Al-SiC Metal Matrix Composites Research Articles

Effect of particle volume fraction on wear behavior in Al–SiC MMC coated on DIN AlZnMgCu1.5 alloy

Abstract In this study, DIN AlZnMgCu1.5 alloy surface (Al + SiC) was coated with metal matrix composite (MMC) by using hot press sintering method (HPSM). Al was used as matrix material and SiC powders were used as reinforcing material in the coating process on DIN AlZnMgCu1.5 alloy surface. Al/SiC MMC coating was produced at 600 °C under 120 MPa pressure and with varying SiC content (5, 10 and 15 vol.%). Optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) were used to examine the microstructure, elemental analysis and phase structure of both the coating zone and the transition zone between the substrate and the coating. The hardness was measured and a dry sliding linear reciprocating wear test was run to determine the mechanical properties of the coating layer. Consequently, the coefficient of friction (COF) and wear volume were determined. OM and SEM images showed a homogeneous distribution of SiC particles and a less porous structure. The hardness of the MMC coating increased with increasing SiC content. Also, the numerical analysis of the wear test simulation was done based on Archard’s law. The results of both wear tests showed that the volume loss values were consistent with each other and the amount of wear significantly reduced by increasing the rate of SiC reinforcement.

Quantitative phase contrast X-ray tomography of aluminium metal matrix composite

The quantitative assessment of micro-structure and load-induced damages in Al–SiC metal matrix composites (MMC) is important for its design optimization, performance evaluation and structure-property correlation. X-ray Phase contrast micro-tomography is potentially used for evaluation of its 3 dimensional micro-structure manifested in the form of voids, cracks, embedded particles, and load-induced damages. However, the contrast between Al matrix and SiC particles is insufficient for their clear morphological identification and quantitative assessment. In the present study, we have proposed and applied single image-based phase retrieval as a pre-processing step to micro-tomography reconstruction for improved assessment of micro-structure and cohesion-induced damages in Al–SiC MMC. The advantages of applying different phase retrieval techniques in the enhancement of image quality and morphological quantification of SiC particles, pores and cohesion damages are discussed. It is observed that the Paganin method offers the best improvement in contrast to noise ratio for the measurement of SiC particles embedded in the Al matrix.

Experimental investigations on electro erosion milling of Al-SiC metal-matrix composite

ABSTRACT This article demonstrates the electro erosion milling process in Al-SiC metal matrix composites. Material Erosion Rate (MER) and Tool Erosion Rate (TER) are measured which depict the productivity aspect of the process. Depth and width of the slots, surface roughness (Ra) is used to indicate the geometrical accuracy. Maximum MER (0.1097 mm3/min) is obtained at 5A. Maximum TER (0.65 µm/min) is obtained at 2.15A. Minimum Ra (2.13 µm) is obtained at 2.15A. Maximum MER (0.1194 mm3/min) is obtained at 100µs. Lowest TER (0.73µm/min) is obtained at 10µs. Lowest Ra (7.66µm) is obtained at Ton of 100µs. Jaya algorithm is used to optimize and create Pareto front from which the results are extracted and reported. Material removal mechanism has been detailed which includes melting / evaporating of matrix material, electrochemical dislodging of SiC grains. Better surfaces have crater diameters ranging from 40–50µm and the bigger craters are in the range of 100–150µm.

Influence of SiC particles orientation on fretting crack extension in an Al-SiC metal matrix composite

The effect of SiC particle orientation regarding the fretting cracking process of an Al-SiC metal matrix composite (MMC) is investigated. Focusing on the crack extension below a sphere-on-flat fretting contact after 106 loading cycles, it is shown that the maximum crack extension is observed when the SiC particles are collinear with the crack path (i.e. perpendicular to the fretting tensile stress). The minimum extension is by contrast observed when the SiC particles are perpendicular to this latter. The crack extension seems favoured when the crack path follows the interface between the SiC particle and the Al matrix but slows down when the particles are perpendicular to the crack path. The crack must then fracture the reinforcing particle. These various experiments are simulated using a 3D finite element modelling (FEM) including the presence of a 3D crack shape. Considering that the crack arrest condition is reached (i.e. plain fretting cracks do not extend anymore after 106 loading cycles), the crack arrest thresholds ΔKth from short to long crack regimes as a function of the SiC particles orientation are extracted from a reverse analysis of the experiments.

