Simulation on the Effect of Porosity in the Elastic Modulus of SiC Particle Reinforced Al Matrix Composites (original) (raw)
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Effect of SiC particles on Young's modulus, peak frequency and porosity of 7075 Al alloy composite
International Journal of Materials Engineering Innovation, 2010
Metallic composite materials reinforced with ceramic particles or short fibres, also known as discontinuously reinforced metal matrix composites (MMCs), have been studied over the past few decades. There is a strong potential for these materials to replace existing metallic systems due to their enhanced mechanical properties (especially higher specific stiffness and strength). Performance of automobile and aircraft parts can be improved through either a reduction in absolute weight or an increase in strength to weight ratio. 7075 Al alloy reinforced with 10 vol. % SiC particles of size 20 to 40 µm was prepared by using stir casting process. The values of Young's modulus and peak frequency for 7075 Al alloy and 10% SiC composite were found out by using dynamic elastic property analyser. Porosity of 10% SiC composite was also calculated. Test results indicate that value of Young's modulus and peak frequency for composite increases 24.898% and 7.38% respectively on average. This is due to addition of 10% SiC particles. The porosity of composite is found to be 3.16%.
IOP Conference Series: Materials Science and Engineering, 2018
Aluminum reinforced with silicon carbide composites areextensively used in automobile industries and aerospaceowing to their favourable microstructure and improved mechanical behaviour with respect to pure aluminium but at a lower cost. Aluminium is remarkable for the low density and its ability to resist corrosion. The aim of present study istoevaluate the mechanical and microstructural properties of aluminum with silicon carbide (average particle size 30-45μm) reinforced in varying weight percentages (wt %) ranging from 0-15 wt% in a step of 5% each. Ultimate tensile strength, micro hardness and density of the fabricated composites were investigated as a function of varying SiC wt%. Microstructure analysis was carried out on casted composites using optical microscopy and scanning electron microscopy. From micrographs it is clear that fair distribution of reinforcing particles in the matrix and also observed some clustering and porosity in the cast material. Results revealed that, the addition of SiC reinforcement in the aluminum matrix increases the hardness and ultimate tensile strength gradually from 23 HV to 47 HV and 84 MPa to 130 MPa respectively.
The interface plays a vital role in composites. Strengthening behavior of SiC-particle reinforced aluminium matrix composites relies on load transfer behavior across the interface, whereas toughness is influenced by crack deflection at the boundary between matrix and reinforcement and ductility is affected by relaxation of peak stresses near the interface. In general, metal matrix composites often behave asymmetrically in tension and in compression and have higher ultimate tensile strength, yet lower proportional limits, than monolithic alloys. Such behavior of composites lies with the factors governing matrix plasticity, which can be divided into two areas: those affecting the stress rate of the matrix, and those which alter the flow properties of the matrix through changes in microstructure induced by inclusion of the reinforcement. This work focuses on the characterization of the mechanical response of the interface to stresses arising from an applied load in SiC-particle reinforced aluminium matrix composites. The composites have been studied in the as-received ͑T1͒ and in the T6 and modified T6 ͑HT1͒ conditions. In the nonequilibrium heat treatment processing of the composites, nonequilibrium segregation arises due to imbalances in point defect concentrations set up around interfaces. Mechanical properties, including microhardness and stress-strain behavior, of aluminum matrix composites containing various percentages of SiC particulate reinforcement have been investigated. The elastic modulus, the yield/tensile strengths, and ductility of the composites were controlled primarily by the volume percentage of SiC reinforcement, the temper condition, and the precipitation hardening.
Elastic modulus of Al–Si/SiC metal matrix composites as a function of volume fraction
2009
Aluminum alloy matrix composites have emerged as candidate materials for electronic packaging applications in the field of aerospace semiconductor electronics. Composites prepared by the pressureless infiltration technique with high volume fractions in the range 0.41-0.70 were studied using ultrasonic velocity measurements. For different volume fractions of SiC, the longitudinal velocity and shear velocity were found to be in the range of 7600-9300 m s −1 and 4400-5500 m s −1 , respectively. The elastic moduli of the composites were determined from ultrasonic velocities and were analysed as a function of the volume fraction of the reinforcement. The observed variation is discussed in the context of existing theoretical models for the effective elastic moduli of two-phase systems.
Effect of crack position and loading conditions on SIF in SiC particles reinforced Al composite
Frattura ed Integrità Strutturale, 2019
In this paper the effect of reinforcement crack position and loading conditions (in mode I) on the stress intensity factors of the Al/SiCp metal matrix composite was examined using a finite element method. A simple cubic cell model with square reinforcement shapes was developed to investigate its effect on the mechanical properties of the MMC. The finite element technique was used to calculate the stress intensity factors KI and KII for crack in the matrix and in particle. The particle and matrix materials were modelled in linear elastic conditions. The obtained results show the important role on the stress intensity factors played by the relative elastic properties of the particle and matrix. The results also show that the loading conditions and inter-distance between two particles with two interfacial cracks has an important effect on the KI and KII stress intensity factors.
Matéria (Rio de Janeiro), 2010
The effect of particle size distribution of SiC particulate reinforcements coated with colloidal SiO 2 on Young´s modulus of Al/SiC p /MgAl 2 O 4 composites fabricated by reactive infiltration was investigated. Composites were prepared from porous preforms of silica-coated α-SiC powders of 10, 54, 86, and 146 μm, 0.6 volume fraction of reinforcements and particle size distribution from monomodal to cuatrimodal. Infiltration tests with the alloy Al-13.3Mg-1.8Si (wt. %) were carried out in Ar→N2 atmosphere at 1100ºC for 60 min. The composites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In addition to density and residual porosity measurements, Young´s modulus was evaluated by ultrasonic techniques. Results show that with increase in particles size distribution, residual porosity decreases and density and Young´s modulus of the composites are improved, the latter from 185.39 ±3.6 to 201.93 ±2.3 GPa. This is attributed to the increased metal-ceramic interfaces and to an enhanced matrix-reinforcement load transmission.
Characterization of Aluminium Alloy/ SiC Metal Matrix Composites
The present research involved the conduction of hardness and compression tests of aluminium AA-2618 alloy matrix composite reinforced with white Silicon Carbide particulates. The composites were fabricated using Stir Casting technique of liquid metallurgy and machined to the required ASTM standards. The hardness tests were conducted using a Brinell hardness tester, whereas the compression tests were conducted using a Universal Testing Machine. Appropriate readings were taken during the conduction of the tests in order to be compared with each other as well as the base alloy. The results and conclusions were analyzed and compared to help determine the nature of the trends that arise due to the incremental addition of reinforcement particulates into the matrix material on the hardness and compressive behavior of the composites, in order to determine their potentiality for application in various industrial fields.