Mechanical and microstructural analysis of cobalt coated CNT/Al2024 reinforced aluminum based composites for aerospace and automotive applications.

Autor: Nambiar S., Sandeep, B. M., Karthik, Sharma, Sathyashankara, Anne, Gajanan, Agarwal, Pranshu, Agrawal, Tanmay, Adiga, Shamantha, Chickkannan, Varun
Zdroj: Cogent Engineering; 2024, Vol. 11 Issue 1, p1-13, 13p
Abstrakt: This study investigates the mechanical and microstructural properties of aluminum matrix composites (AMCs) reinforced with cobalt-coated carbon nanotubes (CNTs) and Al2024 powder, tailored for aircraft and automotive applications. Using Al7075 alloy as the matrix, composites were fabricated via stir casting, incorporating varying proportions of cobalt-coated CNTs and Al2024 powder. The electroless cobalt coating, applied at thicknesses of 4, 6, 8, and 10 µm, facilitated the uniform distribution and enhanced the compatibility of reinforcements with the Al7075 matrix. Four distinct samples were developed: pure Al7075 alloy, Al7075 with 2 wt.% CNTs, Al7075 with 2 wt.% Al2024 powder, and a hybrid composite combining 2 wt.% of each reinforcement. Microstructural analysis revealed that the 10 µm coating thickness was critical for maintaining reinforcement integrity during the melt phase, preventing crack formation and reinforcement agglomeration. Mechanical testing through vickers hardness and phase analysis using X-ray diffraction analysis, demonstrated that the hybrid composite (A3) exhibited superior hardness and reduced natural aging tendencies compared to its counterparts. Peak aging at 120 °C resulted in the formation of intermetallic compounds like CuAl2 and MgZn2, contributing to improved mechanical properties. These findings highlight the significance of optimizing coating thickness and aging conditions to enhance the performance of AMCs, making them suitable for high-performance applications in the aerospace and automotive industries. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index