LM6 Aluminium Alloy Research Articles

Investigation on Microstructure and Mechanical Properties of Solution Heat-Treated and Multi Directional Forging-Processed LM-25 Aluminium Alloy

The experimental study of hypoeutectic Al-7.3Si alloy on microstructure and mechanical properties processed by MDF at room temperature was reported in this paper. A commercial LM-25 aluminium alloy ingot was melted in an electric casting furnace and poured into a preheated rectangular casting die. The samples were then solutionized for 10 h at 535 °C and quenched in water for MDF processing. Microstructure analysis of the samples was done with the help of optical microscopy and scanning electron microscopy. Microstructural observation of MDF processed up to six passes sample showed that coarse eutectic silicon particles with an average length of 16 µm are effectively broken into fine particles with an average length of 4 µm and uniformly distributed in aluminium phase. After six passes, UTS of as-cast specimen is increased from 177 to 441 MPa and microhardness is increased from 75 to 127 Hv. XRD analysis of the samples confirmed the presence of Al phase and eutectic Si phase. Therefore, modification of eutectic Si particle with Al phase refinement has been demonstrated to be a very important factor for enhancing mechanical properties of aluminium–silicon alloy.

Prediction of hardness of stir cast LM13 aluminum alloy ‐ copper coated short steel fiber reinforced composites using response surface methodology

AbstractCopper coated steel fibers reinforced LM13 aluminum alloy composites have been prepared using stir casting process. Experiments have been designed using response surface methodology (RSM) by varying wt % of reinforcement (0–10), stirrer speed (350 min−1–800 min−1) and pouring temperature (700 °C–800 °C). Microstructure and hardness of composites have been investigated. Analysis of variance, significance test and confirmation tests have been performed and regressions model has been developed to predict the hardness of composites. Response surface plots reveal that hardness of composites increases with increasing wt % of reinforcement and stirrer speed. The optimum stir cast process parameters for obtaining higher hardness are found to be the wt % of reinforcement of 8.2, pouring temperature of 748 °C and stirrer speed of 708 min−1.

Tensile and Compressive Behaviour of Hollow Glass Microspheres Reinforced LM13 Aluminum Alloy Based Syntactic Foam

Aluminium compound materials saw to be the best choice with its exceptional utmost of sketching out the material to give required properties. Aluminium alloy composites are expanding broad affirmation for aeronautics application in perspective on their high strength combined with low density. In the present work, an endeavour is made to prepare and focus the tensile and compressive behaviour of Hollow Glass Microspheres (HGM) reinforced Aluminium alloy LM13 based syntactic foam. Stir casting method was used to manufacture the aluminium alloy LM13 based syntactic foam with hollow glass microspheres (HGM) as space holders in 10 v%, 15 v% and 20 v% of concentration. Based on ASTM benchmarks, the composite samples were prepared. Results indicate that there is notable improvement in compressive strength while the tensile strength is on the lower side when observed in reference to the unreinforced LM13 alloy.

Investigation on the Effect of Stirring Process Parameters on the Dispersion of SiC Particles Inside Melting Crucible

Stirring based liquid metal processing is the widely explored process by researchers for the production of metal matrix composites (MMCs). The dispersion of reinforcement particles is the major challenge in the process. The stirring process parameters govern the dispersion of reinforcement particles in MMCs. The important stirring process parameters are stirring speed, stirrer geometry, stirrer position, and stirring time. In the literature, research works are reported, where the effect of such parameters on the dispersion of particles was investigated either by analyzing flow field using computational methods (assuming constant fluid properties) or by sectioning the casted samples. In cast condition, the dispersion of particles is also influenced by the solidification phenomena. The aim of the present work is to investigate the significance and the effect of stirrer geometry, stirrer position and stirring speed on the dispersion of reinforcement particles inside melting crucible, during the stirring. Aluminium alloy LM25 was used as the matrix material and silicon carbide (SiC) particles having mean size 37.58 microns (d50 value) were used as the reinforcement phases. Samples of the composite slurry during the stirring process were dragged using a quartz tube at three levels inside crucible and microstructure analysis was carried out. Number density (ND) and inter particle distance were evaluated for parameter combinations. The uniform dispersion of SiC particles was observed at 45° stirrer blade angle, 400 rpm stirring speed and 40 mm stirrer position. And, significance order of individual parameter was observed as stirring speed < stirrer position < stirrer blade angle.