The influence of Ni and Zr additions on the hot compression properties of Al-SiCp composites

The present work investigates different additions of nickel and zirconium to the matrix alloy of Al-SiC metal matrix composites to enhance their high-temperature performance. These composites are promising for the demand for lightweight solutions for automotive components like brake discs. In such components, the compression behaviour at elevated temperatures is crucial. The resulting properties were combined with microstructural analysis. Ni additions led to a continuous improvement of the mechanical response, but the same result did not hold for the Zr additions. The interaction of SiC particles, eutectic silicon, and eutectic Ni-based phases led to a 44 % increment of the activation energy.

High Temperature and Strain-Rate Response of Al-Sic Metal Matrix Composites

High Temperature and Strain-Rate Response of Al-Sic Metal Matrix Composites

Evaluation of mechanical properties of Al-B4C and Al-SiC metal matrix composites – A comparison

This paper deals with the comparison of Mechanical properties of aluminum alloy (LM 25) with boron carbide and aluminum alloy with silicon carbide metal matrix composite. The boron carbide of particle size 35 to 40 µm and silicon carbide of similar particle size were used as reinforcements. This addition gives excellent hardness and good impact strength. The fabrication was done by using stir casting., The samples are prepared and mechanical testing like tensile, hardness, and impact was done. It was found that aluminum alloy with boron carbide showed better tensile and impact strength whereas aluminum alloy with silicon carbide showed better hardness. The structure was characterized by using optical microscope.

Comparative analysis of Al-SiC metal matrix composite and Al 7075 T651 alloy in the construction of CubeSat frame

CubeSat is one of the trending technologies in the developed and developing countries across the globe. Various materials are used in the manufacturing of a CubeSat’s subsystems. Structural subsystem is an essential one for a CubeSat’s mission as it bears all the components, payload, and withstand space environment. Usually, aluminium alloys are used in the construction of outer structural frame. In this paper, Al-SiC metal matrix composite is analysed and compared with the conventional Al 7075 T651 alloy. Simulation is done with the help of ANSYS 19.2 software. A series of Static structural, Modal, and Transient thermal analysis is carried out on both materials. Al7075 T651 performed better in most cases. But also, Al-SiC showed good results in specific cases like lesser deformation, modal analysis at higher vibrations. Al-SiC could be combined with the existing aluminium alloys in the manufacturing of CubeSat’s structural frame for a better and efficient output in a specific environment.

Comparison of tool wear during friction stir welding of Al alloy and Al-SiC metal matrix composite

Aluminum matrix composites have received considerable attention due to their high specific strength and specific stiffness, high hardness, and wear resistance along with being light in weight. These composites are preferably joined using friction stir welding process. The major concern in friction stir welding is the wear of the welding tool pin which is the backbone of the process. The wear is due to the prolonged contact between the tool and the harder reinforcements in the composite materials. The present work deals with the study of tool wear and its surface roughness with respect to different selected friction stir welding parameters such as rotational speed, transverse speed, length of weld, and different composition of Aluminum composite. It was found that the total amount of material removed from the tool and the surface roughness of the tool is in direct proportion to the rotational speed of the tool and the length of the weld but inversely proportional to the transverse rate. The increase in wt.% of SiC reinforcement leads to the higher tool wear but reduces the surface roughness of the tool.

