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Aluminum-Steel joining is an example of a multi-material design. An amalgamation of both the material is very beneficial, yet they pose their set of difficulties in joining due to a significant difference in properties. Solid-state joining processes such as friction stir welding are beneficial in avoiding fusion and formation of a thick intermetallic layer in the Al-steel joint. Critical control of process parameters and tool geometry is essential in friction stir welding to attain a reasonably sound joint. In present work, butt welding of low carbon steel with Aluminum 5052 alloy is performed with the use of three different tools. Progressive refinement in the geometry of tools was done to achieve the optimized dimensions of the tool. The weld joints obtained from various tools were compared based on heat generation. The joints were characterized based on peak temperature achieved, tensile strength, and the number of steel fragments in the Al matrix through micrographs. The weld joint was observed under an optical microscope and Field emission scanning electron microscope (FESEM) for quantification of intermetallic compounds (IMC) layer. Energy-dispersive X-ray spectroscopy (EDX) and XRD analysis were performed to investigate the phase and composition of the IMC layer. The fractured surface under tensile loading was observed under high magnification scanning electron microscope. The tool with a shoulder diameter of 13 mm and a cylindrical pin was found to be optimized for its minimum heat generation and strongest weld joint formation with a minimum number of void-causing steel fragments.

Electromagnetic impaction forming of 5052 aluminium alloy sheets using a V-shaped die and a conical die was performed. The conventional quasi-static forming limit curve (QS-FLC) is obtained according to the linear loading condition, which can only describe linear strain paths. However, it cannot accurately evaluate the formability of electromagnetic impaction forming, especially strain paths that have become highly non-linear. In this study, the formability of electromagnetic impaction forming, which considers a bilinear strain path and a continuous highly non-linear strain path, was investigated. The conventional QS-FLC is no longer suitable to evaluate the formability of electromagnetic impaction forming. Therefore, modified FLCs were established in strain space that follow bilinear strain paths and continuous non-linear strain paths. The actual formability improvement was compared with the modified FLC. The maximum safe strain of bilinear strain paths near the sidewall of V-shaped specimens increased in formability by approximately 30% at the discharge voltage of 20 kV compared with conventional QS forming. The maximum safe strains near the apex of the conical specimens increased in formability by approximately 100% at the same discharge energy. It should be noted that the increase in formability above the modified FLC is a conservative estimate, because the limit strains at the necking location were not known in the electromagnetic impaction forming. The influencing factors of the formability improvement of 5052 aluminium alloy sheet in electromagnetic impaction forming were also discussed.

In this paper, the morphology, phase composition and corrosion behavior of micro-arc oxidized 5052 aluminum alloy were analyzed. A uniform micro arc oxidation (MAO) coating was performed on 5052 aluminium alloy in different electrolytes (with and without borax additives) for 30 min. The MAO coating thickness was measured around 17–24 µm and nanocrystalline γ-Al2O3 were identified in the MAO coating using XRD analysis. The coating thickness was measured using the eddy current technique and morphology of the coating was analyzed using SEM. The coating formed in the electrolyte with borax showed reduced porosity compared to the sample coated without borax. The corrosion behavior is analyzed by Potentiodynamic polarization. The MAO coated sample offers higher corrosion resistance when compared to the uncoated specimen due to higher corrosion potential.

For enhancing the strength of AA 5052 alloy, cryorolling is performed up to 50% and 75% reduction. The 75% reduction cryorolling shows excellent strength than the unrolled and 50% reduction alloy. However. Cryorolling of AA5052 alloy results in poor corrosion resistance. The reduction in corrosion resistance is due to an increase in dislocation density by cryorolling. Hence micro-arc oxidation (MAO) is adapted to coat Al2O3 on the surface to reduce the corrosion rate of cryorolled sheets. MAO is performed with three borax concentration viz. 0, 1 and 2 g in the solution. The increase in borax concentration up to 1% shows high corrosion resistance and a further increase in borax concentration has shown detrimental influence on corrosion resistance which is due to the delamination of the coating with severe cracking.

