Alloy Based Metal Matrix Composites Research Articles

INVESTIGATION AND OPTIMIZATION OF TRIBO-MECHANICAL BEHAVIOR OF SQUEEZE CASTED AL-SI PISTON ALLOY-BASED METAL MATRIX COMPOSITE USING RESPONSE SURFACE METHODOLOGY AND NEURAL NETWORK

The piston in the automobile engine must withstand high stress and temperatures and also have low weight. The alloy of Al-Si is the most commonly used in the piston. The reinforcement using ceramics, fibres or nanoparticles will increase the properties of the piston alloy. In this work, the piston alloy is fabricated as a metal matrix composite of Al-Si reinforced by TiC-MoS2 using the squeeze casting method. The squeeze casting effect on the matrix and the reinforcement is studied using tensile testing and microstructure analysis. The strength hardness obtained from the experimentation gives the highest tensile strength of 330 MPa and the hardness of 110HBN. The fractography and morphology are investigated using SEM (scanning electron microscope), resulting in the lowest porosity of 3.21% obtained in the composite material. The tribological behavior was also investigated at the condition of dry Sliding using pin on disc tribometer gives the lowest coefficient friction of 0.31 and the wear rate of 0.0051 mm3/m. The experiment is numerically designed and optimized using the response surface methodology (RSM). The obtained value is predicted and validated using a hybrid approach of deep belief network-reptile swarm algorithm (DBN-RSA). The regression of the parameters is about 99.97% showing that the model is very accurate to the experimental results. The RMSE of the proposed method implies less error and shows the accuracy level of the parameters. The result shows that the designed model is best fitted for the tribological and mechanical properties investigation of metal matrix composite.

Optimization of piston material with aluminium alloy based metal matrix composites

Piston failure is caused by a combination of mechanical and thermal loads is a frequent occurrence that can be expensive to repair or replace. In this paper, analysis is carried out to evaluate and improve the performance of a piston intended for deployment in a four-stroke SI engine with a single cylinder. To determine the most suitable material for the piston, different materials, alloys and aluminium based metal matrix composite are examined. Piston is designed using CAD software and static structural analysis and thermal transient analysis is done using finite element analysis. Based on the analysis, Al 6061–1.5% B4C- 1.5% SiC metal matrix composite material is found to be the most desirable choice among the five materials considered due to lower value of deformation (31% to 76% less in comparison) and mechanical stresses (0.38% to 0.83% less in comparison).

A TAGUCHI-TOPSIS HYBRID TECHNIQUE TO ENHANCE THE FRETTING WEAR CHARACTERISTICS FOR SiC AND SILICA-ENRICHED BLA-REINFORCED AZ91D Mg ALLOY-BASED MMCs

This investigation intends to come up with a cost-efficient and easily available bamboo leaf ash (BLA) which has high content of Silica, as an effective and complimenting reinforcement for the production of magnesium alloy-based metal matrix composites. By incorporating SiC and BLA reinforcement to AZ91D Mg alloy, the composites were made using the bottom pouring stir casting technique. The ratio between SiC and BLA in the composite, respectively, varied as 0:0, 6:0, 0:6, 4:2, 3:3, 2:4 wt.%. Fretting wear is one of the fundamental modes of wear for any mating parts which have vibration with low amplitude. In this study, an integrated Taguchi-TOPSIS is adapted to make the process variables more optimal for fretting wear of composites. Material composition, load, temperature, time, frequency and stroke length are selected as process parameters. The objective is to minimize the coefficient of friction, volume loss and surface roughness. Using the TOPSIS approach, the multi-criteria optimization approach was reduced to a single-criteria issue. The results revealed AZ91D/2 wt.% SiC/4 wt.% BLA, 10N, room temperature, 30-min, 30 Hz and 0.7 mm stroke as optimal parameters. Microscopic study demonstrates that fretting wear occurs in the partial slip zone for the composite tested at optimal condition. With temperature, the wear regime in composites shifts from partial slip to mixed fretting, whereas in alloys, the wear regime shifts from mixed fretting to gross slip. When the correct set of circumstances are available, hybrid composite can function well as a replacement for traditional materials in machineries vulnerable to fretting wear.

