Intermetallic Compound Mg17Al12 Research Articles

Welding and Riveting Hybrid Bonding of 6061 Al and Carbon Fiber Reinforced Composites.

Welding and riveting hybrid bonding technology was applied to join 6061 aluminum alloy and carbon fiber reinforced plastics (CFRP). The laser-arc hybrid welding process and stepped rivets were used in the experiments to reduce the impact of the poor heat resistance of composites. The effect of hybrid welding arc current on the formation and mechanical properties of 6061 Al/CFRP joints was studied. Tensile shear load up to 4.65 kN was achieved by adjusting process parameters. The welding process and mode of the fracture were analyzed. The hybrid bonded joint obtained consisted of two parts: a welded joint of Al plate and Al rivet, and a bonded interface between Al plate and CFRP plate. The mechanical properties of the hybrid joint were mainly determined by the Al plate/Al rivet welded joint. The results of the study show that there are three interfacial bonding mechanisms between aluminum and CFRP. In addition to mechanical bonding between the Al plate and CFRP plate, there were also metallurgical bonding of Al-Mg intermetallic compounds with resin matrix and chemical reactions of aluminum with resin and carbon fibers at the interface, which could improve the mechanical properties of the joints.

Effect of electro-spark deposited ZA12 interlayer on the microstructure and mechanical property of A356/AZ91D by liquid-solid compound casting

In this paper, to fabricate high strength Al/Mg bimetallic composite without the formation of Al12Mg17 intermetallic compound at the interface, ZA12 deposited A356/AZ91D bimetal was achieved by liquid-solid compound casting. The combination between electro-spark technology and compound casting was realized. The process parameters of electro-spark deposition were optimized by considering the thickness, quality, and efficiency of the coating. The microstructure, phase composition and mechanical properties of A356/AZ91D bimetal without and with ZA12 coating were investigated. From AZ91D to A356, the main phases formed across the interface region are: Mg17(Al, Zn)12 + α-Mg in diffusion layer I, Al5Mg11Zn4 and Mg32(Al, Zn)49 in diffusion layer II, and Al3Mg2 and Mg2Si in diffusion layer III. The microhardness of the interface is obviously higher than that of the substrate on both sides. The average shear strength of ZA12 coated A356/AZ91D bimetal is 69.2 MPa. The interface microstructure evolution mechanism of ZA12 coated A356/AZ91D by liquid-solid compound casting was analyzed. The result is helpful for further development of high strength Al/Mg bimetallic composites.

Elucidation of the Growth of Filiform Corrosion of AZ91D Mg Alloy in NaCl Solution

Magnesium (Mg) is the lightest structural metallic material with high specific strength. Mg alloys are highly expected to be applied in electronic, automotive vehicles and aerospace, etc. The most severe drawback of Mg and its alloys is corrosion susceptibility. When Mg alloys are used in chloride solutions, filiform corrosion sometimes occur. Being a common practice in the research of Mg corrosion, galvanostatic tests allow for easy comparison of the rate of hydrogen evolution with the applied current. But there are scarce studies reported about the in situ observation of filiform corrosion behavior of Mg alloys under galvanostatic polarization. The purpose of this study is to elucidate the growth of filiform corrosion of AZ91D Mg alloy in NaCl solutions by in situ observation.An ingot of AZ91D die-cast was cut into 25 mm × 30 mm × 5 mm sheets. The specimen surface was polished to 2000 grit with SiC paper and finished with a 0.25 µm diamond paste, followed by ultrasonically cleaning in ethanol. To confirm the metallographic structures, the sample was etched with a mixed reagent of 3 mL HNO3 and 80 mL of ethanol for 3 s. Galvanostatic polarization was performed using a micro electrochemical system with an in situ observation function. The electrolytes used were naturally aerated 0.1 M and 0.01 M NaCl (pH 8.0, adjusted with NaOH). The area of the electrode was about 0.01 mm2 or larger, the surfaces of the sample was covered with a silicone sealant except for the working electrode area. To start the experiments, an objective lens was put down to be immersed in the solution and clear view of the electrode area was attempted to obtain. After polarization, the specimen surface was assessed using OM, AES, FE-SEM and STEM.The AZ91D die-cast Mg alloys mainly consist of an α phase matrix (Mg solid solution) and β phases (Mg17Al12 intermetallic compounds). Lamellar (α + β) structures are also observed in the adjacent of β phases. Among these lamellar structures, some black dots are Mg-Al-Mn compounds. In the video of corrosion process, pits were observed in the boundaries of lamellar (α + β) structures and β phases. After polarization, EDS maps were taken. It was confirmed that filiform corrosion propagated in lamellar (α + β) structures and α phase matrix.

