Microstructure and tribological behavior of tungsten inert gas welding arc brazing tin‐based babbit

Abstract

Abstract The microstructure of the tin‐based babbit obtained by the method of tungsten inert gas welding (TIG) arc brazing was studied by optical microscopy (OM) and X‐ray diffraction (XRD). Tribological behavior was investigated by high‐temperature friction and wear testing machine (HTFWT), laser scanning confocal microscopy (LSCM), scanning electron microscopy (SEM) and energy‐dispersive spectrometer (EDS). It can be found that the higher welding current of the melting tin‐based babbit makes it possible to form isomer structure with fine crystals of the cubic SnSb compounds and large star Cu 6 Sn 5 compounds so that a higher hardness can be achieved, and a lower wear rate can be obtained over the entire distance of sliding friction. When the applied load is 2 N, the contact surface is oxidized due to the accumulation of friction heat and oxide, which plays a role of lubricated film. Also, the softer Sn‐based solid solution forms obvious furrow under abrasive wear, and the harder SbSn and Cu 6 Sn 5 intermetallic compounds shatter and leave a hole under friction.