SiCp Metal Matrix Composites Research Articles

Stir Cast Al–Cu–SiCp Metal Matrix Composites: Effect of SiC Particles on the Mechanical Properties and Optimization of EDM Process Parameters

Stir Cast Al–Cu–SiCp Metal Matrix Composites: Effect of SiC Particles on the Mechanical Properties and Optimization of EDM Process Parameters

An overview of the effect of stirrer design on the mechanical properties of Aluminium Alloy Matrix Composites fabricated by stir casting

An overview of the effect of stirrer design on the mechanical properties of Aluminium Alloy Matrix Composites fabricated by stir casting

Influence of process parameters in additive manufacturing of highly reinforced 316L / SiCp composites

Highly reinforced 316 L / SiCp metal matrix composites (MMC) walls have been additively manufactured by Direct Laser Deposition (DLD) using mixtures with different percentages of 316 L stainless steel powder and SiC particles (SiCp). The effect of the percentages of SiCp of up to 80 wt.% and DLD conditions on the geometry, microstructure, and hardness of the fabricated structures have been analyzed. SiC particles react with the molten 316 L steel and chromium and iron carbides are formed, and also graphite flakes and nodules are formed in the matrix. This reaction is also responsible for the dilution of the SiCp, which lose their initial shape and size. The incorporation of higher percentages of SiCp reduces the degradation of the particles as the matrix saturates in Si and C, and also enhances the size of the graphite precipitated phases. The different phases formed help to increase the hardness of the composites, and a maximum value of 1085 HV 0.1 was obtained for 40 vol.% of SiCp. Increasing further the amount of SiCp reduced the hardness to values of ∼890 HV 0.1 as the matrix is saturated in carbides and bigger and more brittle graphite precipitates are formed. The characteristics of the manufactured samples for the different reinforcement percentages used and for the different manufacturing conditions have been analyzed. From this study, the DLD processing maps for the 316 L/SiC MMC metal matrix composites with different content of reinforcement have been developed, and the optimal values of laser power, scanning speed, and layer height have been determined, and it has been observed that the optimum fabrication conditions displace to lower scanning speed for higher SiCp contents in the 316 L matrix. Showing that it is possible to manufacture cermets based on steel with lower density and greater hardness than the steel used.

Performance evaluation and multi-response hybrid optimization of grinding assisted rotary disk ECDM during cutting of Al-6063 SiCp MMC

The Metal Matrix Composites (MMCs) are being used in many applications, including aerospace, shipbuilding, anddefence industries owing to their high strength to weight ratio. However, the machining of these materials is stillchallenging, necessitating advanced machining techniques. The current investigation aimed to analyze the performance ofthe grinding-assisted rotary disc-electrochemical discharge machining (GA-RD-ECDM) process during cutting Al-6063SiCp MMC. Detailed experimentation was performed to study the energy interaction behavior and effect of input processvariables viz. applied voltage, pulse on time, electrolyte concentration, and disc rotation speed on performance measures.The responses selected were taper, overcut (WOC), and Materials Removal Rate (MRR). The experimentation work wasperformed by adopting response surface methodology. Regression models were developed and statistically analyzed throughanalysis of variance (ANOVA). Eventually, the GA-RD-ECDM process was optimized using the VIKOR methodology ofmulti-criteria decision-making by considering accuracy and productivity simultaneously to obtain minimum taper and WOCand maximum MRR. The results of ANOVA revealed that input variables were statistically significant. Applied voltagemost significantly affects the performance of the GA-RD-ECDM process performance. The optimal values of input processvariables obtained by VIKOR method were applied voltage = 100 V, pulse-on time = 3 ms, Electrolyte concentration = 18%wt/vol. and disc rotation speed = 30 rpm. The present work can provide a productive solution for cutting of difficult-to-cutmaterials. Thus, in future, the GA-RD-ECDM process can be investigated for other advanced materials (i.e., glass, polymercomposites and ceramics) for fabrication of microchannels for microfluidic applications.