Experimental investigation on mechanical properties and wear characterization of Al‐Si12CulMg1 aluminium alloy reinforced with titanium diboride and boron carbide particulate hybrid composites using stir casting process

AbstractLM13 aluminium alloy (Al−Si12CulMg1) with titanium diboride (TiB2) and boron carbide (B4C) particulate hybrid composites have been prepared using stir casting process. Wt% of titanium diboride is varied from 0–10 and constant 5 wt% boron carbide particles have been used to reinforce LM13 aluminium alloy. Microstructure of the composites has been investigated and mechanical properties viz., hardness, the tensile strength of composites have been analyzed. Wear behavior of samples has been tested using a pin on disc apparatus under varying load (20 N–50 N) for a sliding distance of 2000 m. Fracture and wear on the surface of samples have been investigated. Microstructures of composites show uniform dispersion of particles in LM13 aluminium alloy. Hardness and tensile strength of composites increased with increasing wt % of reinforcements. Dry sliding wear test results reveal that weight loss of composites increased with increasing load and sliding distance. Fracture on the surface of composites reveals that the initiation of crack is at the interface of the matrix and reinforcement whereas dimples are observed for LM13 aluminium alloy. Worn surface of composites shows fine grooves and delamination is observed for the matrix.

Compressive deformation behavior of closed cell LM-13 aluminum alloy foam using finite element analysis

Compressive deformation responses of closed-cell AlSi12Mg1Cu1 (LM-13) alloy foam (AFs) was analyzed through the help of ABAQUS Simulation software. An Approximate 2D model was made for closed-cell metal foam specimen of 60% porosity. Required porosity for the Closed Cell Metal foam was obtained by creating circular voids in the Model. The finite element (FE) Results were validated with the experimental results that were calculated from the output data of the computerized UTM machine. By comparing numerical outcomes and experimental data, the modelling and simulation technique was calibrated. Density and dimension of the FE model were kept similar to the experimental specimen. Plateau Stress (σpl), Energy absorption capacity (Eab) and densification strain (εd) of the experimental and FE outcomes were calculated and compared. The results show the approximately similar trend of compressive behavior and predicted FE results were found satisfactory.

Experimental analysis of aluminium alloy LM25 with carbon in composite material

This paper considers the potential use of Aluminium alloy LM25 with carbon in metal matrix composite with reference to the automobile industry. MMC of Aluminum alloy with carbon is done by appropriate casting process. This Work helps to explore the importance of Aluminium LM25 with carbon in automobile, aerospace industries. Mechanical and Microstructure properties are observed to improve the strength of the Aluminium alloy composite material.

Optimization of Machining Parameters in Drilling of Aluminum Matrix Composites (LM6/Fly Ash) utilizing Taguchi Technique

The present study revolves around the possibility of setting machining parameters in the drilling of composites of aluminum matrix (LM6/Fly ash) using the signal to noise ratio analysis. The aim of this work is to consider, the impact of input parameters, feed, speed, drill and percentage of composite material reinforcement on thrust force during AMCs drilling. AMCs were manufactured by the stir casting process with LM6 aluminium alloy as matrix material and fly ash as reinforcement material. Investigations were directed on a CNC vertical machining center for estimating thrust force. The Taguchi strategy for trial configuration is a generally admitted system employed for delivering great items requiring less effort. In the same way, L27 orthogonal array is employed for the analyses. The response table, graphs and variance analyzes are used to demonstrate the potential environment and the effects of machining parameters. It is evident that there is a tremendous improvement in the drilling procedure by using this methodology.

The Effect of Zr on LM6 Aluminum Alloy

In this study, the effect of Zr amount on LM6 alloys which were produced by conventional casting method and contained different amounts of Zr (0.05% and 0.15) on the microstructure and mechanical properties of the alloys was investigated. In addition, produced alloys were modified with 200-250 ppm Strontium (Sr). optic microscope (OM) and scanning electron microscopy (SEM / EDS analysis) were used for microstructure analysis. The hardness and tensile tests of the alloys which were modified by Sr and alloyed with different amounts of zirconium were performed. As a result of the studies that were done, it was determined in the images of optical microscope (OM) and scanning electron microscope (SEM) that the morphology of Al-Si-Fe phase changed depending on the addition of Zr, and that Al-Si-Fe intermetalics having different amounts of Zr composed. While the highest level of percent elongation was obtained from the Al12Si alloy, the highest level of hardness and maximum tensile strength were obtained from the LM6 alloy modified by strontium. The highest level of yield strength was obtained from LM6 alloy which was alloyed with 0.05 Zr. It was found that the amount of added Zr did not show a significant difference at the maximum tensile strength level of Al12Si alloy.

