Stir Casting Route Research Articles

Electric Discharge Machining of AA7075/SiCP/B4CP Hybrid Composites machined with Al2O3 Mixed Used Engine Oil Dielectric fluid

Background: Machining hybrid composites through conventional machining technique was a challenging task as it produces excessive tool wear and exhibits poor surface roughness. In this research work, an attempt was made to electric discharge machining of AA7075/SiCP/B4CP Hybrid Composites produced through the stir casting route. Objective: The used engine oil was as the dielectric fluid with the objective of obtaining wealth from waste. The experiments were performed by varying distinct Electric Discharge Machining (EDM) process parameters with the goal of obtaining a high Material Removal Rate (MRR), low Tool Wear Rate (TWR) and least Surface Roughness (Ra). The experimental runs were optimized using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) optimization techniques. Methods: Experimental runs were designed using the L20 Taguchi orthogonal array in which Powder concentration, Current and Pulse on time were varied for three different levels, and two various dielectric fluids were used for investigation. The characteristics of the Used Engine Oil (UEO) were assessed to find its feasibility as a dielectric fluid. Results: In comparison to EDM oil, the specimen machined in UEO dielectric medium has a somewhat greater MRR. Regardless of the kind of dielectric fluid employed, adding Al2O3 particles increases the MRR because of the bridging effect. Due to its high thermal conductivity, UEO oil produced electrodes with a TWR that was greater than that of EDM oil. The TWR decreases with the addition of Al2O3 particles due to an increase in the spark gap. In comparison to EDM oil, the specimen machined under UEO displays a lower Ra value. Ra decreases with the inclusion of Al2O3 particles due to the thorough flushing of machining waste. Conclusion: The specimen machined under Al2O3 mixed UEO dielectric medium, with the process parameters tuned at 3A current and 20µs Ton, offers better machining performance and was recommended for EDM sector.

Tribological and machining characteristics of AA7075 hybrid composites and optimizing utilizing modified PROMETHEE approach

In this research work an attempt was made to reinforce AA7075 composites with B4C and SiC particles through stir casting route. SEM with EDS mapping revealed that the reinforcement were uniformly over the composites and hardness reduces with the addition of SiC particles owing to the inverse hall petch effect. The results revealed that wear rate reduces with addition of SiC particles owing to the formation of mechanically mixed layer and protective oxide layer confirmed through SEM with EDAX mapping. Three distinct cracks were formed, when slides at different temperature as confirmed through worn surface morphology, pits cracks and plasticization of material were the other features observed. The used motor oil properties were analyzed and results divulged that the oil suitable for dielectric fluid. Increase in Material Removal Rate (MRR), reduction in Tool Wear Ratio (TWR) and Surface Roughness (Ra) was observed with the incorporation of powder particles owing to the bridging effect. Black spots, craters, micro pits, globules and micro crack are the distinct observed on the machined surface topography. The modified Preference Ranking Organization METHod for Enrichment of Evaluations (PROMETHEE) optimization technique was utilized to find the optimal parametric combination.

Tribological characteristics of LM13 alloy based ilmenite-boron carbide reinforced hybrid composites for brake drum applications

Aluminium matrix hybrid composites reinforced with a combination of naturally occurring ilmenite mineral particles (FeTiO3) and synthetically processed boron carbide ceramic particles (B4C) were processed using stir casting route. Reinforcement loading was varied between 0 and 15 wt. percentage (wt.%). For each loading, the two type of fillers were mixed in three wt.% ratio of 1:3, 1:1, and 3:1. Particle size range for both fillers was 106–125 μm. Operating temperature, applied load, and sliding distance were in the range of 25–300 °C, 9.8−49.0 N, and 0−3000 m respectively. Optical and scanning electron micrographs showed nearly uniform distribution of reinforced particles in the matrix. Grain size reduction and morphological changes in the constituent phases of matrix material were noted. Pin-on-disc wear set-up was used to evaluate the wear behaviour of composites (ASTM G99 standard). With increase in operating temperature, the wear rate increased. A sharp rise in wear rate was observed beyond 200 °C. 15HA-31 composite (loading: 15 wt.%; B4C to Ilmenite weight ratio: 3:1) showed maximum improvement in wear rate at all the operating temperatures exhibiting 52−71% reduction in maximum wear rate over the reference sample. Ilmenite particles reduced the coefficient of friction, promoted strong interfacial bonding, and caused early oxidation of sliding surface. On the other hand, B4C particles increased the stability of tribolayer, caused grain refinement, and resulted in morphological changes from acicular to globular for the constituent phases of matrix. Wear rate behaviour of 15HA-31 composite was comparable to the commercially used brake drum material.

