Tribological properties of the SLM-316L filament under the grease lubrication condition

To study the friction and wear properties of 316L stainless steel filaments prepared by selective laser melting (SLM) for metal rubber under the condition of grease lubrication, the friction coefficient and wear rate of SLM-316L filaments under different loads, different friction velocities, and Fv factors of the combined effect with load (F) and friction velocity (v) were discussed. Scanning electron microscope (SEM) was used to observe the surface morphology of filaments after wear, and energy dispersive spectrometer (EDS) was used to detect the element types and atomic percentages of the worn surface. Based on these two methods, the wear mechanism was analyzed. Results show that under the grease lubrication condition and with increased load, the friction coefficient decreases, whereas the wear rate initially decreases and then increases. With increased friction velocity, both the friction coefficient and wear rate tend to initially increase and then decrease. The wear mechanism of SLM-316L filaments under the low load condition is mainly abrasive wear and slight oxidative wear. At a high load, oxidative wear is aggravated and accompanied by fatigue wear. The wear mechanism of SLM-316L filaments at low friction velocities is mainly fatigue wear and oxidative wear. At high friction velocities, oxidative wear weakens, and abrasive wear becomes dominant. With an increased Fv value, the friction coefficient decreases and wear rate tends to initially rise, which then decreases and finally rises again. Therefore, the best working parameter of the metal rubber prepared using SLM-316L filaments under grease lubrication conditions is Fv=0.04 N·m·s⁻¹, which means that the load is equal to 10 N and the friction velocity is 240 mm·min⁻¹.