Effect of addition of SiC particles on the Microstructure and Hardness of Al-SiC composite

This work aims to investigate the effect of the addition of silicon carbide particles on the microstructure and the hardness of the Al-SiC metal matrix composites. The said composite is prepared using the stir casting technique for different weight percentages of the SiC particles. The higher composition of the reinforcement causes the clustering of the particles in the matrix. Thus, research has to be carried out on the aluminum-silicon carbide composites with the reinforcement 3wt%, 6wt%, 9wt%, and 12wt% of SiC particles to obtain the optimized composition. In order to study the microstructure and the reinforcement distribution in the matrix, a scanning electron microscope is utilized. The hardness testing has been carried out using the Vickers’ indentation technique for the as-cast and age hardening conditions. From the microstructural study, it is observed that the microstructure of the said composite exhibits the uniform distribution of the reinforcement. The EDX results show the presence of the reinforcing elements in the Al-SiC composite. From the results obtained from the hardness testing, it is observed that the presence of the carbide element in the composite increases the hardness of the Al-SiC particulate composites.

Experimental Investigation, Predictive Modeling, Parametric Optimization and Cost Analysis in Electrical Discharge Machining of Al-SiC Metal Matrix Composite

This experimental investigation deals with electrical discharge machining of Al-SiC metal matrix composite using a brass electrode to analyze the three major technological response characteristics concerning surface roughness, overcut, and material removal rate. Forty-six sets of experimental trials are conducted by considering five cutting parameters (discharge current, gap voltage, pulse-on-time, pulse-off-time and flushing pressure) based on Box-Behnken’s design of experiments (BBDOEs). Additionally, response surface methodology (RSM), analysis of variance (ANOVA), and statistical technique (here, desirability function approach) followed by computational approach (here, genetic algorithm) are employed respectively for experimental investigation, predictive modeling, and multi-response optimization. Thereafter, the effectiveness of proposed two (RSM, GA) multi-objective optimization techniques are evaluated by the confirmation test. Subsequently, the best optimal solution is employed for economic analysis. Additionally, the effects of discharge current on influencing various response features have also been studied. Finally, an approach has been proposed for sustainability assessment, taking into consideration of the environmental impact and the dielectric consumption created by the electrical discharge machining process. The result shows that discharge current has the significant contribution (72.23% for MRR, 40.56% for Ra, 34.01% in case of OC) in improvement of material removal rate, degradation of surface finish as well as the dimensional deviation of hole diameter, especially overcut. The proposed vegetable oil-based dielectric fluid is biodegradable, eco-friendly, and thus leading sustainable manufacturing.

High speed, high power density laser-assisted machining of Al-SiC metal matrix composite with significant increase in productivity and surface quality

Abstract Al-SiC metal matrix composites (MMCs) are promising materials for aerospace and electronic packaging applications. However, machining of Al-SiC MMC is very challenging, often resulting in surface scratches by the hard SiC particles and extensive tool wear. Recent approaches of laser assisted machining using low cutting speeds and low laser power densities, although reduce the tool wear, lead to overheating of the bulk material and their irreversible thermal deformation. Here we report a new approach of high speed and high-power density laser-assisted turning (LAT) of an Al-SiC MMC (Al2124 + 17 vol% 0.3 μm SiC). The high cutting speed allows the surface of the locally heated parts to be removed timely avoiding the excessive heat transfer from the surface layer to the main body, which also greatly improves the productivity. The diameter of the laser beam spot (0.7 mm) is smaller than the nose radius of the turning insert (0.8 mm) so that the heat generated from the laser radiation can be effectively removed by the chips. As a result, overheating of the entire part is avoided. The maximum laser power density in this work is 3.38 × 106 W/cm2, which is two orders of magnitude higher than that reported in previous LAT publications. A cutting speed of 565 m/min can be achieved leading to over 2.7–140 times increase in productivity compared with previously reported values, and the surface quality has also been substantially improved in addition to reduced tool wear.