Tribological studies on aluminum beryl composites subjected to ECAP process

The strengthening processes of aluminum alloys and their composites are generally assessed after precipitation hardening or following different laid down strain hardening procedures such as Equal Channel Angular Pressing (ECAP), Multi-Axial Forging (MAF), High-Pressure Torsion (HPT), Accumulative Roll Bonding (ARB), etc. Among them, ECAP is considered to be a novel method of producing fine-grained structure with different properties. On-going through the available literature, it is noted that the adoption of ECAP in Aluminum metal matrix composites, especially the Aluminum Beryl composites and then assessing their tribological responses, are scarce to come across. Hence, this particular aspect is addressed in this work.In the present investigation, Al 2024 alloys containing 6% Beryl particles, produced by stir cast route and subjected to ECAP operation up to two passes, have been assessed for slide wear and coefficient of friction (CoF) properties for comparison with un-reinforced Al 2024 alloy for qualitative and quantitative evaluation purposes. The wear and friction evaluation are carried out using the well-known Pin-On-Disc (POD) apparatus for three different loads (49 N, 91 N, and 136 N) and sliding distances (2000, 4000 and 6000 m) at a constant sliding speed of 1.67 m/s.The data reveals that the wear loss decreases with increase in the number of passes due to increase in hardness & decrease in grain size for all the three loads and sliding distances employed. Further, the wear losses show an increasing trend with an increase in the applied load. Also, it is observed that the CoF decreases with increase in number of passes at all loads. It is high in the as cast state and it increases with increase in load. It is inferred from the present findings that the ECAP has made a significant impact on the wear behaviour of Al-Beryl composites, thus emphasizing the fact that the composites are suited for wear resistance applications such as in production engineering sectors.

Assessing the role of reinforcement size and weight percentage on the mechanical and wear characteristics of Al7050‐TiO2‐hBN hybrid composites

In the present study, hybrid composites of Al7050 reinforced with TiO2 (1, 3 and 5%) and hexagonal boron nitride (hBN, 2, 4 and 6%) have been developed by using two different sized reinforcing particles (∼ 40 μm and ∼ 20 μm) through stir casting route with an aim to investigate the role of particles size within the micrometer level on mechanical and wear characteristics. From the microhardness measurements, higher hardness was measured for the composites with the increased content of the reinforcement. Similar trend was observed for the composites with both the reinforcement sizes. From the impact strength measurements, more values were observed for the composites having 20 μm sized reinforcements. With the increased fraction of hBN (6%), no significant improvement in the impact strength was noticed for the composites with 40 μm sized reinforcements. On the other hand, significant increase in the impact strength was measured for the composites with 20 μm sized reinforcements. Increased tensile strength (from 95 ± 4.6 up to 156.8 ± 6.1 MPa) with the higher fraction of reinforcements was measured at the cost of losing ductility as reflected in the decreased % of elongation (from 15.2 to 11.65). With the decreased size of reinforcement from 40 to 20 μm, the composites exhibited more strength and lower ductility. From the wear studies, it was clearly observed a decreased trend in the wear rate and increased coefficient of friction with the increased reinforcement content. Compared with 40 μm reinforcements, adding 20 μm sized reinforcements has shown higher level of impact on reducing the wear rate. The results demonstrate that the size difference of reinforcing particles in the level of a few micrometers also significantly affects the performance of the composites.

Tribological Behavior on Stir-Casted Metal Matrix Composites of Al8011 and Nano Boron Carbide Particles

The aluminum metal matrix composites were broadly exploited in the applications of automotive, aerospace, and other defense with functionally graded materials-related application. Above applications definitely required excellent mechanical characteristics. Therefore, in this way, the major attempt was made on the nano-based composites with aluminum alloy utilization. In this research, aluminum alloy AA8011 and the ceramic-based reinforcement particles of nano boron carbide (B4C) were selected for producing the metal matrix composites by the liquefying process or stir casting route. The weight percentage of nano boron carbide particles having 15 wt% was subjected to add into the aluminum alloy during the stir casting process. Then, processed nano boron carbide and AA8011 specimens were prepared to conduct tribological behaviors with various processing conditions like sliding velocity, setting wear temperature, and applied load by the tribometer setup. The scanning electron microscope was employed to examine the processed composites samples and worn-out surface samples. Finally, the multiobjective optimization was used to measure the individual performances of the tribological parameters by the gray relational technique.

