Fabrication and analysis of AA6082/Si3N4 and AA6082/SiC composites

2019 ◽  
Vol 11 (2) ◽  
pp. 277-285
Author(s):  
Rajesh Kumar Bhushan ◽  
Deepak Sharma

Purpose Sound microstructure components are necessary for reliability and safety; hence, these components are used in aircraft, satellite, automobiles and ships, where many commercial alloys are not suitable. The paper aims to discuss this issue. Design/methodology/approach AA6082/Si3N4 and AA6082/SiC composites were fabricated using the stir-casting process considering 5, 10 and 15 vol.% of reinforcement particles. Density and porosity of AA6082/Si3N4 and AA6082/SiC composites were calculated. Characterization was done using an X-ray (EDX) detector, attached to SEM. The effect of addition of Si3N4 and SiC particulates in the AA6082 was investigated. Findings Results showed that Si3N4 and SiC particulates had good wettability with AA6082 and were uniformly distributed in AA6082 matrix. No adverse effects of reactions were noticed in the microstructure of AA6082/Si3N4 and AA6082/SiC composites. Research limitations/implications AA6082 with more than 15 vol.% of Si3N4 and AA6082/SiC reinforcement particles do not find industrial application where high hardness and tensile strength are required. Practical implications Components made from AA6082/Si3N4 and AA6082/SiC composites find their application where high hardness with better tensile strength is required. Social implications Naturally and locally available materials are utilized for fabrication. Originality/value Little work is available in the literature on fabrication and characterization of AA6082/Si3N4 and AA6082/SiC composites. The authors have identified the process parameters at which proper fabrication is done and sound microstructure is obtained.

2021 ◽  
Vol 73 (6) ◽  
pp. 980-985
Author(s):  
Kalaiyarasan A ◽  
Sundaram S ◽  
Gunasekaran K ◽  
Bensam Raj J.

Purpose Aerospace field is demanding a material with superior strength and high resistance against wear, tear and corrosion. The current study aimed to develop a new material with high performance to be applicable in aerospace field Design/methodology/approach A metal matrix composite AA8090-WC-ZrC was fabricated using stir casting method and its tribological behavior was investigated. Totally, five composites viz. AA/Z, AA/W, AA/WZ (1:3), AA/WZ (1:1) & AA/WZ (3:1) were prepared. Micro hardness, tensile and wear study were performed on the fabricated composites and the results were compared with AA8090 alloy Findings Vickers hardness test resulted that the AA/W composite showed the higher hardness value of 160 HB compared to other materials due to the reinforcing effect of WC particles with high hardness. Tensile test reported that the AA/W composite displayed the maximum tensile strength of 502 MPa owing to the creation of more dislocation density. Further, wear study showed that the AA/W composite exhibited the least wear rate of 0.0011 mm3/m because of the more resisting force offered by the WC particles. Furthermore, the AA/W composite showed the slightest mass loss of 0.0028 g and lower COF value of 0.31 due to the hinder effect of WC particle to the movement of atoms in AA8090 alloy Originality/value This work is original in the field of aerospace engineering and materials science which deals with the fabrication of AA8090 alloy with the reinforcement particles such as tungsten carbide and zirconium carbide. The impact of the combination of hybrid particles and their volume fractions on the tribological properties has been investigated in this work. This work would provide new scientific information to society.


2021 ◽  
Vol 5 (1) ◽  
pp. 381-391
Author(s):  
H. Odiwo ◽  
K. A. Bello ◽  
M. Abdulwahab ◽  
A. A. Adebisi ◽  
M. A. Maleque

The combination of properties of Al/SiC composites make them very attractive materials for applications in automotive and aerospace industries. Several techniques are used in developing Al/SiC composites but stir casting process is most commonly used because it is the simplest and cost effective technique. However, composites produced via stir casting suffer from limitations such as low wettability and inadequate bonding between the molten Al & SiC particulates and the formation of degrading interfacial products like aluminum carbide (Al4C3) which degrades the mechanical properties of the composite. Some of the techniques to improve Al-SiC wettability include addition of surface active elements such as magnesium, heat treatment of particles and application of metallic coating on the reinforcements before addition to the melt. Wetting agents alter the composition of the matrix alloy, while heat treatment of the reinforcement does not completely prevent the formation of Al4C3 when utilized. To reduce the direct interaction and promote wetting between reinforcements and molten aluminum during processing, the surface of SiC particulates can be modified by coating via oxidation, sol-gel and electroless processes. Of all these methods, electroless nickel deposition produces the best coatings with uniform thickness and adequate strength. In the present study, influence of electroless nickel-coating of SiC on the mechanical, corrosion and microstructural properties of Al/SiC composite has been evaluated. Finally, it can be concluded that the Ni and Ni3P intermetallic phases produced via electroless coating improves the wettability between the SiC and molten aluminium leading to enhanced properties of the composite.


