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Hybrid aluminum metal matrix composites have prominence than conventional metals. Aluminum is used as base metal in many metal matrix composites, as it is widely used in industries and researches. The low density that is obtained after alloying is the major advantages of hybrid composite. The present study involves synthesis of Al6061/B4C/Mica hybrid metal matrix composite using stir casting method by mica particles as 3, 4, 5, 6wt.%, while maintaining 10wt.% of boron carbide. The best mechanical properties are reported by inclusion of 3wt.% of mica, while further addition of mica more than 3wt.% pulls down the mechanical properties and hence not sensible. The early-stage of strain hardening, and high tensile strength-yield strength ratio is observed, which concludes the fabricated hybrid aluminum composite is well suitable for automotive-related sheet forming operations.

One of the most extensively used alloys in the 6000 family is aluminium alloy 6061 (AA6061). This basic structural alloy is useful for medium to high strength needs and possesses strong properties, making it one among the most adaptable heat treatable alloys. In this paper, optimization of process parameters for cutting tool-workpiece interface temperature during End Milling of Aluminium Alloy 6061 using Taguchi analysis has been presented. The speed, depth of cut, and feed rate are the process parameters / control elements evaluated in the study. Taguchi design of experiments with L9 orthogonal array was used to plan the experimental setting. ANOVA, on the other hand, is used to find the most relevant factors and interactions. An ideal combination of process parameters for machining AA6061 in order to achieve a low signal to noise ratio (S/N) for surface temperature is obtained at feed rate of 20 mm/min, cutting speed of 4000 RPM, and depth of cut 0.6 mm.Feed rate is a significant control measure for regulating surface temperature based on ANOVA.

Numerous research incorporating precipitation hardening and/or strain hardening on Al-Mg-Si alloys has demonstrated improved mechanical properties in the alloys. However, there is a lack of research on how these processes can be combined efficiently to provide better strength and hardness for the alloys. The present study describes the effects of low temperature thermomechanical treatment (LTMT - combination of conventional age hardening and strain/work hardening) carried at two isothermal aging temperatures on the hardness and strength of the aluminium alloy 6061 (AA6061). Further, an innovative LTMT process is also proposed, which aims at further enhancing the mechanical properties of the alloy. The study revealed the increase in degree of deformation improved the strength and hardness of the alloy with reduced aging time. The effect of the degree of deformation, pre-deformation, and alternate deformation and aging cycles on the hardness and strength of the alloy was studied with the help of fracture surface analysis.

The ceramic particle reinforcement process is one of the most utilized techniques to enhance the metal surface. The current investigation uses vanadium and niobium carbides to reinforce the AA6061 alloy using the friction stir process (FSP). The mechanical properties are evaluated using ultrasound and conventional compressive tests; furthermore, the microstructure and physical properties are carried out to show the effect of single and hybrid additives of ceramic particles on the surface composites of aluminum alloy. Scanning electron microscopy (SEM) is utilized to examine the presence and distribution of the reinforcement VC and NbC particles inside the composite matrix. The microstructure examination revealed a good dispersion and homogenized distribution of the reinforcement particles. The results indicated that reinforcement particles significantly enhanced the mechanical and physical properties. The VC and NbC particles play an important role in improving the surface hardening behavior and grain refinement by restricting grain growth during the dynamic recrystallization process in the FSP action. The hybrid composited AA6061/NbC + VC recorded an increase in the compressive stress, yield stress, and hardness of 25%, 20%, and 50%, respectively, relative to the base metal, in addition to a 55% decrease in the coefficient of the thermal expansion (CTE) was reported. Moreover, the hybrid composite AA6061/NbC + VC significantly affected the corrosion rate with a reduction of 45%.

The objective of this research was to investigate the effect of friction time and friction pressure on the tensile strength of the joining of two dissimilar materials, aluminum alloy AA6061 and carbon steel, with continuous drive friction welding process. Variations of friction times of 5 seconds, 7 seconds, 9 seconds, and 11 seconds, at each variation of friction pressures of 24 MPa, 32 MPa, and 40 MPa. Controlled variables in this friction welding process were rotational speed of 1600 rpm, upset pressure of 79 MPa which was applied for 60 seconds and diameter of friction surface of specimens which were 15 mm. The resulting strength of the bonding were than evaluated on the basis of tensile strength. Observations of temperature change during the welding process, the distribution of Vickers hardness values around the bonds area, and micro photographs, were used as support to the analysis. The results showed that the longer friction time was applied, the higher tensile strength of the bonds would be, until it began to decrease after a certain maximum value of the tensile strength had been reached. Increased of the tensile strength of the bonding did not occur linearly due to the variation of friction pressure at 9 seconds and 11 seconds of friction time. At 5 seconds and 7 seconds of friction time, increase of friction pressure caused a linear increase of tensile strength. Higher temperatures in the welding process increased the thickness of brittle layer at the bonds boundary. The increase of the brittle layer thickness causes decrease of the tensile strength of the bonds.