Examining the influence of shoulder to pin diameter ratio on corrosion behavior of friction stir LM25 aluminum alloy with 10% silicon carbide particles

Friction stir processing (FSP) is a unique method that facilitates the generation of frictional heat between the tool and the workpiece. Stir casted LM 25 aluminum alloy-10% SiCp Metal Matrix Composites (MMC) consists of large aggregated strengthened particles and cast item dendrites. In FSP, a non-consumable instrument made of harder material plays a crucial part in changing the substrate material's surface. In the present study, an attempt has been made to analyze the impact of different ratio of shoulder diameters to pin diameter (D/d) on the immersion corrosion conduct of the LM25AA processed friction stir – 10% SiCp MMCs. The size and dispersion of SiC particles in friction stir processed (FSPed) MMC were studied. The microhardness and tensile characteristics of the FSPed material were assessed and associated with the micro and macro structures. The influence of D/d ratio on the microstructure, micro-hardness, and corrosion rate was analyzed and observed that the hardness and rate of corrosion increase with the decrease in grain size of the matrix and SiC particles.

A Neural Network Model for the Compressive Strength of a Hybrid LM6 Aluminium Alloy Composite

Adding more than one reinforcement increases the flexibility in composites. The objective of the work is to develop a model to predict the compressive strength in an LM6 aluminium alloy reinforced with SiC and flyash particles. Central composite rotatable design had been employed to carry out the experiments with size and composition of the reinforcements as the parameters. ANN model developed has good prediction accuracy with error being less than 5%.

Investigation on mechanical properties and tribological behaviour of stir cast LM13 aluminium alloy based particulate hybrid composites

AbstractLM13 aluminium alloy with boron carbide (0 wt.%–7.5 wt.%) and fly ash (2.5 wt.%) reinforced particulate hybrid composites were fabricated using liquid metallurgy route. Microstructure and mechanical properties viz., hardness, ultimate tensile strength and ductility were investigated. Wear behaviour of composites was tested by varying sliding distance and load. Fracture surface and worn surface of composites were examined using field emission scanning electron microscope. Microstructure of hybrid composites revealed uniform dispersion of particles in LM13 aluminium alloy. Hardness and tensile strength of composites increased with increasing wt.% of boron carbide and fly ash particles. Wear test results showed that addition of particles significantly decreased the weight loss and coefficient of friction. Also cumulative weight loss decreased up to 47.2 % for 10 wt.% of hybrid composites as compared to LM13 aluminium alloy. Fracture surface of composites showed dimples with particle cracking on the surface. Worn surface of LM13 aluminium alloy showed continuous grooves due to ploughing with delamination. However, worn surface of composites showed fine grooves due to the presence of hard reinforcements on the surface. Boron carbide and fly ash reinforced LM13 aluminium hybrid composites exhibited superior mechanical properties with excellent wear resistance as compared to LM13 aluminium alloy.

Optimum Control Parameters During Machining of LM13 Aluminum Alloy Under Dry Electrical Discharge Machining (EDM) With A Modified Tool Design

Dry Electrical Discharge Machining (EDM) is considered as a green manufacturing process in which the liquid dielectric medium is replaced by a high velocity gas, which results improved process stability. A special tool design is adopted to find the optimum control parameters during machining of LM13 Aluminum alloy under dry EDM mode. The drilled and slotted cylindrical copper rod is used as a tool. Discharge current (I), voltage (V), pressure (P) and pulse on time (TON) are considered as varying input process parameters and duty factor and tool rotational speed are chosen at the fixed level. Taguchi L27 orthogonal array is used to design the experiment and the experiments are conducted accordingly. The experimental results are analyzed using Grey Relational Analysis to find the optimal combination of the process parameters. Also, ANOVA test is conducted to ensure the conformity of the simulation results. Pulse on time is found as the most significant parameter which is followed by voltage. Furthermore, the parameters with the highest relational grade (4 A, 200 μs, 60 V and 1.5 kPa) are used in experiment to validate the simulation results. The simulation and experimental results have a good agreement with less than 0.5 % error.