A laser beam joining an Al-on-steel overlap configuration of 5052 aluminum alloy and Q235 steel was conducted with Sn-30Zn filler wire. The influence of processing parameters on weld appearance was investigated. The microstructures and mechanical property of the joints were analyzed. The results show that Sn-Zn filler wire could well wet 5052 aluminum alloy and the steel under heating of defocusing laser. Good weld appearance was obtained by suitable processing parameters. The solid solution interface was formed at the aluminum alloy side and intermetallic compounds (IMCs) interface was formed at the steel side. With increasing laser power, intergranular penetration of the Al side aggravated, and the thickness of the IMCs layer at the steel side increased. It was found that all of the joints fractured in the seam according to the results of the tensile tests. The intergranular penetration and IMCs did not reduce the mechanical property of the joint. The maximum value of fracture load reached 312 N/mm. The fractured surface was characterized as a ductile fracture. The influence of processing parameters on the microstructures and mechanical property was discussed.

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.

Vibration-assisted laser welding experiment of 5052 aluminum alloys was carried out to focus on the influences of vibration parameters on microstructure and fatigue fracture. The experiment found that the vibration process homogenized the microstructure and promoted the formation of fine equiaxed grains significantly. In addition, vibration made the hardness uniform by reducing the area of the fusion zone. Experimental results of double welds showed that residual stress reduced by 58 to 77% under the action of micro-vibration. Vibration frequency and vibration acceleration had significant effects on the longitudinal and transverse residual stress, respectively. Under the same fatigue load condition, the average fatigue limits of the base metal (BM) and the welded joints were 160 and 120 MPa, respectively. Under the conditions of 107 cycles, the maximum fatigue strength of the welded joints has reached 74.95% fatigue strength of the BM. Vibration-assisted laser welding could obviously improve the fatigue performance and increase the fatigue life of the welded joints, which was a potential way to improve the quality of welded joints.

FSSW is a solid state joining method gained its significance as an alternate welding technique in the in electrical, electronic and automobile industries that used FSW welding. FSSW can be used to welding dissimilar joints of material with variation in metallurgical and mechanical characteristics. In this paper, dissimilar welding joints of aluminum alloys (5052) and pure copper (10100) with a thickness of 1.67 mm were welded by FSSW. The variation of rotational speed, dwell time and filler content have been used. The welding joints has been examined by tensile shear test. The scanning electron microscope SEM and X-ray diffraction are used to investigate the hook and intermixing layer characteristics. It was found the best welding condition is (1400 rpm) and (30 sec) which the joint is possess the tensile shear force (3340 N). Adding ZnO filler led to increase the thickness of the copper hook, and expanding the stir zone (weld width bond). Joints with V2-ZnO have highest thickness of intermixing layer (IM), length of weld width bond and best tensile shear force (4300 N).

In the metal inert gas (MIG) weld-brazing process, the lap-joint welds between 5052 aluminum alloy and automotive galvanized steel sheet were achieved employing an automatic MIG welding machine. The different percentage of helium (He) gas addition to pure argon (Ar) shielding gas was selected to investigate the performance of lap-joint welds such as appearance of weld bead surface, weld bead geometry, microstructure, tensile strength, fracture surface of welds and thickness of intermetallic compounds (IMCs) layer between the dissimilar materials in the brazing zone. The results showed that the lap-joint welds produced by adding 5% and 10% He gas to Ar shielding gas were provided with better performance of specimens. The average tensile strength of lap-joint welds between 5052 aluminum alloy and automotive galvanized steel sheet is 206.23 MPa. In additions, the amount of porosity in the fusion zone that specimens produced by using 10% He addition to Ar-based shielding gas is less than others. It can be found that the thickness of IMCs layer between the weld bead and automotive galvanized steel sheet from 3.30 μm to 4.90 μm.

