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The purpose of this paper is to join an anodized aluminium alloy AA6061 sheet with high-density polyethylene (HDPE) using friction spot process.

The surface of AA6061 sheet was anodized to increase the pores’ size. A lap joint configuration was used to join the AA6061 with HDPE sheets by the friction spot process. The joining process was carried out using a rotating tool of different diameters: 14, 16 and 18 mm. Three tool-plunging depths were used – 0.1, 0.2 and 0.3 mm – with three values of the processing time – 20, 30 and 40 s. The joining process parameters were designed according to the Taguchi approach. Two sets of samples were joined: the as-received AA6061/HDPE and the anodized AA6061/HDPE.

Frictional heat melted the HDPE layers near the lap joint line and penetrated it through the surface pores of the AA6061 sheet via the applied pressure of the tool. The tool diameter exhibited higher effect on the joint strength than processing time and the tool-plunging depth. Specimens of highest and lowest tensile force were failed by necking the polymer side and shearing the polymer layers at the lap joint, respectively. Molten HDPE was mechanically interlocked into the pores of the anodized surface of AA6061 with an interface line of 18-m width.

For the first time, HDPE was joined with the anodized AA6061 by the friction spot process. The joint strength reached an ideal efficiency of 100 per cent.

This study aims to develop a less weight high wear resistant material to fabricate brake components especially in automotive sector.

Effort was initiated to design and develop aluminium metal matrix composite by combining aluminium alloy AA6061 and zirconium oxide (ZrO₂) with the help of stir casting coupled with squeeze casting unit. Morphology analysis of advanced composite has been carried out by optical microscopy and scanning electron microscopy (SEM). The hardness of composites having different compositions was tested using Vickers micro hardness tester. The tribological property of the developed three specimens having different composition has been tested using pin-on-disc wear test equipment under dry sliding conditions. To obtain better understanding of wear mechanism, SEM image of worn-out surface was captured and analysed. SEM images and the corresponding Energy-dispersive X-ray spectroscopy (EDX) on the wear surface were carried out.

The optical and SEM images evidenced the existence of ZrO₂ particles along the metal matrix composite. Porosity values shows that the porosity level is acceptable as it falls below 7 per cent. Also, the finding proves that increase in the percentage of reinforcement particle instigates agglomeration on the AA6061 composites. Hardness test demonstrated that the inclusion of hard ZrO₂ particles leads to substantial improvement in hardness and the hardness value started deteriorating when the composition reaches 15 per cent. The wear test results substantiated the enhancement of tribological property due to the inclusion of distinct ZrO₂ particles. Also, despite of addition of reinforcements, the wear rate increased when the load increases. SEM images proved that AA6061/ZrO2-5 per cent composite fashioned steady-state mild and smooth wear. EDX spectrum analysis revealed the existence of ZrO₂ particles along with wear debris, which caused wear of 685 µm in AA6061/ZrO₂-15 per cent composite.

The developed material possesses low wear rate which is the unique property of composite and frictional force which is directly proportional to load but the coefficient of friction remains apparently constant. As a whole, investigations on developed composites introduce a new material which is suitable for manufacturing of brake components for automobile industry.

In the current scenario, air pollution and soil pollution from the industries wastes are one of the major problems all over the world. Further, disposal of these wastes from industries are very costly. However, several attempts were carried out by various researchers in the past to use these wastes. One of the most common waste products is bagasse from sugar industries. These hazardous bagasse wastes lead to air and soil pollution. This study aims to recycle bagasse waste in the development of aluminium base composite as partial replacement of ceramic particles.

In the present investigation, recycled bagasse waste was used in the development of aluminium base composite as partial replacement of ceramic particles such as SiC, Al₂O₃ and B₄C. Production industries of these ceramic particles (SiC, B₄C and Al₂O₃) emit huge amount of greenhouse gases such as N₂O₃, CH₄, CO₂ and H₂O. These green house gases produce lots of environment problem. Furthermore, production of these ceramic particles is also costly. AA6061 aluminium alloy was taken as matrix material. Composite material was developed using the stir casting technique.

Microstructure results showed proper distribution of bagasse ash and MgO powder in the aluminium base metal matrix composite. It was notified from analysis that minimum corrosion loss and minimum porosity were found for Al/2.5% bagasse ash/12.5% MgO powder composite. For the same composition, hardness and thermal expansion were also observed better as compared to other selected compositions. However, density and cost of composites continuously decrease by increasing percentage of bagasse ash in development of composite.

