SiC Reinforcement Research Articles

Analysis of Effect of SiC Reinforcement on Microstructure and Hardness of Al 6061 and Al 7075

In past few decades use of Aluminium Alloys and Aluminium Metal Matrix Composites have increased tremendously. Due to their light weight, corrosion resistance and excellent electrical and thermal conductivity they are fit many automotive and aeronautical applications. In this paper analysis of effect of SiC reinforcement on microstructure and hardness of Al 6061 and Al 7075 is presented. It is clearly evident that, addition SiC to base material changes its microstructural grain formation and size, uniform distribution of grain in the material will enhances mechanical properties. Also the hardness increases with increasing in weight percent of reinforcement composition..

Role of Interfaces in Damage Initiation and Tolerance of Carbon Nanotube-Reinforced HfB2-ZrB2 Ceramics

HfB2-ZrB2 based ultra-high temperature ceramics (UHTCs) are used as protective tiles for leading edges and nose cones of the hypersonic vehicles that face harsh re-entry conditions. In the present work, the effect of SiC (20 vol.%) and carbon nanotube (CNT, 6 vol.%) incorporation on the room temperature damage initiation and wear damage tolerance of HfB2-ZrB2-based ceramics, consolidated via spark plasma sintering (SPS), is assessed. The wear rate decreased by almost > 90% in CNT-reinforced HfB2-ZrB2–SiC composites (for both scratch and fretting tests), and a significant increase in the Hertzian contact pressure (from ~ 15 GPa, in case of fretting to ~ 21 GPa, in case of scratch wear) and scratch hardness (from ~ 27 GPa to ~ 46 GPa, respectively) was observed with synergistic reinforcements of SiC and CNT. The study examines synergistic interfacial strengthening by SiC and CNT reinforcement in HfB2-ZrB2 ceramic composites as potential materials for aerospace applications where damage initiation and tolerance are issues.

Synergistic role of carbon nanotube and SiCn reinforcements on mechanical properties and corrosion behavior of Cu-based nanocomposite developed by flake powder metallurgy and spark plasma sintering process

Hybrid-reinforced metals are novel composite materials in which nano-phases including nanoparticles and nanotubes/nanosheets are used simultaneously to reinforce metals or alloys to enhance physical, mechanical, wear and other properties. In this research, Cu/(CNT-SiC) hybrid nanocomposite was synthesized using flake powder metallurgy and spark plasma sintering method and the effects of hybrid reinforcements on microstructural, wear and corrosion properties of the developed material were investigated and compared with those of copper. Microstructural characterization showed reduction of average grain size from 419 to 307 nm and increase of low angle grain boundaries with the introduction and homogeneous dispersion of hybrid reinforcements. Mechanical tests indicated that the addition of hybrid SiC and CNT reinforcements substantially increased microhardness and reduced wear rate and friction coefficient of the Cu. Also, polarization and EIS tests revealed the suppressing of the anodic dissolution of the matrix, hindering the oxygen reduction reaction and 62.5% improvement of corrosion rate for the composite material. The effects of hybrid nano-reinforcements are presented and discussed.

Investigation of A413 alloy with reinforcement of SiC and flyash hybrid composites by stir cast cum forged process on electric vehicle In-wheel motor casing

The Cardinal goal of this research work is to fabricate a new combination of hybrid composite material and it was suited for a casing cover of an In-wheel motor drive system that works in an electric vehicle. The main objective of the proposed work is to prepare the hybrid metal matrix composite through stir cast cum forging process to attain enhanced property. The preparation of stir casted A413 alloy with 5% SiC and 5% flyash hybrid composites are further processed through uni/bi/multi-directional forging process to enrich the properties. Each cast cum forged samples are tested under various aspects such as density, hardness, ultimate tensile strength, thermal conductivity and coefficient of thermal expansion. By carrying out the above test, it was found that hybrid composite under multi-directional forging process shows an 73% increase in thermal property, 3% lesser in physical property and 20–45% increase in mechanical property when it compared with hybrid composite under un-forged process. The newly fabricated hybrid composite under multi-directional forging has higher properties under all testing aspects due to reduction of grain size. In addition comparing with uni and bi-directional forging process. Multi-directional forging attains higher strength and will reduce the weight of the hybrid composites. Due to reduction of unsprung mass of the vehicle, we recommend hybrid composite obtained by stir cast cum multi-directional forged process for incorporation in In-wheel motor drive system.

