Aluminum Interlayer Research Articles

X-Ray Photoelectron Spectroscopy of TixAl and TixAl/A-Si:H Interlayer with Different Thicknesses on Stainless Steel to Enhancing Adhesion of DLC Films

In this research, two intermediate layers were deposited on 316L stainless steel to improve the adhesion of diamond-like carbon (DLC) films, one composed of TixAl and produced using the RF sputtering technique with three thicknesses, 100 nm, 200 nm, and 300 nm; the other, interlayer composed of amorphous hydrogenated silicon (a-Si:H). The DLC films were deposited using the pulsed-DC PECVD method with an active screen to achieve the AISI 316L/TixAl //DLC and AISI 316L/TiₓAl/a-Si/DLC configurations. The binding energy between the substrate/TixAl and TixAl/a-Si:H was investigated via X-ray photoelectron spectroscopy with high-resolution spectra. The chemical composition and microstructure of the titanium–aluminum interlayers were investigated using energy-dispersive X-ray spectroscopy and X-ray diffraction, and the microstructure of the DLC coatings was studied using Raman spectroscopy. The coatings’ adherence was measured using scratch and indentation tests, and the hardness of the DLC coatings was determined with the nanoindentation test. The X-ray diffractograms did not allow the determination of any crystalline structure in the TixAl interlayers. The XPS results showed that between the AISI 316L substrate and the TixAl intermediate layer, Ti-O-Fe and FeAl2O4 were formed. On the other hand, at the TixAl/a-Si:H interface, TiSi2 and Al2SiO5 compounds were identified. The DLC coatings grew as hydrogenated amorphous carbon with a hydrogen content of around 30 at.% and a hardness of 24 GPa. The deposition methods used and the TixAl/a-Si:H interlayers allowed the obtainment of adherent DLC coatings on AISI 316L stainless steel substrates. High critical load values of about 30 N were obtained. The novelty of this work is underscored by the absence of previous studies that thoroughly examine the bonds present in interlayers used as gradients to enhance the adhesion of DLC.

Microstructure and properties of Mg/Ti joint welded by resistance spot welding with an aluminum interlayer

Magnesium alloy AZ31B and titanium TA2 were welded by resistance spot welding technology employing an interlayer of aluminum foil and asymmetric electrodes. The microstructure of the joint was observed, with an analysis conducted on the impact of welding current and welding time on the tensile shear load of the joint. During the welding process, the aluminum interlayer melted and blended with the molten magnesium alloy, leading to the formation of a eutectic layer consisting of Mg17Al12 and (Mg) in close proximity to the welding interface. As the increasing of welding current or the extending of welding time, there was an initial increase followed by a slight decrease in the tensile shear load of the AZ31B/TA2 joint. At a welding current of 16 kA, the tensile shear load of the joint achieved the maximum, which was approximately 6.48 kN. The findings suggest that it is effective to use an aluminum foil as an intermediary to regulate the metallurgical reaction at the interface and utilize nonsymmetrical electrodes for thermal compensation in the resistance spot welding between titanium and a magnesium alloy.

Study on explosive welding A7075 and Ti–6Al–4 V with aluminum or copper interlayer

Study on explosive welding A7075 and Ti–6Al–4 V with aluminum or copper interlayer

In-Situ Wettability Analysis of Al Coating Influence on Hot-Dip Galvanizing Properties of Advanced High-Strength Steels

We investigated the influence of steel surface properties on the wettability of zinc (Zn). Our main objective is to address the selective oxidation of solute alloying elements and enhance the wetting behavior of Zn on advanced high strength steel (AHSS) by employing an aluminum (Al) interlayer through the physical vapor deposition technique. The deposition of an Al interlayer resulted in a decrease in contact angle and an increase in spread width as the molten Zn interacted with the Al interlay on the steel substrate. Importantly, the incorporation of an Al interlayer demonstrated a significant improvement in wettability by substantially increasing the work of adhesion compared to the uncoated AHSS substrate.

