LM13 Alloy Research Articles

Microstructure and X-Ray Diffraction Analysis of Aluminum-Fly Ash Composites Produced by Compocasting Method

Abstract Industrial and agro-wastes, such as fly ash, red mud, and rice husk ash, have become tremendous materials to be used as reinforcement in composite materials. In addition, these materials have potential to replace conventional ceramic reinforcement materials, such as aluminum oxide (Al2O3) and silicon carbide (SiC), as they can produce better composite materials with excellent properties and reduce the cost of production. Among the various types of waste materials used, fly ash has gained the widespread attention of researchers in aluminum matrix composite (AMC) production as reinforcement to enhance the properties of AMCs and reduce the production cost. In this research, LM6 (aluminum-silicon) alloy was reinforced with different amounts (4, 5, and 6 wt. %) of fly ash. These various compositions of LM6 reinforced with fly ash composites (AMCs) were fabricated by a compocasting method. The AMCs were then characterized based on microstructural (morphology, shape and size of the structure, and structure of existing elements) and phase analysis by scanning electron microscopy (SEM) and X-ray diffraction pattern (XRD). The existence of fly ash particles and some intermetallic compounds, such as Al2O3, silicon oxide, aluminum silicate, aluminum silicon, and calcium silicide, in the fabricated AMCs were confirmed through an XRD pattern. The SEM micrograph revealed that the microstructure of fabricated AMCs was refined with the incorporation of fly ash particles. The size of silicon phases decreased from 50 (unreinforced LM6) to 2.12 μm (LM6 fly ash composite with 6 wt. % of fly ash). Hence, it is found that the incorporation of fly ash particles is able to enhance the microstructure of fabricated AMCs.

Optimization of squeeze casting parameters of hybrid aluminium matrix composite using Taguchi approach

Squeeze casting is one of the simplest processes of manufacturing of composite materials and it attains higher advantages of low material processing cost, easy handling of material, size, design and good stability of matrix structure. LM24 aluminium alloy reinforced with silicon carbide (SiC) and coconut shell ash (CSA) were used to prepare the composite. LM24 alloy had wide engineering applications, wherein the addition of SiC enhances the wear resistance and CSA particles offer significant technical and economic benefits. In the present study, the composite samples were prepared based on Taguchi experimental conditions L16 (4-levels and 5- parameters) through squeeze casting method. From the experimental results, percentage of reinforcement and squeeze pressure were most influential parameters on impact strength. The optimum casting condition was obtained by using Taguchi optimization. From microstructural study, applying high level of squeeze pressure improved the uniform dispersion, good bonding between the matrix and reinforcement. Also, 25% of impact strength was improved the composite using Taguchi optimum conditions compared than conventional alloys. Higher squeeze pressure seen to have refined dendritic structure with uniform distribution of reinforcement materials in the aluminium matrix.

Improvement of mechanical properties of cryorolled LM6 alloy

Mechanical properties and fracture behavior of bulk UFG LM6 alloy processed through cryorolling (CR) is investigated in the current work. LM6 Al alloy is reduced through CR upto thickness reduction of 50%, 75% and 90% at liquid nitrogen temperature. Mechanical properties of bulk and deformed alloys were investigated through tensile and three-point bend test. These properties are correlated with microstructural features by the help of optical microscopy and scanning electron microscopy. The significant improvement in strength (UTS: 64.18% and YS: 125.16%) of CR upto 90% deformed sample were recorded. This enhancement is attributed due to the formation of ultrafine grained (UFG) structure resulting grain boundary strengthening. However, the fracture mode of tensile tested samples is transformed from ductile to brittle nature with the increment in thickness reduction from ST to 90% CR sample substantiating the lack of strain hardening ability of the UFG LM6 alloy.

