measured tensile-shear force of corroded assembly compared to non-corroded assembly. However, it affects the force-displacement response and failure mode compared to the response of aluminium-stainless steel assembly without bimetallic insert due to its effects on the bolt rotation and stress distribution. This needs to be considered in the design of dissimilar material bolted assembly.

Influence of copper interlayer on the interface characteristics of stainless steel–aluminium transitional structure in wire arc directed energy deposition

PurposeThe purpose of this study is to investigate the deposition of SS–Al transitional wall using the wire arc directed energy deposition (WA-DED) process with a Cu interlayer. This study also aims to analyse the metallographic properties of the SS–Cu and Al–Cu interfaces and their mechanical properties.Design/methodology/approachThe study used transitional deposition of SS–Al material over each other by incorporating Cu as interlayer between the two. The scanning electron microscope analysis, energy dispersive X-ray analysis, X-ray diffractometer analysis, tensile testing and micro-hardness measurement were performed to investigate the interface characteristics and mechanical properties of the SS–Al transitional wall.FindingsThe study discovered that the WA-DED process with a Cu interlayer worked well for the deposition of SS–Al transitional walls. The formation of solid solutions of Fe–Cu and Fe–Si was observed at the SS–Cu interface rather than intermetallic compounds (IMCs), according to the metallographic analysis. On the other hand, three different IMCs were formed at the Al–Cu interface, namely, Al–Cu, Al2Cu and Al4Cu9. The study also observed the formation of a lamellar structure of Al and Al2Cu at the hypereutectic phase. The mechanical testing revealed that the Al–Cu interface failed without significant deformation, i.e. < 4.73%, indicating the brittleness of the interface.Originality/valueThe study identified the formation of HCP–Fe at the SS–Cu interface, which has not been previously reported in additive manufacturing literature. Furthermore, the study observed the formation of a lamellar structure of Al and Al2Cu phase at the hypereutectic phase, which has not been previously reported in SS–Al transitional wall deposition.

Prediction of aluminium–stainless steel explosive clad strength through machine learning

Prediction of aluminium–stainless steel explosive clad strength through machine learning

Thermo-Structure Approach to Dissimilar Explosive Cladding with Interlayer

A thermodynamic model capable of predicting the change in internal energy, work done, and thermal energy required during aluminum-stainless steel explosive cladding is presented. The mathematical model is instrumental in determining the temperature and pressure developed at the interface, which characterizes the interface microstructure, compared with the numerical simulation. Numerical simulation is implemented by the Smoothed Particle Hydrodynamics method available in ANSYS Autodyn. Furthermore, the effect of different interlayers, such as Al 1100, copper, and SS 304, on kinetic energy utilization and deformation work is discussed. The increase in ram tensile and shear strengths is also reported.

Deformation Analysis of Novel Sorbite Stainless Steel-Aluminum Alloy Attached Lifting Protection Platform

The all-steel attached lifting protection platform widely employed in recent years has always suffered from self-weight issues and corrosion. Aluminum alloy is the ideal option for steel owing to its low bulk density and resistance to corrosion and rust. However, its elastic modulus is insufficient, causing the deformation of the structure to easily exceed the limitation of the Code for Design of Aluminum Alloy Structures. Therefore, this study recommended using sorbite stainless steel with high strength and a reasonable price as the guide rail of a protection platform having a significant force in conjunction with aluminum alloy to maximize their advantages. Regarding the overall structure, Midas GEN was used to verify whether their deformation adheres to the specifications. For exploring the stiffness of exact nodes, the wall-attached support was modeled by Abaqus, discovering that its maximum composite deformation is 0.725 mm, and its highest stress (490.2 MPa) appears at the intersection of the bottom and the side plate. Additionally, the influence of three key factors (the cantilever height of the protection platform, the horizontal spacing between two wall-attached supports, and the sectional size of the main frame fittings) on the structural deformation was investigated. Finally, the cost per extension meter was compared between the all-steel and the novel sorbite stainless steel-aluminum alloy attached lifting protection platform. The findings of the aforementioned works can effectively guide the design and construction of this novel structure and play a crucial role in its popularization and application.

