Tribological properties of Ti3SiC2 coupled with different counterfaces

This paper reports the dry-sliding tribological properties of Ti3SiC2 at room temperature in air, coupled with different counterfaces, including Ti3SiC2, Al2O3, Si3N4, SiC, and GCr15-bearing-steel. Ti3SiC2 exhibited obviously different tribological properties with different sliding counterfaces. The lowest friction coefficient (0.43) and wear rate (2.09×10−4 mm3/Nm) were obtained in the Ti3SiC2/SiC friction pair. Increased friction coefficient (0.63) and wear rate (3.67×10−4 mm3/Nm) were observed if Ti3SiC2 slides against GCr15-bearing-steel. The highest friction coefficient (1.30) was observed in Ti3SiC2/Al2O3 friction pair and the highest wear rate (1.87×10−3 mm3/Nm) was observed in Ti3SiC2/Ti3SiC2 friction pair. Scanning electron microscopy and X-ray photoelectron spectroscopy showed two main wear mechanisms: mechanical wear and oxidation wear. Mechanical wear was the main mechanism for sliding against Ti3SiC2, Si3N4, or Al2O3. Grain removal was a significant tribological character of self-mated Ti3SiC2 friction pair. For Ti3SiC2/SiC friction pair, oxide wear played a more important role and more oxides were formed than those in other friction pairs. Oxide films protected the surface of Ti3SiC2/SiC friction pair from direct contact, and decreased wear rate and friction coefficient.