The inhibitory effect of stir zone liquefaction and eutectic-phase formation on the growth of γ/β intermetallics during dissimilar FSW of Al/Mg alloys

Controlling the formation of intermetallic compounds (IMCs) is a critical issue in friction stir welding (FSW) of Aluminum (Al) to magnesium (Mg) alloys. During FSW, AlMg IMCs can form through two mechanisms comprising solid-state diffusion and liquefaction. Two kinds of IMCs can form during FSW of Al/Mg, Al3Mg2 (β) and Al12Mg17(γ). The IMCs produced via the former mechanism are identified as continuous whereas the IMCs produced by the latter typically appear as separate islands inside a matrix of eutectic structures. The present study aims to examine the impact of each morphology on the joint strength. For this purpose, dissimilar FSW of AA1050/AZ31 was carried out in lap configuration. The microstructure of the joints, as well as the fracture surfaces, were studied by scanning electron microscopy (SEM) and joint strength was evaluated by shear tensile testing. It was observed that the IMCs formed via diffusion were detrimental when their thickness exceeded 2 μm. It was also shown that liquefaction during FSW could control the thickness of the continuous IMCs layer. To elucidate this phenomenon, analytical and numerical methods were applied to calculate the growth kinetics of IMCs. It was concluded that the liquefaction phenomenon and the subsequent formation of eutectic structures reduced the activity of elements and thereupon hindered the diffusion rate in the solid state. In this case, although liquefaction raised the overall volume fraction of IMCs, the fracture load increased due to the propagated fracture through the eutectic microstructure rather than the continuous IMC layer.

Improving mechanical properties of AZ91D magnesium/A356 aluminum bimetal prepared by compound casting via a high velocity oxygen fuel sprayed Ni coating

In this paper, a Ni coating was deposited on the surface of the A356 aluminum alloy by high velocity oxygen fuel spraying to improve the performance of the AZ91D magnesium/A356 aluminum bimetal prepared by a compound casting. The effects of the Ni coating as well as its thickness on microstructure and mechanical properties of the AZ91D/A356 bimetal were systematically researched for the first time. Results demonstrated that the Ni coating and its thickness had a significant effect on the interfacial phase compositions and mechanical properties of the AZ91D/A356 bimetal. The 10µm's Ni coating cannot prevent the generation of the Al-Mg intermetallic compounds (IMCs) at the interface zone of the AZ91D/A356 bimetal, while the Ni coating with the thickness of 45 µm and 190 µm can avoid the formation of the Al-Mg IMCs. When the Ni coating was 45 µm, the Ni coating disappeared and transformed into Mg-Mg 2 Ni eutectic structures+Ni 2 Mg 3 Al particles at the interface zone. With a thickness of 190µm's Ni coating, part of the Ni coating remained and the interface layer was composed of the Mg-Mg 2 Ni eutectic structures+ Ni 2 Mg 3 Al particles, Mg 2 Ni layer, Ni solid solution (SS) layer, Al 3 Ni 2 layer, Al 3 Ni layer and sporadic Al 3 Ni+Al-Al 3 Ni eutectic structures from AZ91D side to A356 side in sequence. The interface layer consisting of the Mg-Ni and Al-Ni IMCs obtained with the Ni coating had an obvious lower hardness than the Al-Mg IMCs. The shear strength of the AZ91D/A356 bimetal with a Ni coating of 45 µm thickness enhanced 41.4% in comparison with that of the bimetal without Ni coating, and the fracture of the bimetal with 45µm's Ni coating occurred between the Mg matrix and the interface layer with a mixture of brittle fracture and ductile fracture.