The inhomogeneous properties of 5052 aluminum alloy/304 stainless steel rotary friction welded joint and the growth behavior of intermetallic compound (IMC) layer were investigated. The ultimate tensile strength (UTS) of as-welded joint in 0R location with discontinuous IMC layer reached the maximum value of 203 MPa, and that in R/2 and 3R/4 locations decreased with the increase of IMC layer thickness, but that in R/4 location was the lowest due to the initiation of crack. After post-weld heat treatment at 250 °C/20 min, the thickness of IMC layer remained invariant, but the UTS of entire joint increased from 153 MPa to 161.4 MPa. In addition, the difference of UTS along the radius direction decreased, which benefited the engineering application. During post-weld heat treatment at 450 °C, the growth of IMC layer in R/4, R/2 and 3R/4 location were faster than that in 0R location. However, the growth of IMC layer deviated from parabolic law, which was attributed to (i) a large number of dislocations, grain boundaries and storage energy in the interface, (ii) the linear growth of Fe4Al13 phase, and (iii) the effect of Cr element.

Aluminium alloys have recently been utilised in the fabrication of thin-walled members using a roll-forming technique to produce purlins, floor joists and other structural bearers. Such members are often subjected to transversely concentrated loads which may possibly cause a critical web crippling failure. Aluminium specifications do not explicitly provide clear design guidelines for roll-formed members subjected to web crippling actions. Therefore, this study was conducted to investigate the mechanism of web crippling for roll-formed aluminium lipped channel (ALC) sections with flanges attached to supports (fastened) under two-flange loading conditions. Based on the experimental works presented in a companion paper, numerical simulations were conducted including an extensive parametric study covering a wide range of ALC geometrical dimensions, bearing lengths, and 5052 aluminium alloy grade with H32, H36 and H38 tempers. The acquired web crippling data were then used to investigate the influence of the flange restraints on the web crippling mechanism of the ALC sections. Furthermore, a detailed assessment of the consistency and reliability of the currently available design rules used in practice was carried out. The predictions of the web crippling design guidelines given in the Australian, American and European specifications were found to be unsafe and unreliable, whereas a good agreement was obtained between the predictions of our recently proposed design guidelines and acquired web crippling results. Further a suitable Direct Strength Method (DSM)-based design approach was developed in this study with associated equations to predict the elastic bucking and plastic loads of fastened ALC sections under two-flange loading conditions.

Microbiologically influenced corrosion caused by sulfate-reducing bacteria (SRB) poses a serious threat to marine engineering facilities. This study focused on the interaction between the corrosion behavior of two aluminum alloys and SRB metabolic activity. SRB growth curve and sulfate variation with and with aluminum were performed to find the effect of two aluminum alloys on SRB metabolic activity. Corrosion of 5052 aluminum alloy and Al-Zn-In-Cd aluminum alloy with and without SRB were performed. The results showed that both the presence of 5052 and Al-Zn-In-Cd aluminum alloy promoted SRB metabolic activity, with the Al-Zn-In-Cd aluminum alloy having a smaller promotion effect compared with 5052 aluminum alloy. The electrochemical results suggested that the corrosion of the Al-Zn-In-Cd aluminum alloy was accelerated substantially by SRB. Moreover, SRB led to the transformation of Al-Zn-In-Cd aluminum alloy corrosion product from Al(OH)3 to Al2S3 and NaAlO2.

The impact failure experiment of aluminum plate is the main method to study the failure mechanism of aluminum plate under the condition of rapid deformation. In this paper, the impact experiment of 5052 aluminum alloy plate with different impact energy combination were carried out to study the low speed impact behavior of 5052 aluminum alloy plate under various conditions. The effect of different parameters on the impact property of 5052 aluminum alloy plate during impact process were explored by experiments and numerical simulations.The results show that under the same energy, the combined impact of the punch with lower mass and higher impact velocity (i.e., smaller momentum) causes greater damage to the 5052 aluminum alloy plate. The impact load, energy absorption and damage form are closely related to impact energy and punch momentum.The dynamic relations of energy, displacement, velocity and time during the collision process obtained by the actual parameter experiment are basically consistent with the numerical simulation results, which verifies the reliability of the numerical simulation method.

