Effects of thermal ageing on the wear behavior of the cerium modified Al-18si-3.6cu alloy

Gangal, Krishnaraddi, Goudar, Dayanand M, Haider, Julfikar ORCID: https://orcid.org/0000-0001-7010-8285, K, Devendra and Kadi, Rajendrakumar V (2023) Effects of thermal ageing on the wear behavior of the cerium modified Al-18si-3.6cu alloy. Advances in Materials and Processing Technologies. ISSN 2374-068X

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Abstract

In the present investigation, an Al-18Si-3.6Cu alloy was modified by cerium (Ce), heat treated (T6), and aged for 1, 3, 5, and 7 h at 210°C. The resulting microstructures revealed that the addition of Ce as a modifier changed the morphology of the primary Si from coarse with a sharp edge to spherical, large-acicular/needle-like eutectic Si into a fibrous state, and dendrites of the Al phase into round branches with less interface separation. After thermal ageing, the microstructure of the modified alloy revealed no change in the morphology of the primary Si phase. However, a considerable change in the eutectic Si phase and the formation of fine precipitates of Al2Cu and Al2CeSi intermetallics in the matrix. Hardness was found to be significantly higher in the modified and age-hardened alloys. A Pin-on-disc wear tester was used to investigate the dry sliding wear behavior of alloys at different loads (10, 20, 30, and 40 N) and 1.0 m/s sliding velocity. The results indicated that the wear rate in the modified alloy was lower than the base alloy. Furthermore, the modified alloy after 5 h age hardening demonstrated high wear resistance and improved wear bearing capacity compared to the 1, 3, and 7 h age hardened alloys.