Simulation on the Effect of Porosity in the Elastic Modulus of SiC Particle Reinforced Al Matrix Composites

Although the porosity in Al-SiC metal matrix composites (MMC) can be diminished; its existence is unavoidable. The purpose of this work is to study the effect of porosity on Young’s modulus of SiC reinforced aluminum matrix composites. Finite element analysis is performed based on the unit cell and the representative volume element approaches. The reliability of the models is validated by comparing the numerical predictions against several experimental data ranging in low- and high-volume fractions and good agreement is found. It is found that despite the stress transfer from the soft matrix to the reinforcement remains effective in the presence of pores, there is a drop in the stress gathering capability of the particles and thus, the resulting effective elastic modulus of composite decreases. The elastic property of the composite is more sensitive to pores away the reinforcement. It is confirmed, qualitatively, that the experimentally reported in the literature decrease in the elastic modulus is caused by the presence of pores.

Analysis of Surface Characteristics for Al–SiC Metal Matrix Composites Machined by Wire Electrical Discharge Machining (WEDM)

Objectives: The application of light weight products used for automobile needs to require the use of Al metal matrix composites (MMCs). The optimized combination of process variables has been found to accomplish for better machining. Methods/statistical analysis: There is different type of machining methods used for machining of MMC but it is not so easy to machine these materials with full efficiency and desired output responses because of difficult to machine these materials as compared to other unreinforced materials like alloys and smart materials. The main reason behind hardness of aluminum MMCs is heterogeneous structure which makes its surface layer with high fatigue strength, smooth, and tough. L9 orthogonal array has been used to perform the experiments. Findings: The effect of parameters has been calculated and analyzed for response analysis. The effect of various machining parameters like wire diameter, current, voltage, pulse on time, and pulse off time is observed and analyzed on surface properties of the Al–SiC MMCs. As a result of compressive residual stress on the surface that is a plus point for material to use it for tough work, but along with this it will cause high tool wear and surface imperfections while machining, so these are some reasons for the recommendation of non-conventional machining methods to machine aluminum matrix composites. So, several new techniques were added in some past few years of research which is explained in this research article. Application/improvements: Wire electrical discharge machining (WEDM) which is an advanced machining method which is used for manufacture difficult shapes conductive work piece materials. Experimental work will be done on the WEDM of Al–SiC MMC. Keywords: Aluminium Metal Matrix Composite Al–SiC, Surface Roughness, Wire Electrical Discharge Machining (WEDM), Surface Integrity, Taguchi’s Method, Response and Regression Analysis.

Characterization and Defect Analysis of Machined Regions in Al-SiC Metal Matrix Composites Using an Abrasive Water Jet Machining Process

Metal matrix composite (MMC) materials are increasingly used in industrial sectors such as energy, structural, aerospace, and automotive. This is due to the improvement of properties by the addition of reinforcements. Thus, it is possible to obtain properties of higher strength, better rigidity, controlled thermal expansion, and elevated wear resistance. However, due to the extreme hardness achieved during their manufacture, these composites pose a challenge to the conventional machining industry due to the rapid deterioration experienced by cutting tools. This article therefore proposes the use of an unconventional machining method that is becoming increasingly widely used: abrasive water jet cutting. This process is characterized by high production rates, absence of wear, and environmental friendliness, among other advantages. Experimental tests were carried out in order to analyze results that minimize the formation of defects in the machining of metal matrix composite consisting of aluminium matrix with silicon carbide (Al-SiC MMC). To this end, results were analyzed using Scanning Optical and Electron Microscope (SOM/SEM) techniques, the taper angle was calculated, and areas with different surface quality were detected by measuring the roughness.

Machinability analysis and application of response surface approach on CNC turning of LM6/SiCp composites

ABSTRACTThis present exploration detailed the machining performance characteristics of stir-casted aluminum metal matrix composites during CNC turning process with Tungsten Carbide inserts. An endeavor has been taken to attain the possible set of process parameter for obtaining the better machinability performance such as minimized cutting temperature, vibration, and roughness of machined surfaces. Response surface methodology has been adopted to evolve empirical relationship among the desired performance characteristics and effects of interaction among those selected variables were determined. An analysis on wear of the tool was performed with the aid of SEM and EDAX. The outcome of the exploration divulged that the poor surface quality occurred because of adhesion of composites on inserts and abrasion wear in rack face. Notching wear was observed at the time of machining of Al-SiC Metal Matrix Composites (MMC), which produces an abrasive chip. The evolved empirical relationship are validated by confirmation tests, and it is affirmed that the employed RSM approach is an prevailing tool for developing empirical relations and also fruitful approach to envisage the desired performance measures in an effective and efficient manner.

