Ultrasonic Assisted Stir Casting Research Articles

Synthesis and characterization of MWCNTs/Al6082 nanocomposites through ultrasonic assisted stir casting technique

The objectives of this work are to investigate the microstructural characterization of multi-walled carbon nanotubes (MWCNTs) produced by chemical vapor deposition method and to prepare Al6082/MWCNT nanocomposites by stir casting method. MWCNTs were developed and then ball milled with aluminum powder to obtain its coating on MWCNTs to improve wettability. Similarly, ultrasonic mixing was used to de-agglomerate the bundled MWCNTs during the stir casting process. MWCNTs were added to molten Al6082 with varying weight percentages (0.3–1.2 wt. %) during the stirring process, and microstructural characterization was performed with field emission scanning electron microscope (FESEM) along with energy dispersive X-ray spectrometer (EDX) for evaluation of elements. EDX analysis of the developed and purified MWCNTs revealed the absence of nickel and other impurities after purification. The Results from the microstructure of nanocomposites indicate that MWCNTs were uniformly distributed for up to 0.9 wt. % of MWCNT and on further increment of MWCNTs, agglomeration was noticed.

An overview of the effect of stirrer design on the mechanical properties of Aluminium Alloy Matrix Composites fabricated by stir casting

An overview of the effect of stirrer design on the mechanical properties of Aluminium Alloy Matrix Composites fabricated by stir casting

Preparation and characterization of AZ63A/Boron Nitride composites using hybrid mechanical and ultrasonic assisted stir casting

Magnesium (Mg) is become progressively used in the transportation business because of its low weight. The poorer mechanical properties of magnesium (Mg) compared to aluminium and steel limit its widespread use. Improved mechanical properties can be achieved through grain refinement in cast alloys. Particle substrates can be added to the liquid melt to serve as nucleation sites for the formation and development of grains, resulting in a finer grain size. Mechanical stirring (MS) with impeller is most common technique for dispersing inoculants into the molten metal. However, it is difficult to achieve uniform dispersion of inoculants using this method. Ultrasonic treatment (UST) has also been investigated as an alternative to MS treatment. Particle inoculants BN were studied to see how they would disperse inside the alloy AZ63A Mg in this study. To create the cast composites, either MS or UST were used. Thermal tensile tests and theoretical models were used to determine the mechanical properties of these materials. The UST-treated specimens outperformed the base alloy and the MS-produced samples in terms of mechanical properties. Inoculant dispersion in sonicated samples was shown to be improved due to the use of finer grains, a thermal development discrepancy between the refiner and matrix, and other factors. Using sonication and grain refinement, researchers were able to make a exclusive relationship between theoretic strengthening mechanism forecast models and the actual outcomes they attained. The mechanical properties of Mg alloy can be improved by utilising cutting-edge new technologies, such as UST, in the production of cast alloys.

Parametric Optimisation of Tribological Characteristics of Novel Al7010/B4C/BN Hybrid Metal Matrix Nanocomposites Using Taguchi Technique

ABSTRACT In this present experimental investigation, Al7010/B4C/BN hybrid metal matrix nanocomposites with equal weight percent of B4C and BN in steps of 0.5 from 0 to 2.5 are prepared using ultrasonic-assisted stir casting technique. Tribological characteristics of the prepared composites at room temperature are evaluated using pin-on-disc apparatus. Taguchi technique is used to study the influence of process variables on tribological behaviour of nanocomposites. The experiments were conducted based on the orthogonal array L18 through Taguchi technique and evaluated for the optimum process variables using Analysis of Variance (ANOVA). The experimental outcomes reported that the wear rate is mostly affected by composition (78.79) followed by applied load (19.68), sliding speed (0.55) and least is sliding distance (0.02). Coefficient of friction is influenced by composition (60.14) followed by sliding speed (29.34), sliding distance (6.47) and applied load (3.38). The confidence interval was predicted for a confidence level of 95%. Finally, the confirmation test is conducted to check the predictive values with the experimental results. The worn surface of the composite resulted from conformation test is studied using Scanning Electron Microscope (SEM).