To date, various studies have analysed the effects of reinforced ceramic on the properties of AA6061 recycled aluminum alloy chips, such as the tensile strength and fractography. However, a comprehensive analysis of the properties of hybrid composite with the addition of nano-silica oxide and nano-copper oxide reinforcements is still very limited. Therefore, this study aimed to optimise the factors comprising the preheating temperature (PHT), preheating time (PHti), and volume fraction (VF) of reinforcements then determine their impacts on the physical and mechanical properties of the recycled solid-state extruded composite aluminum chips. A total of 45 specimens were fabricated through the hot extrusion technique. The response surface methodology (RSM) was employed to study the optimisation at a PHT range of 450–550 °C with PHti of 1–3 h and VF of 1–3 vol% for both reinforcements (SiO2 and CuO). Moreover, a random forest (RF) model was developed to optimize the model based on a metaheuristic method to improve the model performance. Based on the experimental results the RF model achieve better results than response surface methodology (RSM). The functional quadratic regression is curvature and the tested variable shows stable close data of the mean 0 and α2. Based on the Pareto analysis, the PHT and VF were key variables that significantly affected the UTS, microhardness, and density of the product. The maximum properties were achieved at an optimum PHT, PHti, and VF of 541 °C, 2.25 h, 1 vol% SiO2 and 2.13 vol% CuO, respectively. Furthermore, the morphological results of the tensile fractured surface revealed the homogenous distribution of nano-reinforced CuO and SiO2 particles in the specimens’ structure.

Aluminum 6061 is of great commercial interest due to its ubiquitous use in manufacturing, advantageous mechanical properties, and its successful certification in aerospace applications. However, as an off-eutectic with accompanying large freezing range, attempts to process the material by additive manufacturing have resulted in part cracking and diminished mechanical properties. A unique approach using mixed powders is presented to process this historically difficult-to-process material. Expansion of this combined-powder approach to other materials systems not typically compatible with additive manufacturing is possible. Dense parts without solidification cracking have been produced by the SLM process, as verified using SEM and EDS. An overview of this approach is presented along with test results using an Al-Si mixture.

The use of aluminum alloys, nowadays, is swiftly growing from the prerequisite of producing higher strength to weight ratio. Lightweight components are crucial interest in most manufacturing sectors, especially in transportation, aviation, maritime, automotive, and others. Traditional available joining methods have an adverse effect on joining these lightweight engineering materials, increasing needs for new environmentally friendly joining methods. Hence, friction stir welding (FSW) is introduced. Friction stir welding is a relatively new welding process that can produce high-quality weld joints with a lightweight and low joining cost with no waste. This paper endeavors to deals with optimizing process parameters for quality criteria on tensile and hardness strengths. Samples were taken from a 5 mm 6061-T6 aluminum alloy sheet with butt joint configuration. Controlled process parameters tool profile, rotational speed and transverse speed were utilized. The process parameters are optimized making use of the combination of Grey relation analysis method and L9 orthogonal array. Mechanical properties of the weld joints are examined through tensile, hardness, and liquid penetrant tests at room temperature. From this research, rotational speed and traverse speed become significant parameters at a 99% confidence interval, and the joint efficiency reached 91.3%.

WOS: 000358560800002, In this study, the effects of the artificial-aging temperature and time on the mechanical properties and springback behavior of AA6061 are investigated. The results reveal that the yield strength, the tensile strength and the elongations decreased with the increasing artificial-aging temperature, but increased with the increasing artificial-aging time up to the peak age. The springback of the alloy increased significantly with the increasing artificial-aging time at the artificial-aging temperature ranging from 160 degrees C to 180 degrees C and decreased with the artificial-aging time at 200 degrees C. The springback angle in the as-received condition is lower than in all the aged conditions.

Spent aluminum-clad fuel elements from Argentine experimental nuclear reactors, manufactured with AA6061 aluminum alloy, are submitted to interim storage in demineralized water basins. In order to characterize the oxides grown during the storage, immersion tests of AA6061 samples were performed for periods from 3 days to 4 months at open circuit potential (OCP) and at room temperature in high purity water and in diluted NaCl solution. Electrochemical Impedance Spectroscopy (EIS) measurements were then performed on the oxide samples. The film thicknesses of oxides grown in high purity water, measured by eddy-currents technique, can be fitted to a sigmoidal curve reaching a limit value of ∼11 μm after 60 days of immersion, while the oxides obtained in diluted NaCl solution grow according to a linear law and reach a thickness of ∼26 μm after 120 days. From data obtained of fitting the EIS spectra with equivalent circuits, the thicknesses of the barrier layer present in the oxide were estimated for samples obtained in both media.

