scholarly journals Effect of addition of different reinforcements on the microstructure and mechanical characterization of the Al-Flyash composites

2021 ◽  
Vol 15 (56) ◽  
pp. 217-228
Author(s):  
Milind K. Wasekar ◽  
Mohan P. Khond

The aim of this work is to investigate the influence of the addition of silicon carbide and molybdenum disulfide on the microstructure and the tensile strength of the Al-Flyash hybrid composites prepared using the stir casting technique. The composite with aluminum 6061 alloy as the matrix and flyash as the reinforcement, with different weight fractions, is investigated to study its microstructure and the tensile strength. The same has been compared with the hybrid composites with Aluminum-Flyash/SiC and Aluminum-Flyash/MoS2 for different weight fractions of the reinforcements. The tensile tests were conducted as per ASTM standard testing procedures at room temperature. From the results it is identified that tensile strength of the Al6061-Flyash composite is lesser than the Al6061-Flyash/SiC and Al6061-Flyash/MoS2 hybrid composites. It is also observed that increment in the composition of the SiC and MoS2 causes the increment in the tensile strength of the hybrid composite. This increment in the tensile strength is due to good interface bonding and uniform distribution of the reinforcements in the composite.

2021 ◽  
pp. 002199832110055
Author(s):  
Zeeshan Ahmad ◽  
Sabah Khan

Alumnium alloy LM 25 based composites reinforced with boron carbide at different weight fractions of 4%, 8%, and 12% were fabricated by stir casting technique. The microstructures and morphology of the fabricated composites were studied by scanning electron microscopy and energy dispersive spectroscopy. Elemental mapping of all fabricated composites were done to demonstrate the elements present in the matrix and fabricated composites. The results of microstructural analyses reveal homogenous dispersion of reinforcement particles in the matrix with some little amount of clustering found in composites reinforced with 12% wt. of boron carbide. The mechanical characterization is done for both alloy LM 25 and all fabricated composites based on hardness and tensile strength. The hardness increased from 13.6% to 21.31% and tensile strength 6.4% to 22.8% as reinforcement percentage of boron carbide particles increased from 0% to 12% wt. A fractured surface mapping was also done for all composites.


In this research, an effort is made to familiarize and best potentials of the reinforcing agent in aluminum 7075 matrices with naturally occurring Beryl (Be) and Graphene (Gr) to develop a new hybrid composite material. A stir casting technique was adopted to synthesize the hybrid nanocomposites. GNPS were added in volume fractions of 0.5wt%, 1wt%, 1.5wt%, and 2wt% and with a fixed volume fraction of 6 wt.% of Beryl. As cast hybrid composites were microstructurally characterized with scanning electron microscopy and X-ray diffraction. Microstructure study through scanning electron microscope demonstrated that the homogeneous distribution reinforcement Beryl and GNPs into the Al7075 matrix. Brinell hardness and tensile strength of synthesized materials were investigated. The hybrid Al7075-Beryl-GNPs composites showed better mechanical properties compared with base Al7075 matrix material. The ascast Al7075-6wt.% Beryl-2wt.%GNPs showed 49.41% improvement in hardness and 77.09% enhancement in ultimate tensile strength over Al7075 alloy.


2017 ◽  
Vol 25 (3) ◽  
pp. 209-214 ◽  
Author(s):  
G. Venkatachalam ◽  
A. Kumaravel

This paper presents the characterization of A356 composite reinforced with fly ash and basalt ash produced by stir casting method. Aluminium metal matrix composites (AMC) are used in wide variety of applications such as structural, aerospace, marine, automotive etc. Stir casting is cost effective manufacturing process and it is useful to enhance the attractive properties of AMCs. Three sets of hybrid AMC are prepared by varying the weight fraction of the reinforcements (3% basalt + 7% fly ash, 5% basalt + 5% fly, 7% basalt + 3% fly ash). The effect of reinforcements on the mechanical properties of the hybrid composites such as hardness, tensile, compressive and impact strength were studied. The obtained results reveal that tensile, compressive and impact strength was increased when weight fraction of fly ash increased, whereas the hardness increases when weight fraction of the basalt ash increased. Microscopic study reveals the dispersion of the reinforcements in the matrix.