2020 ◽  
Vol 10 (1) ◽  
pp. 1-8
Author(s):  
Mohammed Qasim Kareem ◽  
Ahlam Hamid Jasim ◽  
Nehad Abid-Allah Hamza

AbstractAluminium Covetic metallurgical synthesis along with the characterization of cast material results were presented in this paper. Aluminium- 3% graphite (carbon) composites were fabricated by applying different voltages and amperages of direct current through the stir-casting process. This process, called Covetic based on patent applications of Third Millennium Metals. Obtained casts were tested for their chemical composition, density, tensile strength, hardness, microstructures, and electrical conductivity measurements using an Oxford PMI-Master Pro spark emission spectrometer, a DA-300M density measurement device, a WDW-200 universal tensile test machine, a HBA-3000S automatic Brinell Hardness Tester, a scanning electron microscope with Energy-Dispersive Spectroscopy and an AT512 Precision Ohmmeter, respectively. Moreover, increasing of amperages and/or decreasing of voltages of direct current ensured considerable increasing of electrical conductivity (≈ 34%), the notable decrement in the density (≈ 0.94%), an enhancement in the tensile strength (≈ 18%) and the hardness (≈ 15%) of aluminium Covetic casts compared to the parent metal. In summary, results show that the increasing of amperages and/or decreasing of voltages of direct current has a superior influence on improving electrical conductivity of aluminium-graphite Covetic casts with better mechanical properties.


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.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
M. Poornesh ◽  
Shreeranga Bhat ◽  
E.V. Gijo ◽  
Pavana Kumara Bellairu

PurposeThis article aims to study the tensile properties of a functionally graded composite structure with Al–18wt%Si alloy as the matrix material and silicon carbide (SiC) particles as the reinforcing element. More specifically, the study's primary objective is to optimize the composition of the material elements using a robust statistical approach.Design/methodology/approachIn this research, the composite material is fabricated using a combination of stir casting and the centrifugal casting technique. Moreover, the test specimen required to study the tensile strength are prepared according to the ASTM (American Society for Testing and Materials) standards. Eventually, optimal composition to maximize the tensile property of the material is determined using the mixture design approach.FindingsThe investigation results imply that the addition of the SiC plays a crucial role in increasing the tensile strength of the composite. The optical microstructural images of the composite show the adequate distribution of the reinforcing particles with the matrix. The proposed regression model shows better predictability of tensile strength. In addition, the methodology aids in optimizing the mixture component values to maximize the tensile strength of the produced functionally graded composite structure.Originality/valueLittle work has been reported so far where a hypereutectic Al–Si alloy is considered the matrix material to produce the composite structure. The article attempts to make a composite structure by using a combination of stir casting and centrifugal casting. Furthermore, it employs the mixture design to optimize the composition and predict the model of the study, which is one of a kind in the field of material science.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lokanadham Dharmana ◽  
Venkata Subbaiah Kambagowni

Purpose This study aims to develop the Al-Si-Mg metal matrix composite, reinforced distinctly with lime stone powder (LSP; 12% by weight) and Al2O3 (12% by weight), and compare their mechanical properties and tribological performance. Design/methodology/approach The composites are fabricated through stir casting process. In view of the previous work, the Al-LSP composite with LSP reinforcement (12 Wt.%) shows enhanced mechanical properties and tribological performance, as compared with other weight percentages. Findings Though the Al-LSP composite is less expensive, it shows similar hardness, tensile strength and specific strength, when compared with Al- Al2O3 composite. However, the Al-LSP composite exhibits significant enhancement of above three properties, when compared with Al-Si-Mg metal. The systematic factorial design of experiments is obtained through Taguchi OA [L9]. The tribological performance is estimated through wear rate (WR-mm3/m) and coefficient of friction (CF) by varying the operating parameters of sliding distance (SD), load (L) and sliding velocity (SV). According to ANOVA results, the optimal condition of WR for all the tested materials is L1SD3SV1. Further, the optimal condition of CF is L1SD1SV3 for Al-LSP and Al-Si-Mg metal, while L2SD3SV2 is for Al-Al2O3 composite. The regression equation predicts the measured experimental values within error band of ± 8 percentage. Originality/value A comparison of two composite materials (Al-LSP and Al-Al2O3) with same weight fractions (12%) shows almost same trend in both the mechanical and tribological testing process. However, the developed Al-LSP composite exhibited better properties than the Al-Al2O3 and Al-base. Therefore, Al-LSP can be suggested for automotive applications (i.e., connecting rod, cylinder liners, camshaft) and structural applications (such as frames, over hanging supports), without compromising in desirable original with properties of constituents in the new material, which is achievable for looking to the end uses.