Optimization of Fretting Wear Parameters and Effect of High Temperature on Fretting Wear Behavior of Al6061 Alloy and Al6061-SiC Composite

Al 6061 alloys are being used in vast industrial applications. The dry sliding wear behavior of SiC based Al6061 composites has been thoroughly explored in recent decade while its fretting wear behavior at high temperatures has not been studied well. In this work, the fretting wear parameters of Al6061 alloy and Al 6061 reinforced with 2 wt% SiC have been optimized and high temperature fretting wear behavior analyzed. Ultrasonic assisted stir casting method has been employed to prepare Al6061-2SiC composite. Integrated Taguchi and TOPSIS methods have been used to optimize the input parameters viz. temperature, material type, applied load, time and frequency of strokes. It is observed that out of temperature, applied load, time and frequency of strokes, temperature proves out to be the most critical parameter affecting the wear behavior of the matrix alloy and its composite the most. Through integrated Taguchi and TOPSIS optimization technique, it is found that the most optimal combination of parameters for minimal wear rate and friction coefficient is Al6061 + 2 wt% SiC composite at 200 N load, 100 °C temperature, 10 min time, and 40 Hz frequency of fretting strokes. The microscopic analysis of the samples revealed that fretting wear operates in partial slip regime in the composite tested at optimum combination of parameters. Wear regime changes from partial slip to mixed fretting with rise in temperature in the composite. In the alloy, the transition from mixed fretting to gross slip regime takes place with the rise in temperature. Al6061 alloy reinforced with 2 wt% SiC at optimum combination of parameters can prove to be a good replacement of conventional materials used in machinery prone to fretting wear.

Influence of the Fly Ash Material Inoculants on the Tensile and Impact Characteristics of the Aluminum AA 5083/7.5SiC Composites.

The choice of suitable inoculants in the grain refinement process and subsequent enhancement of the characteristics of the composites developed is an important materials research topic, having wide scope. In this regard, the present work is aimed at finding the appropriate composition and size of fly ash as inoculants for grain refinement of the aluminum AA 5083 composites. Fly ash particles, which are by products of the combustion process in thermal power plants, contributing to the large-scale pollution and landfills can be effectively utilized as inoculants and interatomic lubricants in the composite matrix–reinforcement subspaces synthesized in the inert atmosphere using ultrasonic assisted stir casting setup. Thus, the work involves the study of the influence of percentage and size of the fly ash dispersions on the tensile and impact strength characteristics of the aluminum AA 5083/7.5SiC composites. The C type of fly ash with the particle size in the series of 40–75 µm, 76–100 µm, and 101–125 µm and weight % in the series of 0.5, 1, 1.5, 2, and 2.5 are selected for the work. The influence of fly ash as distinct material inoculants for the grain refinement has worked out well with the increase in the ultimate tensile strength, yield strength, and impact strength of the composites, with the fly ash as material inoculants up to 2 wt. % beyond which the tensile and impact characteristics decrease due to the micro coring and segregation. This is evident from the microstructural observations for the composite specimens. Moreover, the role of fly ash as material inoculants is distinctly identified with the X-Ray Diffraction (XRD) for the phase and grain growth epitaxy and the Energy Dispersive Spectroscopy (EDS) for analyzing the characteristic X-Rays of the fly ash particles as inoculant agents in the energy spectrum.

Effect of Tribological Properties on Boron Carbide and CNT Reinforced Copper based Composites

The study focuses on the influence and contribution of multi-walled Carbon-Nano tube (MWCNT) and boron carbide (B4C) to the tribological properties of copper matrix composites. The Samples are prepared using ultrasonic assisted stir casting for different weight fractions. The tribological properties like wear and corrosion studies been carried out according to ASTM standards. Wear rate increased with the increase in speed and load for every combination of the composite. However, with CNT being the main reinforcement with addition of CNT wear rate has reduced marginally. Addition of Boron Carbide also to some extent decreased the wear rate but CNT plays a major role in reducing the wear rate. Corrosion studies of the composite materials is carried out by Weight loss corrosion techniques, it is clearly evident from the critical analysis of the results that with the addition of reinforcements to the composite material, the corrosion rate in weight loss corrosion technique decreases drastically with the duration of time, this is due to the formation of a passive oxide layer on the composite specimen.

