LM13 Alloy Research Articles

Tribological and mechanical behavior of alumina particles reinforced LM24 alloy

In this work aluminium alloy LM24 as a matrix and aluminium oxide powder as reinforcement was used. The size of aluminium oxide powder particle taken is 50 μm. In the present work it is aimed to improve the mechanical and tribological properties of aluminium LM24 Al2O3 particulate composite by stir casting process. Aluminium matrix composite (LM24 + Al2O3) were developed by stir casting method using different percentage (5% and 8% by wt.) of Al2O3. Aluminum composite with 8% reinforcement has lowest wear rate compared to base alloy and composite with 5% reinforcement. Wear rate increases with increasing applied load for both base alloy and composites at same sliding distance, and same sliding velocity. Increasing the sliding distance decreases the wear rate under identical conditions -Sliding Velocity, Loading and Reinforcement. Increase in tensile and compressive strength was observed due to proper distribution of alumina particles in the matrix leads to strong bond formation between alumina particles and Aluminium matrix.

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.

The Influence of Deep Cryogenic Treatment (DCT) on the Mechanical Behaviour of Aluminium Metal Matrix Composites

The outcome of cryogenic treatment (CTT) on the mechanical behaviour of Al alloy LM 25, LM25+5% fly ash and LM25+10%fly ash composites was investigated. Cryogenic treatments were performed with threedifferent soaking periods (0 hr (Untreated), 12hr, 24hr) ata constant cryogenic temperature of -196°C. After the CTT, the mechanical behaviour of the materials was measured. It is obvious that LM25+10% fly ash composites exhibitbetter mechanical properties than the LM25 and LM25+10% fly ash composites.As cryogenic soaking period increases mechanical properties of the MMCs tend to increase too. The effect of fly ash mass percentage and cryogenic soaking period on the mechanical behaviour of materials was studied by using Taguchi and Analysis of Variance (ANOVA).

Studies on Bottom ash strengthened LM13 composite

Recent times, the composite materials are extensively used due to their compliance to diverse circumstances and the virtual ease of amalgamation with supplementary materials to provide explicit functions and reveal enviable properties. The application of the same is ornamental to an immense level in any of the field including engineering field. Metal Matrix Composites in short MMCs with less expansive and low density increases the demand in various applications of industrial sector. The present work uses the Bottom ash as reinforcement in MMCs which is a low density and inexpensive spin-off procured during ignition of coal in thermal power plant. Bottom ash particles are prepared to a grain size of 74 nm to 114 nm using ball milling. Basic matrix LM13 alloy is reinforced with Bottom ash particles to prepare MMCs using stir casting method. Reinforcement of Bottom ash is done in terms of weight percentages ranging from 0 to 8 in steps of 2. Composite specimens are prepared as per ASTM standard using cast ingots. Micro-structural examination of composite specimens is carried out to know the dispersion of bottom ash particle in LM13 matrix using SEM and X-ray diffraction test. At the end, the mechanical properties such as tensile, compression and hardness of specimens is evaluated by varying percentage of Bottom ash and found significant improvement in the same.

Effect of SiC Particulate Reinforcement in A356 / LM25 Alloy Composites and in their Hybrids

LM25/A356 Aluminium Silicon alloy is characterized by high mechanical strength, corrosion resistance, machinabilty and excellent castability. Its prominent usage is found in high performance applications like in the automotive piston, cylinder blocks and heads, valve lifters, alloy wheels, brake pads and also in turbine blades. The prospects in applications of A356 are improved by heat treatment processes. Moreover the production of A356 Aluminium alloy composites renders provision for effectively tailoring the mechanical properties of the material by reinforcing the particulates of different ceramic materials at varying propositions. Although there are wide ranges of ceramic materials that could be potentially reinforced into A356 aluminium alloys, this paper exclusively reviews on SiC particulate reinforced A356 alloy composites and also its hybrid composites fabricated by strir casting method. This paper brings out the researches performed with A356/SiC composites under various experiment conditions to make this aluminium alloy available for other wide applications.