Influences of tool velocity ratio on wear behavior of friction stir processed LM25AA-5%SiCp metal matrix composites

Several scientists reviewed the influence of the rotation speed and the transverse velocity of devices with friction stir composite processing (FSP) properties. Results proved that significant microstructural changes were affected by altering these parameters. However, the effect of rotation speed and traverse speed of tool has been less explored. Furthermore, no efforts have been made to investigate the consequence of tool velocity ratio so far to wear the aluminum-based metal matrix composites treated with friction stir processed. Therefore, an effort was made in this research to investigate the actuation of the tool speed ratio on the characteristics of aluminum-SiCp composite processed in friction stir processing. Rotational speed and traverse speed of tools selected. In accord to an optimized working range and the corresponding tool velocity ratios were calculated. The FSPed region's morphology, and wear rate were associated with the corresponding tool velocity ratios. It has been identified from this investigation that the device tool velocity of 2.60 resulted in the FSP region with superior resistance to wear compared to other tools velocity ratios.

Study of machining induced surface defects and its effect on fatigue performance of AZ91/15%SiCp metal matrix composite

The quality of surface generated in a peripheral milling of AZ91/SiCp/15% for varying machining conditions and its effect on the fatigue performance are investigated in this study. The machined surface quality was evaluated through roughness measurements and SEM micrographs of the machined surface. Tensile tests were performed to measure the mechanical properties of the composite. Subsequently, fatigue life of milled specimens was measured through axial fatigue tests at four loading conditions. Optical and SEM/EDS micrographs of the fractured surface were studied to identify the crack initiation site and propagation mechanism. Specimens machined at a lower feed rate of 0.1 mm/rev was found to have excellent surface finish and consequently higher fatigue life. At 0.3 mm/rev, the presence of feed marks and other surface defects resulted in a drastic decrease in fatigue life. Five distinct regions were identified on the fractured surface, particle fracture along and perpendicular to the surface, voids in the matrix due to particle debonding and pull out and typical ductile failure of matrix with embedded SiC particles.

Multi objective optimal scheme for machinability aspects of Al6061-SiCp metal matrix composite during end milling-a hybrid approach

Abstract The present study is aimed to obtain most favorable cutting conditions during end milling of Al 6061 reinforced with SiCp metal matrixcomposite (MMC) for optimized machining force, surface roughness (Ra) and amplitude. Experiments are designed and conducted as per Taguchi L25orthogonal array. Integrated Grey Relational Analysis (GRA) and Principle Component Analysis (PCA) optimal scheme is adopted and performed. The parametric influences are discussed through main effects plot and contour plots. Results revealed that multi objective optimization index Grey Relation Grade (GRG) is affected by the input parameters in the following order weight fraction, depth of cut, speed and feed. The optimum cutting parameters obtained are cutting speed 2500 rpm, feed rate 10 mm/rev, depth of cut 0.2 mm and weight fraction 4%.

Effect of tool pin profile on corrosion behavior of friction stir processed LM25AA 10% SiCp metal matrix composites

Friction stir processing (FSP) is a novel technique for microstructure refinement and for the enhancement of surface characteristics of stir casted LM25AA −10% SiCp Metal matrix composite (MMCs) plates. In FSP, a non-consumable tool made-up of harder material plays a critical part in altering the substrate material’s surface. In this present work, the influence of various tool pin profiles (Cylindrical straight, taper threaded, threaded cylindrical, square and plain tapered) on the corrosion behavior of friction stir processed (FSPed) LM25AA – 10% SiCp MMCs has been evaluated. The size and dispersion of silicon carbide particles in FSPed MMC were studied and the microstructure, micro hardness, corrosion rate, and the optimum tool pin design to attain desired particle distribution in FSPed MMCs was established. It was found that the decrease of the grain size of the SiC particulates and matrix leads to enhancement of hardness and reduction in corrosion rate.

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

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

Solidifying behavior and Characterization of Al (LM6) +SICP Metal Matrix Composites

This paper presents the investigation of moderate properties of solidified Al (LM6)+SiCp metal matrix composite (AMMC). These AMMC is fabricated by considering five different parts of casting and different weight of SiCp for reinforcement. The SiCp wt. % is varied from 5 wt. % to 15 wt. % with a step size 5 %. During casting, temperature is measured using K-thermocouple and temperature vs. solidification curve is traced. These results are compared with the solidification results of Al (LM6) alloy. It is observed that the solidifying duration of AMMC increased as well as decreased liquid temperature by adding SiCp to it. The trend of the curve is also presented that the cooling rate and the duration of solidification are different for different part of casting. Mechanical property of the each five parts of casting is tabulated. It is observed from the properties that the mechanical properties of AMMC increased by increasing the wt. % of the reinforced particles SiCp.