Machining of TiB<sub>2</sub>- SiC Ceramic Composites through WEDM Process

In the present study Spark Plasma Sintering (SPS) technique is used to synthesis of particulate Ceramic Matrix Composites (CMCs). SPS is a type of hot pressing method and in this method, the rate of heating is from 100C to 1000C per minute with high densification. TiB2 (average size of 14 μm) particles were chosen as matrix and SiC (average size of 1 μm) particles were used as reinforcement. In the first stage of the study, synthesis of CMCs with TiB2 matrix and SiC reinforcement with varying volume% (0, 5, 10 and 15 vol.%) was carried out using Spark Plasma Sintering furnace available at IIT Madras in 1100°C, 40MPa and 10 min hold of time. But machining of CMCs from conventional machining processes is difficult especially to make complex and precise parts from CMCs. Hence, in the second stage of the work, Wire Electric Discharge Machining (WEDM) studies were carried out on the processed four composites by varying current (2, 3 and 4 A), Pulse on (Ton-30, 60 and 90 μs) and Pulse off time (Toff-5, 10 and 15 μs) as per Taguchi L9 orthogonal array. WEDM studies revealed that at 4A current, 60μs Ton and 5μs Toff gave maximum material removal rate (MRR) of 2.93 mm3/s, 2.27 mm3/s, 2.71 mm3/s and 0.62 mm3/s for CMC with 0% SiC, 5% SiC, 10% SiC, 15% SiC vol.% reinforcement respectively. To reduce material wastage during machining, kerf width is considered and in which 3A current, 90μs Ton and 5μs Toff gave the least kerf of 0.35 mm, 0.32 mm, 0.33 mm and 0.28 mm for 0% SiC, 5% SiC, 10% SiC, 15% SiC vol.% reinforcement respectively.

Mechanical and Tribological Properties of Al6063 Hybrid Composites Reinforced with SiC/ZrO2 by Stir Casting and Thixoforming Process

Hybrid metal matrix composites new generation of engineering materials with better mechanical and tribological properties. Al6063 alloy has the matrix material and reinforcement SiC and ZrO2 micro particles are selected for the study. In this work, Al6063/ SiC/ZrO2 hybrid composite fabricated with different wt. % of reinforcements (0.5, 1, and 1.5 wt. % SiC and 1 wt. % ZrO2 constant for all composites) by using stir casting process. The thixoforming process applied to casted composite. The SiC and ZrO2 particle was distributed in the Al-matrix are visible in the SEM micrographs .The hardness value of the composite 34.75% increased due to the addition of constant 1 wt. % of ZrO2 and varying SiC reinforcement particles. The charpy impact strength of Al composite was increased by 23.52 % with the addition of the constant 1 % wt. ZrO2 and 1 wt. % SiC particles. Wear behavior of Al6063/SiC/ZrO2 hybrid composite was tested using pin-on-disc machine. The wear volume loss decreased for 1.5 % wt. SiC and 1 wt. % ZrO2 compared to other composite. The worn surface morphology has revealed that Al6063 base alloy with deep groove. The composite with 0.5%, 1% wt. SiC and constant 1 wt.% ZrO2 showed more debris, dilamation and cleavage particles formed on the pin surface. The composite with 1.5 % wt. SiC and constant 1 wt.% ZrO2 showed less wear loss and smooth surface formation.

An electron backscattered diffraction (EBSD) approach to study the role of microstructure on the mechanical behavior of welded joints in aluminum metal matrix composites

In this investigation aluminum metal matrix composites were prepared with varying weight percentages of SiC reinforcement (8, 10 and 12 weight percentages). Samples with identical composition were welded using tungsten inert gas (TIG) welding technique. The welding parameters were maintained same for all the samples. Thermal ageing of welded specimens was conducted to attain the peak age hardening conditions. Microstructural differences between aged and non-age hardened specimens were brought out in terms of misorientation, stored energy and residual stresses. The changes in the mechanical behavior of the welded joints due to varying composition of the specimens correlated to identical changes in the microstructures. The present study aims to address the role of SiC addition in aluminum metal matrix composites on the microstructure and mechanical behavior of the welded joints.

