Influence of Vibratory Excitation on Friction During Sintering of Metal Binder Jetting Components

The deformation of metal binder jetting components during sintering is governed by friction between the part and the setter plate as well as other factors. This study investigates the extent to which this friction can be reduced by targeted vibratory excitation. Additively manufactured 17-4 PH steel specimens are tested on setter plates at both room temperature and 1100 °C. Three different converters, covering excitation frequencies between 0.3 kHz and 37.5 kHz, are used to excite the setter plate either longitudinally or orthogonally to the direction of relative motion. Friction forces are measured using a custom-built high-temperature tribometer, from which static and dynamic coefficients of friction are derived. Even at low-velocity amplitudes (<5 mm/s), the static coefficient of friction decreases by up to 70%, while the dynamic coefficient decreases by up to 80%. Using a more powerful ultrasonic converter, orthogonal excitation achieves peak velocity amplitudes of 40 mm/s, which almost completely eliminates friction. Longitudinal excitation is more effective at low-velocity amplitudes, whereas orthogonal excitation becomes superior at higher velocity amplitudes.