Experimental investigations into rotary mode electrochemical discharge drilling (RM-ECDD) of metal matrix composites

In the present work, rotary mode electrochemical discharge drilling (RM-ECDD) was employed to machine the Al-6063 SiCp metal matrix composites (MMC’s). The effect of various process parameters such as applied voltage, pulse on time, tool rotation rate, electrolyte concentration and current on quality characteristics (hole over cut and depth of penetration) of the drilled holes was investigated. The underlying material removal mechanism during the machining of MMC’s with RM-ECDD is also proposed by considering the scanning electron micrographs (SEM) and simulation results as an evidences. A comparative analysis between RM-ECDD and ECDD was performed during the machining of MMC’s. The experimental results reveal that the integration of tool rotations in ECDD successfully evacuates the sludge/debris from the machining zone, and it also replenishes the electrolyte effectively. Therefore the use of RM-ECDD improves the aspect ratio (L/D), and it exhibits 23.07 times higher L/D ratio than the ECDD process. In ECDM, the discharge characteristics are very important outcome that explores the significant details of the involved mechanisms and phenomena of the process. In the present research, a DSO recorded voltage signals were used to understand the discharge behavior and their characteristics at different parameter combinations. This paper also presents a second-order mathematical models to determine the relation between input process parameters and quality characteristics. Desirability based multi objective optimization approach was employed to optimize the process parameters.

Optimization through NSGA-II during machining of A356Al/20%SiCp metal matrix composites using PCD Tool

Metal matrix composite (MMC) has established growing usages in the engineering for lightweight high-strength application. However, because of abrasive nature of the reinforcement particles in MMC, machinability is reduced, tool wear is high, yet only diamond tools are appropriate for machining MMC. Being a complex process, it is very complicated to establish optimal parameters for improving cutting performance. Tool flank wear (VBmax) and Average surface roughness (Ra) are the most significant output responses, which decide the machinability of a material. The effect of cutting parameters on output responses of tool flank wear and average surface roughness are conflict with each one another so there is no single optimal mixture of cutting parameters. In this study multi regression model function, based on NSGA-II was used to optimize the machining of Al/20%SiCp MMC using tipped polycrystalline diamond (PCD) tool and also characterize the relationship among input parameters and output performance. The NSGA-II based non dominated solutions of 30 combinations chosen from 100 and presented; none of them superior to any other each and every one are best based on engineer requirement.

Fuzzy logic-integrated PSO methodology for parameters optimization in end milling of Al/SiCp MMC

This paper deals with a novel integrated parametric optimization in end milling of Al–SiCp metal–matrix composites using carbide tool. Fuzzy logic modeling combined with particle swarm optimization (PSO) technique is applied as intelligent optimization methodology to obtain optimal process parameters in end milling process. Fuzzy rules-based surface roughness prediction model is developed with SiCp percentage as one the input parameter is addition to spindle speed, feed and depth of cut. Comparison of fuzzy rule model predictions with confirmation data sets showed 95.44% average prediction accuracy. The effect of process parameters on surface roughness is also studied. Analysis of variance established feed rate as the most significant process variable with 69.93% contribution followed by SiCp (19%) and spindle speed (9.73%), respectively. The integrated PSO optimizer optimizes the process parameters for an objective to minimize the machining time satisfying desired surface roughness to be obtained. A number of problems with different values of desired surface roughness are solved and algorithm converged in less than ten iterations.