Study of microstructure and mechanical properties of metal matrix composites subjected to severe plastic deformation – A review

Composite materials have enhanced properties compared to their monolithic materials. Because of its improved properties composite materials find their applications in various fields. Much work has been done on Metal Matrix Composites with different matrix materials such as Aluminium, Aluminium alloys like (Al – 2016, 6061, 6062, 6063, 7068, 7075 etc.), in-situ Aluminium and LM6 alloy and using various reinforcements like Boron Carbide, Hematite, Silicon Carbide, Graphite, Titanium Boride etc. Severe Plastic Deformation [SPD] is a noble process used to refine the grain structure and improves the distribution of reinforcements in the matrix material. Microstructural study is performed by Optical Microscopy, Scanning Electron Microscopy etc. and Mechanical Properties such as Tensile Test, Hardness Test etc. are also studied. Results from various studies showed that Mechanical properties of the composites have improved with increase in reinforcement percentage. 15% of Cenosphere - TiN in Al 6061 – Cenosphere – TiN Composite showed 71.6% increase in tensile strength. Hardness of the composite improved after SPD. Microhardness of in-situ Al – TiB2 increased by 1.9 times after SPD. Microstructural study reveals that after SPD the average size of the grain reinforcement have improved a lot. Grain Size of Al–5 vol% SiC composite was reduced from 45 µm to 8 µm after SPD

Mechanical and wear characterization of LM13/SiC/Gr dispersed hybrid composites formed through stir casting

The modern engineering technology requires materials with high strength, less weight, immense stiffness and superior mechanical properties. Aluminium depended MMCs find diverse applications in defence, aerospace, military, automotive, equipment’s related to electronics and sports for their favorable characteristics. The present investigation focuses on development and characterization of LM13 alloy reinforced with distinct weight ratio of Silicon Carbide (SiC) and Graphite (Gr) hybrid MMCs using conventional casting procedure. The casted samples were designed for the essential testing according to ASTM basic. The properties such as hardness and strength due to tensile behaviour of the manufactured MMCs were discerned by carrying experiments while the wear characteristics were examined via the pin-on-disc technique. Microstructural images reveal the presence of reinforcements and homogeneous distribution over the matrix material. Microhardness and tension characteristics disclosed that the developed hybrid aluminium MMCs had met with a melioration of 11.85% and 24.82% respectively, compared with monolithic matrix. Wear tendencies were pondered by varying load (10–50 N), sliding speed (0.4–2 m/s) and sliding distance (400–2000 m). Statistical interpretation was enacted utilizing Analysis of Variance (ANOVA) procedure to obtain the most appropriate wear approach range for amassing uttermost wear resistance. Experimental data reveal that wear resistance inflation with enhancement in sliding speed, load & sliding distance. Outcomes disclosed that optimum rate of wear (WR) and Frictional coefficient (COF) was obtained at 0.8 m/s, 800 m & 20 N.

Effect of dry sliding wear parameters on the tribological behavior of aluminum hybrid metal matrix composites

Abstract The influence of different weight percentages of Tungsten Carbide (WC) and Graphite (Gr) in an Aluminium LM6 Alloy (Al-Si12) was investigated for the Tribological aspects. Aluminium is known to possess poor tribological characteristics – this research work primarily focuses on how it’s possible to enhance the tribological characteristics of aluminium by incorporating the reinforcements Tungsten Carbide and Graphite. Tungsten Carbide is an extremely hard compound with a Vickers hardness number of about 2600. On the other hand, Graphite and graphite powder, which are highly refractory, are valued in industrial applications for their self-lubricating and dry lubricating properties. We performed standardized tests on the aluminium hybrid metal matrix composite specimens and determined the exact weight percentage of reinforcement for optimum wear properties as well as for tensile strength. The Pin-on-Disc sliding wear test was performed under the action of different contact loads following the ASTM G99 Standard. We then performed statistical analysis by Taguchi’s Technique and Analysis of Variance (ANOVA) to determine the most dominating factor that influences Wear Rate for the optimum weight percentage of reinforcement. By enhancing wear resistance of Aluminium, the material can be used in applications where low weight, high strength and corrosion resistance are key factors in addition to high wear resistance.

