Search Results (39)

Laser–MIG hybrid welding–brazing was performed to join TC4 titanium alloy and 5083 aluminum alloy with ER5356, ER4043 and ER2319 filler wires. The effects of the different filler wires on the microstructural features and mechanical properties of Ti/Al welded–brazed butt joints were investigated in detail. The wetting and spreading effect of the ER4043 filler wire was the best, especially on the weld’s rear surface. Serrated-shaped and rod-like IMCs were generated at the top region of the interface of the joint with ER4043 filler wire, but rod-like IMCs did not appear at the joints with the other filler wires. Only serrated-shaped IMCs appeared in the middle and bottom regions for the three filler wires. The phase compositions of all the IMCs were inferred as being made up of TiAl₃. The average thickness of the IMC layer of joints with the ER5356 and ER2319 filler wires was almost the same and thinner than that of the joint with the ER4043 filler wire. The average thickness was largest in the middle region and smallest in the bottom region for all the joints with the three filler wires. The average microhardness in the weld metal of ER5356, ER4043 and ER2319 filler wires could reach up to 77.7 HV, 91.2 HV and 85.4 HV, respectively. The average tensile strength of joints with the ER5356, ER4043 and ER2319 filler wires was 106 MPa, 238 MPa and 192 MPa, respectively. The tensile samples all fractured at the IMC interface and showed a mixed brittle–ductile fracture feature. These research results could help confirm the appropriate filler wire for the laser–MIG hybrid welding–brazing of Ti/Al dissimilar butt joints. Full article

TC4 titanium alloy and 5083 aluminum alloy with different groove shapes were joined by laser-MIG hybrid welding–brazing using ER4043 filler wire. The effects of groove shape on the weld formation, intermetallic compounds and tensile property of the Ti/Al butt joints were investigated. The welds without obvious defects could be obtained with grooves of I-shape and V-shape on Ti side, while welds quality with grooves of V-shape on Al side and V-shape on both sides were slightly worse. The interfacial intermetallic compounds (IMCs) on the brazing interface were homogeneous in the joints with groove of V-shape on Ti side, and V-shape on both sides, which had similar thickness and were both composed of TiAl₃. Unlike the IMCs mainly composed of TiAl₃ at the I-shape groove interface, TiAl₃, TiAl, and Ti₃Al constituted the IMCs at the V-shape on Al side interface. The average tensile strength of Ti/Al joints with groove of I-shape was the highest at 238 MPa, and was lowest at 140 MPa with groove of V-shape on Al side. The tensile samples mainly fractured at IMCs interface and the fractured surfaces all exhibited mixed brittle–ductile fracture mode. Based on the above research results, I-shape groove was recommended for laser-arc hybrid welding–brazing of 4 mm thick Ti/Al dissimilar butt joints. Full article

The corrosion behavior was investigated for three Al-Mg aluminum alloys (i.e., 5052, 5083 and 5182 aluminum alloys) with different alloying contents in 3.5 wt.% NaCl solution at 35 °C by means of potentiodynamic polarization, electrochemical impedance spectroscopy, immersion test, X-ray photoelectron spectroscopy and microscopy techniques. All alloys spontaneously passivate in the test solution, but the pitting corrosion takes place at the intermetallic phases during the long-term immersion test. The comparative analyses indicate that more Mg and less Cr in aluminum alloys result in increases in the passive current density and the pit depth and decreases in the polarization resistance, the pitting potential and the ratio of Al₂O₃/Al(OH)₃ in the product film. However, the differences in the pitting potentials of the three aluminum alloys are smaller than approximately 22 mV. Their pit depth values are less than 110 μm after 120 days of immersion. The three aluminum alloys have relatively high corrosion resistance in the simulated seawater solution. Full article

The atmospheric corrosion behavior of type 2024, 5083, 6061, and 7075 aluminum alloys in the Antarctic environment was investigated by outdoor exposure tests and indoor characterization. After one year of exposure to the Antarctic atmosphere, significant differences in surface corrosion states were observed among the specimens. The results revealed that the corrosion rate of the 2024 aluminum alloy was the highest, reaching 14.5 g/(m²·year), while the 5083 aluminum alloy exhibited the lowest corrosion rate of 1.36 g/(m²·year). The corrosion products formed on the aluminum alloys exposed to the Antarctic environment were primarily composed of AlOOH and Al₂O₃. In the Antarctic atmosphere environment, the pits were dominated by a freezing–thawing cycle and salt deposition. The freezing–thawing cycle promotes the wedge effect of corrosion products at the grain boundary, resulting in exfoliation corrosion of high-strength aluminum alloys. Full article