Corrosion Behaviors’ Investigation of Carbide Coatings Developed for Sulphuric Acid Recovery Systems

In this study, corrosion resistance of cobalt and nickel, which are known to have high corrosion resistance, reinforced tungsten carbide coatings applied to low carbon stainless steel material surfaces to reduce corrosion-induced losses in sulphuric acid recovery systems were investigated. During the recovery of sulphuric acid, aggressive sulphur systems in the baths cause the metal surface to dissolve and therefore a high amount of material loss occurs. In order to minimize corrosion induced material loss, 316 L stainless steel surfaces were coated with an interlayer of 95% nickel and 5% aluminium alloy, and then tungsten carbide coatings were synthesized on the surfaces of substrate materials reinforced with 13% cobalt and 13% nickel, respectively by thermal spraying method to further reduce the corrosion rate. Characterization of the produced coatings were carried out by X-ray diffraction (XRD), scanning electron microscope (SEM), optical microscope, image analyzer, and surface roughness device. The standard potentiodynamic polarization characteristics of the coatings for 1M H2SO4 solution at room temperature were investigated with a potentiostat/galvanostat device. As the obtained results, nickel reinforced tungsten carbide coatings with nickel aluminium interlayer showed the highest corrosion resistance against sulfuric acid environment with 0,41 mm/year corrosion rate. As a result of the article, the corrosion resistance of 316L stainless steels in sulfuric acid systems was improved by 5.02 and 3.15 times, respectively.

Investigation of friction welding parameters of AISI 304L/Ti-6AL-4V joints

The present paper focuses on evaluating the bonding strength interfaces between the contact materials such as AISI 304L and Ti-6Al-4V via. the friction welding (FW). Experimental tests are performed by considering the process parameters such as friction time, rotational speed and friction pressure, mechanical properties were evaluated. The rotational speed of 1800, 1600, 2100, 2300 and 2500 rpm were considered in the study. The response surface methodology (RSM) is used to predict the outcomes of the work. Experimental tests were revealed that the friction pressure of 160 MPa, 7 sec of friction time and speed of 2300rpm are the optimal parameters based on the joint strength. Also, observed that the aluminum interlayer thickness of 1.25 μm on the Ti-6Al-4V side and 1.38 μm on the AISI 304L side. The tensile strength of 143.39 MPa was noticed at the interface area. The RSM response generates the curved potential line frequency range with 6.5% elongations. Results confirm that, the response surface methodology outcomes and experimental values were in close agreement.

IN BETWEEN: An Interlayer Material Study for Interlocking Cast Glass Blocks

Interlocking cast glass assemblies are a promising solution for architectural cast-glass applications aiming for high transparency and a reversible structure that allows the reuse of the glass components (Oikonomopoulou et al.,2018; Oikonomopoulou,2019b). In such a system, an interlayer material between the glass elements is essential, to assist the homogenous stress distribution and account for the surface microasperities of the glass elements. Towards circularity, this material should be dry (and not an adhesive), allowing for the eventual disassembly of the system. Previous experimental work by (Aurik at al.,2018; Oikonomopoulou at al.,2019b) has focused on the use of PU and PVC interlayers as suitable candidates; the focus in those studies has been solely placed on the mechanical performance of the interlayer material. This research provides a review of potential material candidates suitable for interlayers of an interlocking cast glass assembly based on a set of revised design and performance criteria that are divided into primary and secondary. Furthermore, the impact their unique material properties have on the potential application of the interlocking system is examined. The whole process, from fabrication to construction of the entire assembly, based on an assumed building scenario, is presented in a chain reaction manner, whose starting point is the interlayer itself. After defining the design criteria the interlayer should adhere to, the proposed candidates are: PETG sheets (Vivak®), Neoprene, Aluminum, Laminated Polyurethane (PU) and a Soft-core aluminum interlayer. The unique properties and fabrication challenges of all five proposed interlayers are considered, as well as their properties in relation to assembly, which leads to the development of two distinct assembly sequences. The main distinction concerns the interlayers that risk creeping and those that do not. The research concludes with a comparison between the interlocking assembly and the other glass block assemblies currently applied.