Wear behavior of Ni-P and Al2O3 electroless nano coating on aluminium alloy

Electroless Nickel (ENi-P) is the major evolving surface coating technique employed in today’s industries. This covering is the decision for some design applications with different actual attributes of EN coatings, for example, hardness, wears opposition, covering consistency and erosion obstruction. The major advantages of ENi-P and Al2O3 coatings are uniform coating thickness, improved wear and corrosion resistance, hardness, ability to deposit on surface activated non conductors etc. Typical anionic surfactant and various passive chemical additives and nano additives such as Al2O3 were added to the EN bath. Coating was carried out on Al LM6 alloy specimens. In this research work, Sodium Lauryl Sulphate (SLS) surfactant along with nano additives such as Al2O3 was added to the ENi-P bath. The effect of surfactant along with nano additives on surface properties such as corrosion resistance, wear properties, surface roughness, micro hardness and microstructure of electroless nickel-phosphorus and Aluminum oxide coating was investigated. The surface roughness of the coated specimens was measured using stylus instrument, microhardness was measured using vicker’s hardness tester, microstructure was studied using Scanning Electron Microscope (SEM) and wear test was measured using Pin on disc machine. The result obtained from the above tests clearly indicates that the surfactant and passive additives improves the surface finish, microhardness, and microstructure and wear rate of ENi-P and Al2O3 coatings significantly.

EBSD studies on cryorolled LM6 Al alloy

In present work, EBSD and mechanical properties were studied for cryorolled LM6 Al alloy. Solution treated (ST) alloy was cryorolled for dissimilar thickness reduction upto 50%, 75% and 90%. To analyze the effect of CR on microstructure of LM6 alloy, EBSD and TEM microscopy techniques were made in practiced and its mechanical properties are analyzed by using tensile test and hardness. The CR LM6 Al alloy manifest an enhancement in mechanical properties on comparison with ST LM6 Al alloy. Results revealed that fraction of low angle grain boundaries and kernel average misorientation increases with increase in percentage thickness reduction. CR processed LM6 Al alloy shows the improved mechanical properties among all sample conditions substantiating the effect of grain refinement.

Electroless deposition of SiC Nano Coating on Aluminium alloy and evaluation of wear resistance and electroless characteristics

Electroless Nickel (ENi-P) and silicon carbide (SiC) is the major evolving surface coating technique employed in industries today. Many physical characteristics of EN coatings such as hardness, coating uniformity, wear resistance, and corrosion resistance makes this coating as a decision for many engineering applications. The major advantages of ENi-P coatings are uniform coating thickness, improved wear and hardness, ability to deposit on surface activated non-conductors etc. Typical anionic surfactant and various passive chemical additives and nano additives such as SiC were added to the EN bath. The coating was carried out on Aluminium alloy LM6. In this paper, Sodium Lauryl Sulphate (SLS) surfactants along with nano additives such as SiC were added to the EN bath. The effect of surfactant along with nano additives on surface properties such as wear properties, microhardness and microstructure of electroless nickel-phosphorus and silicon carbide coating was investigated. The microhardness was measured using Vickers hardness tester, the microstructure was examined by using Scanning Electron Microscope (SEM) and wear test was measured using Pin on disc machine. The result obtained from the above tests clearly indicates that the surfactant and passive additives improve the microhardness, microstructure and wear rate of ENi-P and SiC coatings significantly.

Development and Analysis of Metal Matrix Composite of Aluminium LM-25 Alloy using Silicon Nitride and Flyash Reinforcements

Development and Analysis of Metal Matrix Composite of Aluminium LM-25 Alloy using Silicon Nitride and Flyash Reinforcements

Optimization of milling process parameters of aluminium alloy LM6 using response surface methodology

This paper discusses the use of response surface methodology (RSM) for maximizing Metal Removal Rate (MRR) and minimizing Surface Roughness (Ra) in machining LM6 alloy material. The levels of three machining parameters spindle speed, feed rate and depth of cut are optimized during end milling operation. RSM is used for this experimentation. The regression models are developed and effect of each parameter on MRR and Ra is identified through the regression models. The results are analyzed through response surface and contour plots. The significant parameters are identified through Analysis of Variance (ANOVA) for MRR and Ra; all three parameters are significant for MRR, whereas spindle speed and feed rate are significant for Ra. Response surface optimization shows that the milling parameters are 2550RPM, 0.202mm/rev and 1mm for spindle speed, feed rate and depth of cut respectively. The maximum value for MRR is 0.043kg/min and that for surface roughness is 2.007μm at optimal parameter levels.