Effect of pin volume ratio on wear behaviour of friction stir processed LM25AA-5%SiCp metal matrix composites

Friction stir processing (FSP) technique is preferable over other conventional surface modification techniques because of its capability to produce relatively strong and defect free surfaces. However, there are certain parameters in FSP which have to be carefully optimized to obtain defect free surfaces with exceptional properties. From the previous findings, it was understood that the tool pin profile played an important role in determining the characteristics of the processed surfaces. Hence, it was decided to investigate the effect of pin volume ratio (PVR) on various regions of the processed surface. PVR is the ratio of dynamic volume to the static volume of tool pin. Dynamic volume is the volume of the profile generated by the tool pin when it is in motion. Static volume is the volume of the profile produced by the tool pin when it is at rest. The material displaced by the tool has to be in proper proportion with the volume occupied by the pin in static condition, in order to produce optimal surface properties. In this investigation, the tool with Taper cylindrical pin profile produced defect free surfaces with superior micro hardness and wear resistance compared to other tool pin profiles.

Experimental investigations into triplex hybrid process of GA-RDECDM during subtractive processing of MMC’s

ABSTRACTThe use of Al-6063 SiCp metal matrix composites (MMCs) in electronic packaging applications, heat sinks for printed circuit boards and for microwave housings necessitates certain degree of machining operations to meet the specifications of the product. The various conventional and non-conventional machining processes had been used to machine the MMCs. But all such processes have their limitations in providing the desired outcomes. Therefore, the present research endeavor, a new process variant of ECDM for the machining of Al-6063 SiCp MMCs. The developed grinding assisted rotary disk electrochemical discharge machining (GA-RDECDM) process integrates the concept of triplex hybridization. In GA-RDECDM, an abrasive coated rotary disk was used as a tool electrode. The abrasive coated disk provides micro gaps between the tool electrode and work material surface and thereby it results in thin and stable gas film formation. The breakdown of thin and stable gas films produce high frequency, low intensity discharges and consequently improves the machining performance. The additional abrasion action imparted by rotating disk ensures the continuation of ECDM process. The influence of various process parameters including applied voltage, pulse on time, electrolyte concentration and the disk rotation rate on width over cut (WOC) and depth were experimentally investigated. Multi criteria optimization using desirability approach predicts the parametric combination of applied voltage of 99V, pulse on time of 3 ms, electrolyte concentration of 17%wt./vol. and disk rotation rate of 30 rpm as the optimum setting for fabrication of slits on the MMCs. The underlying process mechanism is also investigated and presented with appropriate illustrations. The major contribution of the present research work is the development of a novel method for the fabrication of the slits on MMCs.

Effect of Tool Traverse Speed on Strength, Hardness, and Ductility of Friction-Stir-Processed LM25AA-5% SiCp Metal Matrix Composites

Plates made from stir cast light metal 25 aluminum alloy–5% silicon carbide particle (SiCp) metal matrix composites (LM25AA-5% SiCp MMCs) have sub-optimum mechanical properties because of the uneven distribution of the SiC particles (SiCp) that are used as reinforcement. Currently, friction stir processing (FSP) is used as a secondary processing method to overcome the uneven distribution of particles in the aluminum matrix. The FSP method is controlled by three important parameters: tool rotational speed, tool traverse speed, and axial force. Of these three parameters, the tool traverse speed governs the mechanical properties of the MMCs. Hence, in this investigation, an attempt has been made to study the effect of tool traverse speed on the mechanical properties of friction-stir-processed material. Five different tool traverse speeds (ranging from 20 to 60 mm/min) were used to process LM25AA-5% SiCp MMC plates whose thickness was 12 mm. The tensile strength, ductility, and hardness of the friction-stir-processed material were evaluated. Microstructure and SiCp reinforcement distribution were characterized using optical and scanning electron microscopy. The tool traverse speed of 40 mm/min produced a defect-free processed zone with superior mechanical properties compared to those produced at other speeds.

Production and mechanical properties of nano SiC particle reinforced Ti–6Al–4V matrix composite

Different mass fractions (0, 5%, 10%, and 15%) of the synthesized nano SiC particles reinforced Ti–6Al–4V (Ti64) alloy metal matrix composites (MMCs) were successfully fabricated by the powder metallurgy method. The effects of addition of SiC particle on the mechanical properties of the composites such as hardness and compressive strength were investigated. The optimum density (93.33%) was obtained at the compaction pressure of 6.035 MPa. Scanning electron microscopic (SEM) observations of the microstructures revealed that the wettability and the bonding force were improved in Ti64 alloy/5% nano SiCp composites. The effect of nano SiCp content in Ti64 alloy/SiCp matrix composite on phase formation was investigated by X-ray diffraction. The correlation between mechanical parameter and phase formation was analyzed. The new phase of brittle interfaced reaction formed in the 10% and 15% SiCp composite specimens and resulted in no beneficial effect on the strength and hardness. The compressive strength and hardness of Ti64 alloy/5% nano SiCp MMCs showed higher values. Hence, 5% SiCp can be considered to be the optimal replacement content for the composite.

