Effect of Hybrid Reinforcements on the Mechanical and Micro structural Properties of AA6061 Nano-Composites

Abstract

Now-a-days we are widely using aluminum based metal matrix composites. To overcome the problems faced in conventional materials, lots of studies are going on replace them with composites/alloys. In these metal matrix composites are heavily used in structural, aerospace, weapons, machinery parts, marine and automobile applications for its light weight, high strength and low production cost. As developments of light weight materials has provided numerous possibilities for weight reduction. In this project we are casting aluminum based (AA6061) composites with magnesium and fly ash as reinforcements, fly ash is one of the inexpensive and low density material and it is easily available as the product during coal combustion and then casted components are machined specimen dimension and different materials testing had been conducted to the obtain material properties, characteristics and micro structures. We are varying mass fraction of fly ash (0%, 5%, 10%, 15%, and 20%) and keeping 4% of magnesium as constant. We had got well advancements in mechanical properties like tensile, hardness and impact strength with increase in wt% of reinforcement.

Introduction

This research focuses on developing aluminum-based metal matrix composites (MMCs) using AA6061 aluminum alloy reinforced with magnesium (Mg) and fly ash particles to improve mechanical properties while reducing weight and cost. Due to their high strength, low density, wear resistance, and affordability, aluminum composites are widely used in automotive, aerospace, marine, and structural applications. The study aims to replace conventional materials by producing lightweight and high-performance composites through the stir casting method.

In this work, AA6061 alloy is used as the matrix material, with 4% magnesium as a wetting agent and different fly ash concentrations (0%, 5%, 10%, 15%, and 20% by weight) as reinforcement. The fabricated composites are machined and tested for mechanical properties such as tensile strength, hardness, impact strength, and microstructural characteristics. Results show that increasing the fly ash content improves the mechanical performance of the composite.

The literature review highlights previous research on aluminum composites reinforced with materials like fly ash, silicon carbide, CNTs, and other nanoparticles. Studies show that proper dispersion of reinforcement particles improves strength, hardness, and wear resistance. Techniques such as ultrasonic treatment and stir casting help achieve better particle distribution and reduce defects like particle agglomeration.

The fabrication process involves melting AA6061 alloy in a furnace, adding magnesium and preheated fly ash particles, and mixing them using stir casting. Argon gas is used to reduce oxidation, and controlled stirring ensures uniform distribution of reinforcement particles. The composite samples are then cast into molds and prepared for testing.

Microstructural analysis using optical microscopy and SEM images confirms that fly ash particles are uniformly distributed within the aluminum matrix. The addition of fly ash reduces grain size and improves the structure of the composite. SEM and EDS analysis verify the presence and dispersion of reinforcement particles with low oxidation levels, indicating successful composite fabrication.

Conclusion

The conclusions drawn from the present investigation are as per the following: 1) The result affirmed that mix framed AA6061 with Magnesium/Fly-Ash strengthened composites is plainly better than base AA6061 in the correlation of elasticity, hardness and effect quality. 2) It is discovered that prolongation will in general decline with expanding particles wt% which affirms that 4% magnesium and variety of Fly-Ash expansion builds weakness. 3) It appeares from this investigation that UTS and Yield Strength tend beginnings to increments with increment in weight level of magnesium and variety of fly debris. 4) Impact quality is expanded when 15% fly debris was included and same way sway quality is diminishes when fly debris is expanded by over 15%. 5) Hardness of aluminum (AA6061) is expanded from 60BHN to 80BHN with expansion of fly debris and magnesium. 6) It can be seen from the SEM pictures and EDS examination that the particles are all around dispersed in the base amalgam and agglomeration of the particles are extraordinarily diminished, and the dissolve pool is all around shielded from the barometrical conditions. 7) The extreme rigidity of the base amalgam is seen to be 335MPa. 8) On expansion of the fly debris for weight percent of 5% the UTS esteem expanded to 348MPa. 9) On expansion of the fly debris for weight percent of 10% the UTS esteem expanded to 360MPa. 10) On expansion of the fly debris for weight percent of 15% the UTS esteem expanded to 330MPa. 11) On expansion of the fly debris for weight percent of 20% the UTS esteem expanded to 310MPa. 12) 260MPa is where the yielding beginnings for the base combination. 13) On expansion of the fly debris for weight percent 5% the yield quality expanded to 302MPa. 14) On expansion of the fly debris for weight percent 10% the yield quality worth expanded to 325MPa. 15) On expansion of the fly debris for weight percent 15% the yield quality worth expanded to 280MPa. 16) On expansion of the fly debris for weight percent 20% the yield quality worth expanded to 240MPa. 17) Ductility esteem on expansion of the fly debris for weight percent 5% is 9.0%. 18) Ductility esteem on expansion of the fly debris for to weight percent 10% is 8.3%. 19) Ductility esteem on expansion of the fly debris for weight percent 15% is 8.0%. 20) Ductility esteem on expansion of the fly debris for weight percent 20% is 7.5%. 21) With up to 10% expansion of fly debris Mechanical properties are upgraded and with further expansion of fly ash the properties begins decreasing.

References

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Copyright

Copyright © 2026 Tatapudi Krishna, P. Surya, K. Ashok. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.