AlSi-SiC Composites for Automotive Brake Rotor

This manuscript investigates the Fabrication and Microstructure of Automotive Brake Rotor Made of AlSi-SiC Composites. This work is oriented toward fabrication of automotive brake rotors from Al-9Si and Al-12Si reinforced with 10 and 20% SiC particles using stir-casting method. The brake rotors were subjected to heat treatment. Aging behavior showed that hardness increased with the addition of SiC reinforcements by 104%, comparing to solution treatment condition. Also, the addition of SiC particles accelerates formation of precipitates. Microstructure of brake rotors made of composite revealed uniform distribution of SiC particles, primary phase (⍺-Al) and modified eutectic Si. EDX analysis showed the presence of Al, Mg and O at the interface between matrix and SiC particles.

Micromechanics-based prediction of the effective properties of piezoelectric composite having interfacial imperfections

We derive an analytical expression to predict the effective properties of a particulate-reinforced piezoelectric composite with interfacial imperfections using a micromechanics-based mean–field approach. We correctly derive the analytical formula of the modified Eshelby tensor, the modified concentration tensor, and the effective property equations based on the modified Mori–Tanaka method in the presence of interfacial imperfections. Our results are validated against finite element analyses (FEA) for the entire range of interfacial damage levels, from a perfect to a completely disconnected and insulated interface. For the facile evaluation of the nontrivial tensorial equations, we adopt the Mandel notation to perform tensor operations with 9×9 symmetric matrix operations. We apply the method to predict the effective properties of a representative piezoelectric composite consisting of polyvinylidene fluoride (PVDF) and SiC reinforcements.

Selected Aspects of Electrodischarge Milling of Aluminum Alloy-Based Metal Matrix Composite with SiC Reinforcement

In the paper an experimental investigation of the electrodischarge machining of Al-SiC composite material was presented. This material belongs to a group of metal matrix composites (MMCs). Due to enhanced mechanical properties and relative lightweight MMCs are currently implemented in advanced branches of industry such as aerospace, nuclear and automotive and its area of application will significantly increase in the nearest future. However, machining of MMCs remains a challenging task. Because of structural heterogeneity they are difficult-to-machine. It’s machining by conventional and also by non-conventional way is not effective. The paper reports an experimental investigation on electrodischarge milling (3D-EDM) of Al-SiC composite. During the research, the following three input factors were taken into account: working voltage, current amplitude and pulse duration. The experimental part consists of fifteen tests carried out according to the three-level experimental plan. As output factors machining speed and accuracy, tool wear and surface roughness were selected. Also, based on SEM photographs, a qualitative discussion on machined surface integrity was presented. The obtained results prove, that EDM can be effectively applied to machine aluminium alloy-based metal matrix composites with SiC reinforcement.

Multifactor optimization for development of hybrid aluminium matrix composites

The present study aims to multi factor optimization for preparation of aluminum matrix composites (AMC) by reinforcement of SiC/ Al2O3/ Al2O3+ SiC particles having dual particle size (DPS) and triplicate particle size (TPS) based upon signal to noise (S/N) ratio analysis. In this work the amalgamation of fused deposition modelling (FDM) and vacuum moulding (V-process) assisted stir casting (SC) has been employed for the development of AMC. The process parameters under investigation are: particle size (DPS/ TPS); reinforcement type (Al2O3/ SiC/ Al2O3+ SiC); vacuum pressure (VP) (300-400 mm of Hg); moulding sand grit size (American foundry society (AFS) No. 50-70); vibration time (VT) (4-6 sec) and reinforcement proportion/composition (5/7.5/10 by wt.%). The S/N ratio based upon the wear performance (pin-on disc tester), micro hardness (HV) and dimensional accuracy/deviation (Δt) has been evaluated by using Minitab-17 software which further acts as input for multifactor optimization. The best parametric setting proposed for multi objective/factor optimization is: DPS of Al2O3+ SiC reinforcement at 350 mm of Hg VP with 50 AFS No. sand grain size, 4sec VT and 10% composition/proportion. The results of analysis of variance (ANOVA) highlight that particle size (with 18.49% contribution) and reinforcement type (with 42.13% contribution) have significant influence on multi factor optimization for the development of AMC. Confirmatory experiments have been performed which shows that the proposed amalgamation of FDM and V-process assisted SC can be successfully applied for enhancing the performance of AMC. Finally the X-chart and R-chart have been plotted at the proposed settings, which highlights that amalgamation process is controlled and useful for mass/ batch production.