A laser penetration welding-brazing combined with Cold Metal Transfer (CMT) arc, was proposed to improve weld shape and interfacial reaction inhomogeneity of 5052 aluminum alloy and Q235 low carbon steel with ER5356 welding wire in butt joint. The effects of wire feed speed, beam offset and welding speed on weld shape, interfacial microstructures and tensile strength of joints was studied. This method improved the undercut defect existed in butt laser welding-brazing, obtained well-formed joints and promoted the uniform distribution of the interface reaction. The interfacial intermetallic compounds (IMCs) layer consisted of Fe2Al5 and Fe4Al13 and the thicknesses were controlled to 3-5 μm. Microstructures of weld seam was composed of α-Al and Al3Mg2. The brittle IMCs layer thickened and then the tensile strength decreased with increasing the wire feed speed. The thickness of the IMCs layer decreased but weld shape became worse when the welding speed or the offset increased. The tensile strength increased first and then decreased. The highest tensile strength reached higher than 80 MPa and the joint fractured in IMCs layer along the interface.

In the design of hot forming processes for aluminum alloys, hot processing maps are usually used as a powerful tool for processing parameters optimizations. Although the stability of deformation is considered in conventional hot processing (CHP) maps, the difficulty of deformation, i.e., whether deformation is easy to occur, is not taken into account. Therefore, it is difficult for CHP maps to efficiently and accurately obtain the optimal processing parameters and achieve satisfying hot workability. Hence, in this study, thermal compression tests were performed to investigate the hot forming behavior of 5052 aluminum alloy in the deformation temperature range of 553-733 K and strain rate range of 0.001-1 s−1. We proposed an activation energy-processing (AEP) map by coupling the CHP map and the activation energy value, and thereby applied it to evaluate the hot workability of 5052 aluminum alloy. In CHP maps, the region with the highest power dissipation efficiency is generally considered to be the best processing region. However, the AEP map shows that materials with satisfying hot workability not only depends on high power dissipation efficiency, but also on low activation energy values. At the strain of 0.7, the optimal hot processing region predicted by the CHP map lies in the temperature range of 583-673 K and strain rate range of 0.001-0.1 s−1, but that predicted by AEP map locates in the temperature range of 643-733 K and strain rate range of 0.001-0.1 s−1. Microstructure characterization implies that the optimal processing region predicted by the CHP map presents necklace-like structures, which are non-uniform and unbeneficial for deformation, while that predicted by the AEP map consists of fine, uniform and equiaxed grains. Thus, it is implied that the processing regions predicted by the AEP map are more suitable for forming, i.e., the reasonability of the AEP map is verified.

The reaction layer of rotary friction welded 5052 aluminum alloy/304 stainless steel dissimilar joints consisted of Fe2Al5 and Fe4Al13 phases, and the distribution of intermetallic compounds (IMCs) and mechanical properties were inhomogeneous due to the inhomogeneity of heat generation along the radius direction. Almost no brittle IMCs formed in center part, while continuous and thicker IMCs formed in R/4, R/2, 3R/4 and edge locations, and the thickness of IMCs reached the maximum value in 3R/4 rather than in edge location. The joint efficiency was 99.51% in center location, higher than that in R/4, R/2, 3R/4 and edge locations. Meanwhile, the width of heat-affected zone on 304 stainless steel side decreased, but that of softened zone on 5052 aluminum alloy side increased from center to edge location. The entire joint fractured through the interface and predominantly presented brittle fracture feature. Cracks mainly propagated along the IMCs/AA5052 substrate interface for samples from center and R/4 locations, between the IMCs and the IMCs/AA5052 substrate interface alternately from R/2 and partial 3R/4 locations, and along the IMCs/304SS substrate interface from partial 3R/4 and edge locations.

