Temperature-Dependent Friction and Wear Properties of Laser Powder Bed Fused Maraging Steel 300: Impact of Direct Aging Post-Processing

Abstract

Abstract. This research explores the high-temperature tribological characteristics of laser powder bed fused (LPBF) maraging steel 300, with emphasis on how temperature and post-processing via direct aging impact its wear and frictional behavior. Dry sliding wear experiments were carried out for both as-built and directly aged samples across a temperature range from ambient conditions to 400 °C. Characterization involved scanning electron microscopy, energy-dispersive spectroscopy (EDS), X-ray diffraction, and microhardness measurements. The results indicated that at room temperature, abrasion dominated the wear mechanism without oxide formation, while higher temperatures induced oxidation, delamination, and adhesive wear. The coefficient of friction (COF) and wear-rate both rose with increasing temperature, with the as-built condition reaching COF values of up to 0.67 and experiencing higher wear at 400 °C. Conversely, the directly aged samples consistently showed lower COF and wear rates at all tested temperatures, achieving a maximum reduction of 8.33% in the COF relative to the as-built counterparts. EDS analysis showed a steady increase in surface oxygen and a decrease in iron content with rising temperature, indicating thermally activated oxidation. These results highlight the significance of heat treatment and temperature on wear performance, offering key insights for applying LPBF-manufactured maraging steel 300 in high-temperature, wear-critical sectors like aerospace and power systems.