Fabrication and characterization of stir cast Al2024/SiCp metal matrix composite

The arising issues concerning to requirement of high strength, light weight and energy conservation among automobile, aircraft and marine applications has significantly increased the demand for advanced materials having enhanced capabilities to sustain and perform efficiently at elevated temperature. Aluminum alloys have been selected as ultimate choice for the fabrication of structural components for aircraft and marine ships. These alloys are being reinforced with different kind of reinforcements to yield desired properties like high fatigue strength, heat and wear resistance combined with improved mechanical properties. The ongoing developments among these materials have allowed the product designer to select variety of materials to minimize cost, increase effectiveness with optimal utilization of resources. The aim of this study is to fabricate Al2024/SiCp metal matrix composite through stir casting route with variation in proportion of SiC reinforcement. The objective of study is to investigate the effect of variation in proportion of SiC in matrix on the mechanical properties of processed composite. SiC reinforcement of 400 Mesh has been used to produce the samples with 2, 4, 6, and 8 wt% using stir casting technique. After the fabrication of composite tests were conducted to assess the mechanical properties such as impact strength, hardness, and tensile strength. It has been observed that overall tensile strength decreases with increase in proportion of SiC whereas overall hardness and impact strength increases with increase in proportion of SiC.

Simulation and experiments of abrasive assisted electrochemical jet machining of SiC reinforced aluminum matrix composites

Silicon carbide reinforced aluminum matrix composites (SiCp/Al) exhibit excellent properties and performance in fields of aerospace, electronic packaging, precision instrumentation and automotive industry. The SiCp/Al composites are hard-to-machine materials due to different physical properties between reinforcement material and matrix material. This study investigated the removal mechanism of the reinforcement in abrasive assisted electrochemical jet machining (AECJM) of SiCp/Al composites through simulation and experiments. The results show that the lifetime of the bonding interface between SiC and matrix significantly decreases with lowering of the bonding area. For a given bonding area, the lifetime of that is proportional to the SiC size. Therefore, the material removal rate is markedly influenced by the SiC particle size. The SiC reinforcement can be extracted out when the bonding area drops off to a low level. This results in many micro pits left at the machined surface. The roughness of the surface is highly related to the number and size of these micro pits. Larger size of or higher volume fraction of the reinforcement will result in rougher machined surfaces.

Multi-Response Optimization of Mechanical Properties of Al reinforced by Al2O3 and/or SiC using Grey Relational Analysis

Metal matrix composites (MMCs) combine attractive characteristics of ceramics and metals. Al-hybrid composites are a recent generation of MMCs and have the potential to satisfy new demands in advanced engineering applications. In this work, Al-MMC has been fabricated by mixing various percentages of Al2O3 and/or SiC reinforcement into the Al alloy, using stir casting. The mechanical properties (hardness, yield strength, tensile strength, elongation and flexural strength) have been measured for the fabricated MMCs. Grey relational analysis (GRA), based on the Taguchi method, is applied using three factors Al2O3, SiC and Al2O3 + SiC with three levels. Results show that the all reinforcement materials have a significant influence on the response. Results also show that the Taguchi-based grey relational approach improved the properties of output response of hybrid MMC.

Mechanical behavior of AA2024/SiC AMCs

In the present research work aluminium matrix composites were manufactured by taking SiC as reinforcement; while Al2024 alloy was taken as metal matrix. Weight percentages of SiC particles were varied as 0, 2, 4, 6 and 8 wt%. Particle size of SiC reinforcement in the range of 30–50 μm was used to develop composite materials for investigation. Aluminium matrix Composites (AMCs) were manufactured by liquid casting technique. The hardness and tensile strength of material was improved from 51 VHN to 74 VHN and from 163 MPa to 186 MPa respectively; with increase in the SiC contents from 0% to 8 wt%. A decrease in ductility from 8.6 to 5.1 was observed with the increase in SiC contents from 0% to 8 wt%.

Effect of Addition of Graphite on Tribological Behaviour of Sic and Fly Ash Reinforced Copper Based Self-Lubricating Composites

In the present study 4 different combinations of composites are prepared with varying proportions of graphite content by keeping the same proportion of copper, SiC and Fly ash through powder metallurgy process. hardness, Microstructure and tribological properties are studied with varying sliding velocities(1, 2 & 3m/s) and loading conditions (10, 30 and 50N). The addition of graphite reduces the hardness, but the wear behaviour is enhanced with its addition.

