Strengthening phase and mechanical property analysis of artificially aged Al7075 – Ni coated Al2024 composites

Karthik B M; Sathish Kumar K M; Sathyashankara Sharma; Gowrishankar M C; Ananda Hegde; Nithesh K

doi:10.1088/2053-1591/ad028a

Materials Research Express (Jan 2023)

Strengthening phase and mechanical property analysis of artificially aged Al7075 – Ni coated Al2024 composites

Karthik B M,
Sathish Kumar K M,
Sathyashankara Sharma,
Gowrishankar M C,
Ananda Hegde,
Nithesh K

Affiliations

Karthik B M: Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education , Manipal-576104, Karnataka, India
Sathish Kumar K M: Department of Mechanical Engineering, BMS Institute of Technology and Management , Bangalore 560064, India
Sathyashankara Sharma: ORCiD; Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education , Manipal-576104, Karnataka, India
Gowrishankar M C: Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education , Manipal-576104, Karnataka, India
Ananda Hegde: ORCiD; Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education , Manipal-576104, Karnataka, India
Nithesh K: Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education , Manipal-576104, Karnataka, India

DOI: https://doi.org/10.1088/2053-1591/ad028a
Journal volume & issue: Vol. 10, no. 10
p. 106520

Abstract

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This technical paper demonstrates the possibilities of nickel (Ni) coated Al2024 powder reinforcement in an Al7075 matrix using the liquid stir casting technique. Additionally, the paper focuses on achieving stable properties by implementing artificial aging heat treatment. To apply the Ni coating, the electroless nickel plating technique was utilized, and a minimum coating thickness of 8 μ m was determined to effectively prevent the dissolution of Al2024 powder reinforcements within the Al7075 matrix. Stir casting facilitated the uniform dispersion of the coated Al2024 powder up to a weight percentage of 7%. Subsequently, the Al7075 alloy and composites underwent artificial aging through solution heat treatment (SHT) at 450 °C for 4 h, followed by water quenching and aging at temperatures of 120, 150, and 180 °C. Aging at 120 °C was found to yield superior results compared to aging at 150 and 180 °C, thus identified as the optimum aging temperature. When the Ni coating thickness was increased beyond the optimal 8 μ m, the resulting enhancements in hardness for both as-cast and peak-aged specimens, as well as the tensile strength, were not significant. The improvements observed were only marginal, ranging between 2 to 3%. Fracture surface analysis revealed that the predominant fracture mode in the Al7075 alloy was ductile, characterized by dimple rupture. In the as-cast Al7075-(7%, 8 μ m) Al2024 composite, a mixed fracture mode comprising both brittle and ductile characteristics was observed. In the peak-aged (120 °C) Al7075-(7%, 8 μ m)Al2024 composite, the overall fracture mode exhibited a dominant brittle nature. Analytical techniques including XRD, TEM, and EDS confirmed the presence of Mg _2 Si, MgZn _2 , CuAl _2 , and CuAl _2 Mg phases in the peak-aged (120 °C) Al7075-(7%, 8 μ m) Al2024 composite. These phases contributed to the enhancement of the properties of both the Al7075 alloy and its composites. The developed composites can be used in automobile parts and aerospace applications.

Published in Materials Research Express

ISSN: 2053-1591 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials; Technology: Chemical technology
Website: https://iopscience.iop.org/journal/2053-1591

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