Stir Casting Method Research Articles

The influence of the modifying elements on the microstructure, mechanical, and deformation properties of aluminum alloys

In the current work, the standard A242 aluminum cast alloy is modified using the stir casting method with titanium (Ti) (0.5% wt.) and boron (B) (0.1% wt.) modifiers. Polarized optical and scanning electron microscopy were utilized to examine the A242 base microstructure, and A242 + TiB modified alloys; the results revealed that the modified A242 + TiB alloy was refined by 13.5 times more than the as-cast alloy. The mechanical properties were investigated experimentally using compression test in addition to the hardness test; the results revealed that the ultimate compressive strength of the A242 + TiB modified alloy was increased by 9.0% more than those of the A242 standard alloy. Moreover, the yield stress was enhanced by 40% at room temperature and 20% at 250 °C. The dynamic properties were studied using a free vibration impact test to study the modifiers’ effect on the dynamic behavior. The grain refinement notably impacted the damping capacity; due to the as-cast inhomogeneity, the conventional alloy A242 exhibited a greater FRF than the modified alloy A242 + TiB. The modified alloy displayed fewer resonance peaks due to grain refinement and excellent intermetallic phase distribution. The simulation process of the investigated alloys was performed using ABAQUS finite element software to predict the deformation behavior under different temperatures. The FE results showed that the modified alloy was more resistant to deformation by 9.1% than the reference alloy, A242, at room temperature and 7.6% at 250 °C, which agreed with the experimental findings.

Creep Behavior of A356 Aluminum Alloy Reinforced with Multi-Walled Carbon Nanotubes by Stir Casting.

Lightweight aluminum alloy components are often used to manufacture a variety of engineering components in many industries. In recent years, researchers have studied the effect of improving the mechanical properties of metal alloys by incorporating nano-carbon into its structure. In this study, the effect of the addition of 0.2, 0.5, and 1 wt% of multi-walled carbon nanotubes (MWCNTs) on the stress-strain behavior and creep phenomenon of an A356 aluminum alloy were studied. The effect of nickel coating on 0.2 wt% MWCNTs was also investigated. Samples were prepared using the stir-casting method. The results revealed that the grain size became finer when MWCNT nano-particulates were introduced. Although the MWCNTs were distributed homogeneously in the A356 matrix, as confirmed by FESEM analysis, there were some agglomerations observed in a specific area with dimensions smaller than 100 nm. Nevertheless, the addition of MWCNTs was found to be beneficial in enhancing the hardness of alloys containing 0.2 wt%, 0.2 wt% nickel-coated, 0.5 wt%, and 1 wt% MWCNTs by 9%, 24%, 32%, and 15%, respectively, as compared with the unreinforced A345 matrix. It was also found that the 0.5 wt% MWCNT-A356 matrix exhibited an improvement in the creep lifetime by more than two orders of magnitude.

Microstructural Evaluation and Fracture Behavior of AZ31/Nb2O5 Metal Matrix Composite

There have been remarkable improvements in the research field of magnesium over the last few decades, especially in the magnesium metal matrix composite in which micro and nanoparticles are used as reinforcement. The dispersion phase of nanoparticles shows a better microstructural morphology than pure magnesium. The magnesium metal matrix nanocomposite shows improved strength with a balance of plasticity as compared to the traditional magnesium metal matrix composite. In this research, Nb2O5 (0 wt.%, 3 wt.%, and 6 wt.%) nanoparticles were used to reinforce AZ31 with the stir casting method, followed by heat treatment, and finally, an investigation was conducted using microstructural analysis. Factors such as the degree of crystallinity, crystallite size, and dislocation density are affected by the concentration of Nb2O5 and heat treatment. With the compositional increase in Nb2O5 weight percentage, the grain size decreases up to 3% Nb2O5 and then increases gradually. The SEM image analysis showed a grain size reduction of up to 3% Nb2O5 and fracture morphology changed from basal slip to a mixture of basal slip and adiabatic shear band.