This paper aims to investigate the crashworthiness performance degradation of a damaged 5052 aluminum honeycomb panels under in-plane uniaxial quasi-static compression and the possibility of improving it using reinforcement tubes. The in-plane crushing behaviors and energy absorption capacities of the intact, damaged, and tube-reinforced damaged panels with different damage sizes in both X1 and X2 directions are numerically simulated by using the nonlinear FE method Abaqus/Explicit, and the crashworthiness performances are compared with each other. The validation of finite element model involves comparing the obtained simulation results with theoretical and experimental ones. Very good agreement between numerical, experimental, and theoretical results is achieved. The first maximum compressive load and the mean crushing load of the different honeycomb configurations are analyzed and compared through the load–strain curves. The energy absorption capacity of the damaged and the tube-reinforced damaged panels is calculated and then compared with their corresponding intact ones. The deformation modes are explained in detail. The obtained results show that the crashworthiness performance degradation is directly proportional to the damage size as well as the insertion of reinforcement tubes considerably improves in-plane crushing resistance of damaged honeycomb panels.

Progress in sustainable manufacturing is a crucial element to minimise negative environmental impacts. The conventional fusion weld process used to join aluminium alloys resulted in coarse grain structure, inevitable defects, and severe joint softening. Friction stir processing (FSP) has the potential to modify the microstructure of materials in joint structure and improve the mechanical properties. In this investigation, the effect of friction stir post–processing was evaluated to study the microstructural characteristics and mechanical properties of GTAW (gas tungsten arc welding) welds in the aluminium 5052 alloy. During FSP, the grains’ dendritic microstructure was destroyed, and the dynamic recrystallisation resulted in a very fine and equiaxed grains structure in the fusion zone. The hardness of the friction-stir-processed welds significantly improved because of microstructure grain refinement. The processed joint demonstrated higher ultimate tensile and yield strength (~275 MPa and 221 MPa, respectively) and superior elongation (31.1%) compared to the unprocessed weld, at the same time, the mechanical strength (yield and ultimate tensile) is similar to that of the base metal.

The Hosford yield function can be used to describe both the plastic yield and plastic deformation of metal plates very well when the value of its exponential parameter $$\eta$$ is known. The values of $$\eta$$ for BCC and FCC metals have been determined to be 6 and 8, respectively, based on the Taylor crystal plasticity model. However, an effective experimental method has not been developed to determine the value of $$\eta$$ for metal plates. This work addresses the above issue by developing an experimental method for determining the value of $$\eta$$ for metal plates based on a theoretical model. Deep drawing experiments are conducted with 0.8 mm thick 5052 aluminum alloy plates, and the experimental value of $$\eta$$ is determined according to the theoretical model based on the experimentally measured thickness anisotropy coefficient, the known drawing coefficient, and the radial elongation ratio of the drawing cup obtained during the deep drawing experiments. The experiments yield an $$\eta$$ value of 8.02 for the aluminum alloy plates. The experimental value is verified by applying it within deep drawing simulations using Dynaform software based on the finite element method. The simulated cup height is in good agreement with the experimentally derived cup height. The value of $$\eta$$ can be determined for metal plates through deep drawing experiments based on the proposed methodology.

Nowadays the different industries is searching continuous improvements in the welding processes of the components of its products, in order to avoid the disadvantages obtained in the past by joining their parts through conventional fusion welding processes, affecting their microstructural development and consequently decreasing the principal mechanical properties. The friction-stir welding process is a solid state technique which does not reach the melting point of the material, promoting the plasticization of the metal by controlling its microstructure and mechanical behavior. However, the after mentioned advantages are the result of an adequate control of the process parameters, so that the aim of the present investigation is to study the microstructural and mechanical development of 5052-H32 butt joints welded by FSW process using a high wear resistance tool (PCBN tool) as well as the mechanical behavior suffered.