Influence of nano fly ash on wear behavior of friction stir weld joints of Al6063/nano fly ash composites

The manufacturing industries attracted aluminium metal matrix composites (AMCs) to utilize in the modern spectrum of applications. Inexpensive particulate reinforced composites are exhibiting superior qualities at reduced costs. Fly ash is an industrial waste that can be adopted as reinforcement, particularly for aluminium matrix materials. Friction stir welding (FSW) is best suitable to weld aluminum-based materials. In this work, the Al6063/nano fly ash composites with 0, 1, 2, and 3% wt. of nano fly ash were fabricated through ultrasonic-assisted stir casting. Consequently, FSW joints were obtained for the fabricated composites by considering rotational tool speed and transverse tool speed as welding parameters. Wear analysis carried on weld beads of composites through the pin on disc equipment. The nano fly ash addition in the composites results in increased wear resistance in the FSW joints. Higher wear resistance was achieved with increased reinforcement inclusion. Increased tool feed rate also enhances the wear resistance of FSW joints. It can be concluded that the nano fly ash particles are the most influential in improving the mechanical properties of the AMC weld beads, and FSW is the better option to weld aluminum composites.

End mill studies on Al6061 hybrid composite prepared by ultrasonic-assisted stir casting

To produce the lightweight material for the high payload with excellent strength in particular for defense applications, reinforcements were introduced into the aluminum to form a hybrid composite. SiO2 was extracted through suitable techniques from rice husk ash particles. Through the ultrasonic probe sonication stir-casting process, the standard composition of 3% SiO2 was added along with varying weight percentages (3, 6, 9, and 12) of TiC particles as reinforcement in Al 6061 matrix. The machinability of the fabricated hybrid composite was evaluated through end face milling with varied machining parameters such as spindle speed, feed rate, and depth of cut. The output performance measurable characteristics were temperature and Ra. Thermal energy generated during the machining conditions was studied through the thermal image FLIR camera. From the machining conditions, machining level with SS of 1000, FR of 100, and DOC of 0.2 lead to having the highest temperature of 119 °C. The working temperature for the N2 sample was recorded to be 17% higher with an increase of 3% of TiC. The impact of wt% of reinforcements and governing parameters on tool wear was analyzed by SEM images. The addition of RHA and TiC reinforcements leads to raising cutting zone temperature, tool wear, and Ra. The thermal distortion effect on tool wear, chip morphology, and the surface profile of the samples were discussed and reported.

Effects of Ultrasonic Treatment and Nanoparticles Addition on Microstructure and Mechanical Properties of AS41A Magnesium Alloy

TiB2 nanoparticles reinforced AS41A alloys were fabricated by ultrasonic assisted stir casting. The influence of ultrasonic treatment and TiB2 nanoparticles on the microstructure and mechanical properties of AS41A magnesium alloy was investigated. The results showed that the ultrasonic treatment obviously refined microstructure, thereby improving the mechanical properties of the magnesium alloys. The addition of TiB2 further increased the tensile strength slightly while maintaining the improved elongation as the ultrasound-treated matrix alloys.The ultimate tensile strength, yield strength and elongation of the obtained nanocomposites were improved by 27.4%, 43.5% and 84.6% compared with those of the as-cast matrix alloys, respectively.

New Emerging Al7075 Based Hybrid Nanocomposite for Automotive Applications: A Sustainability Approach

Aluminium matrix composites (AMCs) have emerged as the substitute for the monolithic (unreinforced) materials over the past few decades. The applications of AMCs are common in automotive, aerospace, defence and biomedical sectors due to its lower weight, high strength, high resistance against corrosion and high thermal and electrical conductivity. In this work, it is aimed fabricate a new class Al 7075 based hybrid composites reinforcing with nanoparticulates suitable for automotive application. Al7075 reinforced with fixed quantity of boron carbide (B4C) (1.5 wt.%) and varying wt % of flyash (0.5 wt.%, 1.0 wt.%, 1.5 wt.%) is fabricated using ultrasonic-assisted stir casting technique. Physical and mechanical characterization such as density, porosity, micro hardness, tensile strength and impact strength were estimated for three different compositions. The tensile strength and percentage increase in hardness value of the nanocomposite Al7075-B4C (1.5 wt. %)-flyash (0.5 wt. %): HNC3 found maximum as 294 MPa and 32.93%. In comparison with Al7075 alloy the impact strength of HNC3 shows the highest percentage of 9.31% respectively.