Optimization the machining parameters by using VIKOR and Entropy Weight method during EDM process of Al–18% SiCp Metal matrix composite

Article history: Received June 25, 2015 Received in revised format: October 12, 2015 Accepted November 15, 2015 Available online November 16 2015 The objective of this paper is to optimize the process parameters by combined approach of VIKOR and Entropy weight measurement method during Electrical discharge machining (EDM) process of Al-18wt.%SiCp metal matrix composite (MMC). The central composite design (CCD) method is considered to evaluate the effect of three process parameters; namely pulse on time (Ton), peak current (Ip) and flushing pressure (Fp) on the responses like material removal rate (MRR), tool wear rate (TWR), Radial over cut (ROC) and surface roughness (Ra). The Entropy weight measurement method evaluates the individual weights of each response and, using VIKOR method, the multi-objective responses are optimized to get a single numerical index known as VIKOR Index. Then the Analysis of Variance (ANOVA) technique is used to determine the significance of the process parameters on the VIKOR Index. Finally, the result of the VIKOR Indexed is validated by conformation test using the liner mathematical model equation develop by responses surface methodology to identify the effectiveness of the proposed method. Growing Science Ltd. All rights reserved. 6 © 201

Heat treatment optimization for tensile properties of 8011 Al/15% SiCp metal matrix composite using response surface methodology

Abstract In this study, a mathematical model was developed to optimize the heat treatment process for maximum tensile strength and ductility of aluminum (8011) silicon carbide particulate composites. The process parameters are solutionizing time, aging temperature, and aging time. The experiments were performed on an universal testing machine according to centre rotatable design matrix. A mathematical model was developed with the main and interactive effects of the parameters considered. The analysis of variance technique was used to check the adequacy of the developed model. The optimum parameters were obtained for maximum tensile strength. Fractographic examination shows the cracks and dimples on the fractured surfaces of heat-treated specimen.

Multi Response Optimization of Tungsten Inert Gas (TIG) Welding of Al6063/15%Sicp Metal Matrix Composites

Material scientists and researchers in this area have been fulfilling the demand of the engineering sector since decades in synthesizing materials to attain the demanded properties to enhance efficiency and cost savings in the manufacturing sector Aluminium metal matrix composites (AMMCs) are becoming more popular as structural materials and joining them is therefore of paramount importance. Joining of advanced materials plays an increasingly important role in modern manufacturing industries. AMMCs have a unique combination of mechanical and physical properties, such as high specific strength, specific modulus of elasticity, low thermal expansion coefficient and good wear resistance; these are being widely used in aerospace engineering, automotive industry, electronic packaging, medical appliances, heat exchanger fins and other related industries. As these new materials become available it is necessary to define and optimize joining techniques, and a thorough understanding of process. The present work first deals with the fabrication of SiCp reinforced AMMCs (Al6063/15%SiCp) with Liquid Processing Technique, i.e. Stir casting method and later to seek for possibilities of successful joining with TIG process, for possible structural applications. The present study deals with an experimental study carried out in order to optimize the process parameters namely Frequency (Hz), Current (A), Shielding gas flow rate (l/m), Percentage time electrode positive (μs). The performance measures evaluated are namely Micro- hardness, (VHN) and Impact strength, (Joule), for Tig welding of Al6063/15%SiCp. The results have been analysed using Taguchis methodology. The optimal values of micro-hardness are A1B3C3D1 (frequency HF Hz, current 105 A, shielding gas flow rate 14 l/m, percentage time electrode positive 60 μs). The optimal values for impact strength are A2B1C1D3 (frequency LF Hz, current 85 A, shielding gas flow rate 10 l/m, percentage time electrode positive 70 μs).