Performance of ANN in Predicting the Tensile and Shear Strength of Al-Steel Explosive Clads

In this study, an artificial neural network (ANN) model is created to predict aluminium-stainless steel explosive clads' tensile and shear strengths. The parameters for the explosive cladding process, such as the loading ratio (mass ratio of the explosive and the flyer, 0.6-1.0), standoff distance (5-9 mm), preset angle (0°-10°), and groove in the base plate (V/Dovetail), were altered. The ANN algorithm was trained in Python using the tensile and shear strengths gathered from 80% of the experiments (60), trials, and prior results. The constructed model was evaluated utilizing the remaining experimental results. The ANN model successfully predicts the tensile and shear strengths with an accuracy of less than 10% deviation from the experimental result.

Investigation on the effect of Zn interlayer and process parameters optimisation in the production of Al-SS bimetallic castings

The effect of Zn interlayer on the stainless steel insert in the fabrication of Aluminium-Stainless Steel (Al-SS) Bimetallic casting (BmC) is reported. The design of Experiments was conducted with pouring temperature (680°C–730°C), insert preheat temperature (100°C–400°C) and insert thickness (1–3 mm) as influencing process parameters to produce Al-SS BmC. The maximum bond strength of 25.33 MPa was achieved when the experimental conditions were 705°C pouring temperature, 250°C insert temperature and 2 mm insert thickness. Using Response Surface Methodology (RSM), the interaction between the process parameters has been studied and a second-order polynomial equation was derived for maximising the bond strength. The predicted maximum bond strength using RSM for the above experimental conditions is 26.75 MPa. The output of RSM was given to the Genetic Algorithm (GA) to identify the maximum bond strength at forbidden parametric values. The maximum bond strength predicted using GA by interpolation is 26.87 MPa. However, the three process parametric conditions are 707°C, 277°C, and 1.86 mm respectively for achieving the maximum bond strength in the given Al-SS BmC’s. Experimental validation of the above conditions was conducted and the results obtained confirmed the predicted bond strength value using the GA technique. Spiral morphology due to the formation of Zn10Fe3 intermetallics was observed at the Zn-SS interface when the pouring temperature increased to 730°C and this might have led to the reduced bond strength of BmC than the bond strength achieved at 705°C and 707°C. The formation of the Al-rich and Fe-rich solid solutions as reaction layer between Al and SS without the micro gap around 705°C may contribute to the significant increase in bond strength of produced BmC with different insert temperatures and insert thickness.

Sliding movement temperature analysis between composite conductor rail and a collector shoe

Electrical traction systems come in different forms, depending on the railway and terrain. The collector shoe is a critical component that impacts the train’s overall safety. The majority of collector shoes consist of several types of gray cast iron that are highly resistant to sliding wear. Wear is produced by friction and electrical current at temperatures over the melting point, which results in decreased sliding speeds. Applying an electric current to a sliding contact alters the process temperature of the wear without changing the sliding speed. The study is essential for industrial applications, especially in subway transit. This study aims to learn more about the wear characteristics of a composite aluminum–stainless steel conductor rail moving across a current collector. The authors employed a finite element analysis and a series of electric current testing. This research will produce some intriguing test findings. Based on a friction pair consisting of a composite conductor rail of aluminum and stainless steel and gray cast iron, a sliding friction contact model was built in the COMSOL finite element software. When the findings of the finite element analysis and the pin-on-plate test technique are compared, the maximum temperature variance is 10%, while the minimum temperature variation is 0.8%. Additionally, the results reveal that acclimation and rupture occur more rapidly when speed rises, and a steady temperature rise may be achieved more quickly.

Soft computing approaches for comparative prediction of ram tensile and shear strength in aluminium–stainless steel explosive cladding

Soft computing approaches for comparative prediction of ram tensile and shear strength in aluminium–stainless steel explosive cladding

Enhancing the Strength of Aluminum–Stainless Steel Spot Weld using Magnetic Pulses

Enhancing the Strength of Aluminum–Stainless Steel Spot Weld using Magnetic Pulses

Interfacial Morphology and Bonding Mechanism of Explosive Weld Joints

Interfacial structure greatly affects the mechanical properties of laminated plates. However, the critical material properties that impact the interfacial morphology, appearance, and associated bonding mechanism of explosive welded plates are still unknown. In this paper, the same base plate (AZ31B alloy) and different flyer metals (aluminum alloy, copper, and stainless steel) were used to investigate interfacial morphology and structure. SEM and TEM results showed that typical sine wave, wave-like, and half-wave-like interfaces were found at the bonding interfaces of Al/Mg, Cu/Mg and SS/Mg clad plates, respectively. The different interfacial morphologies were mainly due to the differences in hardness and yield strength between the flyer and base metals. The results of the microstructural distribution at the bonding interface indicated metallurgical bonding, instead of the commonly believed solid-state bonding, in the explosive welded clad plate. In addition, the shear strength of the bonding interface of the explosive welded Al/Mg, Cu/Mg and SS/Mg clad plates can reach up to 201.2 MPa, 147.8 MPa, and 128.4 MPa, respectively. The proposed research provides the design basis for laminated composite metal plates fabrication by explosive welding technology.