The effect of aluminum interlayer on weld strength, microstructure analysis, and welding parameters optimization in resistance spot welding of stainless steel 316L and Ti6Al4V titanium alloy

Stainless steel (SS) and Titanium alloy (Ti) are the most commonly used materials in many industrial fields such as the automotive and aerospace industry. Stainless steel has good corrosion resistance and titanium alloy has an extremely lightweight characteristic. The combination of both materials has become a tremendous innovation in the industrial sector. Resistance spot welding which has commonly applied in many industrial fields is a good consideration to join these two dissimilar materials due to the high efficiency that could be achieved by using this method. However, the way of joining these dissimilar materials should be carefully considered due to the significant difference in mechanical properties between SS and Ti. In the present study, 3 mm of SS316L and Ti6Al4V sheets were joint under the resistance spot welding method with an aluminum interlayer. The optimized welding parameters were provided under the Taguchi method L9 orthogonal array along with the mechanical properties’ investigation. The optimum welding parameters were 11 kA of weld current, 30 Cycles of welding time, and 5 kN of electrode force which produced 8.83 kN tensile-shear load of the joint. The mechanical structure analysis shows the different morphology between stainless steel and titanium interfaces and the intermetallic compound layer was formed on the SS/Al and Al/Ti interfaces. The EDX analysis shows the atomic diffusion-reaction on the application of aluminum as an interlayer on the SS/Ti joint.

Gradient magnetron co-sputtered μ m-thick Al–Si films on dielectric substrates for operation in the millimeter-wave band

Ongoing active development of modern radio frequency electronic devices operating in the millimeter (V) band, such as fifth-generation wireless communications, demands new materials to control electromagnetic interference, compatibility, and reliability of such systems. This work investigates feasibility absorptive non-reflective thin coatings deposition on dielectric substrates using simultaneous magnetron co-deposition. For this, electromagnetic waves propagation in the millimeter band through in micrometer-thick Al–Si films of varied composition was studied. The co-deposition process was controlled by the ratio of sputtered atoms fluxes. Graded segregation was observed under certain parameters of the co-deposition process, resulting in a depth gradient of an aluminum content, as confirmed by the secondary ion mass spectrometry study. A qualitative model was proposed involving aluminum-induced silicon recrystallization happening in the course of a known aluminum interlayer exchange process. The observed Al–Si segregation effect in micrometer-thick films allows for preparation of the non-reflective and absorptive material for operation in the V-band with reflection losses more than 10 dB and transmission losses around 5 dB in the bandwidth of up to 20 GHz.

Tensile modeling of titanium-aluminum composite with a wave profile of a welded joint and local melts

Finite element simulation of tensile deformation of titanium-aluminum composite D20 – AD1 – VT6 was carried out. The joint boundary had a wave profile and local melts. 3D modeling of deformation of the composite D20 – AD1 – VT6 with a wave profile of the welded joint was carried out using the SIMULIA / Abaqus software. The relative thickness of the AD1 interlayer and the area of the melt were varied during the simulation. To determine for metal hardening during plastic deformation and the failure deformations for aluminum and aluminum alloy both Johnson-Cook deformation and fracture models was used. The influence of the size of the local melting zone and thickness of the soft interlayer on the distribution of stresses and strains in the composite is shown. The wave profile of the boundaries junction leads initially to localization of plastic deformation in the aluminum interlayer in the zone of free surfaces of the sample near the interface with the titanium alloy. A change in the length of vortices with areas of local melting near the tops of the wave profile from 0.3 to 0.8 mm had little effect on the profile of the curves “equivalent stress-absolute elongation of the sample”.