This paper presents a comparative research on 5052 aluminum alloy sheets joined by magnetic pulse welding (MPW), adhesive bonding (AB), and magnetic pulse weld bonding (MPWB) processes. Mechanical properties and failure mechanism of the joints were mainly focused on and investigated. Strain and fractured surface of joints were systematically analyzed to reveal the coupling effect of weld area and adhesive layer during lap-shear tensile test. Results showed that MPWB joint was capable of withstanding 6.09-kN lap-shear load increased to 91% and 41.06 J energy absorption which increased 6 times over those of MPW joint. In MPWB joint, adhesive layer firstly separated from the edge of overlap area to the middle, with weld area fractured subsequently. The weld area delayed the initiation and propagation of crack in the adhesive layer. In addition, different stress states of MPW and MPWB joints contributed to different shapes of dimples in the fractured surface. MPWB joint was occupied by a typical shear dimple, whereas both equal-axis and shear dimples were observed in MPW joint.

To solve the problems of poor quality and insufficient joint strength of aluminum alloy weld, a laser scanning welding test platform for aluminum alloy was built. Taking the butt welding of 5052 aluminum alloy with 5 mm and 3 mm thick specimens as the research objects, the study of a “∞”-shaped laser scanning welding process was conducted, and the similarities and differences between the welding process and that of single pass laser welding were compared. The influence of “∞”-shaped laser scanning welding parameters on the weld formation was investigated by the factor variable method. The change of the surface morphology and dynamic evolution of the molten pool was observed by a high-speed camera system. The optimal combination of the welding parameters was obtained by an orthogonal test. The research showed that the “∞”-shaped laser scanning welding pool had good stability and a good weld quality. Under suitable welding parameters, the length and width of the molten pool could be increased significantly compared with those of the single pass laser welding. The growth rate of the length and width could reach 110.19% and 57.69%, respectively. The surface of the weld was evenly distributed with dense fish scales, and the porosity was less than 1%. The tensile strength of the specimen could reach 205.242 MPa, which was 93% that of the base metal; the topography of fracture was full of dimples, and the metallographic structure of the weld was fine and distributed with equiaxed dendrites.

In this paper, the effects of temperature and strain rate on the plastic deformation behavior of 5052 aluminum alloy were investigated by quasi-static tensile test and split Hopkinson pressure bar (SHPB) experiments. Meanwhile, the stress-strain relations obtained through these experiments were employed for calibrating Johnson-Cook (J-C) plastic flow constitutive parameters of 5052 aluminum alloy. The results show that the strain rate sensitivity of 5052 aluminum alloy is insignificant in the range of 0.001s-1~3000s-1, while temperature has a great effect on the material plastic behavior. The experimental data are basically consistent with the predicted outcome of J-C constitutive model.

The purpose of this research is to investigate the corrosion resistance of 5052 aluminum alloy to increasing salinity in sea water. Salt spray chamber was used to measure and compare the corrosion rate of 5052 aluminum alloy with weight reduction method. The experiment was conducted by varying the three concentrations of NaCl solution to compare the corrosion rate of the metal. The test specimens used were aluminum alloy 5052 with length of 6 cm, width of 4 cm and thickness of 0.7 cm. The tests were carried out for 48 hours, aggressive NaCl solutions with concentrations of 3.5%, 4% and 5% were used as an artificial sea water corrosion medium and the temperature in the test chamber was maintained at 35 °C. Corrosion rate for 3.5% NaCl solution, 4% NaCl solution and 5% NaCl solution were 0.197 mm/year, 0.541 mm/year and 0.558 mm/year, respectively. The higher concentration leads to greater corrosion rate.