Development and evaluation of mechanical properties of aluminium alloys and boron fiber composite material by powder metallurgy route

In recent year, aluminum alloy based metal matrix composites (MMC) are gaining in the field of aerospace and automotive industries, in order to improve by the advancement of modern technology, led to a rapid development of metal matrix composites. Properties can be tailored in the metal matrix composite as per the requirement for specific applications. In these composites the prime function of the fibers is that of supporting most of the applied load, while the role of the matrix is to bind the fibers together and to transmit and distribute the external loads to the individual filaments. Aluminum has been used matrix material owing of its excellent mechanical properties coupled with good formability. Addition of boron fiber as reinforcement inaluminum systemsimprovesthe mechanical propertiesof composites. In the present investigation Al-boron fiber composite was prepared by powder metallurgy route. Powder metallurgy homogeneously distributes the reinforcement in the matrix with no internal reaction and with less porosity. Boron fiber particles containing different weight fractions (5, 10 and 15 %) and mesh size (50 μm and 125 μm) are used as reinforcement. Though Al-boron fiber possess superior mechanical properties, the high abrasiveness of the boron fiber particles obstaclewiderapplication. The Mechanical Properties of Aluminum Alloy (AL2024) were assessed and the compression test was directedatthe material under tempered condition. Al-boron fiber composite has the widest application in the aerospace industry due to high hardness and light weight material. After the development of material that specimens were tested the under the optical, physical and mechanical properties.

Effect of hybrid reinforcement and number of passes on microstructure, mechanical and corrosion behavior of WE43 Mg alloy based metal matrix composite

In this work, a hybrid metal matrix composite with WE43 magnesium alloy as matrix and a hybrid mixture of NiTi, iron, and tin as reinforcement was fabricated using friction stir processing (FSP). The effect of the number of FSP passes on the grain morphology, distribution of reinforced particles, and mechanical properties were evaluated. Scanning electron microscope with energy dispersive spectroscopy was used to study the distribution of reinforced particles, a more uniform distribution was found in the double pass friction stir processed (DP-FSPed) specimen. The grain size was marginally smaller in the DP-FSPed sample compared to the single pass friction stir processed (SP-FSPed) sample. The processed samples showed an increment in hardness values, however, the distribution of hardness values was found uniform in the case of the DP-FSPed specimen, due to better mixing and homogenous distribution of reinforcement particles. The ductility of the DP-FSPed specimen increased by 126 % as compared to the SP-FSPed specimen. The corrosion rate was evaluated using the potentiodynamic polarization test and was found to be higher in the case of the DP-FSPed specimen.

Effect of SiC and WC Reinforcements on Microstructural and Mechanical Characteristics of Copper Alloy-Based Metal Matrix Composites Using Stir Casting Route

This study focuses on a comparative analysis of mechanical behavior and microstructural characteristics of Cu matrix (C87600) based hybrid composites reinforced with SiC-Grp and WC-Grp fabricated by the stir casting process. The graphite particle percentage was kept constant, whereas the content of SiC and WC in the respective composites was varied to analyze the mechanical properties of the fabricated composites. The morphological observation was carried out by field emission scanning electron microscope (FESEM), which revealed uniform dispersion of the reinforced particles in the hybrid composites. Clear phases of SiC and WC along with the Cu alloy were identified by the x-ray diffractometer (XRD). Further, a comparative study was conducted to analyze the mechanical behavior of the Cu-SiC-Gr and Cu-WC-Gr hybrid composites. With the addition of the hard ceramic materials, the tensile behavior and microhardness of both the Cu-based MMCs were improved. The WC-Gr reinforced composites exhibited higher mechanical properties than the SiC-Gr reinforced hybrid composites. Further, the fracture surfaces were also characterized to study the tensile behavior of the fabricated copper-based hybrid composites, which shows that ductile fracture was mainly associated with both hybrid composites.

Investigate of Creep Response in Functionally Graded Material Rotating Disc with variable Thickness

The objective of this paper to investigate analysis of creep in the Functionally Graded Material disc with variable thickness made of aluminum alloy-based metal matrix composite containing silicon carbide particles in presence of thermal gradients in the radial direction. It has been concluded that distributions of the stress and strain rate in an anisotropic disc got affected from the thermal gradients. Thus, the presence of thermal gradients in rotating disc plays a significant role in developing the creep response.