Ultrasonic welding of magnetic hybrid material systems \u2013316L stainless steel to Ni/Cu/Ni-coated Nd2Fe14B magnets

The performance of electric sensors is continuously improving due to the demands of modern vehicles and electronic devices. Magnetic sensors are used in a wide field of applications. However, handling and mounting the typical high-performance rare earth permanent magnets are challenging due to their brittleness. A constant magnetic flux is a key property of the magnetic setup in many devices. State-of-the-art adhesive bonding of magnets in devices can cause problems due to the low durability and viscous behaviour of adhesive polymers, as the magnet may change its position and hence, the magnetic flux distribution in the magnetic setup changes.Ultrasonic welding is a powerful technique to join hybrid material systems quickly and reliably, providing high joint strength, even for brittle materials such as glasses, ceramics and rare earth permanent magnets. The latter is being investigated in this work for the first time. The ultrasonic welding process was adapted to join 316L stainless steel, representing potential components of magnetic devices, to Ni/Cu/Ni-coated Nd2Fe14B. In addition to directly joined steel/magnet-hybrids, ductile aluminium and nickel interlayers were used in order to enhance the joint strength.Process parameters were developed and evaluated considering the resulting shear strength of the joints. The highest shear strength of 35 MPa was achieved for 316L/Nd2Fe14B and 316L/Al/Nd2Fe14B, which is more than twice the shear strength of adhesively bonded joints of up to 20 MPa, according to the literature. The functional performance of the hybrid material systems, evaluated by the magnetic flux density of the hybrid material systems was the highest for directly bonded joints, and those with a nickel interlayer, which did not show any losses in comparison to the single magnet in its initial state. Joints with an aluminium interlayer showed losses of 3% and adhesively bonded joints showed losses of 7% of the magnetic flux density.In summary, the results of this work indicate that ultrasonic welding is a suitable technique to improve the production process and performance of magnetic devices.

The Effect of Welding Current and Electrode Force on the Heat Input, Weld Diameter, and Physical and Mechanical Properties of SS316L/Ti6Al4V Dissimilar Resistance Spot Welding with Aluminum Interlayer.

Welding parameters obviously determine the joint quality during the resistance spot welding process. This study aimed to investigate the effect of welding current and electrode force on the heat input and the physical and mechanical properties of a SS316L and Ti6Al4V joint with an aluminum interlayer. The weld current values used in this study were 11, 12, and 13 kA, while the electrode force values were 3, 4, and 5 kN. Welding time and holding time remained constant at 30 cycles. The study revealed that, as the welding current and electrode force increased, the generated heat input increased significantly. The highest tensile-shear load was recorded at 8.71 kN using 11 kA of weld current and 3 kN of electrode force. The physical properties examined the formation of a brittle fracture and several weld defects on the high current welded joint. The increase in weld current also increased the weld diameter. The microstructure analysis revealed no phase transformation on the SS316L interface; instead, the significant grain growth occurred. The phase transformation has occurred on the Ti6Al4V interface. The intermetallic compound layer was also investigated in detail using the EDX (Energy Dispersive X-Ray) and XRD (X-Ray Diffraction) analyses. It was also found that both stainless steel and titanium alloy have their own fusion zone, which is indicated by the highest microhardness value.

Corrosion resistance of hypersonic metallization coatings sprayed

The study of the structural-phase state and anticorrosive properties in a 10 % aqueous solution of NaCl of hypersonic metallization coatings made of 08Mn2Si, 40Cr13, 09Cr19Ni9Ti steels, A199,3 aluminum and pseudo-alloys Fe—Al and Fe—Ni—Cr has been carried out. It has been established that hypersonic metallization coatings made of A199,3 aluminum and pseudo-alloys Fe—Al and Fe—Ni—Cr have the highest corrosion resistance. High corrosion resistance of the coating made of pseudo-alloy Fe—Al is achieved due to the enveloping of steel particles with aluminum during the spraying process, as well as due to the formation of a film of aluminum oxides on the surface of aluminum interlayers and aluminum-alloyed iron interlayers. High corrosion resistance of coatings made of high-chromium steels is due to their alloying with chromium and nickel.

