Influence of laser-nitriding on mechanical and elevated temperature fretting wear behavior of A356-alloy

Abstract

Laser nitriding (LN) was found to be an effective method for refining the surface characteristics of aluminum and its alloys. However, this process necessitates a nitriding chamber, and this dramatically confines the feasibility in industrial applications, which involves big and intricate shapes with curved surfaces of automobile engine parts. To conquer this problem, in this research, the authors tried to explore the possibilities in performing open environment laser nitriding on A356 Al alloy with the help of N2 gas purging using Nd+3: YAG laser. The presence of the AlN thin layer formed on the substrate material was also confirmed using GI-XRD, XPS, and FE-SEM analysis. The influence of varying process parameters, for instance, laser fluence (mJ/mm2) on the average surface roughness (Ra), hardness, and elevated temperature (200 °C) fretting wear behavior were quantified and compared. The optimized hardness (2.8 GPa, at 25 °C) and fretting wear resistance (1307.18 mm−3, at 200 °C) in comparison to untreated samples were found to be enhanced by 84% and 23%, respectively. © 2021 Elsevier B.V.