Study on Mechanical, Wear and Thermal Properties of AL2O3/Graphite Reinforced AA2024 Aluminum Alloy Based Metal Matrix Composites

Abstract: Metal matrix composites (MMC) play a vital role to satisfy global needs for low low-cost and high-performance mechanical, and thermal properties and quality materials in the composite industry.Aluminium MMCs are preferred to other conventional materials in the fields of aerospace, automotive and marine applications owing to theirimproved propertieslike high strength-to-weightratio, good wear resistance, etc. In the present work, an attempt has been made to synthesize metalmatrix composite using AA2024 as matrix material reinforced with Al2O3 and Graphite (Gr) particulates using a liquid metallurgy route in particularstir casting technique. 2024 aluminium alloyis reinforced by different weight fractions of Al2O3 and Gr particles up to 5 wt%. The effect of wt% of Al2O3 and Gr on the properties such as density, hardness, tensile strength, wear rate, flexural strength, and coefficient of thermal expansion were evaluated. Scanning electron microscope and X-ray Diffraction (XRD) were used to examine the microstructure of the produced hybrid MMC composite. The addition of Al2O3 and Gr pronounced improved mechanical properties and wear. Results indicated that aluminium ceramic composites can be considered as an alternate material for AA2024, where high strength and wear-resistant components are of major importance,particularly in the aerospace and automotive engineering sectors.

Influence of boron carbide content on dry sliding wear performances of AZ91D magnesium alloy

In this study, AZ91 magnesium alloy based metal matrix composites are made-up of bottom pouring stir casting with 0 wt.%, 1.5 wt.% and 3 wt.% boron carbide (B4C) particles reinforcements. The influence of hard reinforcements on mechanical properties such as hardness and tensile strength has been investigated for the casted composites samples. It was found that by adding 1.5 wt. % and 3 wt.% B4C particles, the Rockwell hardness value of 3.2% and 4.6%, Ultimate Tensile Strength (UTS) values of 15.5% and 26.3% of the composites increased respectively. The influence of B4C contents on AZ91D mg alloy wear study was carried out using pin on disc apparatus. Also, the effect of applied load (5N, 10N, and 20N) on wear properties was investigated. The results of the dry sliding wear tests show that AZ91D- B4C magnesium composite has less wear loss than the unreinforced AZ91D magnesium alloy. X-ray diffraction (XRD) analysis were performed for finding the various compounds such as MgO, B4C and Mg17Al12 present in the developed composites. Further, scanning electron microscopy (SEM) analysis were performed on the worn-out pin surfaces to investigate the wear pattern. These findings indicate that the addition of B4C content improved mechanical characteristics and wear resistance, which may also be used in the automotive and aerospace industries.

Effect of Friction stir processing parameters on microstructure and microhardness of aluminium based Metal matrix composites

The present article demonstrates the Friction Stir Processing (FSP) of the stir cast Aluminium Alloy based Metal Matrix Composites (MMC). Generally, composites manufactured using the stir casting process tends to have several casting defects along with some agglomeration of reinforcement particles. These defects in stir cast composites can be resolved by implementing FSP. MMC was manufactured using the matrix of aluminium alloy 2014, which was reinforced with different weight percent of Silicon Carbide (SiC) particles (5%, 10% and 15%). FSP was performed by considering two different combinations of rotational speed and transverse speed i.e. (i) 270 rpm and 78 mm/min (First Combination) and (ii) 190 rpm and 50 mm/min (Second Combination). The article discusses the variation in microstructure and microhardness of all the friction stir processed composites and the effects of process parameters were examined. Lastly, the conclusion of the article suggests the best combination of processes parameters for performing FSP of manufactured composites.

WEAR CHARACTERIZATION OF LM29 ALLOY WITH40 MICRON SIZED B4C REINFORCED METAL COMPOSITES

This paper deals with the fabrication and evaluation of wear properties by introducing40 micron size B4C particulates into LM29 alloy matrix. LM29 alloy based metal matrix composites were prepared by stir casting method. 3, 6 and 9 wt. % of 40 micron sized B4C particulates were added to the base matrix. For each composite, the reinforcement particles were pre-heated to a temperature of 600 degree Celsius and then dispersed in steps of two into the vortex of molten LM29 alloy to improve wettability. The Micostructural study was done by using Scanning Electron Microscope (SEM), which revealed the uniform distribution of B4C particles in matrix alloy, EDS analysis confirmed the presence of B4C particles in the LM29 alloy matrix.A pin-on-disc wear testing machine was used to evaluate the wear loss of prepared specimens, in which a hardened EN32 steel disc was used as the counter face. The results revealed that the wear loss was increased with increase in normal load and sliding speed for all the specimens. The results also indicated that the wear loss of the LM29-B4C composites were lesser than that of the LM29 matrix. The worn surfaces and wear debris were characterized by SEM microanalysis.

