Development of AA6061/SiCp Metal Matrix Composites by Conventional Stir Casting and Ultrasonic Assisted Casting Routes – A Comparative Study

2014 ◽  
Vol 984-985 ◽  
pp. 384-389 ◽  
Author(s):  
L. Poovazhagan ◽  
K. Kalaichelvan ◽  
V.R. Balaji ◽  
P. Ganesh ◽  
A. Kali Avudaiappan

The major problem associated with the fabrication of cast metal matrix composites is the agglomeration tendency of the particles in the metal matrix. The agglomeration of the particles in the metal matrix greatly reduces the mechanical properties of the fabricated composite materials. In this work, to reduce the agglomeration tendency of SiC particles in Al matrix, different weight percentages of SiC particles reinforced Al composites were fabricated by the conventional stir casting and the ultrasonic cavitation assisted casting routes. Results indicate that in both the methods, particle distribution was uniform upto certain weight percentage after that agglomeration of particles were observed. The mechanical properties of the as-cast composites were superior to that of the as-cast alloys. Composites fabricated by the ultrasonic cavitation method showed slightly better mechanical properties than the composites fabricated by the conventional stir casting route. From the consolidated results it was also observed that 10 weight % of SiCpreinforced composite fabricated by the ultrasonic cavitation method yields the better mechanical properties when compared to the other composites fabricated in this study. Keywords: Metal Matrix Composites, Stir Casting, Ultrasonic Cavitation, Mechanical Properties, Microstructure, Comparative Study

2015 ◽  
Vol 813-814 ◽  
pp. 230-234 ◽  
Author(s):  
T.S.A. Suryakumari ◽  
S. Ranganathan ◽  
P. Shankar

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Shashi Prakash Dwivedi ◽  
Satpal Sharma ◽  
Raghvendra Kumar Mishra

A356/SiC metal matrix composites with different weight percent of SiC particles were fabricated by two different techniques such as mechanical stir casting and electromagnetic stir casting. The results of macrostructure, microstructure, and XRD study revealed uniform distribution, grain refinement, and low porosity in electromagnetic stir casing samples. The mechanical results showed that the addition of SiC particles led to the improvement in tensile strength, hardness, toughness, and fatigue life. It indicates that type of fabrication process and percentage of reinforcement are the effective factors influencing the mechanical properties. It is observed that when percentage of reinforcement increases in electromagnetic stir casting, best mechanical properties are obtained.


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.


2013 ◽  
Vol 592-593 ◽  
pp. 614-617 ◽  
Author(s):  
Konstantinos Anthymidis ◽  
Kostas David ◽  
Pavlos Agrianidis ◽  
Afroditi Trakali

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.


2012 ◽  
Vol 622-623 ◽  
pp. 1275-1279
Author(s):  
L. Poovazhagan ◽  
K. Kalaichelvan ◽  
D. Shanmugasundaram

The combined use of ultrasonic cavitation and mechanical stirring to disperse the silicon carbide particles (SiCp) in molten aluminum alloys has been studied. Composite materials with various weight percentage of Al 6061 alloy (matrix) and SiCp (reinforcement, average particle size 10 micrometers) were fabricated. The microstructure of the composites was investigated by optical microscopy (OM) and scanning electron microscopy (SEM). The micro structural analysis validates the good dispersion of SiCp in the metal matrix. The tension test results reveal that the tensile strength of the as-cast metal matrix composites (MMCs) have been improved significantly for the 5 and 10 weight percentage of SiCp and then decreases. The hardness of MMCs increases and the ductility decreases as the particle percentage increases. The ultrasonic cavitation based fabrication is a novel route for producing wide range of MMCs.


2015 ◽  
Vol 787 ◽  
pp. 553-557 ◽  
Author(s):  
L. Poovazhagan ◽  
K. Rajkumar ◽  
P. Saravanamuthukumar ◽  
S. Javed Syed Ibrahim ◽  
S. Santhosh

Metal matrix composites (MMCs) play a vital role in today’s engineering industries. Stir casting is one of the most inexpensive methods for the production of particulate reinforced metal matrix composites. However there are few problems encountered in stir casting such as the problem of poor wettability of the reinforcement particles in the matrix metal. The reinforcement particles have the tendency to either settle at the bottom of the crucible or they tend to float at the top of molten metal. This is due to the greater surface tension of the molten metal. Various techniques are available to improve the wettability of the ceramic particles in metal matrix which includes Particle treatment, Particle coating and Addition of alloying agent. In this work, Magnesium (Mg) was used as the alloying element to improve the wettability of SiC particles in the Al matrix. Mg is used to reduce the surface tension of molten aluminum (Al) thus promoting proper wetting. To understand the effect of Mg on improving the wettability of SiC in aluminum matrix, different weight percentages of SiC particles reinforced aluminum alloy 6061(AA6061) based MMCs were fabricated in stir casting method by adding Mg as alloying element. The cast specimens were subjected to microstructural analysis, tension tests and hardness tests. Results showed that addition of Mg with SiC in AA6061 matrix significantly improved the wetting between Al and SiC; subsequently MMCs possessed enhanced mechanical properties.


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