CORROSION BEHAVIOR OF Al/SiC/PKSA HYBRID COMPOSITES IN 1.0 M H2SO4 ENVIRONMENT USING POTENTIODYNAMIC POLARIZATION TECHNIQUE

The potentiodynamic polarization of aluminium 6063 alloy reinforced with silicon carbide (SiC) and palm kernel shell ash (PKSA) particulates at various mixing ratios were investigated. Double stir casting method was adopted for the production of the hybrid reinforced composites. The existence of the reinforcements within the matrix alloy acted as active sites for corrosion initiation. Hence, pitting corrosion was observed. The range of values for Ecorr and Icorr obtained at 24 h in 1.0 M H2SO4 were between -627.74 and -644.46 mV, and between 423.81 and 860.23 µA/cm2, respectively. The Ecorr values ranged from -654 to -697.22 mV, and the Icorr ranged from 1075.65 to 3057.16 µA/cm2 at 72 h in 1.0 M H2SO4. The relative resistance to corrosion of the samples is dependent on the thin oxide film formed on the surface of the samples.

Assessment of the Mechanical and Corrosion Properties of Mg-1Zn-0.6Ca/Diamond Nanocomposites for Biomedical Applications.

In this work, the microstructure, mechanical properties, and corrosion behavior of the Mg-1Zn-0.6Ca matrix alloy (ZX10), reinforced by adding various amounts of nanodiamond particles (0.5, 1, and 2 wt.%), prepared by the ultrasound-assisted stir-casting method, were investigated as they are deemed as potential implant materials in biomedical applications. Microstructure, nanoindentation, mechanical tensile, immersion, and potentiodynamic polarization tests were performed for evaluating the influence of the addition of nanodiamond particles on the alloy's mechanical and biocorrosion properties. The results revealed that the addition of nanodiamond particles causes a reduction in the alloy's grain size. The alloy's nanohardness and elastic modulus values increased when the amount of added nanodiamond particles were increased. The nanocomposite with an addition of 0.5% ND showed the best composition with regard to an acceptable corrosion rate as the corrosion rates are too high with higher additions of 1 or 2% NDs. At the same time, the yield strength, tensile strength, and elongation improved slightly compared to the matrix alloy.

Manufacturing and FSW of hybrid functionally graded metal matrix composite

Abstract This study focuses on the manufacturing of hybrid functionally graded metal matrix composite (HFGMMC) using Al7039 alloy matrix phase which is used as armor material in today’s world. In this context, manufacturing stages of matrix material were analyzed, and necessary parameters were determined for remanufacturing using casting method. With the determined parameters, the matrix material was reinforced by SiC, Al2O3, and B4C particles in different volume rates at an average size of 3–10 µm using stir casting method. Three metal matrix composite (MMC) plates which were manufactured using different reinforcement particles in different volume rates were joined as semi-solid with the effect of temperature and pressure in a specially designed mold. In order to complete the manufacturing process, hot forging, and heat treatment were applied to the manufactured composite plate in accordance with the parameters determined in the manufacturing of the matrix. The manufactured MMC and HFGMMC plates were compared in terms of their micro structure, micro hardness, tensile strength, and wear behavior. Finally, HFGMMC plates were joined together by friction stir welding (FSW) in order to analyze their micro structures and mechanical properties after welding.

Nanosize Al2O3 reinforcement in Si-rich aluminum MMC for enhanced tribological performance in engine components

Aluminum metal matrix composites are increasingly popular nowadays because of their wide range of uses. The low weight and excellent mechanical qualities, such as strength and hardness, of Al-Al2O3 composites make them useful in many fields, including automotive, aerospace, electronics, aeronautics, and military. Most of the engine components are made of aluminum-silicon alloys because of their excellent casting and forming properties. In engine components wear is a crucial parameter to be considered therefore in this investigation Al-Si alloy with varying percentages of V2O5 has been considered to develop the Al-Al2O3 composite and evaluate its tribological aspect. For composite development, a novel in-situ approach has been used with the help of the stir-casting method. The tribological behavior of the different composites was examined experimentally and studied with sliding distance, applied load, and the amount of reinforcement. Composites show a significant increase in hardness relative to the base alloy because of the generation of hard alumina particles within the melt. The wear behavior of in-situ Al-Al2O3 composites was studied using a pin-on-disc setup. In terms of COF and wear rate, the composite with a 1% addition of V2O5 performed better in the trial.