Study on Microstructure and Tribological Properties of Plasma Processed LM6 Alloy

In the research work, LM6 alloy prepared by plasma processed technique is studied for wear behavior. The wear behavior of the plasma processed LM6 alloy sample is study at room conditions at four different loads,i.e. 10N, 20N, 30N, 40N and with different sliding speeds, i.e. 200, 300, 400, 600 rpm’s for about 2 min,5 min,10min,15 min respectively, using a pin-on-disk wear testing instrument. From the pin-on-disk experiment, cumulative mass loss varying with the sliding speed, applied load and time was studied. The existence of eutectic silicon is sensed by the microstructure. The wear of plasma processed LM6 alloy sample increased as applied load, sliding speed and time increased.

The Effect of Cryogenic Treatment on the Wear Resistance of Al Alloy-Fly Ash Composites

The effect of cryogenic treatment on the wear resistance of aluminium alloy LM 25, LM25+5 % fly ash and LM25+10% fly ash composites, which are synthesized by squeeze casting method, was investigated. The impact of the parameters on the wear resistance was studied under two different cryogenic soaking periods [0hrs (untreated), 12hrs and 24 hrs.] and three different load and sliding velocities with the help of pin-on-disc test rig. The wear tests were performed according to Taguchi’s approach. The percentage contribution of the cryogenic soaking period was determined by means of analysis of variance. The load was found to be more significant than cryogenic soaking period and velocity on wear loss of the composites. Regression model was generated to envisage the wear loss.

The microstructure and wear behaviour of garnet particle reinforced Al matrix composites

Composites containing different size range of garnet reinforced in LM13 alloy were prepared by liquid metallurgy route. Wear tests of composites were done at a constant sliding velocity of 1.6 m/s for a sliding distance of 3000 m at different loads varying from 9.8 to 49 N. The particle size variation of garnet mineral and its content used as reinforcement significantly influenced the microstructure, microhardness and wear behaviour of the composites. The wear rate of fine size garnet mineral reinforced composites is low as compared to composites reinforced with coarse size garnet mineral particles at all loads. The wear rate of 15 wt.% fine size garnet mineral reinforced composite is minimum even at higher load (49 N) when compared to the cast iron used in brake drum of vehicles.

Effect of different machining parameters on surface roughness of aluminium alloys based on Si and Mg content

Aluminium-based alloys are considered lengthily for many applications in engineering areas due to their good mechanical properties. Machining these alloys had attracted the attention of many researchers on how to improve the machining, especially when high manufacturing rate is demanded. Usually, machining these materials poses some difficulties such as burr formation, roughness of the surface, continuous chip formation and build-up edge on cutting edge. In this study, AA6061T6, LM6 and AA5083 aluminium-based alloys were considered to research the optimum drilling parameters with the aim to address the earlier started challenges. Drillings were carried out by using a MAHO three-axis CNC drilling machine with an HSS drilling bit at three different spindle speeds and feed rates. From the results, it was established that each aluminium alloy has different surface roughnesses and this surface roughness decreases as spindle speeds increased. A minimum build-up edge was achieved for AA5083 and AA6061T6 alloys. However, a relatively high BUE was noticed in LM6.

Effect of Grain Refiners and/or Modifiers on the Microstructure and Mechanical Properties of Al-Si Alloy (LM6)

Grain refinement is one of the most important and popular melt treatment process for Al-Si alloy casting. Microstructure and mechanical properties of commercially available Aluminium Silicon alloy LM6 can be improved with the addition of grain refiners and modifiers as these provide technical and economic advantages. This paper is an effort to study the effects of addition of grain refiners and modifiers to the eutectic Al – Si alloy LM6. Commercially available Al - Si alloy LM6 (eutectic = 12% Si) is grain refined with Al-5Ti-1B and Al-3B; and modified with Al-10Sr master alloys. These were added individually and then tested for its unique mechanical properties such as ultimate tensile strength, hardness and wear; which are co-related with the machining tests such as turning, surface roughness and drilling. The test results are compared with microstructure of the samples observed through SEM.The mechanical properties of this alloy can be altered after addition of master alloys, which in turn alter the grain size. Thus the results conclude that the mechanical properties of Al-Si alloys in general are controlled by a number of principal microstructural features. A fine grain size is desirable, leading to improvement of mechanical properties.

