Relationship between Al-Ni intermetallic Phases and Bond Strength in Roll Bonded Steel-Aluminum Composites with Nickel Interlayers (original) (raw)
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Al/Ni metal intermetallic composite produced by accumulative roll bonding and reaction annealing
Journal of Alloys and Compounds, 2011
In this research, Al/Ni multilayers composites were produced by accumulative roll bonding and then annealed at different temperatures and durations. The structure and mechanical properties of the fabricated metal intermetallic composites (MICs) were investigated. Scanning electron microscopy and X-ray diffraction analyses were used to evaluate the structure and composition of the composite. The Al 3 Ni intermetallic phase is formed in the Al/Ni interface of the samples annealed at 300 and 400 • C. When the temperature increased to 500 • C, the Al 3 Ni 2 phase was formed in the composite structure and grew, while the Al 3 Ni and Al phases were simultaneously dissociated. At these conditions, the strength of MIC reached the highest content and was enhanced by increasing time. At 600 • C, the AlNi phase was formed and the mechanical properties of MIC were intensively degraded due to the formation of structural porosities.
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.
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.
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.
Materials & Design, 2012
In this study, the effect of coating nickel and also its different thicknesses on the bond strength of Al-Ni-Cu layers was investigated. Furthermore, the effect of reduction in thickness and post-rolling annealing on the bond strength was evaluated in order to achieve the optimum parameter in rolling Al/Cu/Ni composites. So, after preparing samples, using peeling test, we investigated the bond strength of Al-Cu strips. The results showed that coating copper with nickel reduces the bond strength of Al-Cu strips. However, by increasing the thickness of coating, the bond strength was increased, reaching the highest level compared with the strips without coating. Also, the increase in the reduction enhanced the bond strength of the layered strips. Yet, a decrease in bond strength was achieved by post-rolling annealing of the layered strips.
Development of IF steel–Al multilayer composite by repetitive roll bonding and annealing process
Materials Science and Technology, 2008
The present study shows feasibility of synthesising steel-aluminium based metal intermetallic laminate (MIL) composites by an industrially viable and repetitive roll bonding process and subsequent annealing. Roll bonding process has been utilised to achieve solid state bonding of interstitial free (IF) steel and aluminium with simultaneous reduction in sheet thickness. Further annealing of roll bonded laminate sheets gives rise to IF steel-aluminides/aluminium multilayer composites. Formation of Al 5 Fe 2 phase at the interface is confirmed by X-ray diffraction (XRD) analysis.
Bonding behavior during cold roll-cladding of tri-layered Al/brass/Al composite
elsevier, 2016
Tri-layered Al/brass/Al composite was fabricated by cold roll bonding (CRB). The bond strength, threshold deformation and peeled off surface were examined and compared with that of Al/Al strip. To find the best bonding quality during the roll bonding, the effect of reduction in thickness, brass layer, friction conditions and post-rolling annealing on the bond strength was evaluated. The bond strength was estimated by the peeling test. Scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) was utilized to investigate the peeled off surfaces. In order to detect the new phases after annealing, the X-ray diffraction (XRD) was used. In accordance with the film theory, the bond strength of Al/Al strip and Al/brass/Al composite enhanced with increasing the reduction in thickness. In comparison to Al/Al strip, the Al/brass/Al composites exhibited the lower bond strength and the higher threshold reduction, which was explained by the energy barrier theory. The highest bond strength was obtained in the high friction condition because of the higher contact pressure in this condition. Post-rolling annealing caused the bond strength to decrease due to the formation of intermetallic compounds.
Growth of intermetallic layer at roll bonded IF-steel/aluminum interface
Journal of Materials Processing Technology, 2008
Steel/aluminum Diffusion Al 5 Fe 2 EHF theory a b s t r a c t The solid-state reactive diffusion between IF-steel and Al was experimentally studied using IF-steel/Al/IF-steel diffusion couples. The specimens were prepared by a roll bonding technique and then annealed at temperatures 773 K for different time span. At the IF-steel/Al interface in the annealed diffusion couple, wavy layer of Al 5 Fe 2 was observed. The average thickness (T avg ) of Al 5 Fe 2 layer monotonically increases with increasing annealing time (t) according to the equation T avg = k(t) n , where t is time in second. Value of n = 0.5 indicates that interdiffusion through aluminide phase is the rate controlling step. During annealing, IF-steel matrix has undergone recrystallization. Microstructure and hardness measurement of IF-steel shows that recrystallization process completes within 30 min. Effective heat of formation theory has been applied to predict phase formation sequence during annealing of IF-steel/Al/IF-steel diffusion couples.
Metallurgical and Materials Transactions A, 2002
This article presents experimental results of important properties of aluminum-matrix (AA 2014) composite materials reinforced with different intermetallics of the Ni-Al system. For the present study, the intermetallics are prepared either by mechanical alloying (MA) or by gas atomization (GA). The reinforced composite materials were manufactured by mixing the constituents, followed by uniaxial compacting of a preform and subsequent extrusion without canning or degassing. The present study considered the materials in the extruded state and after T6 heat treatment. Assessments were made from the viewpoint of microstructure (by means of optical and scanning electron microscopy (SEM)) and thermal characteristics (by differential scanning calorimetry (DSC)), with special emphasis on studying the reactions that take place between the matrix and the reinforcement and which produce a highly copper-enriched interphase.
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.