Experimental investigation on feasibility of industrial waste to resource conversion for cupola slag

Cupola slag, an industrial waste produced as by-product in producing cast iron. Demand for cast iron is high consequently, there is significant slag formation. These waste slags ends in landfill and pollutes the environment. Pollution due to cupola slag can be reduced by conversion of waste to resource. In this work waste slag has been analysed physically and chemically to understand its conversion potential. An experimental attempt has been made to convert cupola slag to reinforcement in aluminium metal matrix composite (AMC) for fabrication of economic metal matrix composites by stir casting route. Experimental studies are designed to observe the feasibility of waste to resource conversion along with effect of size of reinforcement on the mechanical, physical and microstructural properties of AMCs. The results indicate feasible conversion from waste to resource. Microstructural studies baked by energy dispersive spectroscopy (EDS) and elemental mapping indicates uniform and successful inclusion of reinforcement in the matrix of composites. The grains have been refined by the addition of slag particle in the Al alloy matrix. Microhardness has been increased in composites when compared to base alloy. Coarse (100 μm) reinforcement particle composites are observed to have better mechanical properties than that of fine (40 μm) reinforcement particles.

Influence of Cu particulates on a356mmc using frequency response function and damping ratio

ABSTRACT Aluminium and aluminium alloy MMCs (AAMMCs) tend to be the most explored materials in MMC development due to their broad range of properties such as wear resistance, light weight, strength with durability, and improved damping capabilities for automobiles, aerospace, and marine at reasonable production costs among other materials. However, the reinforcements chosen will have an impact on the properties of the composite, bridging the gap between the research problem and the desired specialised application. In that effort, numerous researchers have subsequently explored the influence of AAMMCs with various reinforcements aimed at increasing damping properties. In this work, MMCs alloy as matrix and copper particles as reinforcement sat 0 to 15% were synthesised using stir casting route. MMCs/Cu MMC samples were then investigated using SEM to ensure the dispersion of Cu particles in MMCS MMC before being exposed to a frequency response function to determine the modal frequencies and damping ratios. The acquired results on the influence of Cu particles in MMCs matrix on frequency responses and damping ratios were clearly presented.

Fabrication of AA2024/SiC/eggshell reinforced hybrid green aluminium matrix composite by stir casting route

Fabrication of AA2024/SiC/eggshell reinforced hybrid green aluminium matrix composite by stir casting route

Recycling Plastic Waste as Composite Reinforcement

Environmental pollution due to improper disposal of plastic waste has greatly degraded the livelihood of both humans and animals. In this article, polyethylene terephthalate (PET) bottles were used as reinforcement in scrap aluminum. The composite material was made through the stir-casting route. The samples were characterized using the microstructure, tensile strength, and hardness. Results show an increase in tensile strength up to 4% addition of PET and steady hardness reduction as reinforcement composition increases. However, the mechanical strength declines as reinforcement goes beyond 8%.

Optimization of process variables on Electrical Discharge Machining of novel Al7010/B4C/BN hybrid metal matrix nanocomposite

In this paper, determination of optimum EDM input variables like discharge current (DC), pulse on time (Pon), pulse off time (Poff), and gap voltage (GV) on responses like material removal rate (MRR) and surface roughness (SR) using Taguchi technique on the novel Al7010/2%B4C/2%BN hybrid metal matrix nanocomposite (HMMNC) manufactured through ultrasonic assisted stir casting (UASC) route. The various experiments were planned and carried out L16 orthogonal array and regression equations were established by using Analysis of variance (ANOVA) to examine the impact of pulse factors. The outcomes exposed that discharge current greatest effect factor on MRR and SR was found with % contribution of 82.07% and 86.86%. It is also identified that the optimum level conditions of pulse factors for MRR and SR is A4B4C1D1 and A1B1C4D4. The outcomes were further determined by utilizing confirmatory experiment. The machined surface morphology was observed through Scanning electron microscope (SEM).

To Study the Mechanical Properties of Slag and Fly Ash Reinforced As 2024 Composites

Metal matrix composites (MMCs) possess significantly improved properties compared to unreinforced alloys. There has been an increasing interest in composites containing low density and low cost reinforcements. In view of the generation of large quantities of solid waste by products like fly ash and slags, the present study is discarded, new methods for treating and using these solid wastes are required. Hence, composites with fly ash and Granulated blast furnace slag as reinforcements are likely to overcome the cost barrier for wide spread applications in automotive and small engine applications. In the present investigation, AA 2024 alloy – 5 wt. % fly ash and slag composites separately were made by stir casting route. Phase identification and structural characterization were carried out on fly ash and GBF slag by X-ray diffraction studies.The hardness and compression tests were carried out on all these alloy and composites. The reinforcement Improved hardness and mechanical properties were observed for both the composites compared to alloy; this increase is higher for AA2024-Fly ash composite than AA2024- Granulated blast furnace slag composite.