AlSi10Mg alloys reinforced by TiC particles were fabricated on 5052 aluminum alloys by laser additive manufacturing. The surface morphology, microstructure, microhardness, and tensile properties of the alloys fabricated with different processing parameters were investigated by optical microscope (OM), scanning electron microscope (SEM), Vickers hardness tester, and high-precision electronic universal testing machine. The results show that appropriate laser energy input leads to uniform distribution of TiC particles in the alloy. Fine needle-like TiC particles are precipitated from the grain boundary, which is beneficial to the improvement of mechanical properties of the alloy. The optimum process parameters are found to be 2500–3500 W for laser power, 600 mm/min for scanning velocity, and 2.0 mm for hatch spacing. For lower or higher laser energy input, aggregations are formed in the coatings. At the optimum processing parameters, the maximum microhardness and tensile strength of the TiC/AlSi10Mg alloys are much higher than those of others, which are 139.1 HV0.05 and 278.8 MPa, respectively. A large number of dimples have been found on the fracture surface of the alloys, which indicates the fracture mechanism of the alloy is ductile fracture.

The stress–strain relationship of 5052 aluminium alloy was investigated via quasi-static tensile tests and split Hopkinson pressure bar tests. The specimens were exposed to various temperatures (25–500°C) and strain rates (10−4–0.7 × 104 s−1). At strain rates ranging from 0.001 to 3000 s−1, the material underwent significant work hardening. When the strain rate exceeded 5000 s−1, the work hardening effect decreased and the flow stress was relatively constant. The Johnson–Cook constitutive model was modified to describe the deformation behaviour of the material subjected to high temperatures and strain rates. The accuracy of the modified model was verified through ballistic impact testing.

In order to achieve the finishing of complex microsurface, the magnetic abrasive finishing process using alternating magnetic field was proposed. In this paper, the mechanism of the magnetic abrasive finishing process using alternating magnetic field was investigated. At the same time, the influence of magnetic particle size and magnetic field frequency on magnetic cluster changes was observed and the relationship between finishing force and alternating magnetic field was analyzed. In addition, the feasibility of ultraprecision finishing of 5052 aluminum alloy plate through this process was studied, and the influence of relevant process parameters on the finishing characteristics was analyzed. The experimental results show that the surface roughness of 5052 aluminum alloy plate improved from 318 to 3 nm Ra in 15 min.

Stir tools with different pin eccentricities were applied to the friction stir processing of Al-5052 alloy. Results show that pin eccentricity enhances material flow and refines grains of stir zone. The stir zone produced by a stir tool with 0.4 mm pin eccentricity performs the highest hardness and yield strength, attributing to the enhanced grain-boundary strengthening.

Hot deformation behavior of cast 5052 aluminum alloy was investigated at the temperature between 300°C and 500°C and the strain rate range from 0.01 s-1 to 10 s-1 by hot compression tests. The constitutive model was established through the flow stress–strain curves, the activation energy was 207 kJ/mol, and the correlation coefficient for linear regression of constitutive model was 0.98. The processing map was established to optimize the deformation parameters, such as the optimize deformation parameters with 0.6 strain was at 420℃-480℃ and 0.01 s-1-0.223 s-1.

Rolling edge crack of 5052 aluminum alloy under one-pass (reductions of 35%, 40%, 50%, 60%, respectively) and multi-pass rolling at total reductions of 60% (two-pass, three-pass, four-pass and five-pass, respectively) at room temperature was analyzed by numerical simulation combined with experiments. Through the simulation of rolling process, damage was obtained. The maximum damage concentrated in the edge position and grew gradually with the increase of reduction (one-pass). As changing the rolling passes, damage with three-pass rolling is the least. Experimental results and simulation results were in good agreement. The optimum rolling scheme under 60% reductions was 3-time rolling with the least crack length (test: 1.3 mm, simulation: 1.4 mm, error of 7%).