To effectively use aluminum, which is inherently weak under heat, as a material for hull construction, it is crucial to precisely predict the thermal deformation in the weld zone. Most studies employing finite element (FE) methods to predict thermal deformation due to welding typically use estimated heat source conditions based on the results of the weld. However, these estimated values can differ significantly from the actual welding conditions. In this study, we investigated whether using the actual shape of the heat source, rather than an estimated value, can serve as a reliable condition for analysis in predicting thermal deformation. This prediction is essential for minimizing deformation in the fillet welds of an aluminum hull. To compare deformation outcomes, Al 5083, commonly used in hull construction, was selected as the base material. The thermal deformation of aluminum hull fillet welds, welded using the Cold Metal Transfer (CMT) welding method, which reduces heat input, was measured. The simulation results demonstrated similar deformation trends, with discrepancies ranging from a minimum of 0.02 mm to a maximum of 1.4 mm when using actual welding conditions and heat source shapes. The results of this study confirm that the actual heat source shape can be utilized as a reliable condition for predicting thermal deformation in aluminum hull welds. The aim is to contribute to the improvement of aluminum hull manufacturing quality by providing essential data for establishing welding conditions and minimizing deformation. Full article

The wetting behaviors of Al-Si-Cu-Mg-Zn brazing materials on 5083 aluminum alloy substrate were investigated through changing the proportion of Mg from 0 to 2 wt.%. The experimental results showed that the welding process goes through the three following stages: slow spreading, fast spreading, and stabilizing. The wettability of the brazing material was improved effectively, and the porosity of the interfacial layer was reduced, with the addition of Mg. With Mg content at 1 wt.%, the wetting diameter reached a maximum value of 20.46 mm. The reaction mechanism of the wetted interfacial layer between the brazing material and substrate alloy was illustrated with dynamic data, provided through experimentation and simulated thermodynamic calculation, and showed that the wetting behavior of the resultant Al-7.5Si-15Cu-1Mg-5Zn brazing material was dominated primarily by a diffusion reaction from elemental magnesium. Full article

The present study deals with the parameters for Stainless Steel 304 and Aluminum 5083 optimized with an emphasis on surface roughness, cure time, and their impact on the tensile strength of single-lap shear joints. Utilizing a central composite design, the effects of these factors were examined. Acetone was used to polish the surfaces, and silicon carbide sheets (P30, P36, and P60) were used to abrade them. Utilizing Henkel Loctite HY4090 glue, testing was conducted in accordance with ASTM D1002 guidelines. The variables were optimized with Design-Expert 11. Maximum tensile strengths were obtained with P30 abrasion and a 48-h cure time for SS304 (Ra = 3.2 µm) and Al5083 (Ra = 5 µm), respectively. Full article

In this study, as a vital part of the production of Mn-increased 5083 Al alloy, i.e., homogenization annealing before hot rolling, the target states of key Al₆Mn precipitation, including the dispersed, initial coarsening and intensive coarsening states, were designed, and the corresponding precipitates formed via the control of the temperature and holding time in the annealing process. By means of metallographic corrosion and nitric acid mass loss tests (NAMLT) for assessing the intergranular corrosion (IGC) resistance, temperatures ranging from 175 °C to 225 °C were determined to induce a transition from sensitization to stabilization for this innovative 5083. At a temperature of 175 °C for a duration of up to 24 h (2 h, 4 h, 8 h, 16 h, 24 h), the results show that when the soak time is 24 h, the sample with initially coarsened Al₆Mn phases has a lower degree of sensitization (DOS) compared to the samples with Al₆Mn phases in both the dispersed and intensive coarsening states, and its NAMLT is reduced by 11% and 15%, respectively. Subsequently, transmission electron microscopy (TEM) analysis has investigated that for the sample with the best IGC resistance, i.e., that with initially coarsened Al₆Mn phases, plate-like Al₆Mn particles (200~500 nm) can act as heterogenous nucleation sites for β phases, driving their preferential precipitation on Al₆Mn particles and resisting their precipitation along grain boundaries, ultimately improving the IGC resistance of 5083 Al alloy after homogenization annealing. Full article