Optimization of Micro Hardness of Al-SiC 6061 MMC Machined by Wire EDM with Taguchi Method

The usage of Al-SiC metal matrix composites is constantly increasing since the last many years due to their many unique properties such as light weight, high strength, high specific modulus, high fatigue strength, low density, and high hardness. However, because of their high hardness, their machining, that too within close tolerance limits, is often a big challenge. Wire EDM (Electric Discharge Machining) however offers a good method to machine these deemed difficult to machine alloys. This research work focuses on the wire EDM machining of Al-SiC 6061 metal matrix composite which is one of the most widely used metal matrix composites in the world today. Here, Taguchi approach has been applied to study the work-piece composition and machining parameters during the wire EDM machining and to maximize the micro hardness of the surface obtained after the machining process. Different compositions of the Al-SiC MMC in terms of reinforcement percentages, along with six other operating parameters have been studied. L-16 Orthogonal Array (pronounced as ell-sixteen Orthogonal Array) has been used in the Taguchi approach for this purpose. Contributions of various factors to surface micro hardness have been determined, amongst which, SiC percentage in the Al-SiC MMC had the greatest contribution. The conclusions and future scope of this study have also been discussed

Engineered Synthetic Diamond Film as a Protective Layer for Tribological and Machining Applications: A Review

Cobalt-based tungsten carbide composite (WC-Co, with different grades) is the commonly used material for cutting tools and tribological components, because of its high hardness and high wear and corrosion resistance. The carbon fiber-reinforced plastics (CFRP) and Al-SiC metal-matrix composites (MMCS) are materials mostly used in aerospace and automobile industries due to their high strength-to-weight ratio. During the machining of these composite materials, the conventional WC-Co cutting tools are subjected to high abrasive wear because they contain constituent hard reinforced particles. Thus, these types of machining applications need super-hard coatings for better performance and durability. Nowadays, synthetic diamond coatings obtained by chemical vapour deposition (CVD) process play an important role in improving the performance of the carbide tools while machining these composite materials, because of their superior mechanical and tribological properties. CVD diamond coatings with good wear resistance, super hardness, and low friction coefficient are in demand for industrial applications. But, the main problem of these diamond coatings is the coating de-lamination under high mechanical loads experienced during the machining process. Presently, researchers concentrate on the improvement of the coating adhesion for their better performance. However, to achieve the desired synthetic diamond coating for industrial applications many characteristics of the coating-substrate system need to be considered like good adhesion, optimum coating thickness, and minimum thermal residual stresses. Therefore, the microstructure and architecture of the synthetic diamond coatings should be adjusted to achieve the basic practical requirements like high wear resistance, high hardness, enough adhesion strength, and low friction coefficient.

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.

Microstructure, wear and mechanical properties of plasma sprayed TiO2 coating on Al–SiC metal matrix composite

In the present study, the hard TiO2 coating was plasma sprayed on the Al/SiC composite substrate. The coating was characterised for microstructure, mechanical and tribological properties and compared with the substrate. The key findings from the present study are: (1) The lamellae structure of the coating contains semi and fully melted particles, round porosity without any evidence of spallation or delamination or un-melted particles and non-stoichiometric and oxygen deficient phases and shorter stand-off distance would be a probable reason for the occurrence of partial melted regions and porosity in the coating, (2) The coating has improved significantly scratch resistance, hardness, fracture roughness, friction coefficient and wear resistance of the substrate, and (3) mild abrasive wear is responsible for low wear loss in the coated sample whereas the combination of severe delamination wear and abrasive wear causes the considerable wear loss in the uncoated sample.