Mechanical Properties and Morphological Analysis of Copper Filled Aluminum Alloy Hybrid Matrix Composite

This paper presents the characterization of LM6 aluminum alloy with varying copper addition. LM6 is a soft, light-weight and corrosion resistant metal. Due to these characteristics, the material was selected to be added with copper to identify improved properties. The amount of copper addition was varied from 0%wt with intervals of 3%wt for every alloying run. Vibration casting, or vibration molding, was conducted. The vibration process is said to give a better result in terms of the alloy’s grain size and arrangement. Mechanical testing and microstructure analysis were performed to prove the theory. Specimens with various amounts of copper were successfully produced and tested. The LM6 alloy specimen casted without copper and with vibration casting at 20 Hz had the highest tensile strength and percentage of elongation, while the LM6 alloy specimen casted with 9%wt of copper without mechanical vibration casting had the best mechanical properties based on the overall results and criteria. The percentage of copper addition that produced the optimum properties was found to be 9%wt of copper without vibration molding (hardness 46.2HRB, 125 MPa).

Tribological characteristics of friction stir processed graphite and tin/LM24 surface composites

Friction stir processing (FSP) is an emerging solid-state technique for preparing surface composites using various reinforcements. Ceramics and metallic particles are easily reinforced in a matrix by this technique. Surface composites made from an LM24 alloy reinforced with graphite and tin, with good wettability and material flow owing to the low melting point of tin, were fabricated by FSP at two rotational speeds of 1,400 and 1,000 rpm. Despite its low hardness, the graphite/LM24 surface composite fabricated at a higher rotational speed of 1,400 rpm exhibited better wear resistance. However, its frictional behavior was not significantly affected by the reinforcement. The fabricated surface composites with graphite and tin reinforcement as well as graphite-only reinforcement exhibited contradicting behaviors under sliding wear conditions. The post wear analysis indicated that abrasion, adhesion, layer formation, and delamination occurred on the composite surfaces.

Elastic properties of aluminum boron carbide metal matrix composites

Metal matrix composites are being used increasingly for various applications in automotive, aerospace and industrial applications. The present investigation deals with boron carbide used as reinforcement with Aluminum alloy LM6. They offer distinct advantage as they result in a composite with net weight decreasing since density of boron carbide is less compared to aluminum. Since aluminum has better strength to weight ration compared to steel they can be proposed as the candidate material for automotive and especially driveshaft applications. Tension test and Torsion test were carried out according to ASTM E8 and ASTM E143 standards respectively. The weight percentage of reinforcement was chosen up to 7.5 percent. The prepared composite specimen’s demonstrated increase in tensile strength, young’s modulus, torsional strength and shear modulus up to 6 percent weight percentage of reinforcement. Consequently, there was decrease in percentage of elongation, angle of twist and Poisson’s ratio with the incorporation of boron carbide.

Fabrication of ultra-light LM13 alloy hybrid foam reinforced by MWCNTs and SiC through stir casting technique

In the present work, a novel approach was used for the synthesis of ultra-light closed cell Al-hybrid foam reinforced with functionalized Multiwall carbon nanotubes (MWCNTs) and silicon carbide (SiC) particles through stir casting technique. In this work, up to 93%, porous hybrid foam with uniform cell size were successfully prepared. For uniform dispersion of MWCNTs within the matrix, first MWCNTs were functionalized in HNO3 solvent with magnetic stirring followed by partial ball milling with Al powder and SiC particles. Obtained results show that the plateau stress and energy absorption capacity of prepared ultra-light foams are excellent.

Tensile, compressive and heat transfer analysis of ZrO2 reinforced aluminum LM6 alloy metal matrix composites

In the present investigation, aluminum LM6 alloy is used as a matrix and it was reinforced with various weight fractions of ZrO2 Such as 0, 3, 6, 9 and 12 wt%. The composite materials were cast using the stir casting method. The various stir cast samples were subjected to Energy Dispersive Spectrometry (EDS) analysis, mechanical and thermal analysis. The mechanical analysis of tensile and compressive strength was carried out for the five various weight proportions of ZrO2. The EDS analysis confirmed that the presence of aluminum and, ZrO2 particles in developed composites. Tensile and compressive strength was increased by the addition of ZrO2. In this work, mainly deals with the analysis of heat transfer for the newly developed aluminum-based composite materials when it is used as a pin fin for varying the weight percentages of ZrO2 with the aluminum particles. The Heat transfer analysis was carried out for the Aluminum LM6 matrix in addition to that varying the weight proportions of ZrO2. The efficiency and effectiveness of each fin were measured during this test. From the analysis, it was revealed that heat transfer rate was increased for the increased weight fraction of ZrO2. Similarly, the efficiency of the pin and effectiveness was increased for the increasing weight percentages of zirconium dioxide. A similar test was carried out for the same materials for varying the input voltage and current. From that test, it was identified that heat transfer is gradually increased for the increasing supply of voltage and current.

