Al/Ni metal intermetallic composite produced by accumulative roll bonding and reaction annealing (original) (raw)
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Journal of Materials Engineering and Performance, 2012
The present investigation is an attempt to develop metal-intermetallic laminate composites based on Ni-Al system. In this study, Ni sheets and Al foils have been used for the development of Ni-Al laminate using accumulative roll-bonding technique at 773 K. The laminate composites were then subjected to the controlled annealing to affect reactive diffusion at the Ni/Al interface leading to intermetallic compound formation. The accumulative roll-bonded laminates showed good bonding of layers. Annealing treatment at 773 K led to formation of reaction product and maintained the interface integrity. A qualitative compositional analysis at the interfaces reflected the formation of Al-Ni compounds, and a gradual compositional gradient also across the interface. This process seems to be of promise so far as the continuous production of large scale metal-intermetallic laminate composites is concerned.
Metals, 2019
In this work, the interface characteristics and resulting bond strength were investigated for roll bonded steel-aluminum composites with nickel interlayers, both after rolling and after post-rolling heat treatments at 400 °C–550 °C. After rolling, only mechanical interlocking was achieved between the steel and nickel layers, which resulted in delamination. Post-rolling heat treatments resulted in sufficient metallurgical bonding between the steel and nickel layers, and a significant increase in the bond strength. An intermetallic phase layer formed during the heat treatments, which below 500 °C consisted of Al3Ni and above, Al3Ni and Al3Ni2. With increasing temperature and time, the Al3Ni2 phase consumed the Al3Ni layer, voids developed along the Al3Ni2-aluminum interface, and a duplex morphology developed inside the Al3Ni2 layer, in accordance with the Kirkendall effect. The highest bond strength was obtained for the composites that only had an Al3Ni layer along the interface, and ...
Materials Science and Engineering: A, 2012
Al-Ni-Cu composite was produced using accumulative roll bonding (ARB) and electroplating processes. Nickel was electroplated on copper substrate for a certain time and voltage. In this study, the microstructural evolution and mechanical properties of the Al-Ni-Cu composite during various ARB cycles were studied by optical and scanning electron microscopes, microhardness, tensile and bending tests. It was observed that at first, nickel layers and then copper layers, were necked, fractured and distributed in aluminum matrix as accumulative roll bonding cycles were increased. Finally, after 11 cycles of ARB process, a completely uniform composite was produced with a homogeneous distribution of copper and nickel particles in aluminum matrix. The results showed that by increasing the number of ARB cycles, the bending strength of produced composite was increased. Also, it was found that when the number of cycles was increased, not only elongation was increased but also the tensile strength of the composite was improved. Microhardness for different elements in different cycles was also evaluated. Finally, fracture surfaces of samples were studied, using scanning electron microscopy (SEM), to reveal the failure mechanism.
The Effect of Strain on the Formation of an Intermetallic Layer in an Al-Ni Laminated Composite
Metals
In the present work, the influence of strain on phase formation at the Al/Ni interface was investigated during cold roll bonding and annealing. A sandwich sample composed of an Al-Ni-Al stack was cold rolled with reductions in the range of 50% to 90%, followed by annealing at 450 • C for 60 min. The crystallography of the annealed sandwich samples was analyzed by XRD (X-ray diffraction), whereas the microstructure was studied by scanning electron microscopy, equipped with EDS (energy dispersive spectrometer) analysis, and optical microscope. In the annealed samples, the intermetallic phase Al 3 Ni has formed at the Ni/Al interface, preferentially on the Al side of the interface. It is found that the applied strains did not have an effect on the type of intermetallic phase that was formed. However, the rolling reduction has a significant effect on the morphology of the intermetallic layer, as it was observed that after the lowest reduction of 50% only some scattered intermetallic nuclei were present, whereas at the highest rolling reduction of 90% a continuous intermetallic layer of 4.1 µm was exhibited. The formation of the intermetallic layer is discussed in terms of Al and Ni diffusion at the interface and irregular nature of the Al/Ni bonded interface after rolling reductions.
Application of accumulative roll bonding and anodizing process to produce Al–Cu–Al2O3 composite
Materials & Design, 2015
In the present investigation, production of Al-Cu-Al 2 O 3 composite by means of Accumulative Roll Bonding (ARB) coupled with the anodizing process was studied. For this purpose, the alumina was grown on Al sheets by electrolyte technique and then the coated Al was laid between two Cu sheets followed by roll bonding to a specific reduction. This process was repeated up to seven times in order to achieve a bulk composite. The microstructure was characterized by SEM and optical microscopy while the mechanical properties were measured by microhardness, triple point bending and tensile testing. Microstructural evolution of the produced composite revealed that alumina was fractured in the primary sandwich and distributed non-uniformly throughout the composite. However, the alumina distribution was improved as the ARB cycles proceeded. It was also found that the tensile strength was improved up to the third cycle, after which it was decreased for the fourth and fifth cycles and again, it was increased for the last cycles. The bend strength showed the same trend as the tensile strength, while the elongation represented weak values for almost all cycles. Moreover, it was observed that as strain was increased (more ARB cycles), the microhardness for both Al and Cu layers was increased by two different trends. Additionally, failure analysis revealed that the mode of fracture was governed by two mechanisms: micro crack initiation between the metallic layers and formation of micro voids mainly around the alumina particles followed by their coalescence.