Hydrogenation of Eutectic Alloy in the Mg–Al System

To optimize hydrogenation conditions for microcrystalline eutectic alloy with the composition Mg69Al31 (a mixture of magnesium with the γ-Mg17Al12 intermetallic compound), we have studied reactions of 200-μm powder of the alloy with hydrogen and ammonia in the temperature range 100–500°C. We have determined the composition of the reaction products and demonstrated that the use of hydrogen allows magnesium dihydride to be obtained at a temperature of 420°C and that the hydrogenation of the eutectic alloy with ammonia as a hydriding agent leads to the formation of MgH2 and a solid solution of hydrogen in the Mg17Al12 intermetallic compound at 250°C. The hydrogen content in the reaction products obtained by hydrogenation with hydrogen is 4.4 wt %.

Friction self-piercing riveting (F-SPR) of aluminum alloy to magnesium alloy using a flat die

Friction self-piercing riveting (F-SPR) process based on a pip die has been invented to solve the cracking problems in riveting high-strength and low-ductility light metals, such as magnesium alloys, cast aluminum, and 7 series aluminum alloys. In this paper, in order to solve quality issues caused by the misalignment between rivet and pip-die in F-SPR, a flat-die based F-SPR process was proposed and employed to join 1.27 mm-thick AA6061-T6 to 3 mm-thick AZ31B. The results indicate that a 1.0 mm die distance is effective to avoid rivet upset and insufficient flaring. As the feed rate increases, the heat input in the whole process decreases, resulting in a larger riveting force, which in turn increases both the bottom thickness and interlock amount. Besides, solid-state bonding, including Al-Mg intermetallic compounds (IMCs), Al-Mg mechanical mixture, and Al-Fe atom interdiffusion was observed at the joint interfaces. The upper Al layer was softened, but the lower Mg layer was hardened, and both sheets exhibited a narrowed affected region with the increase of feed rate, while the rivet hardness shows no obvious change. Three fracture modes appeared accompanying the variations in lap-shear strength and energy absorption as the feed rate increased from 2 mm/s to 8 mm/s. Finally, the F-SPR process using a flat die was compared to those using a pip die and a flat bottom die to show the advantage of flat die on coping with the misalignment problem.

Compressive properties and energy absorption behavior of Mg17Al12/Al ordered structure composites

In this study, Mg17Al12/Al ordered structure composites were prepared by infiltrating the ordered porous aluminum with the intermetallic compound Mg17Al12 under gravity condition. Their compressive properties and energy absorption behavior were investigated by quasi-static compression tests. The results showed that Mg17Al12/Al ordered structure composites exhibited distinctly different compressive stress-strain curves with a prominent linear elastic stage and had an advantage over ordered porous aluminum and Mg17Al12/Al composites with irregular structures on mechanical properties. Moreover, Mg17Al12/Al composites with strengthened truss structure showed better compressive properties than Mg17Al12/Al composites with basic truss structure. The ordered porous aluminum that acted as matrix skeleton showed great plasticity and ductility while the intermetallic compound Mg17Al12 as filler exhibited high compressive strength and obvious brittleness. The improvement of mechanical properties of Mg17Al12/Al ordered structure composites was attributed to the ordered composite structure and the distinct mechanical property of co-continuous intermetallic compound Mg17Al12 and pure Al.

Multiphase-field modeling of temperature-driven intermetallic compound evolution in an Al–Mg system for application to solid-state joining processes

Solid-state joining of dissimilar materials results typically in the formation of intermetallic compounds at the weld interface, which strongly determines the resulting mechanical properties. To tailor the joint strength, understanding of the formation of the intermetallic compound and their driving mechanisms is crucial. In this study, the evolution of temperature-driven Al3Mg2 and Al12Mg17 intermetallic compounds in an Al–Mg system for application to solid-state joining processes via a multiphase-field approach is numerically investigated. To this end, the CALPHAD approach to obtain the thermodynamic parameters of the relevant phases is used in conjunction with the multiphase-field model. The simulation results are qualitatively compared with experimental results in the literature in terms of thickness and morphology of intermetallic grains, exhibiting a reasonable agreement. The influence of grain boundary diffusion and interface energy on the morphology and kinetics of the intermetallic compound grains is investigated in detail with the established multiphase-field model.

