scholarly journals Investigating the Hall-Petch Constants for As-Cast and Aged AZ61/CNTs Metal Matrix Composites and Their Role on Superposition Law Exponent

2021 ◽  
Vol 5 (4) ◽  
pp. 103
Author(s):  
Aqeel Abbas ◽  
Song-Jeng Huang
Keyword(s):  
Carbon Nanotubes ◽  
Grain Size ◽  
Metal Matrix ◽  
Stir Casting ◽  
Frictional Stress ◽  
Matrix Composites ◽  
Strengthening Mechanisms ◽  
Casting Method ◽  
Maximum Value ◽  
Cast Composites

AZ61/carbon nanotubes (CNTs) (0, 0.1, 0.5, and 1 wt.%) composites were successfully fabricated by using the stir-casting method. Hall–Petch relationship and superposition of different strengthening mechanisms were analyzed for aged and as-cast AZ61/CNTs composites. Aged composites showed higher frictional stress (108.81 MPa) than that of as-cast (31.56 Mpa) composites when the grain size was fitted directly against the experimentally measured yield strength. In contrast, considering the superposition of all contributing strengthening mechanisms, the Hall–Petch constants contributed by only grain-size strengthening were found (σ0 = 100.06 Mpa and Kf = 0.3048 Mpa m1/2) for as-cast and (σ0 = 87.154 Mpa and Kf = 0.3407 Mpa m1/2) for aged composites when superposition law exponent is unity. The dislocation density for the as-cast composites was maximum (8.3239 × 1013 m−2) in the case of the AZ61/0.5 wt.%CNT composite, and for aged composites, it increased with the increase in CNTs concentration and reached the maximum value (1.0518 × 1014 m−2) in the case of the AZ61/1 wt.%CNT composite.

scholarly journals Properties of AlSi9Cu3 metal matrix micro and nano composites produced via stir casting

2018 ◽  
Vol 16 (1) ◽  
pp. 726-731 ◽  
Author(s):  
Tennur Gülşen Ünal ◽  
Ege Anıl Diler
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix ◽  
Weight Fraction ◽  
Stir Casting ◽  
Mechanical Tests ◽  
Matrix Composites ◽  
Casting Method ◽  
Porosity Formation ◽  
Three Point Bending ◽  
Hardness Values

AbstractThe effects of micro and nano sized reinforcement particles on microstructure and mechanical properties of aluminium alloy-based metal matrix composites were investigated in this study. AlSi9Cu3 alloy was reinforced with micro and nano sized ceramic reinforcement particles at different weight fractions by using a stir casting method. The mechanical tests (hardness, three point bending) were performed to determine the mechanical properties of AlSi9Cu3 alloy-based microcomposites (AMMCs) and nanocomposites (AMMNCs). The experimental results have shown that the size and weight fraction of reinforcement particles have a strong influence on the microstructure and the mechanical properties of AlSi9Cu3 alloy-based microcomposites and nanocomposites. The relative densities of all AMMC and AMMNC samples are lower than unreinforced AlSi9Cu3 alloy due to porosity formation with the increase of weight fraction of reinforcement particles. As weight fraction increases, hardness values of AMMCs and AMMNCs increase. Maximum flexural strength can be obtained at 3.5wt.% for the AMMC sample with microsized Al2O3 particles and at 2wt.% for the AMMNC sample with nano-sized Al2O3 particles. After the weight fractions exceed these values, flexural strengths of both AMMCs and AMMNCs decrease due to clustering of Al2O3 particles.

Production of Al Metal Matrix Composites by the Stir-Casting Method

2013 ◽  
Vol 592-593 ◽  
pp. 614-617 ◽  
Author(s):  
Konstantinos Anthymidis ◽  
Kostas David ◽  
Pavlos Agrianidis ◽  
Afroditi Trakali
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix Composites ◽  
Automobile Industry ◽  
Metal Matrix ◽  
Aluminum Matrix ◽  
Stir Casting ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Casting Method ◽  
Alloy Matrix

It is well known that the addition of ceramic phases in an alloy e.g. aluminum, in form of fibers or particles influences its mechanical properties. This leads to a new generation of materials, which are called metal matrix composites (MMCs). They have found a lot of application during the last twenty-five years due to their low density, high strength and toughness, good fatigue and wear resistance. Aluminum matrix composites reinforced by ceramic particles are well known for their good thermophysical and mechanical properties. As a result, during the last years, there has been a considerable interest in using aluminum metal matrix composites in the automobile industry. Automobile industry use aluminum alloy matrix composites reinforced with SiC or Al2O3 particles for the production of pistons, brake rotors, calipers and liners. However, no reference could be cited in the international literature concerning aluminum reinforced with TiB particles and Fe and Cr, although these composites are very promising for improving the mechanical properties of this metal without significantly alter its corrosion behavior. Several processing techniques have been developed for the production of reinforced aluminum alloys. This paper is concerned with the study of TiB, Fe and Cr reinforced aluminum produced by the stir-casting method.

