Insight into the tribological behavior of the dual-phase nickel aluminum bronze alloy by multiscale characterization

In this work, the microstructure and tribological properties of coarse-grained nickel aluminum bronze (NAB) alloys with different ratios of α/β′ phases were studied at room temperature. For revealing the intrinsic tribology behavior, the hard SiC sanding disc with a microhardness of 2400∼2800 HV, almost 10 times higher than that of the NAB alloy, was selected as the counter material. The tribological behavior was investigated using multiscale characterization, including macroscale X-ray diffraction (XRD) and laser scanning confocal microscopy (LCM), microscale scanning electron microscopy (SEM), as well as nanoscale transmission electron microscopy (TEM). The findings reveal that abrasive wear predominates in these samples, with delamination, oxidation, and fatigue wear also present. Notably, the dual-phase alloy exhibits inferior wear resistance compared to the single-phase alloy, attributed to the alternating-wear process of the two phases. Additionally, we observed the in-situ formation of a nano oxide film during the friction process, highlighting its significant role in enhancing the wear resistance of NAB alloys through a self-lubricating effect.