Parametric Optimization of CNC Turning on LM25 Aluminum Alloy Using Taguchi Based Grey Relational Analysis

This paper presents a novel approach in parametric optimization of machining LM 25 aluminium alloy by Taguchi based grey relational analysis. The optimization of cutting speed (V), feed rate (F), depth of cut (D), and cutting fluid flow rate (R) is performed taking into account the surface roughness (Ra) and the material removal rate (MRR). Ahonol- 7 is the cutting fluid utilized for machining operation. The optimum machining parameters are determined based on the grey relational grade (GRG) values. A statistical technique comprising of orthogonal array and analysis of variance (ANOVA) is employed in order to find the significant contribution of parameters. A Confirmation test is conducted in order to validate the optimal machining parameters. From this analysis, it is predicted that cutting fluid flow rate is the most influential parameter that affects the turning of LM 25 Aluminum alloy. Cutting fluid flow rate influences R (47.70%) more, followed by feed rate F (35.94 %), depth of cut D (12.16%) and cutting speed V (3.02 %).

Investigation on mechanical properties and dry sliding wear characterization of stir cast LM13 aluminium alloy-ZrB2-TiC particulate hybrid composites

In this study, the ceramic particles of titanium carbide (TiC) and zirconium diboride (ZrB2) were used as reinforcements in LM13 alloy matrix to fabricate hybrid composites. The composites along with unreinforced aluminium alloy were produced by varying the weight percentage (wt%) of ZrB2 (0, 2.5, 5 and 10) with a constant 5 wt% TiC through liquid metallurgy stir casting technique. Microstructural analysis of cast samples was made using optical microscope. Various mechanical characteristics such as hardness, tensile strength and ductility were evaluated for the composites and unreinforced aluminium alloy to investigate the effect of different wt% of reinforcements in LM13 alloy matrix. Dry sliding wear performance of the pin samples of LM13 alloy and composites was examined using a pin-on-disk tribometer to study the influence of sliding distance and wt% of reinforcements on the responses like weight loss, wear rate and friction coefficient. Fractured surface of tensile test samples and dry sliding worn surface of pin samples were analyzed through field emission scanning electron microscope. From the experimental study, it is observed that the trend of hardness, tensile strength and wear resistance of hybrid composites increases proportionately with increasing ZrB2 wt% in LM13 matrix. The degree of wear in pin samples exhibited an inverse relationship with the sliding distance after a run of 500 m. Cumulative weight loss of the composites depicted an increasing trend with the applied load during wear test. As compared to unreinforced LM13 aluminium alloy, the hardness, ultimate tensile strength and wear resistance of LM13-10ZrB2-5TiC hybrid composite increased up to 63%, 49% and 69% respectively. FESEM worn surface analysis results indicated the transition of wear mechanism from mild abrasive wear to severe delamination with increasing load. ZrB2 and TiC particle reinforced hybrid composites offered better mechanical and tribological properties than TiC reinforced composite and LM13 alloy.

INVESTIGATION ON MECHANICAL AND WEAR PROPERTIES OF ZINC-COATED STEEL WIRES REINFORCED LM6 ALUMINIUM ALLOY COMPOSITES BY SQUEEZE CASTING

Zinc-coated steel wires (1–5 numbers) reinforced in LM6 matrix composites have been prepared by squeeze casting process. Microstructure, hardness, tensile strength, ductility and dry sliding wear behavior of composites have been investigated by varying sliding distance and load. Fracture surface of tensile specimens and worn out surface of wear samples have been examined using field emission scanning electron microscope (FESEM). The results reveal that hardness of composites increased with increasing distance from matrix to steel wires. Maximum hardness values of 751 VHN and 611 VHN are observed in steel wire and at the interface of steel wire — aluminium, respectively. Tensile strength of composites increased upto 24% by reinforcing three steel wires in matrix. During the wear test, weight loss, wear rate and coefficient of friction decreased with increasing number of wires embedded in matrix and increased with increasing sliding distance and load. LM6 aluminium alloy reinforced with five numbers of steel wires decreased the weight loss upto 17% as compared to matrix under 40[Formula: see text]N load and a sliding distance of 2000[Formula: see text]m. Fracture surface of tensile specimen shows dimple formation in matrix and broken wires are observed in composites. Worn surface of composites shows fine grooves, whereas delamination is observed in matrix. In general, reinforcement of zinc-coated steel wires in LM6 aluminium alloy exhibited better mechanical properties and wear resistance compared to matrix.