Mechanism of hydrogen formation during the corrosion of Mg17Al12

Previous investigations (DFT calculations) showed that hydrogen atoms adsorption and H2 desorption can occur on MgO and Al2O3 and that H atoms can diffuse on Mg and Al surfaces. However, these three simultaneous actions, i.e. H adsorption, H diffusion and H2 desorption, have not been experimentally proved. In this paper, we propose a mechanism of formation of H2 during the corrosion of an intermetallic compound Mg17Al12 in 3.5 wt.% NaCl aqueous solution based on in situ Raman spectroscopy analysis. We found that, through the passivation zone (e.g. E varying from the open circuit potential (OCP) to +100 mV/OCP), the oxide layer is destroyed in favor of the appearance of Mg and H atoms. Moreover, the formed H atoms are adsorbed on the oxide surface and then diffuse on either the oxide surface or the unreacted metal surface where they recombine forming H2. In situ Raman measurements during anodic polarization experimentally prove, for the first time, the formation of a reaction intermediate which weakens the H–H bond. The obtained results explain the mechanism of hydrogen production under anodic polarization of the intermetallic compound at normal conditions of temperature and pressure.

Microstructure, mechanical properties and corrosion resistance of A356 aluminum/AZ91D magnesium bimetal prepared by a compound casting combined with a novel Ni-Cu composite interlayer

In the present work, a novel Ni-Cu composite interlayer was prepared on the surface of A356 aluminum alloy solid insert using the chemical nickel-plating and electro-coppering technology, in order to restrain the generation of brittle phases and enhance the shear strength of A356 aluminum/AZ91D magnesium bimetal manufactured using a compound casting. The effect of the Ni-Cu composite interlayer on the microstructure, mechanical properties and corrosion resistance of the bimetal was studied. The results show that the Ni-Cu composite interlayer effectively restrained the generation of the brittle and hard Al-Mg intermetallic compounds (IMCs). The interface layer of the A356/AZ91D bimetal without Ni-Cu composite interlayer was composed of Al 3 Mg 2 , Al 12 Mg 17 , δ-Mg and Mg 2 Si phases, while the interfacial reactants of the A356/AZ91D bimetal with Ni-Cu composite interlayer were mainly Al 3 Ni, Ni (Cu), Cu (Ni), Mg 2 Cu and Al 7 Cu 3 Mg 6 phases. With the application of the Ni-Cu composite interlayer, the thickness of the interface of the A356/AZ91D bimetal remarkably decreased from 1400 μm of the sample without Ni-Cu composite interlayer to 40 μm. The shear strength of the A356/AZ91D bimetal using Ni-Cu composite interlayer increased by 20.3 % compared with that of the bimetal without Ni-Cu composite interlayer. The fractures of the A356/AZ91D bimetals with and without Ni-Cu composite interlayers belonged to a brittle rupture mode. The breakage of the bimetal with Ni-Cu composite interlayer mainly took place between the Ni-Cu layer and AZ91D matrix, while the rupture of the A356/AZ91D bimetal without Ni-Cu composite interlayer was located in the interface layer. The Cu(Ni) and Ni(Cu) layers had a lower nano-hardness than the Al-Mg IMCs, and the elasticity modulus for the Cu(Ni), Ni(Cu) and Al 3 Ni phases were higher compared to those of the Al-Mg IMCs. The results of corrosion test exhibited that the Ni-Cu composite interlayer had little influence on the corrosion resistance of the A356/AZ91D bimetal.

Microstructure and mechanical properties of Mg-to-Al dissimilar welded joints with an Ag interlayer using ultrasonic spot welding

Lightweight ZEK100-O Mg alloy and Al6022-T43 Al alloy with an Ag interlayer were joined via ultrasonic spot welding (USW), focusing on the microstructural change and tensile lap shear strength of the welded joints in relation to welding energy. Mg/Al interface was superseded by Mg/Ag and Al/Ag interfaces, and unfavorable Mg17Al12 intermetallic compound was eliminated. Ag foil was observed to be intact in the nugget center, while it was broken or dissolved at the nugget edge at high welding energy levels. The diffusion layer at the Mg/Ag interface consisted of two distinctive sub-layers: Mg3Ag intermetallic compound adjoining Ag foil, and Mg3Ag + Mg eutectic structure adjacent to Mg. Only a thin diffusion layer consisting mainly of Ag3Al occurred at the Al/Ag interface. The tensile lap shear strength first increased, reached its peak value, and then decreased with increasing welding energy. The shear strength achieved in the present study was ∼31% higher than that of the joint without interlayer. Interfacial failure occurred at all energy levels, with Ag foil particles or fragments being stuck on both Mg and Al sides due to its intense interaction with Mg and Al via accelerated diffusion during USW. The results obtained pave the way for the challenging dissimilar welding between Mg and Al alloys.