Studies on wear behavior of hybrid aluminum alloy (7075) reinforced with B₄C and BN

This paper investigates mechanical properties of a newly synthesized Al7075-B4C-BN (hybrid metal matrix composite), such as hardness, wear and microstructure analysis of an composite. In this study, we used ultrasonic stir casting method to fabricate the hybrid aluminium alloy and reinforcement are added in varied weight ratios to Al7075. Ultrasonic stir casting is used to manufacture reinforcement weights ranging from (0.1 to 0.9) wt.% B4C and (0.1 to 0.9) wt.% BN. The microstructure of the generated Al7075 hybrid metal matrix composite is examined using field emission scanning electron microscopy (SEM). The bonding dispersion is seems homogenous and the sample of 6 (0.4B4C &0.6BN) shows maximum hardness after heat treatment and influence hardness similarly decreases the wear rate of an composite.

Mechanical properties and frictional behavior of SiCp/Al-Si-Cu-Ni-Mg hybrid composites at an elevated temperature

PurposeThis paper aims to investigate the effect of Cu content and T6 heat treatment on the mechanical properties and the tribological performance of SiCp/Al-Si-Cu-Ni-Mg hybrid composites at an elevated temperature.Design/methodology/approachThe stir casting method was used to synthesize SiCp/Al-12Si-xCu-1Ni-1Mg (x = 2, 3, 3.5, 4, 4.5, 5 Wt.%) composites containing 20 vol% SiC. The hardness and tensile strength of the aluminum matrix composites (AMCs) at room temperature and elevated temperature were studied, and the wear mechanism was investigated using scanning electron microscopic and energy dispersive spectroscopy.FindingsResults indicate that the hardness and tensile strength of the AMCs are affected significantly by T6 heat treatment and Cu content. The high-temperature friction and wear mechanism of AMCs is the composite wear mechanism of oxidation wear, adhesion wear, abrasive wear, peeling wear, high-temperature softening and partial melting. Among them, adhesion wear, high-temperature matrix softening and local melting are the main wear mechanisms.Originality/valueThe influence mechanism of Cu content on the hardness, tensile strength and high temperature resistance of AMCs was explained by microstructure. And the results further help to explore the application of AMCs in high temperature.

Investigating the Synergic Effects of WS2 and ECAP on Degradation Behavior of AZ91 Magnesium Alloy

In this research, WS2/AZ91 metal matrix composites were manufactured using the stir casting method. The composites were severely deformed using equal channel angular pressing (ECAP). The degradation behavior of severely deformed and as-cast samples was investigated using the three-electrode system in a 3.5 wt% NaCl solution. The corrosion products and surface morphology of the corroded surfaces were investigated using an x-ray diffractometer and scanning electron microscopy. The results revealed that as-cast monolithic AZ91 exhibited the highest corrosion potential of (−1.553 mV) and a minimum degradation rate (4.099 m·a−1). The reduction ion grain size after severe plastic deformation increased the degradability of WS2/AZ91 composites. Severe plastic deformation reduced the grain size, which led to an increase in the corrosion rate. The synergic effects of (tungsten disulfide) WS2 and ECAP increased the degradation rate to (4.59 m·a−1) in two-pass 1 wt% WS2/AZ91. The increase in WS2 contents decreased the degradation rate (4.512 m·a−1) in homogenized 1 wt% WS2/AZ91 composites. The degradability of AZ91 increased in all conditions under the synergic effects of WS2 and severe plastic deformation. Magnesium and magnesium hydroxide were observed as corrosion products. The maximum surface roughness in two-pass 1 wt% WS2/AZ91 indicated the highest material removed by corrosion from the surface of the composites.