Fuzzy logic algorithm based optimization of the tribological behavior of Al-Gr-Si3N4 hybrid composite

The tribological behaviour of LM6 alloy with Graphite, Si3N4 nano particle and Graphite-Si3N4 hybrid composite is investigated in this study. Al-Gr, Al-Si3N4 nano and Al-Gr-Si3N4 hybrid composites were casted by gravity die stir casting to investigate under dry sliding conditions for the wear and frictional characteristics. The wear rate & co-efficient decreased by 25% & 15% for the hybrid composite when compared with the Al-Si3N4 nano composite, whereas very minimal wear rate and co-efficient of friction was observed for Al-Gr. The results show that the Micro Vicker hardness of the Al-Gr-Si3N4 hybrid composite is 16% more than that of the nano composite and no significant variation is observed for Al-Gr and Al-Si3N4 nano composites. SEM was used to analyse the worn surface and subsurface. The predominant wear mechanisms observed were abrasive for the nano composite and adhesive and abrasive mechanism for the hybrid composite. The Al-Gr-Si3N4 hybrid composite wear rate was optimized with fuzzy logic analysis and compared with the experimental data. The fuzzy logic model was developed to evaluate the wear rate of Al-Gr-Si3N4 hybrid composite and with low prediction errors of 4.27%. The ANOVA analysis yielded the optimum parameter conditions for the wear process. The Regression model was used to estimate the relationships among the variables for the wear rate of different composites.

Eksperimentalne raziskave na Al zlitini LM25, ojačani z delci SiC, grafita in pepela Moringe

Eksperimentalne raziskave na Al zlitini LM25, ojačani z delci SiC, grafita in pepela Moringe

Synthesis of Aluminium Composites Using Squeeze Casting and Investigating the Effect of Reinforcements on Their Mechanical and Wear Properties

The research aims to fabricate LM25 alloy and composites reinforced with 15 wt% TiB2, 15 wt% ZrO2 and 15 wt% WC using squeeze casting technique. The fabricated cylindrical castings were of dimensions 50 mm diameter and 150 mm length. Microstructural analysis revealed better distribution of reinforcement particles for each composite, which provided better hardness and tensile properties. Physical and wear properties were studied comparatively to understand the influence of reinforcements, and tungsten carbide (WC)-reinforced composites showed better performance. Fractographic analysis revealed ductile mode of failure for LM25 and a combination of ductile and brittle mode for its composites. Dry sliding performance of both alloy and composites was analysed under different sliding conditions of applied load (10–50 N), slide distance (500–2500 m) and slide velocity (1–5 m/s) using pin-on-disc tribometer. WC-reinforced composite improved resistance to wear by 70% compared to alloy. Wear analysis of composite using scanning electron microscope showed change in wear features from mild to severe at high loads. The developed LM25/WC composite was found to be most suitable for non-lubricated slide applications.

Evaluation of hardness and impact strength of aluminium alloy (LM6)–soda–lime composite

ABSTRACT Aluminium is one of the lightweight materials which is the principal necessity in many applications worldwide and is less luxurious than other light metals such as titanium and magnesium. With the increasing requirements of strength and toughness of aluminium castings, there is a huge demand to improve the mechanical properties of available aluminium alloys. It had been noticed and scientifically proved that when reinforced with other materials, properties of aluminium alloys will get enhanced. In this research work, an investigation was performed on cast-ability, microstructure and mechanical properties (hardness and impact strength) of a composite with LM6 alloy (Al–11.6% Si) as the matrix, and varying sizes and volume fractions of glass powder as the reinforcement. In this work, Al–Si metal matrix composites with soda–lime glass powder as reinforcement were produced using stir casting technique. Composites were produced with varying percentage of glass (1.5–4.5% by weight) as reinforcing particles. Commercially, available LM6 alloy (Al–11.6% Si) was selected as the matrix material. The composite produced has superior mechanical properties and it has been observed that the mechanical properties are improving with increase in the percentage of glass powder. The best distribution of glass in the matrix was when 3% glass of 125 µm particle size was reinforced. The microstructures of the developed LM6–glass composite were studied using optical microscopy. This work was part of the feasibility study performed as part of a new product development in armoured protection equipment by Mobile Land Systems LLC, South Africa.

