Title: Control of short-pulsed laser-induced periodic surface structures with magnetic abrasive finishing

Abstract:

Laser-induced periodic surface structures (LIPSS) have been studied to alter surface functions such as tribology, wettability, optical properties and bioaffinity. It has been found that microgrooves produced by using ultraprecision cutting are effective to control LIPSS with the nickelphosphorus (Ni-P) plating layer substrate due to the propagation of plasma waves improved by the grooves. However, microgrooves can remain on the irradiated surface. On the other hand, it has been founded that the geometry (the pitch length, the height and the direction) of LIPSS varies by crystal structures on the 304 stainless steel (SUS304) surface. In this study, to clarify the phenomenon and principles of groove-assisted LIPSS and to control LIPSS with the surfaces of

various materials, a finite-difference time-domain simulation and experiments are conducted with SUS304 and Ni-P plating layer substrates. The use of magnetic abrasive finishing (MAF) is proposed to create micro/nano-grooves prior to the shortpulsed-laser irradiation. The subsequent laser irradiation fabricated straight LIPSS superimposed on the MAF-processed surface. While the height of LIPSS was increased by the MAF-groove, the pitch length of LIPSS depended on the laser wavelength.This demonstrates the efficacy of the developed method for controlling LIPSS. The surface geometry prior to the short-pulsed laser irradiation is the dominant factor in determining the geometry of the LIPSS. 

Biography:

Shuhei Kodama is an assistant professor at Tokyo University of Agriculture and technology in Tokyo, Japan. He holds a Bachelor and a Master in Engineering and received a PhD in Engineering from Tohoku University in March 2019. Dr. Kodama is working as an assistant professor from April 2019. His research activities focus on short-pulsed laser-induced periodic surface structures (SPLIPSS) to clarify principles and phenomena, to control LIPSS and to provide a material surface with various functionalities such as reduction of friction, water repellency, anti-reflection and bioaffinity. He gave 9 presentations and 1 lecture about SPLIPSS at international and domestic conferences. Dr. Kodama is passionate about precision processing.