Effect of Tool Offset on the Microstructure and Properties of AA6061/AZ31B Friction Stir Welding Joints

Friction stir welding was carried out on AA6061/AZ31B alloy, and the influence of tool offset on microstructures and mechanical properties of the joints was studied. The results showed that preferred properties were obtained when Mg was placed in the Advancing Side (AS) and offset was positioned into Mg. The distribution of Al3Mg2 and Al12Mg17 intermetallic compounds (IMCs) could be improved with offset in a certain range. The tensile strength of the joints was elevated with the increase of the offset due to the superior distribution and diminished size of IMCs, and when the offset was 1.5 mm, the joint strength reached the maximum value of 107 MPa. The microhardness of the stirring zone decreased with the increased offset.

The mechanical properties and formation mechanism of Al/Mg composite interface prepared by spark plasma sintering under different sintering pressures

In this study, a high strength aluminum-magnesium interface structure was prepared by spark plasma sintering using powder metallurgy. Effects of sintering pressure on the Al–Mg interfacial structure and bonding strength were investigated. The mechanism of formation and evolution of the interface were obtained from characterizing the interface. Results from microstructural observations indicate that interfacial structure changes from solid layers to liquid layers with an increase in sintering pressure; also, bonding strength increases. Maximum interfacial bonding strength reached 59.96 MPa with a sintering pressure of 40 MPa. Each fracture shows characteristics of brittle fracture. Solid layers are composed of a Cu segmentation region and Al3Mg2 and Al12Mg17 intermetallic compound layers. The orientation relationship between Al3Mg2 and Al12Mg17 was determined to be [1‾33]Al3Mg2||[014]Al12Mg17 and 2‾00Al12Mg17||(02‾2)Al3Mg2. Formation of a liquid layer is related to the production of Al–Mg eutectic phase. A model describing the formation and evolution of the Al/Mg interface is proposed.

Microstructure, Mechanical Properties and Fracture Behavior of Magnesium/Steel Bimetal Using Compound Casting Assisted with Hot-Dip Aluminizing

In this work, microstructure, mechanical properties and fracture behavior of the magnesium/steel bimetal using compound casting assisted with hot-dip aluminizing were investigated, and the interface bonding mechanism of the magnesium/steel bimetal were also analyzed. The results indicate that the magnesium/steel bimetal obtained without hot-dip aluminizing had larger gaps through the whole interface without reaction layers between magnesium and steel, leading to a poor mechanical bonding. After the steel substrate was hot-dip aluminized, an intermetallic layer along with an Al topcoat layer were formed on the surface of the steel substrate, and the intermetallic layer was constituted by Fe2Al5, τ10-Al9Fe4Si3, FeAl3 and τ6-Al4.5FeSi phases. In the case of the magnesium/steel bimetal obtained with hot-dip aluminizing, a compact and uniform interface layer with an average thickness of about 17 μm that consisted of Fe2Al5, τ10-Al9Fe4Si3, FeAl3 and Al12Mg17 intermetallic compounds was formed between the magnesium and the steel, obtaining a superior metallurgical bonding. The interface layer had much higher nano-hardnesses compared to the magnesium and steel matrixes, and its average nano-hardness was up to 11.1 GPa, while there were respectively 1.1 and 4.2 GPa for the magnesium and steel matrixes. The shear strength of the magnesium/steel bimetal with hot-dip aluminizing reached to 23.3 MPa, which increased by 8.59 times than that of the composites without hot-dip aluminizing. The fracture of the magnesium/steel bimetal with hot-dip aluminizing represented a brittle fracture nature, initiating from the interface layer.

Effect of ball milling in presence of additives (Graphite, AlCl3, MgCl2 and NaCl) on the hydrolysis performances of Mg17Al12

In most of the Mg–Al alloys, Al forms with Mg the intermetallic compound Mg17Al12. In order to understand the hydrogen production from the Mg–Al alloys waste by the hydrolysis reaction in “model” seawater (i.e. 3.5 wt % NaCl), hydrolysis with Mg17Al12 was investigated. The effect of ball milling time, the nature of the additives (graphite, NaCl, MgCl2 and AlCl3) and the synergetic effects of both graphite and AlCl3 were investigated. It has been established that increasing ball milling time up to 5 h is necessary to activate the intermetallic and to decrease sufficiently its crystallites and particles size. On one hand, the presence of AlCl3 provides the best hydrolysis performance (14% of the theoretical hydrogen volume in 1 h). On the other hand, the mixture obtained by simultaneous addition of graphite and AlCl3 shows the best hydrolysis performances with 16% of the theoretical H2 volume reached in 1 h.