Comparative study on welding energy and Interface characteristics of titanium‑aluminum explosive composites with and without interlayer

In order to obtain titanium and aluminum composites with excellent performance and master the energy flow form when interlayer is used in explosive welding technology, energy calculation, SPH numerical simulation and experiment were used to conduct a comparative study of TA2/5083 and TA2/1060/5083 in this paper. Under the experiment conditions, TA2/1060, 1060/5083, TA2/5083 interface welding energy are respectively 547.17 MJ, 1178.86 MJ and 1455.5 MJ.The use of 1060 interlayer improves energy utilization efficiency by 14%. Numerical simulations and experiments showed that there was a continuous melting zone and a non-welded zone at the interface without interlayer. After the interlayer was used, the TA2/1060 interface was flat and the 1060/5083 interface showed a wave. There was no brittle intermetallic compound at the titanium‑aluminum composite interface. The use of interlayer reduces the welding energy of a single interface, and the constructed theoretical equation showed that the interface energy can be accurately designed by adjusting parameters of explosives, flyer plates, interlayers and base plates. The use of pure aluminum interlayer is an effective means to improve titanium‑aluminum explosive welding conditions

Investigation and Joint effect Analysis of Ti-6AL-4V & SS-304L in Aerospace Applications

The friction welding basic principle is connecting two materials with the help of friction generated between them using pressure and frictional time. The material used for this is Ti-6AL-4V & SS-304L with aluminum interlayers. The mechanical and metallurgical experimental strengths are investigated successfully. Titanium and stainless steel joined materials are commonly used for different aerospace, chemical, automotive and nuclear applications. The primary investigation of this present work is the connection between titanium and stainless steel with an aluminum interlayer. Initially, stainless steel and aluminum joints were made, and then the aluminum other surface was connected with titanium alloy. Joined welded samples are analyzed with scanning electron microscopes. Welded joint strength and characteristics were determined with the help of the tensile test, micro hardness and impact test. These investigation results were studied and compared with previous experimental studies.

The effect of holding time on dissimilar resistance spot welding of stainless steel 316L and Ti6Al4V titanium alloy with aluminum interlayer

A combination of stainless steel and titanium alloy is obviously a good choice for the industrial application using resistance spot welding process. However, to provide good quality of the welded joint was difficult due to the different types of materials. To enhance the weld quality, aluminum was placed in between stainless steel and titanium alloy as an interlayer. The mechanical and physical properties of the welded joint were investigated. The results of the SS316L/Ti6Al4V joint show that the tensile-shear load was 895 N and the maximum hardness value was 367.3 HV under the weld current of 12 kA, welding time and holding time of 10 cycles and electrode force of 4 kN. The microstructure result shows that a very thin reaction layer was formed on the intermetallic compound of the SS316L/AA5754 interface. Meanwhile, a diffusion–reaction has occurred on the interface of AA5754/Ti6Al4V during resistance spot welding. The effect of holding time was investigated due to the void appears in the middle of the weld nugget. The existence of the void will significantly reduce weld strength. The increase of holding time successfully remove the void and increase the weld strength of the joint under the tensile-shear test.

Ultrasonic spot welded NiTi joints using an aluminum interlayer: Microstructure and mechanical behavior

NiTi shape memory alloys were successfully joined by ultrasonic spot welding (USW) using an aluminum interlayer. The microstructural phase transition and the mechanical properties of the joints were investigated. The results have shown that the NiTi/Al/NiTi (with thicknesses of 0.5 mm/0.1 mm/0.5 mm, respectively) interfaces were evenly connected, and there were no unconnected areas nor welding defects when a welding energy of 1000 J, welding pressure of 0.4 MPa, and welding amplitude of 55 μm were used. As a solid-state joining technique, no intermetallic compounds (IMCs) formed at the interface of the USWed joints. The joining mechanisms of NiTi to the Al interlayer were based on atomic diffusion and metallic bonding. At room temperature, the NiTi USWed joint exhibits a fully austenitic structure. Meanwhile, the welded area has a broader transition temperature range and hysteresis compared to the non-affected NiTi base material. Digital image correlation (DIC) was used during mechanical testing to accurately determine the strain fields during deformation. The fracture morphology was a mixture of cleavage (brittle) fracture and ductile with dimples throughout the fracture surface with an interfacial fracture mode.