Role of Reinforcement Particle Size and Its Dispersion on Room Temperature Dry Sliding Wear of AA7075/TiB2 Composites

Aluminum alloy based metal matrix composites (AMCs) are widely accepted material in the aerospace, automotive, military, and defence applications due to lightweight and high strength. For tribological applications, high-performance wear-resistant materials like AMCs are the candidate materials. In this investigation, AA7075 based composites with different size TiB2 particles were fabricated using in-situ and ultrasound casting techniques (UST). The AMCs were tested using pin-on-disc tribo tester and the effects of different sized TiB2 particles on wear resistance of AA7075/TiB2 composites have been investigated. The wear resistance of AA7075/TiB2 composite fabricated using UST is found to significantly improve when compared to base alloy and also in-situ composite due to refinement in the particle size, reduced the agglomeration, and improved the distribution of TiB2 particles. The test results also revealed the existence of a mixture of mechanically mixed Al–Zn–Fe intermetallic alloy and oxides of these elements.

Microstructure, mechanical and wear resistance properties of low-pressure cold-sprayed Al-7\xa0Mg/Al2O3 and Al-10\xa0Mg/Al2O3 composite coatings

Aluminium alloy-based metal matrix composites have successfully provided effective wear resistance and repair solutions in the automotive and aerospace sectors; however, the design and manufacture of these alloys are still under development. In this study, the microstructure, mechanical properties and wear resistance of low-pressure cold-sprayed Al-7 Mg/Al2O3 and Al-10 Mg/Al2O3 composite coatings were investigated. The specific wear rates of the coatings were measured when testing them against alumina (Al2O3) counterbody, and the results showed that the cold-sprayed Al-10 Mg/Al2O3 composite coating showed less wear due to its superior hardness, lower porosity and shorter mean free path compared to the Al-7 Mg/Al2O3 composite coating. The microstructural analysis of the worn surfaces of the composite coatings revealed abrasive wear as the primary wear mechanism, and more damages were observed on Al-7 Mg/Al2O3 composite coatings. Most notably, Al2O3 particles were pulled out from the coating and were entrapped between the Al2O3 counterbody and the coating contact surfaces, resulting in a three-body abrasion mode.

A study on microstructure and mechanical properties of in-situ processed Aluminum alloy composites

The combined influence of aluminum–silicon (Al-Si) alloys along with an in-situ titanium boride (TiB2) particulate reinforcement is beneficial for obtaining improved mechanical properties and physical properties. In this paper is presented and discussed the results of a recent study on an Al-Si alloy based metal matrix composites containing different volume fraction of in-situ developed TiB2 particulate reinforcements that were successfully synthesized using a combination of inorganic salts at a temperature of 800 °C. Noticeable enhanced mechanical properties, to include hardness and tensile properties, were successfully achieved in comparison with the unreinforced alloy. Microstructural characterization of the as-synthesized composites was conducted using a field emission scanning electron microscope (FESEM) and x-ray diffraction analysis (XRD). Careful observation of the microstructure revealed an observable change in grain size of the aluminum–silicon matrix due to the presence and distribution of the reinforcing TiB2 particulates through the aluminum–silicon alloy. The reinforcing TiB2 particles were either hexagonal in shape or spherical in shape. The use of intermittent stirring during synthesis did exert an influence on overall distribution of the reinforcing particles through the microstructure of the composite material.

Reinforcements, production techniques and property analysis of AA7075 matrix composites − a critical review

Aluminium alloy based metal matrix composites are being extensively used in the aerospace, automobile, defense, marine and electronic industries owing to their excellent strength, high resistance to wear, corrosion and better thermal stability. Many investigators have explored different aluminium alloy series composites, like heat treatable AA2024, AA6061 and AA7075 since the properties of these matrix alloys can be easily tailor made to suite specific application due to easy processability and heat treatability. AA7075 alloy matrix is predominantly being used, as it exhibits high ultimate tensile strength, resistance to corrosion and fatigue in the group. In the current review work, attention is focused to present types of reinforcing materials used, benefits of reinforcement hybridization, methods employed for composite production and critical property analysis, with conclusions of experimentation and the suggested prospective applications of AA7075 composites. Due to good castability and moldability variety of processing techniques in solid, semisolid and liquid states are possible. As matrix alloy, low processing temperature, ability to accommodate reinforcements and adoptability to different reinforcing techniques, it is easy to obtain optimal properties as per the application. AA7075 with small addition of copper is paved the path in the field of electronic and military applications due to high thermal and electrical conductance. Even pure metal addition & magnesium with copper facilitate good weldability, plasticity and corrosion resistance. Due to the flexibility in accommodating carbide and oxide compound reinforcements in the matrix, this matrix composite widens versatility limit due to excellent hardness and wear resistance. CNT and graphite reinforcements to this aluminium series matrix are marked as ultra-high precision components in defense field.