Exploration on WEDM process parameters effect on LM13 alloy and LM13/SiC composites using Taguchi method

In manufacturing sectors and the automobile field’s aluminium and aluminium based composites usage in various range of applications owing to their higher physical and mechanical properties. Wire electrical discharge machining process is a highly complex, time varying & stochastic process. The process output is affected by input variables. Therefore a suitable selection of input variables for the wire electrical discharge machining (WEDM) process relies heavily on the operator's technology & experience due to wide range of demand. Metal removal rate (MRR) & surface finish (Ra) are sought to obtain precision work. Using Taguchi's parameter design, significant machining parameters affecting the performance measures are identified as pulse off time (Toff), pulse on time (Ton) and input current (amps). In the present study, first experimentation on LM13 aluminium alloy and LM13/SiC composites has been fabricated by squeeze casting process under optimal parametric condition to attain better hardness and tensile strength. In second phase of examination the machinability study were carried out of LM13 alloy and LM13/SiC composites through WEDM techniques input process variables such as pulse on time (Ton, 30–40 µs), pulse off time (Toff, 4–10 µs) and peak current (Ip, 1–3 Amp) on response of material removal rate (MRR) and surface roughness (Ra). The L9 OA Taguchi method was implemented for calculating the machining characteristics. The effect of each control factor on the performance measure is studied individually using the plots of signal to noise (S/N) ratio. The study demonstrates that the WEDM process parameters can be adjusted so as to achieve better metal removal rate and surface finish. Therefore, the optimal set of WEDM parameters is suggested for all manufacturing sectors.

Wear Behavior of Plasma Processed LM6 Alloy

In the current work, wear behavior of plasma processed LM6 alloy is investigated. LM6 alloy was prepared by plasma technique. The samples were aged at 350°C & 450°C for 2 hours followed by water quenching. A comparative study of the metallographic structure and properties viz. hardness, density and wear of the non-heat and heat treated alloy samples were carried out. A very fine lamellar structure is observed in case of 450°C heat treated samples than that of sample heat treated at 350°C and non-heat treated samples. Highest hardness value of 68.11 VHN is observed with the sample heat treated at 450°C. Density is found to be the lowest in non-heat treated samples and it increases with increasing heat treatment temperature. Wear experiments were carried on a pin-on-disc set up (of Ducom make), varying applied loads (between 10-40Newton and varying sliding speed (from 0.94 m. s-1 to 2. 83m.s-1). Maximum wear resistance is observed with the specimen heat treated at 450°C.

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.

Effect of Reinforcements and Abrasive Size on High-Stress Tribological Behaviour of Aluminium Piston Matrix Composites

The aim of this research paper was to look into the high-stress abrasive or sliding wear of the LM13 and ADC12 alloy and its composites as LM13-7% SiC, LM13-7% TiB2, ADC12-7% SiC and ADC12-7% TiB2 reinforced with SiC and TiB2 particles. The high-stress abrasive test was examined at various emery grit meshes as 180, 220, 320 and 400 correspond to 88, 60, 44 and 37 micron, and a load of 20 N and 30 N was applied for scratching distance of 200 m and 300 m at a sliding speed of 5.2 m/s. Smooth wear track or channel was shown in case of alloys. Wider and discontinuous wear tracks were depicted in case of composites due to inclusion of strengthen particles. Alloys showed less frictional heating as compared to their composites and among composites titanium diboride amalgam showed more frictional heating as compared to silicon carbide strengthen composites. There was rapid increase in frictional heating in composites as compared to alloys due to presence of hard particles. Frictional heating increased on inclusion of ceramic particles. Experiment result showed that titanium diboride composites in aluminium base alloy considered excellent material for tribological and general purpose engineering application.