Influence of aluminum interlayer on optical properties of very thin silver thin film

Generally, Ag thin films on glass substrates grow three-dimensionally because of the high Ag/glass interface free energy. However, flatter growth has been reported to be achieved by introducing an appropriate interlayer between the substrate and Ag film. With flatter growth, enhanced optical properties are expected. In the present study, very thin Ag films were deposited on an Al interlayer and their optical properties over a wide wavelength range from the visible-light region to the infrared region were investigated. Ag/Al films and Ag films were formed on substrates via resistance-heating vacuum evaporation. The Al interlayer thickness was fixed at 1 nm, and the Ag thickness was varied from 6 to 15 nm. The surface morphology was observed by atomic force microscopy, and the sheet resistance was measured by the four-point-probe method. The visible-light transmittance was evaluated using a spectrophotometer, and the infrared reflectance was evaluated using Fourier transform infrared spectroscopy. The surface roughness of a 6 nm-thick Ag film was found to be reduced from 1.0 nm to 0.6 nm by the introduction of the interlayer. In the absence of the interlayer, the sheet resistance was too high to be measured; however a sheet resistance of 16.2 Ω/sq. was obtained when the interlayer was present. Similar effects were observed for a 10 nm-thick Ag film. Ag films with thicknesses of 6 and 10 nm showed improved visible-light transmittance and infrared reflectance upon introduction of the interlayer. However, when the thickness of the Ag film was 15 nm, no difference in the sheet resistance or optical properties was observed between samples with and without the interlayer. As a consequence, we found that introducing an Al interlayer is effective for two-dimensional-like growth of Ag films, leading to enhanced visible-light transmittance and infrared reflectance.

Diffusion Bonding of 1420 Al-Li Alloy Assisted by Pure Aluminum Foil as Interlayer.

The Al–Li alloy is becoming popular for aerospace application owing to their low density, high specific strength, good corrosion resistance, etc. The diffusion bonding/superplastic forming (DB/SPF) structure of titanium alloy has been widely used in the aerospace industry. In order to broaden the application of Al–Li alloy, it is necessary to develop its diffusion bonding and superplastic forming (DB/SPF) technology. In the present study, diffusion bonding of 1420 Al–Li alloy assisted by pure aluminum foil was conducted on Gleeble-3500 thermal simulation system under different bonding parameters, the results show that the bonding temperatures have direct influence on the interface microstructure and bond strength of joints. Meanwhile, when the pure aluminum interlayer was introduced into the diffusion bonding process, the alloying element diffusion across the bond can improve the interface integrity and the mechanical properties. The joint formation mechanism with interlayer was investigated in detail, the development and application of this method was explored.

Effect of Equal Channel Angular Pressing on Mechanical and Tribological Properties of Sintered Al-Sn Composites

Evolution of structure of two-phase sintered Al-Sn composites during equal channel angular pressing (ECAP) without rotation of the sample between the passes (route A) was studied. The macrostructure with alternating thin Al and Sn interlayers was formed in the flow plane of the samples under the ECAP processing. It was found that the law of the changes in the parameters of the structure of the composites can be described using the geometry of ECAP. The greatest changes in the macrostructural parameters and increase in the strength of the composites were observed during the first two passes. The consequence of the thinning of aluminum interlayers is an increase in the depth of deformation of the subsurface layer and decrease in distance between tin interlayers which are sources of solid lubricant. As a result, the wear intensity of the sintered Al-Sn composites is additionally decreased under dry friction against steel if the sliding direction is perpendicular to the elongated phases interlayers. It was established that the composite containing about 40% Sn has the highest wear resistance.