Metals and Materials International, 2012
The purpose of this study is to discuss the effect of annealing temperatures on growth of intermetallic phases in Al/Cu composites during the accumulative roll bonding (ARB) process. Pure Al (AA1100) and pure Cu (C11000) were stacked into layered structures at 8 cycles as annealed at 300°C and 400°C using the ARB technique. Microstructural results indicate that the necking of layered structures occur after 300°C annealing. Intermetallic phases grow and form a smashed morphology of Al and Cu when annealed at 400°C. From the XRD and EDS analysis results, the intermetallic phases of Al2Cu (θ) and Al4Cu9 (γ2) formed over 6 cycles and the AlCu (η2) precipitated at 8 cycles after 300°C annealing. Three phases (Al2Cu (θ), Al4Cu9 (γ2), and AlCu (η2)) were formed over 2 cycles after 400°C annealing.
Journal of Composite Materials, 2019
This research studies the structure and mechanical properties of Ni/Ti multilayered composites produced from commercial pure Ni and Ti foils by accumulative roll-bonding technique. To investigate these properties, scanning electron microscopy, Vickers microhardness, and uniaxial tensile tests were conducted at different processing cycles. Studies showed that in terms of structure, Ni and Ti layers maintain their continuity even up to 10 cycles of accumulative roll-bonding. Moreover, the energy-dispersive spectroscopy in scanning electron microscopy detected no deformation induced diffusion or reactive interfacial zones. It was found that by increasing the accumulative roll-bonding cycles, tensile and yield strengths as well as the hardness of the composite enhance and the total elongation reduces continuously.
Investigation of nanostructured Al/Al 2O 3 composite produced by accumulative roll bonding process
Materials and Design, 2012
In this study, the accumulative roll bonding (ARB) process was used for manufacturing nanostructured aluminum/15 vol.% alumina composites. Microstructural characterization by transmission electron microscopy (TEM) identified the severe shear deformation, however, the grain growth was restrained by particles of oxide film and recrystallization produced the nanograins with an average size <100 nm after the 13th cycle of composite strip. The findings also indicated that the presence of large particles and deformation structure in the vicinity of the particles made the particle stimulated nucleation (PSN) of recrystallization possible. The Williamson-Hall method was used to calculate the grain size from the X-ray diffraction (XRD) patterns, which were 150 nm for pure aluminum and 63 nm for aluminum/ alumina composite after 13 cycles of the ARB process. The findings also revealed that after the first cycle, hardness rapidly increased, then dwindled, and finally reached saturation as the number of ARB cycles increased.
International Journal of Minerals Metallurgy and Materials, 2018
Layered composites have attracted considerable interest in the recent literature on metal composites. Their mechanical properties depend on the quality of the bonding provided by the intermediate layers. In this study, we analyzed the mechanical properties and bond strengths provided by the nickel layer with respect to its thickness and nature (either powder or coating). The results suggest that bond strength decreases with an increase in the content of nickel powder. At 0.3vol% of nickel coating, we found the nature of nickel to be less efficient in terms of bond strength. A different picture arose when the content of nickel was increased and the bond strength increased in nickel coated samples. In addition, the results demonstrate that mechanical properties such as bend strength are strongly dependent on bond strength.
Effect of interface morphology on intermetallics formation upon annealing of Al–Ni multilayer
Journal of Alloys and Compounds, 2013
Following Benès rule, the initial phase formed at interface of Al-Ni multilayer on annealing is Al 3 Ni. On further annealing it should give rise to intermetallics Al 3 Ni 2 , AlNi and AlNi 3 , gradually increasing in Ni content. Using X-ray and polarized neutron reflectivity (PNR) we studied the depth dependent structure and magnetization of as-deposited and annealed Al-Ni multilayer, with thickness ratio of Al:Ni equal to 1:2 giving an overall atomic stoichiometry of 1:3 for Al:Ni. We identified asymmetric initial alloy phase formation at two interfaces, i.e. Ni on Al (Ni/Al) and Al on Ni (Al/Ni), of Al-Ni multilayer on annealing. The phases are identified as Al 3 Ni and Al 3 Ni 2 at Al/Ni and Ni/Al interfaces respectively. Our results indicate that the asymmetric alloy formation at interfaces is directly correlated with the interface morphology of as-deposited multilayer. Higher roughness at Ni/Al interface changes the local concentration of elements at interface, which results into change in effective heat of formation of the alloys and thus makes Al 3 Ni 2 more favourable at Ni/Al interfaces. PNR results also suggested that alloy layers are magnetically dead.