Enhanced mechanical properties of AA6061-B4C composites developed by a novel ultra-sonic assisted stir casting

The increase of B4C addition into an AA6061-B4C composite system will not be always an ideal choice for improved properties because of the issues related to incorporation, distribution, and interfacial wetting while stir-casting. In such a case, ultrasonication is considered to be an alternative to get the advantage of microstructural changes which in turn improve the properties. In the present study individual B4C distribution and the refinement of microstructure was achieved at 4wt.%B4C. The improved specific ultimate and compressive strengths at 4wt.%B4C were observed as 36.32% and 43.92% whereas specific Vicker’s and Brinell hardness as 53.41% and 50.89% respectively.2009 Elsevier Ltd. All rights reserved.

Experimental inspection of aluminium matrix composites reinforced with SiC particles fabricated through ultrasonic assisted stir casting process

Al-SiC composite has improved mechanical properties which can be used in automobile sector to make different automobile parts. In the present study Al-SiC composites with different wt% of micron SiC particles have been fabricated by stir casting and the ultrasonic assisted stir casting process. The effect of ultrasonication for uniform mixing of the micron size SiC particles on the mechanical properties has been studied. The various mechanical properties like Tensile strength, Compressive strength, density, hardness etc. have been measured.

Tribological behavior of aluminum nanocomposites studied by application of response surface methodology

An aluminum Al-0.8Al2O3 and Al − 1.6Al2O3 nanocomposite was prepared by a novel ultrasonic assisted stir casting method. A three-level Box-Behnken design of experiment was developed using response surface methodology. Dry sliding wear tests were performed as per the experimental design using a pin-on disc setup at room temperature. Analysis of variance (ANOVA) was applied to investigate the influence of process parameters, viz., wt.% reinforcement, load and sliding distance, and their interactions on specific wear rate and coefficient of friction. Further, a mathematical model has been formulated by applying response surface method in order to estimate the tribology characteristics such as wear and COF of the nanocomposites. The specific wear rate and coefficient of friction are significantly influenced by % of Al2O3 and load. The wear test parameters were optimized for minimizing specific wear rate and COF using desirability function approach. A set of optimum parameters of combination for AMMNC was identified as Al2O3–1.1 wt.%; load, 34 N and sliding distance, 2931 m with specific wear rate, 1.06 g/N-m; and coefficient of friction, 0.305. The AFM image of Al6061–1.1Al2O3 nanocomposite at optimized condition confirms the improvement in the wear surface smoothness of the nanocomposite compared to Al6061.

Microstructure studies of AA7150-hBN nanocomposites fabricated by ultrasonic assisted stir casting

For two decades, the Al7XXX series alloys have been playing an extensive role in aerospace and automotive industrial applications due their excellent properties such as toughness, fatigue, strength and low density. However, the current scenario for all these applications, there is a significant improvement at service loads as well as wear resistance properties at elevated temperatures. The main focus of the current investigation is with the microstructure analysis of AA7150-hexagonal Boron Nitride (hBN) nanocomposites which are fabricated through ultrasonic assisted double stir casting process. The Scanning Electron Microscope and Optical Microscope were used to study the particle distribution, grain refinement of the monolithic AA7150 alloy, nanocomposites. The fractured surfaces and wear surfaces were also studied the influence of applied load as well as hBN weight percentage on nanocomposites and compared with base matrix.