Mechanical properties of Al–Si–SiC composites

This paper dealt with cyclic stress properties of Al-Si (LM13) alloy and 10 wt% SiC particle reinforced composite in the cast and T6 temper conditions at ambient temperature. Fully inverse loading was applied to the materials with stress amplitude maximum up to 50 000 cycles. Stress versus No of cycle curve was generated. Fatigue strength of artificially aged LM13 alloy was found more than the cast alloy; however, dispersion of SiC particles deteriorated the fatigue life under the present domain of experiments. The mechanical properties such as ultimate tensile strength, offset yield strength and % elongation were found inferior for composites compared to the base alloy. Remarkable improvement in mechanical properties was observed in heat-treated alloy and composites. Scanning Electron Microscopic examinations of fatigue fractured surfaces of LM13 alloy depicted interface decohesion, was the predominant mechanism for failure in T6 tempered alloy, whereas fracturing of eutectic silicon was predominant in cast alloy. In (Al–Si)–SiC composites, cracks were initiated due to decohesion of the particle-matrix interface and in some instances breaking of the SiC particles. It was observed that heat treated eutectic silicon, which was near-spherical in shape, resisted fatigue crack growth because of better cohesive force with the Aluminium matrix as compared to SiC particle and fewer sites for stress riser. Better bonding between eutectic silicon and Aluminium matrix caused the crack to pass through the interface whereas Si particle endures fatigue load and ultimately, crack surpassed particle by fracturing it.

Microstructure Analysis and Mechanical Properties of LM25 alloy with AC4B Nano-Composite using Gravity Die Casting Method

Casting of Aluminium alloys with zero defects would be the ultimate aim of any manufacturer. In the present work, the Alloy LM25 which was being used for the manufacturing of intricate Automobile components is compared to Alloy AC4B Nano-composite using Gravity Die Casting method. In order to investigate the mechanical properties of the concerned materials, Tensile followed by Hardness, and Compressive tests was implemented. Microstructure investigation is examined using Scanning Electron Microscope. The outcome from micro structural study confesses the uniform distribution, grain refinement, and low porosity in Nano-composite specimen. Mechanical results affirm that addition of B4C Nano-composite leads to enhancement of yield strength, ultimate strength and hardness. The uplift in mechanical properties manifested that the type of fabrication process and particle size involved in it.

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.

Tensile and Wear Behaviour of Aluminium Alloy LM6 Reinforced with Magnesium and Copper

The aim of this research is to fabricate aluminum based metal matrix composite and reviewing its tensile strength and wear behavior of produced test specimen. In this work an attempt is made to develop an aluminium based MMCs with reinforcing material and stir casting technique has been used to achieve this. Aluminum alloy (LM6) and Magnesium (Mg), Copper (Cu) was chosen as metal matrix and composite materials respectively, tensile and wear experiments has been conducted by varying the composition of Cu (0.150%, 0.175% and 2%) while keeping Mg (0.150%) as constant. The result shows that the increase in addition of copper increases the tensile strength and wears resistance and decreases the percentage of elongation.

Investigating the Wear and Hardness of Aluminium LM25 Alloy Reinforced With Nano Al2O3 and Nano TiB2

Abstract The present paper deals with the study of hardness and wear characteristics of Al2O3 (Nano size) and TiB2(Nano size) reinforced aluminum LM25 Metal Matrix Composites (MMC). Matrix alloy with 1, 1.5 and 2, 5% of Al2O3 and TiB2 were made using stir casting technique. A pin on disc wear testing machine was used to find out the wear rate in which E24 steel disc under dry condition and Brinell hardness testing machine was used to find the hardness of the both material made by stir casting. This work mainly emphasis on the comparison of hardness and wear property of the casted material. The wear properties compared in both load and unload conditions. Wear resistance and hardness of the material will be increased when adding the Al2O3 and TiB2. The results shown properties of stir casting material having composition 2.5% Al2O3+ 2.5% TiB2 + 95%LM25 is good compared to the other composition. Because of good dispersion of Nano powders.

Effect Of Warm Rolling On Microstructure, Porosity And Hardness Of Spray Formed LM25 Alloy

Abstract LM25 alloy was obtained by the consolidated spray forming method. By using power saw the central portion was cut down into 20mmX20mm and then warm rolled with 20%,40%, 60% and 80 % at 1000c.Samples were prepared as per standards to see the microstructure by using the optical microscope. The results show that fine microstructure was observed in LM25 spray deposited Al alloy after warm rolling process due to the expediting cooling and freezing rate of spray deposit. Porosity and Mechanical properties of the warm rolled LM 25 substrate was improved than the spray casted and cold rolled.