Investigation on Microstructure and Tensile Fractography of RE Oxides (CeO2/Y2O3) Reinforced AZ91D Magnesium Matrix Composites

The current work aims to investigate the mechanical properties of rare oxide reinforced Mg alloy based MMCs. Magnesium matrix considered in the study is AZ91D alloy, whereas rare earth oxides reinforced were CeO2 and Y2O3. The Y2O3 particulate reinforcement percentage was varied from 1 to 3% in the steps of 1% to study its influence on mechanical properties of MMCs. Stir casting route was adopted to fabricate sample for study. Microstructure analysis illustrated the uniform distribution of particulate in matrix alloys. The obtained results revealed the enhanced mechanical properties such as tensile strength, yield strength, elongation and hardness of MMCs due to increased percentage of reinforcement. Fractography analysis of fracture surfaces demonstrated the microcracks and cleavage were dominant in pure alloy. While particle debonding, extensive plastics deformation were prominent in-addition to microcracks in MMCs.

Effects of TiB2 reinforcement proportion on structure and properties of stir cast A713 composites

ABSTRACT Aluminium matrix composites (AMCs) can be used in applications which require high strength and hardness. Present work aims to explore the influence of titanium diboride (TiB2) addition on the structure properties of A713-TiB2 composites. The composites were fabricated using the stir casting route by varying the weight fractions (0, 2, 4, and 6 wt.%) of TiB2 particles. All composites were cast at the same level of stirring time (10 min) and speed (500 rpm). Microstructural characterisation, microhardness and tensile testing of cast composites have been carried out. It has been observed that composites fabricated with 6 wt.% TiB2 give optimum results. The hardness and tensile strength of A713-6 wt.% TiB2 composite are 35.86% and 21.81% higher than those of A713 alloy. Hardness and tensile strength of the prepared composites were improved as the weight proportion of TiB2 particulates increased due to grain refinement and dispersion strengthening mechanism.

Optimization of Wire-EDM Process Parameters for Al-Mg-0.6Si-0.35Fe/15%RHA/5%Cu Hybrid Metal Matrix Composite Using TOPSIS: Processing and Characterizations

The current experimental study concerns obtaining the optimal set of wire-EDM processing factors for a novel Al-Mg-0.6Si-0.35Fe/15%RHA/5%Cu hybrid aluminum matrix composite. The composite exhibits hardness of 64.2 HRB, tensile strength 104.6 MPa, impact energy 4.8 joules, when tested using standard testing techniques. For this, composite is formulated with the help of a stir casting route. The tests are conducted as per Taguchi’s L27 OA, to explore the influence of processing factors on the surface roughness (Ra), radial overcut (ROC) and material removal rate (MRR). The optimization is executed using the Taguchi approach, followed by multiple objective optimizations with TOPSIS (one of the MADM techniques). For optimal values of Ra, MRR and ROC, the optimum set of input variables is suggested as 150 A of current, 125 μs of pulse duration, 50 μs of pulse interval and 8 mm/min of wire feed-rate. Predicted performance index value was calculated and was compared with the experiment value. It has been observed that both values are very close to each other with only 1.33% error, which means the results are validated. ANOVA confirms that current is a predominant factor influencing response characteristic parameters, which contributes 24.09%, followed by pulse duration (16.78%) and pulse interval (15.18%). The surface characterization using a scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersive spectroscope (EDS) and optical microscope (OM) has also been carried out to affirm the existence of the reinforcing particles in the base matrix.

Influence of AlN reinforcement on properties of AA5083 matrix composite

The material properties of metal matrix are progressively enhancing by the accumulation of aluminium nitride (AlN). It has high temperature resistance. In current scenario, aluminium composite is playing a vital role in industrial applications. AlN reinforced AA5083 is synthesized by stir casting route. The material properties of AA5083 composite are evaluated with and without AlN. The great enhancement of substance properties such as tensile strength, hardness and impact strength are achieved by the presence of AlN. Taguchi approach is used to optimize the stir casting factors. The aim of the research work is to increase the performance of AA5083 composite. Tensile strength has been increased from 355 MPa to 400 MPa by the addition of AlN particles.