Aluminium alloy (AA6061) is reinforced with fine particulates are produced composite and discussed in this work. The reinforced aluminium alloy hybrid metal matrix composites (HMMCs) with 5 to 25% vol. fractions of Silicon Carbide and Aluminium Oxidereinforcements were created by stir casting technique. The metal to metal wear behavior of these hybrid composite and that of un-reinforced alloy was investigated by pin-on-disc wear testing machine. The optical micrographs in use for the micro structure investigation of the hybrid composite show that the Silicon Carbide and Aluminium Oxideparticulates reinforcement are regularly distributed in the matrix materials. The surfaces of the wear area were analyzed by SEM, which are shown that wear surface of the hybrid composite materials was normally much rougher than that of the non-reinforced alloy

Este artículo es un estudio experimental sobre la caracterización de las emisiones de nanopartículas en el tratamiento superficial por ondas de choque generadas por LASER (LSP) de materiales metálicos: aceros inoxidables, aleaciones de aluminio y de titanio. Se confirmó que la emisión de partículas de tamaño nanométrico consiste en agregados compuestos de partículas esféricas en el rango de 10-20 nm, cubiertas por una pequeña “capa” concéntrica correspondiente a óxidos metálicos. El análisis de las nanopartículas mostró la presencia de los principales elementos presentes en las aleaciones ensayadas, y también un contenido elevado de oxígeno que corrobora la presencia de óxidos de Fe, Al y Ti. La cantidad de nanopartículas emitidas, mostró aumentos considerables sobre la línea de base medida para el ambiente de trabajo, y estos aumentos corresponden a los impulsos más intensos de LASER. Se observó que la densidad del material influí en la cantidad de nanopartículas emitidas. Durante el LSP de aleación de aluminio (el material más ligero) se midió una gran cantidad de nanopartículas, mientras que en LSP de acero inoxidable se observaron pocas nanopartículas, y este es el material más denso, entre los tres ensayados. La aleación de titanio da como resultado valores intermedios. El estudio de estas emisiones es innovador y relevante para entornos industriales donde el proceso de fabricación está en uso.

Microstructure and corrosion behaviour of 6061 and 6013 sheet material were investigated in the naturally aged and peak-aged heat treatment conditions. Transmission electron microscopy did not reveal strengthening phases in the naturally aged sheet. In the peak-aged temper, β’’ precipitates were observed in alloy 6061, whereas both β’’ and Q’ phases were present in 6013- T6 sheet. Marked grain boundary precipitation was not found. Corrosion potentials of the alloys 6061 and 6013 shifted to more active values with increasing aging. For the copper containing 6013 sheet, the potential difference between the tempers T4 and T6 was more pronounced. When immersed in an aqueous chloride-peroxide solution, alloy 6061 suffered predominantly intergranular corrosion and pitting in the tempers T4 and T6, respectively. On the contrary, 6013 sheet was sensitive to pitting in the naturally aged condition, and intergranular corrosion was the prevailing attack in the peak-aged material. Both alloys 6061 and 6013 were resistant to stress corrosion cracking in the tempers T4 and T6.

This thesis systematically investigates the effects of a recently developed modified ageing procedure of aluminium alloys, termed the T6I6 temper, on the microstructural development and mechanical properties of the Al Mg Si - Cu alloy 6061. For the T6I6 temper, a conventional single stage T6 temper is interrupted by an ageing period at a reduced temperature (65ºC) to facilitate secondary precipitation, before resuming the final ageing at the temperature of the initial T6 treatment. The T6I6 temper was found to cause simultaneous increases in tensile properties, hardness, and toughness as compared with 6061 T6. Al Mg Si Cu alloys are medium strength alloys widely used in the automotive industry and their further improvement is underpinned by stringent demands for weight reduction placed on the transportation industry in recent years. The potential for further improvement of the mechanical properties was found in the control of secondary precipitation that may take place even in some fully aged alloys when exposed to reduced temperatures. The overall improvement in the mechanical properties of 6061 T6I6 was attributed to the formation of finer and more densely dispersed precipitates in the final microstructure. The refinement of precipitates was facilitated by control of the precipitation processes and gradual evolution of the microstructure throughout each stage of the T6I6 treatment. The results indicated that the concentration and the chemical environment of the vacancies controlled the precipitation processes in this alloy. Findings also show that the proportion of the different precipitate phases present in the final microstructure, as well as the amount of the solute in these precipitates, can be controlled and modified utilizing secondary precipitation. A number of analytical techniques were used in this study. The evolution of the microstructure was studied using Transmission Electron Microscopy (TEM), High Resolution TEM (HRTEM) and Three Dimensional Atom Probe (3DAP). Vacancy-solute interactions were studied using Positron Annihilation Lifetime Spectroscopy (PALS) and 3DAP. The distribution of the solute was studied using 3DAP and Nuclear Magnetic Resonance (NMR). Differential Scanning Calorimetry (DSC) was used to identify precipitation reactions and to determine the stability of vacancy-associated aggregates.