Aluminium–magnesium alloys find widespread application in diverse industrial and technological fields owing to their unique characteristics such as lightweight nature, favourable physical and mechanical properties, corrosion resistance and cost-effectiveness. During production, these alloys often undergo various forming processes that significantly affect the morphology and microstructure of their surface layers. Consequently, the surface properties, including corrosion resistance, are notably influenced by these treatments. In this study, the impact of cold rolling on the corrosion behaviour of the 5083 aluminium alloy, which is considered as an important alloy for the aerospace and naval industry, was investigated. The 5083 Al alloy underwent a cold-rolling process, resulting in specimens with reduced average thicknesses of 7% and 15%, respectively. The microstructure of the alloy was examined by using X-ray diffraction, optical and scanning electron microscopy techniques. Furthermore, the corrosion behaviour of both the as-received and cold-rolled aluminium alloy specimens was evaluated through potentiostatic and potentiodynamic corrosion measurements. The experimental results demonstrated that higher cold deformation percentages, within the specified experimental parameters, led to an enhanced corrosion resistance for the alloy. This improvement was primarily attributed to the reduction in grain size induced by recrystallization and to the formation of a passivating aluminium oxide film. Full article

Aluminum alloys 5083, 6061, and 7075 are prone to hot tearing under direct-chill casting conditions; the defects that form during solidification of those alloys are highly sensitive to variation in the alloying elements, with these elements commonly being Si, Fe, Cu, and Ti. This study investigates the influence of the morphology, content, and size of intermetallic compounds on the hot tearing behavior of the 5083, 6061, and 7075 aluminum alloys by combining a constrained rod casting technique, phase diagram calculation, and multiscale microstructural characterizations. The fishbone-shaped α-Al₁₅(Fe,Mn)₃Si₂ in 5083 can serve as a path for crack nucleation and growth, and an increase in Si content results in Mg₂Si assuming fishbone morphology, thereby increasing hot tearing susceptibility. The amount of plate-like β-Al₅FeSi is the primary factor controlling the hot tearing susceptibility of 6061. For 7075, increasing the Cu content can greatly enhance the remaining liquid fraction, feeding, and hot tearing susceptibility. For all three alloys, TiB₂ grain refiner minimizes hot tearing. This study elucidates the influences of the amounts of Fe, Si, Cu, and TiB₂ grain refiner on hot tearing susceptibility. The findings can help establish compositional control standards for the 5083, 6061, and 7075 aluminum alloy series, particularly when the recycling rate must be increased. Full article

In this paper, 5083 aluminum alloy and T2 copper were selected for the friction stir lap welding test. The effect of intermetallic compounds on the microstructure and properties of Al/Cu dissimilar metal lap joints was studied. The results showed that the circulating Al/Cu composite structure was formed on the advancing side of the lap joint, and the Al/Cu staggered hook-like structure and copper-rich region were generated on the retreating side. There was no typical ‘onion ring’ structure in the joint. Element diffusion occurred at the interface of the joint, forming a thin and uniform interfacial layer of Al/Cu intermetallic compounds, thus achieving a well-metallurgical bond at the Al/Cu interface. There were the intermetallic compounds Al₂Cu and Al₄Cu₉, without AlCu, in the lap joint. In addition, dynamic recrystallization occurred in the nugget zone, and higher dislocation density and dislocation entanglement were generated, which enhanced the deformation resistance in the nugget zone and increased the joint strength. The tensile test showed that the ductile–brittle mixed fracture occurred in the heat-affected zone on the advancing side of the aluminum plate, and the fracture had necking. The failure load of the lap joint was 4350 ± 30 N, about 80% of the aluminum base metal. The elongation of the Al/Cu dissimilar lap joint tensile specimen was 2.5%. Full article