Dry sliding wear and heat flux mapping of closed-cell Mg-2Zn-2Ca foam fabricated by stir casting route

Dry sliding wear mechanisms and of closed-cell Mg-2Zn-2Ca foam fabricated by stir-casting were investigated using pin-on-disc tribometer. Wear tests were conducted in wide range of varying load of 5–100 N and sliding velocities of 2,3 and 4 m/s at constant sliding distance of 1000 m to develop wear and heat flux mapping plots. Transition of mild to severe wear by establishing different wear mechanisms, its comparative study with solid alloy and microstructure characterization were carried out for potential sustainability of Mg-alloy foam in automotive and biomedical applications. Wear rate was reduced while increasing the effects of work hardening and decreasing the effects of thermal softening occurred during frictional heat flux generation due to competition between work hardening and thermal softening. The results were concluded that Mg-2Zn-2Ca foam exhibited good wear resistance at load up to 25 N, sliding velocity up to 2 m/s and recommended for low load bearing light-weight tribological applications.

Correlation between the Mechanical and Tribological Properties of Rutile Reinforced LM27 Alloy Composite

To meet the global requirements of the industry, there is a need for innovative light weight, low cost, eco-friendly, high quality engineering materials with superior performance at a wide range of temperatures. Aluminum Matrix Composites (AMCs) are lightweight materials with isotropic properties, a suitable choice for modern industry. Low-cost aluminum alloys reinforced with minerals have found a special place in the automotive industry for the manufacture of automobile parts. Rutile particles improve the mechanical properties of the aluminum matrix, making it attractive for structural applications as well as providing greater wear resistance to the composite during sliding. In the present studies, a rutile mineral reinforced LM27 aluminum alloy composite was developed through a stir casting route with 6, 9 and 12 wt.% reinforcements. To study the effect of particle size on the mechanical and tribological properties of composite samples reinforced with fine-sized (50–75 μm) and coarse-sized (106–125 μm) rutile particles were prepared From the results of the experiment, it was found that the hardness, compressive strength and wear resistance increase with increasing rutile wt.% addition. The worn surface and re-groove of the new surface are restored during sliding with the help of oxide films. The analysis of the fractured surface clearly indicates with the help of energy dispersive X-ray spectroscopy (EDS) that with the increase in the volume fraction of the reinforced particles, the porosity increases, which could be the main reason for the compression failure of the composite material.

Investigation on corrosion and wear properties of Al-7075/TiC composites fabricated by stir casting route

Metal matrix composites (MMCs) play a crucial role in the aerospace, automotive and mineral processing industries. The properties of aluminum matrix composites (AMC) that are renowned for their high strength, good stiffness and excellent thermal conductivity can be enhanced by incorporating various reinforcements. In this investigation, Al7075 alloy with TiC (3, 6, and 9 wt.%) reinforcements was processed via stir casting. Optical microscope (OM) and scanning electron microscope (SEM) were utilized to study the microstructural changes. The chemical composition and phases were analyzed using energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) respectively. Evaluations were conducted on properties such as hardness, tensile strength, corrosion and wear behavior. On increasing the wt.% of TiC from 3 to 9 wt.%, it was observed that the hardness increased by 11%, the tensile strength increased by 200%, and the wear rate decreased by 50%. The composite containing 9 wt.% TiC had the lowest corrosion resistance.

Investigation of wear and friction characteristic of Al/(Si3N4)np nano composites under as-cast and heat-treated conditions

Several automotive components, such as clutch plate, piston and cylinder liner, etc., require excellent wear characteristics. The current study focused on fabricating nano Si3N4 reinforced Al alloy composites through a stir casting route with ultrasonic assistance, then performing T-6 heat treatment to alter their properties. Dry sliding wear tests were performed to investigate the frictional and wear characteristics at various applied loads and sliding distances. Results reveal that the coarse grain of α-Al was significantly refined after incorporating nano Si3N4 particles in it, and their structure was transformed from coarse columnar to rosette-like dendrites. The hardness and wear resistance increase with nano Si3N4 addition and T-6 heat treatment. The formation of SiO2 and Fe2O3 layers at the interacting interface significantly reduces the coefficient of friction of nanocomposites. The volumetric loss increased with load (15 N to 45 N) and sliding distance (500 m to 3000 m) for cast and heat-treated samples. The maximum volumetric loss was found in the case of as-cast alloy and the minimum for heat-treated Al/2wt.% Si3N4 nanocomposites. The SEM investigation of worn surfaces shows that the adhesive mechanism is more dominant in alloys, whereas the abrasive wear mechanism was associated with nanocomposites.