Results showed about 11.30% improvement in tensile strength, 11.64% improvement in specific strength and 40% improvement in hardness by using bagasse ash as reinforcement with MgO powder in development of aluminium base composite.

The purpose of this paper is to join aluminium alloy AA6061 with polyvinyl chloride (PVC) sheets using the friction spot technique.

The AA6061 specimen was drilled with a semi-conical hole and put over the PVC specimen with a lap configuration. A friction spot technique was used to generate the required heat to melt and extrude the PVC through the aluminium hole. In this study, three process parameters were used: time, plunging depth and rotating speed of the tool. Thermal finite element model was built to analyse the process temperature. Effect of the process parameters on the joint shear strength and temperature was analysed using the design of experiments method. The microstructure investigation of the joint cross section was examined.

The input heat melted and extruded the polymer into the aluminium hole with the aid of tool pressure. A mechanical interlock was observed at the interface line between the polymer and aluminium. The scattered aluminium fragments into the molten polymer increased the shear strength of the joint. The hole diameter exhibited the highest effect on the joint strength compared with the other parameters. Specimen of minimum hole diameter recorded the maximum shear strength of 224 MPa. The proposed model gave a good agreement with the experimental data.

For the first time, the PVC was joined with AA6061 by the hot extrusion using the friction spot technique. The shear strength of joint reached 7.5 times of the base material (PVC).

The aim of this work is to investigate the self-healing performance of epoxy coatings containing microcapsules. The microcapsule-based coatings were applied on AA6061 Al alloy and immersed in 3.5 per cent NaCl solution.

Microcapsules with urea–formaldehyde as the shell and linseed oil as the healing agent were prepared by in situ polymerization in an oil-in-water emulsion. For the sake of an optimum self-healing system, some coating samples were prepared by using different microcapsule concentrations: 0, 5, 10 and 20 Wt.%. The scratch-filling efficiency as the theoretical estimate of the self-healing performance was calculated for the coating samples with different microcapsule concentrations. The scratch-sealing efficiency (SSE) as a particularly crucial parameter in the self-healing evaluation of coatings was measured by both electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) techniques.

According to EIS and EN results, the coating samples containing 5 and 10 per cent microcapsules provided the insignificant self-healing performance, while the coating sample containing 20 per cent microcapsules exhibited the acceptable self-healing performance to AA6061 alloy in the NaCl solution. The measured SSE values confirmed the good agreement of EN data with electrochemical parameters obtained from the EIS technique.

This work is an attempt to evaluate the self-healing performance of microcapsule-based epoxy coatings applied on AA6061 Al alloy in sea water.

Composite materials are replacing the traditional materials because of their remarkable properties and the addition of nanoparticles making a new trend in material world. The nano addition effect on tribological properties is essential to be used in automotive and industrial applications. The current work investigates the sliding wear behavior of an aluminum alloy (AA) 6061-based hybrid metal matrix composites (HMMCs) reinforced with SiC and B₄C ceramic nanoparticles.

The hybrid composites are fabricated using stir casting process. Two different compositions were fabricated by varying the weight percentage of the ceramic reinforcements. An attempt has been made to study the wear and friction behavior of the composites using pin-on-disc tribometer to consider the effects of sliding speed, sliding distance and the normal load applied.

The tribological tests are carried out and the performances were compared. Increase in sliding speed to 500 rpm resulted in the rise of temperature of the contacting tribo-surface which intensified the wear rate at 30N load for the HMMC. The presence of the ceramic particles further reduced the contact region of the mating surface thus reducing the coefficient of friction at higher sliding speeds. Oxidation, adhesion, and abrasion were identified to be the main wear mechanisms which were further confirmed using energy dispersive spectroscopy and field emission scanning electron microscopy (FESEM) of the worn out samples.

The enhancement of wear properties is achieved because of the addition of the SiC and B₄C ceramic nanoparticles, in which these composites can be applied to automobile, aerospace and industrial products where the mating parts with less weight is required.

The influence of nanoparticles on the tribological performance is studied in detail comprising of two different ceramic particles which is almost new research. The sliding effect of hybrid composites with nano materials paves the way for using these materials in engineering and domestic applications.

The purpose of this paper is to develop a chrome-free and phosphorus-free chemical conversion coating with good corrosion resistance, a novel chemical conversion coating was prepared by adding cerium nitrate hexahydrate and salicylic acid in the treatment solution containing titanium/zirconium ions on 6061 aluminum alloy.