2019 ◽  
Vol 41 (4) ◽  
pp. 650-650
Author(s):  
Ali Dad Chandio Ali Dad Chandio ◽  
Muhammad Basit Ansari Muhammad Basit Ansari ◽  
Shahid Hussain Shahid Hussain ◽  
Muhammad Ali Siddiqui Muhammad Ali Siddiqui

In the present study aluminium silicon carbide (Al/SiC) composites were prepared by powder metallurgical method. The mechanical and morphological evaluation were studied upon the variation of reinforcements percentages i.e.10, 15 and 20 wt.% of SiC powder were used as the reinforcements in aluminium matrix. The comparison of powder metallurgy method with stir casting method of Al/ (SiC) composites preparation was performed and the particle reinforcements were visualized through Scanning Electron Microscopy (SEM). The results demonstrated increased hardness with increasing wt. % of SiC particles. This was attributed to efficient stress transfer and dislocation strengthening. In addition, the densification behaviour of the composites was also studied and SiC particulates were found to exhibit profound effect on composites density.


2019 ◽  
Vol 130 ◽  
pp. 01005
Author(s):  
Cindy Retno Putri ◽  
Anne Zulfia Syahrial ◽  
Salahuddin Yunus ◽  
Budi Wahyu Utomo

The goal of this research is to improve the mechanical properties such as strength, hardness and wear resistance for automotive application such as brake shoe and bearings due to high cycle, load and impact during their usage. Therefore, another alloying element or reinforcement addition is necessary. In this work, the composites are made by ADC 12 (Al-Si aluminum alloy) as the matrix and reinforced with micro SiC through stir casting process and TiB is added various from (0.04, 0.06, 0.15, 0.3 and 0.5) wt.% that act as grain refiners and 5 wt.% of Mg is added to improve the wettability of the composites. The addition of TiB improves the mechanical properties because the grain becomes finer and uniform, and the addition of Mg makes the matrix and reinforce have better adhesion. The results obtained that the optimum composition was found by adding 0.15 wt.% of TiB with tensile strength improve from 98 MPa to 136.3 MPa, hardness from 35 to 53 HRB and wear rate reduced from 0.006 2 mm3 s−1 to 0.002 3 mm3 s−1 respectively.


2018 ◽  
Vol 120 (2) ◽  
pp. 378-391 ◽  
Author(s):  
Naiara Barbosa Carvalho ◽  
Luis Antonio Minim ◽  
Moysés Nascimento ◽  
Gustavo Henrique de Castro Ferreira ◽  
Valéria Paula Rodrigues Minim

Purpose The purpose of this paper is to determine the demographic characteristics and habits of craft beer consumers, as well as to identify the motivational factors for consumption. Design/methodology/approach Data were collected through questionnaires applied to 316 Brazilian craft beer consumers, and results were evaluated descriptively and by multivariate statistics. Findings The results of the survey revealed that there is a growing market segment with different buying habits and behaviors compared to traditional beer consumers. Demographically, it was found that these consumers are an attractive part of the beer market in terms of age, schooling and, more importantly, in terms of income, factors that indicate the probability of continued growth in the sector. Research limitations/implications The research was limited to craft beer consumers in the metropolitan region of Belo Horizonte/MG, Brazil. Practical implications The results obtained are important, as they can help new craft breweries, as well as help established industry managers to create strategies related to marketing four Ps in order to increase the consumption of its products, with competitive advantages to the market. Originality/value This research presents the characteristics of the consumers of craft beer, a market segment in evident rise in Brazil, about which there are few studies. In addition, it provides valuable information to both the new beverage manufacturers as well as to the already established entrepreneurs in the market so that they can increase the consumption of their products in a strategic way.


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