Effect of Sintering Temperature on Microstructure and Hardness of SiC and Fly Ash Reinforced Copper Matrix Composite

Copper based composites with SiC and Fly ash as reinforcement is prepared by powder metallurgy process. During processing of composites the compaction pressure is maintained as 400MPa for all combination of materials. The prepared green compacts were sintered on both 700℃ and 900℃ and the results microstructure and hardness obtained through Brinell harness test were compared.

Influence of SiC and TiC nanoparticles reinforcement on the microstructure, tribological, and scratch resistance behavior of electroless Ni–P coatings

Two different ceramic carbide nanoparticles (SiC, and TiC) were separately incorporated into the Ni–P matrix via the electroless deposition method. As prepared Ni–P, Ni–P–SiC, and Ni–P–TiC coatings were subjected to heat treatment at 400 °C for 1 h. The surface morphology, microstructural transformation, Vicker’s microhardness, tribological and scratch resistance properties were studied with reference to the different carbide reinforcements as well as heat treatment. Inter-nodular space, craters and kinks are created due to the branching effect of nodules in the surface of the Ni–P–SiC (TiC) composite coatings. After the heat treatment, the matrix phase transformation was not altered due to the incorporation of SiC or TiC into the Ni–P coating; however, a slight increase in residual stress was identified from the XRD analysis. In addition, the content of carbon deposition was found to be higher in the matrix of Ni–P–SiC composite coating than that in the Ni–P–TiC coating. The agglomeration of SiC particles was higher than TiC particles in the coating matrix, which was also supported by the result of Zeta potential measurement. Heat treatment improved wear and coefficient of friction in the Ni–P–SiC and Ni–P–TiC composite coatings. Compared to Ni–P–SiC coating, Ni–P–TiC coating revealed the enhanced tribological and scratch resistance performance after the heat treatment.

Study of Tribological Behaviour of AA6351/SiC/Gr Hybrid Metal Matrix Composite using Taguchi Technique

Using stir-casting, the hybrid aluminium metal matrix composites are prepared with the reinforcement of SiC and graphite particulates by varying equally 2%, 4%, 6%, and 8% by weight. The wear and frictional force for the prepared specimens were investigated through pin on disc wear testing machine. Exercising ANOVA technique, the wear rate and coefficient of friction was accomplished with the impact of applied load, sliding speed and sliding distance. Using Taguchi technique, experiments have been performed depending on the design of experiments. For analysis of data L9 Orthogonal array was preferred. Wear resistance and frictional force were influenced majorly with the reinforcement of graphite. The morphology of the depleted surfaces and the wear fragments were analysed to recognize the wear property. Distinguished to other percentages of reinforcements, 6% wt. of SiC and 6% wt. of graphite has demonstrated high wear resistance.

Investigation of wear behavior of aged and non-aged SiC-reinforced AlSi7Mg2 metal matrix composites in dry sliding conditions

Metal matrix composites (MMCs) with their splendid mechanical properties have been specifically designed for use in fields such as aerospace and aviation. The presence of hard ceramic particles in MMC increases the hardness of the matrix product and decreases its coefficient of friction. Therefore, the wear resistance is improved. Moreover, the mechanical properties of these composite materials can be improved by applying heat treatments. In this study, AlSi7Mg2 MMCs with 15 wt% SiC reinforcement were produced by squeeze casting technique. Some of the composites were aged by heat treatment. Hardness values of aged and non-aged composites were compared. In addition, abrasive wear behaviors of these composites were investigated on pin-on-disk device, depending on the load (7, 12 and 17 N), the sliding speed (0.2, 0.3 and 0.4 m/s) and the sliding distance (700, 1000 and 1300 m). Worn surfaces were also analyzed by scanning electron microscopy (SEM). As a result of the analyses, it was determined that both the hardness values and the wear resistance were higher in the composites subjected to aging treatment. Furthermore, it was observed that the increase in the applied load led up to the weight loss. The increase in the sliding distance increased both friction coefficient and weight loss. The increase in sliding speed also made way for the friction coefficient but ensured less weight loss. When SEM images were examined, it was ascertained that deformation and tribo-surface formation had a significant effect on weight losses.