Compared with the AA6061 aluminum alloy matrix, the self-corrosion potential of the conversion coating is significantly positively shifted, the self-corrosion current density is greatly reduced and its corrosion resistance is significantly improved. Morphology and composition of the conversion coatings were observed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The microdomain structure of conversion coatings at different formation stages was analyzed by electron probe microanalyzer.

An optimized preparation technique of titanium–zirconium chemical conversion coating for AA6061 aluminum alloy is obtained: H₂TiF₆ 4 mL/L, H₂ZrF₆ 0.4 mL/L, salicylic acid 0.35 g/L, Ce(NO₃)₃·6H₂O 0.14 g/L, reaction temperature 30°C, reaction time 120 s and pH 4.0.

The coating forms on the Al(Fe)Si intermetallic compound, and Ce³⁺ is preferentially adsorbed on the intermetallic compound. The hydrolysis of Ce³⁺ causes the local pH of the solution to decrease, which promotes matrix dissolution and charge migration. As the microanode/microcathode reaction occurs, the local pH of the solution increases, and Al₂O₃/ZrO₂/TiO₂ begins to deposit on the surface of the metal substrate.

This paper aims to present a friction stir molding (FSM) method for the rapid manufacturing of metal tooling. The method uses additive and subtractive techniques to sequentially friction stir bond and then mill slabs of metal. Mold tooling is grown in a bottom-up fashion, overcoming machining accessibility problems typically associated with deep cavity tooling.

To test the feasibility of FSM in building functional molds, a layer addition procedure that combines friction stir spot welding (FSSW) with an initial glue application and clamping for slabs of AA6061-T651 was investigated. Additionally, FSSW parameters and the mechanical behavior of test mold materials, including shear strength and hardness, were studied. Further, scanning electron microscopy (SEM)/elemental map analysis (EDS) of the spot weld zones was carried out to understand the effect of FSSW on the glue materials and to study potential mixing of glue with the plate materials in the welded zone.

The results indicate that FSM provides good layer stacking without gaps when slabs are pre-processed through sand blasting, moistening, uniform clamping and FSSW using a tapered pin tool. The tensile shear strength results revealed that the welded spots were able to withstand cutting forces during machining stages; however, FSSW was found to cause hardness reduction among spot zones because of over-aging. The SEM/EDS results showed that glue was not mixed with slab materials in spot zones. The proposed process was able to build a test tooling sample successfully using AA6061-T651 plates welded and machined on a three-axis computer numerical control (CNC) mill.

The proposed FSM process is a new process presented by the authors, developed for the rapid manufacturing of metal tooling. The method uses additive and subtractive techniques to sequentially friction stir bond and then mill slabs of metal. The use of FSSW process for materials addition is an original contribution that enables automatic process planning for this new process.

The purpose of this study to analyze the plastic anisotropy of 6061 aluminum alloy with finite deformation using crystal plasticity finite element method.

A representative volume element (RVE) model was constructed by Voronoi tessellation. In this model, grain shapes, grain orientations and distribution of grains were involved. The mechanical response of the component under composite loading was tested using specify cruciform specimen. Moreover, different stress and strain states in the specific central region were analyzed to reveal the effects of complex loading.

We calculated the influence of misorientation of adjacent grains as well as the evolution of the micro structure’s plastic deformation on the macroscopic deformation of the structure. Geometry design for the cruciform specimen helps obtain a homogenous distribution of the stress and strain at the specimen center. In this process, the initial grain orientation is also an important factor, and the larger misorientations between special grains may cause greater stress concentration.

The influence of micro-scale factors on macro-scale plastic anisotropy of AA6061 is analyzed using RVE model and cruciform specimen, and they offer a reference for related research.

The purpose of this paper is to propose a mathematical model to estimate required energy and temperature distribution during cold extrusion process.

An admissible velocity field is generated based on stream function technique. Then, the required energy and the temperature distributions in the metal and the extrusion die are determined by a coupled upper bound‐finite element analysis.

To examine the proposed model, cold extrusion of AA6061‐10%SiC_p is considered and the predicted extrusion force‐displacement diagrams in different reductions are compared with the experimental ones and reasonable agreement is observed. Furthermore, it is found that there is a linear relationship between maximum temperature and logarithm of ram velocity for the examined composite.

This approach requires shorter run‐time as compared with fully finite element analyses while the model is particularly appropriate for high speed extrusion processes where the adiabatic heating is of importance.