The tribological performance of grooved surfaces has been thoroughly analyzed, and such surfaces are thought to have great potential for hard-on-hard joint prosthesis. In related research, femtosecond laser-induced periodic surface structures (FLIPSSs) have been well developed to achieve grooved structures with submicron spacing (700nm) and amplitude (200nm). In this study, submicron-scale periodic grooved structures were made on SUS440C using a femtosecond laser, and its tribological performance was evaluated by both a pin-on-plate reciprocating sliding test and a ring-on-disk test. The pin-on-plate reciprocating test was performed using PAO6 (30.51cP at 37°C) as the lubricant. The pin and plate specimens were made of SUS440C and were polished to a surface roughness of 0.02μm Ra. The pin specimens were columnar in shape, and radial periodic grooved structures (700nm spacing x 200nm amplitude) were formed on the pin's outer periphery (from 4mm to 5mm in diameter). The ring-on-disk test was performed using lubricants with different viscosity: PAO6 and PAO2 (4.60cP at 37°C). The ring-on-disk specimens were made of SUS440C and were polished to a surface roughness of 0.03μm Ra. Along the surface of the ring specimens, material was removed to create 4 elevated sections at 0°, 90°, 180° and 270°. These 4 sections were then polished and concentric grooved structures (700nm spacing x 200nm amplitude) were created along a 1.4mm circumferential path within each of these areas.Introduction
Method