Fabrication and characterization two step stir casting with ultrasonic assisted novel AA7150-hBN nanocomposites

The Al7150 alloy plays a vital role in aerospace and automotive industry applications due to its extraordinary characteristics like strength to weight ratio, toughness and fatigue resistance. But in the current scenario researchers are looking for significant improvement in wear resistance at various service loads. It is in such a context this paper deals with the fabrication, mechanical and wear resistance properties investigation of the Al7150-hBN nanocomposites, which is fabricated through ultrasonic assisted double Stir casting technique and compared with monolithic material. The microstructure studies were carried out through Optical Microscope (OM) for grain structure, Scanning Electron Microscope (SEM) for particle distribution, ultimate tensile strength including the morphological studies related to fracture surface and Energy Dispersive X-ray (EDX) spectroscopy for elemental analysis. The pin on disc tribometer was used to study the tribological characteristics of the developed nano-composite materials by varying the applied loads and weight percentage of hBN reinforcement at a constant sliding speed and distance. The SEM images of the worn-out surfaces were studied extensively to study the tribological properties.

The effect of B4C and BN nanoparticles on the mechanical and microstructural properties of Al7010 hybrid metal matrix

In the present study, Aluminum 7010 hybrid metal matrix nanocomposites with Boron Carbide (B4C) and Boron Nitride (BN) nanoparticles as reinforcement materials, combined in equal proportions with 0 to 2.5 weight percent (Wt%) of nanoparticles in steps of 0.5 are prepared using ultrasonic assisted stir casting technique. The composites thus obtained are tested for their microhardness, tensile strength and impact strength by using vickers micro hardness tester, universal testing machine and impact testing machine. The microstructural characterization of the composites is carried using scanning electron microscope and x-ray diffractometer. By analyzing the data obtained it was found that the percentage of elongation and impact strength of the composite are reduced with increase in particle reinforcement up to 2 Wt% and thereafter increased. While the tensile strength and microhardness increased with increase in Wt% of B4C and BN particles up to 2 and thereafter decreased.

Recent Studies on the Fabrication of Magnesium Based Metal Matrix Nano-Composites by Using Ultrasonic Stir Casting Technique - A Review

This paper presents the recent studies on the fabrication of magnesium based metal matrix nanocomposites (MMMC) by using ultrasonic assisted stir casting technique. The pure metal and alloys, due to their limited mechanical properties are not suitable for various engineering applications. It has been observed that the addition of suitable reinforcements into metallic matrix improves the specific strength, ultimate tensile strength, porosity and wear properties as compared to the conventional and monolithic engineering materials for aerospace and automotive applications. The effects of ultrasonic vibrations and the resulting uniform dispersion of reinforcements on the mechanical and tribological properties of magnesium based MMCs are specifically highlighted in this paper.

Experimental optimization of mechanical properties of Al7010/B4C/BN hybrid metal matrix nanocomposites using Taguchi technique

The composite material properties largely dependent on the processing methods and the parameters employed during their manufacturing. In the present study, the effect of B4C and BN nanoparticles on tensile strength and microhardness of Al7010 hybrid metal matrix nanocomposite is investigated. The composite is prepared using ultrasonic assisted stir casting technique, and the effect of processing parameters like weight percentage of particles, stirrer speed, stirring time and temperature on ultimate tensile strength and microhardness are optimized using Analysis of Variance technique. The experiments are planned using Taguchi design of experiment based on the L25 orthogonal array. In all the input parameters, the wt% of B4C and BN is most significant on ultimate tensile strength and microhardness followed by other parameters. Further, the verification of optimal experimental results the confirmation tests was conducted and also a percentage error is found.

Conventional stir casting versus ultrasonic assisted stir casting process: Mechanical and physical characteristics of AMCs

In this study, aluminum matrix composites (AMCs) were developed using two different techniques, conventional stir casting and ultrasonic assisted stir casting. The drawbacks of the conventional stir casting technique were eliminated by employing an alternative process to produce the composite, wherein ultrasonic energy was introduced into the molten metal using an ultrasonic probe. AMCs were produced by using different concentrations of SiC (3%, 5%, 8%, and 10%) microparticles with a size of 40 μm. Mechanical and physical properties of the composites developed using both techniques were examined and compared. Moreover, the effect of filler inclusion on AMC density was assessed. The microstructural investigation revealed that SiC microparticles were dispersed homogeneously in the matrix material when the ultrasonic probe was used. Furthermore, test results indicated that mechanical and physical characteristics improved with the ultrasonic-assisted stir casting process.