Experimental Investigation of Alumina Reinforced Copper Metal Matrix Composite by Stir Casting Method

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Palanivendhan ◽  
J. Chandradass ◽  
Ajith Rajendran ◽  
Nishanth M. Govindarajan ◽  
M. Adwait Krishnaa
Keyword(s):  
Thermal Conductivity ◽  
Metal Matrix ◽  
Weight Ratio ◽  
Copper Matrix ◽  
Stir Casting ◽  
Mechanical Tests ◽  
Matrix Composites ◽  
Copper Metal ◽  
Casting Method ◽  
Combined Loads

In the present study, alumina reinforced copper metal matrix composites were prepared by stir casting method. Three different specimens were prepared by changing the weight ratio of alumina to copper. The samples were prepared by adding 10%, 20% and 30% alumina to copper matrix. The three specimens were subjected to mechanical, thermal and corrosion testing, in order to find out the properties of the material. Various mechanical tests like hardness, impact and corrosion were performed including thermal conductivity to understand the behaviour of the specimens under combined loads. Specimen number 2 which was 80%-20% copper to alumina was found to be the best combination for such type of applications.

scholarly journals Effect of Holding Time on Density and Morphological Property of Aluminium Composite Using Recycled Materials by Stir Casting Method

2018 ◽  
Vol 7 (4.30) ◽  
pp. 429
Author(s):  
Awwal Hussain Nuhu ◽  
Suzi Salwah Binti Jikan ◽  
Saliza Binti Asman ◽  
Nur Azam Bin Badarulzaman ◽  
Dagaci Muhammad Zago
Keyword(s):  
Metal Matrix ◽  
Stir Casting ◽  
Optical Microscope ◽  
Holding Time ◽  
Matrix Composites ◽  
Aluminium Composite ◽  
Casting Method ◽  
Recycled Materials ◽  
Significant Difference ◽  
Aluminium Metal

Aluminium metal matrix composites were fabricated from recycled materials via stir casting method. The composites differed in their holding time (ht) that is 30 minutes, 45 minutes and 60 minutes accordingly. The microstructures of the composites were analysed using optical microscope as well as scanning electron microscope in order to examine their morphological make-up. The average densities of the composites were determined and compared with one another. There is no significant difference between average densities of the fabricated composites. The observations revealed that varying the ht has greater impact the composites’ morphology, particularly on those composites which have been fabricated at 60 minutes ht.

scholarly journals Structural Characterization and Dielectric Properties of the Effect of Carbon Nanotubes and Silicon on AA2024 Metal Matrix Composites

2021 ◽  
Author(s):  
Muniyappan Mani ◽  
Iyandurai Natesan
Keyword(s):  
Carbon Nanotubes ◽  
Dielectric Properties ◽  
Metal Matrix Composites ◽  
Structural Characterization ◽  
Metal Matrix ◽  
Research Work ◽  
Dissipation Factor ◽  
Stir Casting ◽  
Matrix Composites ◽  
Aa 2024

Abstract This research work focus on the formation of AA2024-carbon nanotubes-silicon hybrid metal matrixcomposites. Structure morphology, structural characterization, elemental identification and dielectric properties of AA 2024 in the presence of carbon nanotubes, silicon andits combinations at various proportions was evaluated using SEM, XRD, EDX and Hioki 3532-50 LCR Hi-Tester. A two-stage stir casting method was used for the fabrication of AA2024 hybrid metal matrix composites. It was observed that the size of the AA 2024 + 4% CNT + 2% Si composite wasfound to be 23.6 nm, this shows enhanced results than other composites prepared. Dielectric properties of composites were characterized as a function of composition and frequency. It was found that the dielectric constant, dielectric loss and dissipation factor decreases smoothly with an increase of reinforcements and also frequency.

scholarly journals Microstructure and Mechanical Testing of Al 6061-Si3n4 Metal Matrix Composites

2019 ◽  
Vol 8 (9) ◽  
pp. 3404-3407 ◽  
Keyword(s):  
Mechanical Testing ◽  
Metal Matrix ◽  
Charpy Impact ◽  
Stir Casting ◽  
Matrix Composites ◽  
Casting Method ◽  
Powder Composition ◽  
Wide Range ◽  
Aerospace Medical ◽  
Corrosive Resistance

In these days exceptional properties are needed for wide range of applications like aerospace, medical, and automobile to improve strength, corrosive resistance and weight reduction. For these purposes composites have been developed. Metal matrix composite (MMC) is one of them, and aluminium composites have been using in various fields because of its less weight, thermal and electrical conduction and corrosive resistance. Here we are introducing silicon nitride (Si3N4 ) as reinforcement which is a ceramic in aluminium 6061 which is effectively used in many applications these days. Our composite has been made using Stir casting method for proper dispersion. Mechanical testing methods like Brinell’s, Charpy impact tests are carried out to identify properties of composite and microstructure is also been figured out through SEM. Properties of both 5% and 15% Si3N4 powder composition of MMC are compared with each other and discussions are made.

Study on Mechanical Properties of Al 7075 Hybrid Metal Matrix Composites

2015 ◽  
Vol 813-814 ◽  
pp. 230-234 ◽  
Author(s):  
T.S.A. Suryakumari ◽  
S. Ranganathan ◽  
P. Shankar
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Stir Casting ◽  
Impact Loads ◽  
Matrix Composites ◽  
Casting Method ◽  
Weight Percentage ◽  
Hybrid Metal Matrix Composites ◽  
Al 7075

The present investigation involves studying the mechanical properties of the fabricated aluminium 7075 hybrid metal matrix composites reinforced with various weight % of SiC and Al2 O3 particulates by stir casting method. The Al 7075 hybrid metal matrix composites specimen were fabricated using L9 orthogonal array. The mechanical properties like Brinell Harness (BHN), Rockwell Hardness (HRC) and impact loads were experimented. The mechanical properties like hardness and impact loads have improved with the increase in weight percentage of SiC and Al2O3 particulates in the hybrid aluminium matrix.

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