Silver alloy-based metal matrix composites: a potential material for reliable transparent thin film heaters

A Zn–SnOx/optimized Ag-0.07 at%-0.67 at%Cr/Zn–SnOxmultilayer thin film with reliable and reversible heating performance as a flexible transparent thin film heater was fabricated.

Investigate the Effectiveness of Tribological and Mechanical Properties of Rice husk ash reinforced LM6 Aluminium alloy-based Metal Matrix composites

Investigate the Effectiveness of Tribological and Mechanical Properties of Rice husk ash reinforced LM6 Aluminium alloy-based Metal Matrix composites

Comparative study on the mechanical, tribological, morphological and structural properties of vortex casting processed, Al–SiC–Cr hybrid metal matrix composites for high strength wear-resistant applications: Fabrication and characterizations

The cast aluminum–silicon alloys are used to make various automobile components like pistons, cylinder blocks, piston insert rings, connecting rod, brake disc, etc. but low strength, hardness, and wear resistance restricted their use in several applications. Silicon carbide reinforced aluminum matrix composites exhibit better properties than base metal alloys. As an alloying element, the chromium improves the hardness, strength, and elastic limit of the steel. In this study, the characterization of Al–Si alloy-based metal matrix composites that are reinforced with silicon carbide and chromium is performed with the help of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction analysis (XRD), microhardness test, tensile test, sliding wear test, scratch test, and porosity analysis. The aluminum matrix composites with a varying weight percent of chromium (0–3 wt.% in steps of 1.5) and a fixed percentage of silicon carbide (10%) were formulated through the vortex casting process. The SEM and EDS images illustrate the occurrence and somewhat uniform dispersion of the reinforcement particulates. In hybrid composites, the Cr3C2 compound formation is observed with the least intensity. The reinforcement content contributes significantly to improve the hardness, strength, abrasion resistance, and wear résistance along with a modest reduction in the ductility and gain in friction coefficient. The porosity level obtained in the composites revealed that composites are free from casting defects.

Mechanical behaviour of SiC particulate reinforced Cu alloy based metal matrix composite

In this study, Cu-alloy (RG10) metal matrix composite reinforced with different percentages of SiC (3%, 6%, 9%, and 12%) reinforcement were prepared using in-house developed stir casting set-up. Microstructural and wear character was performed. The microstructural study reveals that there is a uniform distribution of SiC particulates throughout the composite, and very little porosity exists. Vicker's microhardness test was conducted for the fabricated composites. It was found that the hardness increases with an increase in the percentage of SiC particulate reinforcement. The pin-on-disc testing method was used for tribological characterization. With the addition of reinforcement SiC, wear resistance of base alloys is improved enormously, and as the sliding velocity increases, the wear volume increases because of an increase in sliding distance. From density calculation, it was seen that the density of the composite decreases with an increase in addition to SiC particulate reinforcement.

Fabrication of Al Alloy-Based Metal Matrix Composites and Use the Interpolation Approach for Mechanical Properties Estimation

Aluminum alloy-based metal matrix composites (AMMCs) are extensively utilized due to their distinctive mechanical properties. Al-6%Si alloy was reinforced with different contents of alumina (Al2O3) particles (0, 1.5, 3, 4.5, 6, 7.5, 9, 10.5 and 12% wt.) and the MMCs were prepared by stir casting at 800°C. Microstructural characterization of AMMCs was studied using optical microscopy, to emphasize the homogeneous distribution of the reinforcement particles (Al2O3) in the Al alloy matrix. Hardness and wear tests were used to study the influence of Al2O3 addition on the mechanical properties of the prepared composites. The interpolation method is applied as a perfect alternative approach for saving the consumed time during the experimental work. The used mathematical expression can be utilized for an early prediction of the mechanical properties of AMMCs at different contents of Al2O3 particles without carrying out much experimental analysis. The current study shows that the linear interpolator is the optimal one where it achieved Mean square error (MSE) equals 0.1875, and 0.0119 for hardness and wear loss tests, respectively.