Effect of Operating Conditions on the Treatment of Cr (VI) Containing Wastewater by Electrocoagulation with Aluminum and Stainless Steel Electrodes

This work is aimed to evaluate the influence of operating conditions on the removal of Cr (VI) from wastewater by the application of electrocoagulation. For this, a bench-scale electrocoagulation reactor provided with aluminum stainless steel electrodes was built and used in the treatment of chromium-containing synthetic wastewater in a range of 10–50 mg/L. According to our results, the use of stainless steel electrodes placed with a gap separation of 1.0–2.0 cm, initial pH of 8.5, and 30 V electric potential led to the best results. Additionally, by a simplified operating costs estimation it was found that from 7.04 to 8.13 USD/m3 are required to reach complete removal of Cr (VI).

Aluminum-to-Steel Cladding by Explosive Welding

The production of aluminum-carbon steel and aluminum-stainless steel clads is challenging, and explosive welding is one of the most suitable processes to achieve them. The present work aims to investigate the coupled effect of two strategies for optimizing the production of these clads by explosive welding: the use of a low-density interlayer and the use of a low-density and low-detonation velocity explosive mixture. A broad range of techniques was used to characterize the microstructural and the mechanical properties of the welds, specifically, optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, electron backscatter diffraction, microhardness and tensile-shear testing with digital image correlation analysis. Although aluminum-carbon steel and aluminum-stainless steel have different weldabilities, clads with sound microstructure and good mechanical behavior were achieved for both combinations. These results were associated with the low values of collision point and impact velocities provided by the tested explosive mixture, which made the weldability difference between these combinations less significant. The successful testing of this explosive mixture indicates that it is suitable to be used for welding very thin flyers and/or dissimilar materials that easily form intermetallic phases.

Temperature cycle analysis of A6061-AISI304 dissimilar metal continuous drive friction welding

In the previous study, Continuous Drive Friction Welding (CDFW) had been investigated to determine the strength of joining, burn off, and temperature distribution. In this study, Dissimilar Metal CDFW was studied to assess temperature cycle analysis. Aluminum 6061 (A6061) workpiece was fixed, and an AISI 304 was rotated at 1,000 rpm. The temperature distribution was measured by using an OMEGA Thermocouple Data Logger. The thermocouple was installed near joining location 5 mm distance from the joint. In the computer simulation, the geometry of CDFW was designed using ANSYS Design Modeler. Computer simulation with transient thermal combined with static structural analysis was modeled by using ANSYS academic version Rel. 18.1. The boundary condition was set based on the experimental condition, where the Aluminum 6061 was fixed, and the AISI 304 was rotated at 1,000 rpm. Based on the experimental results, the temperature profile as the outer surface of the distance of the center of the joint location can be measured. From the simulation results, it can be seen that the temperature cycle profile is the same trend with experimental results. The mechanical properties provided that this phenomenon is shown in the characteristics of tensile strength, microstructure and hardness test as model analysis to denote the connection from temperature cycle profile with mechanical properties test results. Microstructure observation revealed that there is no significant difference in grain size and grain shape on the stainless steel side. Computer simulation results showed that the welded aluminum-stainless steel joint shows marks of heat affected zone near the weld interface only on the aluminum side, and this was confirmed by experimental results

Comparative evaluation of aluminum and stainless steel dissimilar welded joints

Today’s need of lightweight and fuel efficient vehicles in automobile triggers the researchers to develop light weight structures through hybrid or dissimilar welding joints. Dissimilar weld of aluminum and stainless steel offers promising solution in this direction. Many researchers have tried different techniques to produce dissimilar aluminum stainless steel weld using existing commercialized techniques like MIG welding and friction stir welding. In this communication effort have been made to make aluminum stainless steel dissimilar weld with newly friction crush welding technique and weld compression was made with the other techniques available in literature base on micro structural studies. The result shows FCW and FSW weld having good diffusion and inter-looking between dissimilar metals as compared to MIG welding technique.

