Eur. Phys. J. Plus (2018) 133: 49
https://doi.org/10.1140/epjp/i2018-11879-1

Regular Article

Laser-assisted generation of periodic structures on a steel surface: A method for increasing microhardness

¹ Faculty of Electrical Engineering, Urmia University of Technology -UUT, Urmia, Iran
² Young Researchers and elite Club, Bandar Abbas Branch, Islamic Azad University, Bandar Abbas, Iran

^* e-mail: S.razi@uut.ac.ir

Received: 31 October 2017
Accepted: 15 January 2018
Published online: 13 February 2018

Abstract

Stainless steel grade 316L is a commonly used metal in various industrial applications because of its excellent resistance to corrosion and great welding and biocompatibility characteristics. Here, the laser-induced micro/nanostructures generation on the steel surface is investigated. A femtosecond ultrashort pulsed laser is selected in this regard, and various irradiation circumstances are considered for two groups of specimens possessing different initial roughness. It turns out that regular periodic ripples with spatial periodicities less than the laser wavelength are generated on both groups at irradiation fluences J/cm². Furthermore, it figures out that each ripple is composed of the closely created nano dimension structures. Vickers micro-hardness test is also utilized to examine the alterations of the surface hardness features. Moreover, variations of the surface chemistry are studied and discussions related to the most effective factors in surface hardness raise/decrease are presented. Results reveal the potential benefits of the femtosecond laser technique, such as its flexibility and ease of implementation in controlled modification of the surface features. Thus, it might be of interest to manufacturers looking for precise surface morphology, chemistry and hardness alterations.