Effect of ZrO2 incorporation on the mechanical behavior of an AlSi alloy

AlSi–ZrO2 composite was prepared by stir casting method using a vortex technique. Micrograph observations exhibit a microstructure containing primary Si particles, eutectic silicon cells and intermetallic particles embedded in a dendritic primary α-phase in both Al–Si and AlSi–ZrO2 homogenized alloys. Difference in thermal conductivity between the α matrix and the ZrO2 particles generates a high temperature gradient resulting in an increase in the cooling rate which affects the microstructure and, consequently, the mechanical properties. On the other hand, the difference of the structures and the thermal expansion coefficient between ZrO2 particles and the matrix generates stress and increases the dislocation density. Presence of the ZrO2 particles enhances the ductility of the composite materials and reduces its Young's modulus. Addition of the ZrO2 particles increases the hardness of the composite materials at low aging temperature and reduces it at higher aging temperature.

Review on synthesis of AA 6061 metal matrix alloy using stir casting method

The composites of aluminum AA6061 alloy have superior performance and material characteristics in comparison with base alloy. Present study gives a detailed review on the AA 6061 metal matrix composite (MMC) manufactured with conventional stir casting method, where the process parameters used and characterization method used have been deliberated upon. On review it has been observed that reinforcements like Al2O3, B4C, SiC and TiC have been most commonly used for manufacturing of AA 6061 metal matrix nano composite (MMNC). In current trend other suitable reinforcements like hybrid, inorganic, nanomaterials and organic reinforcements are being looked upon. The AA 6061 hybrid composites consists of two or more reinforcements and reported comparatively superior properties as compared to single component composite. There is huge scope for research on AA 6061 nanocomposite that has much higher strength and wear resistance and useful for aerospace and defence applications.

Mechanical and wear properties of Al7075- B4C–Gr metal matrix composites fabricated by the using stir casting method

Engine parts like pistons, cylinders and valves are made of aluminium metal matrix composite due to their less weight and high thermal conductivity. Aluminium has less wear resistance and a high thermal expansion coefficient is the main disadvantage. Engine parts are subject to high mechanical thermal stress leads to experiences of wear during service which consequently reduces the service life of the component. In this research work, hardness and wear Behaviour of Al7075 with Boron Carbide 5% and Graphite particles as reinforcements were investigated Graphite and Boron carbide is mixed with aluminium in weight percent of boron carbide 5% (i.e. 50 g per kg) and Graphite 1%, 2% (i.e. 10,20 g per kg) of different samples using a stir casting process.Adding Graphite and boron carbide to aluminium (Sample2 (Al85 %+ B4C 10 % +Gr 5 %)) improves the tensile strength increases 3 % compare to Sample1 (Al 90 %+ B4C 5 % +Gr 5 %). Sample3 (Al80% + B4C 10 % + Gr 10 %) having 1.12 % higher hardness compare to Sample1 (Al 90 %+ B4C 5 % +Gr 5 %) hardness of the material gradually increases by adding boron carbide.

Investigation of electrochemical discharge machining process variables during µ - drilling on stir casted novel Zn/ (Ag+ Fe)-MMC for biomedical applications

ABSTRACT Stainless steel, titanium alloy, and cobalt have long-term risks when used as metallic implants. Zinc is essential component of human body and can be used for metallic implants. The research presents the fabrication of novel hybrid Zn/(Ag + Fe)-MMC using stir casting method, analysis of microstructural and mechanical properties of fabricated MMC specimen. Electrochemical Discharge Machining (ECDM) was employed for the µ-drilling on the fabricated MMC. The effect of ECDM process variables like supply voltage, peak current, pulse-on-time, pulse-off-time, feed rate and electrolyte concentration on material removal rate (MRR), overcut (OC) and tool wear (TW) were identified during µ-drilling. Experiments had been performed based on the one factor-at-a-time approach. From the experiments it was found that MRR, OC and TW increase as supply voltage, peak current, pulse-on-time, electrolyte concentration increase and decrease as pulse-off-time increases. An increment in feed rate increases the MRR and TW but overcut decreases. Scanning electron microscopy (SEM) analysis at maximum MRR condition shows rough surface finish and ovality in µ-drilled hole. Whereas high circularity and uniform drilling attributes were obtained along the whole depth at minimum OC condition.