Fuzzy optimization for the removal of uranium from mine water using batch electrocoagulation: A case study

This research presents a case study on the remediation of a radioactive waste (uranium: U) utilizing a multi-objective fuzzy optimization in an electrocoagulation process for the iron-stainless steel and aluminum-stainless steel anode/cathode systems. The incorporation of the cumulative uncertainty of result, operational cost and energy consumption are essential key elements in determining the feasibility of the developed model equations in satisfying specific maximum contaminant level (MCL) required by stringent environmental regulations worldwide. Pareto-optimal solutions showed that the iron system (0 μg/L U: 492 USD/g-U) outperformed the aluminum system (96 μg/L U: 747 USD/g-U) in terms of the retained uranium concentration and energy consumption. Thus, the iron system was further carried out in a multi-objective analysis due to its feasibility in satisfying various uranium standard regulatory limits. Based on the 30 μg/L MCL, the decision-making process via fuzzy logic showed an overall satisfaction of 6.1% at a treatment time and current density of 101.6 min and 59.9 mA/cm2, respectively. The fuzzy optimal solution reveals the following: uranium concentration – 5 μg/L, cumulative uncertainty – 25 μg/L, energy consumption – 461.7 kWh/g-U and operational cost based on electricity cost in the United States – 60.0 USD/g-U, South Korea – 55.4 USD/g-U and Finland – 78.5 USD/g-U.

Influence of Grooved Base Plate on Microstructure and Mechanical Strength of Aluminum–Stainless Steel Explosive Cladding

In this study, aluminum 6061 (AA6061) plates are explosively cladded with stainless steel 304 (SS304) plates having ‘V’ and dovetail grooves machined on the mating surfaces of the stainless steel plates. The results are correlated with the outcome of Al 6061-groove less SS 304 explosive clads. The machining of the grooves promotes undulating interfaces, due to the enhancement in the kinetic energy utilization. Though, a slender molten layer formation comprising of FeAl2, Al3Fe and Al5Fe2 compounds are observed in the crest of the grooves, mechanical strength of the clads increases because of the enhanced integrity across the grooved region. Micro-hardness increases in the closer proximity of the collision surface, while the tensile and shear strength of the AA6061-grooved SS304 explosive clads are higher than the conventional Al-groove less steel explosive clads. Of the two grooved base plates attempted, V-grooved base plate exhibits superior microstructure and strength characteristics. Fracture surface of both tensile and shear test specimens exhibits ductile and mixed mode of fracture at different locations of the clad.

Microstructure and mechanical behaviour of aluminium-carbon steel and aluminium-stainless steel clads produced with an aluminium interlayer

The influence of an interlayer on the microstructure and the mechanical behaviour of aluminium‑carbon steel and aluminium-stainless steel clads produced by explosive welding was studied. Different series of welds were produced both with and without an aluminium interlayer, testing different welding parameters. The combination of aluminium to carbon steel presented a better weldability than aluminium to stainless steel. For both couples, low-velocity welds presented the best microstructure and mechanical strength. The mechanical tests showed that the aluminium to carbon steel joining did not benefit from the use of the interlayer. A joint with good interfacial morphology and excellent tensile-shear properties was achieved by low-velocity direct welding, with the fracture occurring outside the joining region. For the aluminium to stainless steel couple, the use of the interlayer increased its weldability. However, the mechanical strength of the joint is restricted by the low strength of the interlayer. The presence of intermetallic compounds at the weld interface, does not, by itself, promote the poor-quality of the explosive weld. The way the interface accommodates and distributes these intermetallics dictates the weld's quality.

Effect of core materials on the low-velocity impact behaviour of trapezoidal corrugated sandwich panels

A combined experimental study and numerical simulation is performed to investigate the effect of core materials on low-velocity impact behaviour of sandwich panels. Dynamic responses of three types of corrugated sandwich panels with the same geometric configurations, which consist of the same CFRP (carbon fibre-reinforced plastic) face sheets, but the different corrugated cores including aluminium alloy, stainless steel and CFRP are investigated in the present research. Reasonably good agreement has been achieved by comparing impact force, energy absorption and failure modes between experimental results and numerical simulation predictions. The present research reveals that fracture stress and fracture strain of the core material have a significant influence on the performances of the sandwich panels under low-velocity local impact, sandwich panels with stainless steel core has the largest capability of load carrying and energy absorption. Conclusions presented in the present research would be used in the development of neoteric lightweight multifunctional smart structures.