Friction Stir Welding of Dissimilar AA6061-T6 to AZ31B-H24 Alloys

Abstract: Friction Stir Welding (FSW) is a solid-state joining process that uses a non-consumable tool to join two facing workpieces without melting the workpiece material. FSW is predominantly used for welding lightweight materials such as aluminum and magnesium alloys. In the present investigation, AA6061-T6 and AZ31B-H24 alloys were joined by FSW using the following parameters: rotational speed of 400, 800, 1200 and 1600 rpm, welding speed of 30 and 60 mm/min and tilt angle of 1° and 3°. In some cases, a tool offset of 1 mm was used into the Mg-based alloy. Microstructural characteristics of the weld joints were analyzed by optical microscopy and scanning electron microscopy. The experimental results show that dissimilar welds can be obtained by placing the AA6061-T6 alloy on the advancing side under two processing conditions: i) without a tool offset using a welding speed of 30 mm/min, a rotational speed of 400 rpm and a tilt angle of 1° (M7) and ii) with a tool offset and a welding speed of 30 mm/min, using a rotational speed of 1200 rpm and a tilt angle of 3° (M3). Al3Mg2 and Al12Mg17 intermetallic compounds were observed in the stir zone. Hardness and tensile strength of joints M7 varied from 76 to 129 HV, and 88.2 MPa respectively, and these properties varied from 95 to 153 HV, and 18.95 MPa in joints M3.

Effect of rare earth (Sc, Y, La, Sm and Gd) doping on mechanical and thermodynamic properties of Al12Mg17 intermetallic compounds

The structural, electronic, mechanical and thermodynamic properties for [Formula: see text] and [Formula: see text] (RE = Sc, Y, La, Sm and Gd) compounds have been calculated by first-principles theory. The obtained structural parameters and elastic constants of two kinds of doped [Formula: see text] are compared with some theoretical and experimental data. The electronic structure analysis, such as density of states, explains the bonding character of Al–Mg–RE. All the doped [Formula: see text] are influenced by the high-energy electrons directly. Furthermore, the basic mechanical properties which are derived from the elastic constants and the thermal stability of doped [Formula: see text] are discussed. The predicted brittleness of [Formula: see text] and [Formula: see text] is consistent with the available experiments.

Hydrogenation of Intermetallic Compound Mg17Al12

A 200-micron powder of γ-Mg17Al12 was reacted with hydrogen and ammonia at temperatures in the range 20–500°C with the goal to determine optimal hydrogenation parameters for this intermetallic compound as a potential hydrogen storage material. Direct hydriding of the intermetallic compound was found to occur at 390°C, but was accompanied by decomposition to a mixture of magnesium hydride with aluminum containing 4 wt % hydrogen. The hydriding of the intermetallic compound by ammonia was also accompanied by the appearance of magnesium hydride in the reaction product, but at 300°C. The hydrogen capacity of the products of reaction between the intermetallic compound and ammonia at 350°C was 3.9 wt % hydrogen. The product of ammonia treatment of the intermetallic compound Mg17Al12 at 450–500°C was a mixture of aluminum with magnesium nitride.

Effect of Zn-brazed-interface on microstructures and mechanical properties of dissimilar 2A12/AZ31 alloys friction stir lap welds

Abstract To improve the mechanical behavior of dissimilar Al/Mg joints, Zn foil, as a brazing filler, was added to the Al/Mg interface when conducting friction stir lap welding with 2A12/AZ31 alloys. Results showed that new phases, such as Mg0.97Zn0.03, Al0.403Zn0.597 and MgZn2, rather than the continuous brittle Al12Mg17 intermetallic compound (IMC), are formed in the brazing area. At a rotation speed of 375 rpm and a travel speed of 30 mm/min, the tensile shear load of the hybrid joint reached 5.5 kN through a Zn-brazed interface, thereby preventing the formation of the continuous brittle IMC Al12Mg17 and enlarging the overlap bonding area.