2020 ◽  
Vol 856 ◽  
pp. 29-35
Author(s):  
Sweety Mahanta ◽  
M. Chandrasekaran ◽  
Sutanu Samanta

Aluminium matrix composites (AMCs) have emerged as the substitute for the monolithic (unreinforced) materials over the past few decades. The applications of AMCs are common in automotive, aerospace, defence and biomedical sectors due to its lower weight, high strength, high resistance against corrosion and high thermal and electrical conductivity. In this work, it is aimed fabricate a new class Al 7075 based hybrid composites reinforcing with nanoparticulates suitable for automotive application. Al7075 reinforced with fixed quantity of boron carbide (B4C) (1.5 wt.%) and varying wt % of flyash (0.5 wt.%, 1.0 wt.%, 1.5 wt.%) is fabricated using ultrasonic-assisted stir casting technique. Physical and mechanical characterization such as density, porosity, micro hardness, tensile strength and impact strength were estimated for three different compositions. The tensile strength and percentage increase in hardness value of the nanocomposite Al7075-B4C (1.5 wt. %)-flyash (0.5 wt. %): HNC3 found maximum as 294 MPa and 32.93%. In comparison with Al7075 alloy the impact strength of HNC3 shows the highest percentage of 9.31% respectively.


2019 ◽  
Vol 817 ◽  
pp. 365-370 ◽  
Author(s):  
Alessandro Bellini ◽  
Marco Bovo ◽  
Andrea Incerti ◽  
Claudio Mazzotti

Structural retrofitting with composite materials proved to be an effective technique for rehabilitation of degraded or damaged masonry and concrete buildings. Nowadays, Fiber Reinforced Cementitious Matrix (FRCM) composites are widely used as externally bonded strengthening systems thanks to their high performance, low weight and easiness of installation. Several experimental tests and numerical studies are currently available concerning the tensile and bond behavior of FRCM systems, but a debated and still open issue concerns the methods for the mechanical characterization of the mortar used as matrix within the strengthening system. The present paper analyses and compares different test methods for determining the matrix tensile strength. Pure tensile and flexural tests have been carried out on different mortar matrix samples. In order to evaluate which is the most suitable value to be considered for a correct interpretation and modeling of the composite system, the experimental results obtained through flexural tests on standard mortar specimens have been compared with the outcomes obtained from direct tensile tests on FRCM coupons. The present study represents only a first step for the definition of the most appropriate test method for the mechanical characterization of the matrix used within FRCM strengthening systems.


2020 ◽  
Vol 44 (5) ◽  
pp. 333-338
Author(s):  
Muthamizh Selvan Bellamballi Munivenkatappan ◽  
Sathish Shanmugam ◽  
Anandakrishnan Veeramani

In-situ aluminium alloy 8011 matrix composites containing different weight percentages of titanium diboride were synthesized by flux assisted synthesis using stir casting technique. The metallurgy of the in-situ AA8011-TiB2 composites was analyzed using X-ray diffractometer, scanning electron microscope and energy dispersive spectroscope to disseminate the formation and distribution of reinforcements. Density, microhardness and tensile strength of cast AA8011 and in-situ AA8011-TiB2 composites were measured and analyzed. The in-situ formed TiB2 reinforcements showed the maximum hardness of 55.03 Hv and the maximum tensile strength of 158.2 MPa for 8 wt. % of TiB2 whereas the percentage elongation of 7.2% is observed at 4 wt. % of TiB2. Further, the fractography analysis performed on the fractured tensile samples and the mechanism of failures were identified and reported.