A series of experiments was conducted to investigate the effect of projectile head shape on hypervelocity impact cratering. Aluminum 5052–H112 alloy thick targets were impacted by projectiles which had different heads at velocities of approximately 7.1 km/s. The head shape was classified into five types of head shape, i.e. flat-head and, two types of concave-head and two-types of convex-head. The effect of the head shape was evaluated by final morphology of craters, i.e. variables of the penetration depth, the crater diameter and the crater volume. The concave-head and convex-head projectiles produced shallow-shaped craters and deep-ones, respectively. The ratio of the crater penetration-to-diameter P/D increased as the head shape became more convex, and vice versa. The P/D ratio varied from 0.41 to 0.77. However, the penetration depth and the crater diameter had different dependencies based on the head shape. ‘Flat-head conversion’, in which the concave-head and the convex-head projectiles were imaginarily regarded as flat-head projectiles with a converted diameter, gave the consistent effect on the crater variables to the concave-head and the convex-head projectiles. A new coupling parameter of the point source solution was defined as a function of impact variables. The crater variables scaled by this coupling parameter was expressed as power laws of impact variables. The coefficient and the exponents of obtained relations were determined by using multiple regression analysis. Regression equations closely estimated the experimental results.

Low-temperature high-frequency induction brazing of 5052 aluminum alloy to stainless steel was carried out using Sn-30Zn with reactive-flux 88ZnCl2-10NH4Cl-2NaF wt.%. The influence of processing parameters on microstructures, mechanical property and fracture behavior was investigated. Intermetallic compounds were not observed at the interface of the steel. The brazing seam consisted of Sn-Zn eutectic structures, Zn-rich solid solution and oxide inclusion. The diffusion of Sn and Zn into the aluminum grain boundary led to an intergranular penetration layer. When brazing at 370°C for 30 s, the joint fractured in the brazing seam and the shear strength reached the highest at 87 MPa. The fracture surface of the joint presented ductile characteristics. The diffusion of F− in the flux made the oxide film expand and crack. Zn2+ permeated through the crack of the film and then reacted with Al, which removed the film from aluminum substrate.

The hot tensile deformation behavior of 5052 aluminum alloy is investigated by uniaxial tensile tests with the temperature range of 523–723 K and strain rate range of 0.001–0.1 s−1. The constitutive equation is established based on the Arrhenius-type equation and Zener–Hollomon parameters, which are applied to numerical simulation for solid boss forming by plate forging process. As a result, the flow stresses obtained from the constitutive equation are consistent with the experiments, and the proposed constitutive equation is succeeded to predict the deformation behavior in the plate forging process. The best forming temperature for boss solid forming is 673 K based on the boss forming ability analysis.

The hybrid structure composed of aluminum alloy and carbon fiber reinforced plastics could combine their advantages. In order to investigate the weldability of these two lightweight materials, the hybrid joints of 5052 aluminum alloy (AA5052) and carbon fiber reinforced polyether ether ketone composites (CF-PEEK) were fabricated by friction stir spot welding. The variance analysis revealed that the dwell time and plunge speed were the most significant factors. By optimizing the welding parameters, the ultimate tensile shear load reached 2690±64 N (the dwell time: 8 s, the plunge speed: 10 mm/min). The interface could be divided into pin-affected zone, shoulder-affected zone, resin adhesive zone and resin concentrated zone. Since resin concentrated zone could not provide interfacial bonding due to delamination, the shoulder-affected zone and pin-affected zone were decisive regions for mechanical properties. The bonding mechanism included three parts: adhesive bonding provided by re-solidified resin, macro-mechanical interlocking of aluminum alloy that entered CF-PEEK, and micro-mechanical interlocking of resin that was tightly trapped at surface slits as well as the carbon fibers beset into AA5052. This work clarifies the interfacial characteristics of AA5052/CF-PEEK hybrid joints and provides an approach to improve the mechanical properties.