Wear and microstructure analysis of aluminium based composite using eggshell and rice husk ash as reinforcement

PurposeThe purpose of this paper is to study Al-based green composite. To make composite samples of aluminium alloy (AA3105) with different weight percentages of rice husk ash (RHA) and eggshell (ES) particles as reinforcement, stir casting method was used.Design/methodology/approachSeveral other aspects, including the weight percent of reinforcing agent particles, the applied stress and the sliding speed, were taken into consideration. During the course of the wear test, the sliding distance that was recorded varied from a minimum of 1,000 m all the way up to a maximum of 3,135 m (10, 15, 20, 25 and 30 min). The typical range for normal loads is 8–24 N, and their speed is 1.58 m/s.FindingsWith the AA/ES/RHA composite, the wear rates decreases when the grain size of the reinforcing particles enhanced. Scanning electron microscopy images of worn surfaces show that at low speeds, delaminating and ploughing are the main causes of wear. At high speeds, ploughing is major cause of wear. Composites with better wear-resistant properties can be used in wide range of tribological applications, especially in the automotive industry. It was found that hardness increases at the same time as the weight of the reinforcement increases. Tensile and hardness were maximized at 10% reinforcement mix in Al3105.Originality/valueIn this work, ES and RHA has been used to develop green metal matrix composite to support green revolution as promoted/suggested by United Nations thus reducing the environmental pollution.

Machinability behaviors of synthesized beryllium composite

Currently, it is difficult to attain the composite with high quality material behaviors. The synthesized Titanium carbide based beryllium composite fulfills the need of excellent material behaviors. Titanium Carbide (TiC) particulate reinforced beryllium composite is synthesized through stir casting method as well as characterization of material has been studied by using Energy Dispersive Analysis of X-rays (EDAX) and Scanning Electron Microscope (SEM). The ultrasonic machining behaviors of the beryllium composite were evaluated using different input constraints such as power rating, abrasive size and frequency. Based on the input constraints, rate of metal removal was evaluated. The optimal factor was used to enhance the machinability behaviors using Taguchi approach.

Mechanical behaviour of stir cast TiO2/Redmud/Al6061 metal matrix composites

The present work deals with mechanical characterization of titanium oxide (TiO2)/Redmud/Aluminium alloy 6061 (Al6061) hybrid metal matrix composites (HMMC’s) processed using stir casting method. The weight fractions of TiO2 are varied (2%,4% and 6%) and amount of redmud is kept constant (2%) in Al6061. The optimised parameters for stir casting are employed for fabrication the samples of all the configurations and cut according to ASTM standards. The presence of the elements of the constituents is confirmed by XRD and EDS. Effect of TiO2 and redmud content on Tensile, Compression and Hardness are studied in detail. The results reveal that the tensile, compressive and hardness of the prepared composites enhance with TiO2 content. The yield and ultimate strength increase in the range of 29.77%–72.36% and 29.96%–63.90% respectively than the Al6061. The compressive strength enhanced in the range of 9.28%–33.20% than the Al6061. Enhancement of hardness in the range of 9.41%–41.17% is observed as compared to Al6061. The fractography studies confirm uniform mixing of the constituents and load transfer mechanism.

Estimation of electromagnetic shielding properties of wire mesh with AL6061 composite material for oblique incidence