2014 ◽  
Vol 592-594 ◽  
pp. 705-710 ◽  
Author(s):  
S. Dhanalakshmi ◽  
N Mohanasundararaju ◽  
P.G. Venkatakrishnan

A hybrid Al7075 metal matrix composites have been fabricated through liquid metallurgy route (Stir Casting method) using Al2O3 and B4C as reinforcement materials. The effect of weight percentage of reinforcement materials on mechanical properties of the composites have been studied by varying the weight percentage of Al2O3 as 3, 6, 9, 12 and 15% while keeping constant weight percentage of B4C (3%). The as-cast microstructure, tensile strength, micro and macro hardness of the fabricated hybrid composites have been studied. The mechanical properties of the prepared composites were increased with increasing the weight percentage of the reinforcement in the composite. The maximum tensile strength, micro-hardness and macro-hardness of 309 MPa, 140 VHN, and 112 BHN, respectively, were obtained for a hybrid Al7075 matrix composite containing 15% Al2O3 and 3% B4C.


2015 ◽  
Vol 1101 ◽  
pp. 28-31 ◽  
Author(s):  
G.S. Shiva Shankar ◽  
S. Basavarajappa

An attempt has been made to develop and characterize the Al2219 reinforced with Boron carbide (B4C) and Molybdenum disulfide (MoS2) hybridcomposites. The hybrid composites were prepared by using stir casting technique. Theexperimentalresult evaluates the density,micro hardness test & tensiletest.Themicrostructure shows existence of randomly dispersed reinforcement particles andfine reinforcement particles in prepared hybrid composites.X-Ray powder diffraction (XRD) analysis were conducted this confirms the physical content of constituents present in prepared composites. SEM is used to examine fracture surface of tensile specimens for hybrid composites & this consists of ductile& brittle fracture of mixed mode.The test results revels that, themicro hardness and density is minimum for Al2219 and maximum for Al+3%B4C+5%MoS2. The tensile properties of the material vary according to the percentage of reinforcing material added.


2021 ◽  
Vol 31 (1) ◽  
pp. 51-56
Author(s):  
Ashish Kumar Srivastava ◽  
Ambuj Saxena ◽  
Nagendra Kumar Maurya ◽  
Shashi Prakash Dwivedi

In the current scenario, the development of high strength and low weight material is the demand of the aerospace defence organizations. Magnesium alloy based composite has low density, good mechanical and physical properties. In this study, magnesium alloy AZ31B is used as reinforcement material and graphene nanoparticle is used as reinforcement material. Stir casting technique is used for the development of composite material. Three weight percentages i.e. 0.4%, 0.8% and 1.2% are used for the casting. The microstructural analysis is performed to validate the presence of graphene particles in the developed composite. Further mechanical properties such as tensile strength, hardness and toughness are evaluated. Experimental results confirm that GNPs particles are uniformly distributed into the matrix material. It was observed that due to the reinforcement of GNPs particles tensile strength of the material is improved by 31.17%, hardness is improved about 46.9%. However, the peak value of toughness is observed 12.6 Jule/cm2 in the matrix material, it decreases by increasing the wt% of reinforcement particle and lowest value of toughness of 6.82 Jule/cm2 is observed in AZ31B/1.2%GNP composite.


2018 ◽  
Vol 144 ◽  
pp. 02007 ◽  
Author(s):  
Jamaluddin Hindi ◽  
Kini Achuta ◽  
Murthy Amar

Al7075 alloy is the most commonly used by the aerospace industry. Al7075 alloy is characterized by its improved properties such as higher toughness, specific strength and hardness. The current work focuses on the preparation and characterization of age hardened Al7075-Grey cast iron composites. Two stage stir casting technique is used for the preparation of the composite. Age hardening treatment is imparted to enhance the mechanical characteristics. The variation of hardness and tensile strength with respect to aging temperature and percentage of reinforcement is analyzed. The composites exhibit higher hardness and tensile strength as the reinforcement percentage is increased at an aging temperature of 100°C.


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