Analysis of mechanical and micro structural property of aluminium metal matrix (LM25) composite hybrid with nano silicon carbide and nano alumina as reinforcement particles

The effect of reinforcement of silicon carbide nano particle (SiCnp) and nano alumina particle (Al2O3np) in base matrix composite of aluminium (LM25) alloy is studied. By using stir casting method, the hybrid aluminium matrix-based nano composites (AMNC) samples are made. The addition of nano particles in a base matrix increases the strength compared to pure LM25 aluminium alloy. The distributions of reinforcement particles are evident in the EDAX and SEM analysis. Both the density test and compression test results of AMNC samples are compared with the pure LM25 aluminium alloy. By increasing the percentage of reinforcements in matrix phase influences the increase in their mechanical properties. Aluminium matrix-based nano composites having high density, compression strength and wear resistance than pure aluminium. The above results indicates that the AMNC have excellent corrosion resistance and good fluidity but limited strength in high temperature.

Analysis of mechanical and micro structural property of aluminium metal matrix (LM25) composite hybrid with nano silicon carbide and nano alumina as reinforcement particles

The effect of reinforcement of silicon carbide nano particle (SiCnp) and nano alumina particle (Al2O3np) in base matrix composite of aluminium (LM25) alloy is studied. By using stir casting method, the hybrid aluminium matrix-based nano composites (AMNC) samples are made. The addition of nano particles in a base matrix increases the strength compared to pure LM25 aluminium alloy. The distributions of reinforcement particles are evident in the EDAX and SEM analysis. Both the density test and compression test results of AMNC samples are compared with the pure LM25 aluminium alloy. By increasing the percentage of reinforcements in matrix phase influences the increase in their mechanical properties. Aluminium matrix-based nano composites having high density, compression strength and wear resistance than pure aluminium. The above results indicates that the AMNC have excellent corrosion resistance and good fluidity but limited strength in high temperature.

Effect of end chills, reinforcement content and carburization on the hardness of LM25-borosilicate glass particulate composite

Aluminium metal matrix composites (AMCs) are widely employed in aerospace and automobile applications. Thus, they are required to operate reliably under a severe corrosive, high temperature and carbonaceous environments, without undergoing any deterioration in their mechanical properties. The paper is the compilation of the experimental results and analysis carried out to investigate the effect of different end chills, reinforcement content and carburization on the LM25 aluminium alloy reinforced with borosilicate glass powder. The composites are prepared via stir casting route by varying the weight percent (wt.%) of the reinforcement starting from 3 wt.% and going up till 12 wt.% with an increment of 3wt.% in every step. To obtain quality castings, end chills are placed within the sand mould. The specimens drawn from the chill-end of the castings are pack carburized in a muffle furnace for a set duration of time. The hardness of the specimens before and after carburization is recorded. The analysis of the results illustrates that the hardness increases linearly with the increase in the reinforcement content within the matrix from 3 wt.% up to 9 wt.%. It is also evident that the Volumetric Heat Capacities (VHC) of the chill material bears a strong effect not only on the quality of the castings produced but also on the hardness of the AMCs. Carburization leads to carbon deposition on the surface causing a change in the hardness of the specimens.

Recycling of LM25 aluminum alloy scraps

Abstract These days, a lot of metal scraps are generated by the automobile industry since the use of vehicles is increasing globally. As the production of automobile increases, the use of aluminum alloys has been increasing in automobile applications. Since the resources for the production of primary aluminum are getting scarce and the production of primary aluminum is highly expensive, production of components using secondary aluminum alloy in the form of scraps is highly essential. The present study deals with the re-melting of aluminium alloy scraps and the production of secondary aluminum alloy through a gravity die casting process. An investigation of its microstructure, chemical composition and mechanical properties such as hardness, tensile strength and an impact test have been performed and compared with the properties of primary and standard aluminum alloy. Porosity of secondary aluminum alloy is observed macroscopically. In addition a radiograph test was performed to study the internal defects of the secondary aluminum alloy.