This study deals with the microstructure of rolled Al5083-H111 materials, their hardness, corrosion in different solutions, and rotary bending fatigue properties of non-corroded and corroded samples in different solutions. This study is the first to report the fatigue behavior of corroded samples in different aggressive corrosion environments of Al5083. The microstructure of the Al5083-H111 material is in the form of grains oriented towards the rolling direction and it consists of binary Al-Mg, Al-Mn, and Mg-Si; ternary Al-Mg-Si; and quaternary Al-Mn-Fe-Si and Al-Cr-Mn precipitated randomly at the grain boundary. The Brinell hardness of the Al5083-H111 material is 68.67 HB. According to the results of the immersion corrosion, while the sample was more resistant to corrosion in a 3.5% NaCl environment, it showed a less resistant behavior in a 3.5% NaCl + 10% HCl environment. As a result of the fatigue test, it was observed that the sample that did not undergo corrosion showed a higher fatigue life than the samples that were exposed to corrosion. The fatigue rate of the 3.5% NaCl corrosion sample was 3.5 times lower than the fatigue rate of the 3.5% NaCl + 10% HCl corrosion sample. Full article

In this study, Al_0.8CrFeCoNiCu_0.5B_0.1 high-entropy alloy coating was prepared on the surface of 5083 aluminum alloy using laser cladding technology. The corrosion behavior of the coating and substrate in 3.5% NaCl solution was analyzed using experimental methods, including polarization curves and electrochemical impedance spectroscopy. The corrosion current density of Al_0.8CrFeCoNiCu_0.5B_0.1 coating is 2.04 × 10⁻⁷ A/cm ². The passivation range width reaches 2.771 V, and these polarization test results are superior to the substrate. The Al_0.8CrFeCoNiCu_0.5B_0.1 coating exhibited selective corrosion behavior, with the Cu-rich FCC1 phase and Cr-poor phase being susceptible to corrosion, leading to localized pitting and intergranular corrosion traces, but the corrosion did not spread extensively. The intergranular distribution of Cu is the main reason for the intergranular corrosion trace features. In contrast, the substrate exhibited overall corrosion. The Nyquist plot of the Al_0.8CrFeCoNiCu_0.5B_0.1 coating consisted of a single capacitive semicircle arc in the high-frequency region with a larger radius than the substrate. In conclusion, using the Al_0.8CrFeCoNiCu_0.5B_0.1 high-entropy alloy as a coating can significantly improve the corrosion resistance of the 5083 aluminum alloy substrate. Full article

Ultrafine-grained Al matrix nanocomposites, reinforced with Al₂O₃ nanoparticles, were produced from milled powders, either by equal channel angular pressing (ECAP), at room or high temperature, with or without back pressure, or by spark plasma sintering (SPS). Their microstructures, mechanical properties (compression, hardness, and sliding wear), and thermal stabilities (thermally induced softening and cracking) were compared, and the advantages and limitations of each process discussed on a scientific but also practical point of view. For the most successful set of process parameters, the yield stress in compression reached 380 MPa, the hardness, HV = 139, remained stable up to 500 °C, and the resistance to sliding wear was comparable to that of Al 5083, and better than that of Al 7075-T6. While the samples consolidated at high temperatures (by ECAP or SPS) showed a good thermal stability, those consolidated by ECAP at room temperature were prone to thermally induced softening and cracking, which was related to trapped and pressurized gases. Full article

Aluminum alloy has been used as the skin material for rail vehicles and automobiles to meet the requirements of environmental protection. The hot stamping-in-die quenching composite forming (HFQ) process is a promising technology to compensate for the poor formability of the aluminum alloy sheet at room temperature. In this paper, the high-temperature mechanical properties of 5083 aluminum alloy under various temperature (200 °C, 300 °C, 400 °C, 450 °C) and strain rate conditions (0.01 s⁻¹, 0.10 s⁻¹, 1.00 s⁻¹) were investigated by uniaxial tensile tests. The finite element software of PAM-STAMP was employed to simulate the forming process of high-speed train skin. The effects of forming method and process parameters on the minimum thickness and springback of the skin were analyzed using the Response Surface Methodology (RSM). After parameter optimization, the forming experiment verified the simulation results and the test part met the quality requirements: the thickness above 3.84 mm and the springback within 1.1 mm. Mechanical properties of the sheet before and after HFQ were examined by uniaxial tensile tests at room temperature. It can be inferred from the comparison that the yield strength of the Al5083 sheet increases, but the elongation decreases from the HFQ process. Full article