Since composite materials were initially used in airplanes a few decades ago, substantial research has been done on problems such as lightning strike protection (LSP) and electromagnetic interference (EMI) shielding. In the current state of technology, the aerospace industry needs cutting-edge materials to meet requirements like lower weight and higher values of strength and stiffness and protect against electromagnetic interference. On the other hand, the metallic mesh performs poorly at high frequencies (UHF and SHF). Many present and future equipment on airplanes can only operate in the frequency range referred to above. Metal wire mesh matrix composite (MWMMC) materials may be employed to shield airplanes against electromagnetic interference (EMI) as a result of this research. In this work, we made three different MWMMCs represented as MMC-1 with 95% AL6061+5% Fly ash, MMC-2 with 90% AL6061+10% Fly ash, and MMC-3 with 85% AL6061+15% Fly ash. In this article, a stir-casting method was used to try to make Al6061 metal matrix composites that were made stronger with different amounts of fly ash particles. With fly ash, the AL6061 metal matrix composite protects against lightning strikes. So that it may serve as an aircraft surface MWMMC. The material's thickness should be maintained as low as possible. It decided to explore oblique incidence with a different mix of fly ash, reinforced to pure AL6061, to provide more significant shielding to better approximate the signal toward the practical case. Compared to the plane sheet, the shielding effectiveness of the materials and the weight of the material will be reduced. In other words, the maximum shielding effectiveness obtained was 37dB and 20 dB. The shielding effectiveness of 40.5 dB of the manufactured composite is obtained, and it is beneficial for aerospace applications.

Investigations on mechanical and wear behaviour of graphene and zirconia reinforced AA6061 hybrid nanocomposites using ANN and Sugeno-type fuzzy inference systems

This research work investigates the mechanical and wear behaviour of graphene (C) and zirconium di-oxide (ZrO2) reinforced Aluminium alloy 6061 hybrid nano composites (AMMHNCs) fabricated by ultrasonic-assisted stir casting method. Graphene and ZrO2 are selected as reinforcements for increasing the wear resistance and hardness of the base alloy AA6061. The mixing proportions of graphene and ZrO2 reinforced with AA6061 in weight are 100% AA6061/0% Graphene/0% ZrO2, 98.5% AA6061/0.5% Graphene/1% ZrO2, 97.5% AA6061/0.5% Graphene/2% ZrO2, 98% AA6061/1% Graphene/1% ZrO2, 97% AA6061/1% Graphene/2% ZrO2. Microstructural study was carried out using optical and scanning electron microscopic images to analyse the dispersion of reinforcements in the composite. The results shown that, ultrasonic-assisted stir casting method improves the uniformity in dispersion of reinforcements. The hardness, tensile, impact and wear test were carried out based on ASTM standards to analyse the properties in the proposed composite specimens. It was observed that, the hardness, tensile strength and impact strength are increases by 21.88%, 69.42% and 78.57% respectively and percentage elongation is decreased by 63.52% with the increase of reinforcements. Wear resistance increases with the increase of reinforcements. In order to analyse the wear behaviour originality of new composite under wear test parameters, Artificial Neural Network (ANN) and Artificial Neuro Fuzzy Inference Systems (ANFIS) models were used to predict the wear rate for experimented and non-experimented parameters. The prediction analysis was useful in studying the wear behaviour of the composite. Comparative analysis for ANN and ANFIS was performed and the results shown that, ANFIS model predicted with accuracy of R2 with 99.9%.

Development of Wear Resistant Aluminum Based Nano-Composite Reinforced With Nano-AlN

Abstract The present study aims at development of nano-AlN reinforced aluminum metal matrix composite through stir casting method. For this commercially pure aluminum (CP-Al) and CP-Al + 2 wt% AlN nano-composite were casted at 760 °C by stir casting method. Both the alloy and the composite were subsequently characterized using optical microscopy and scanning electron microscopy. They were further tested for mechanical properties and dry sliding pin-on-disk wear studies were carried out at three different loads at room temperature at 200 rpm up to a sliding distance of 2 Km. The results indicate good particle dispersion into the matrix and massive grain refinement in the nano-composite. Accordingly, there is an improvement in UTS and 0.2% YS values by more than 100% by keeping ductility unaffected in the composite compared to the base alloy. Grain refinement and strengthening effect of nano-particles are the reasons for this improvement. Moreover, the wear study reflects considerable improvement in wear resistance in the composite at all loads. Suppression of adhesion (at all loads) and plowing abrasion (at 60 N load) are attributed to this improvement in wear resistance in the composite.