Additive manufacturing by laser beam powder bed fusion (PBF-LB) enables the integration of particle dampers into components through enclosed, powder-filled cavities. However, the filling ratio of these dampers cannot be specifically adjusted during the manufacturing process, even though it is known to have a significant influence on the damping performance in the case of conventional particle dampers. In this study, a heat treatment is employed to systematically reduce the filling ratio of PBF-LB/AlSi10Mg particle dampers. The heat-induced expansion of the cavities reliably decreases their filling ratio without leading to irreversible sintering of the enclosed powder. Experimental and numerical modal analyses are used to investigate the effects of the reduced filling ratio on natural frequencies, mode shapes, and damping behaviour. It is shown that changes in natural frequencies and mode shapes are attributed to macro- and microscopic effects of the heat treatment on the specimens rather than to the altered filling ratio. In contrast, the damping behaviour is strongly affected by the reduced filling ratio: For the lowest investigated bending mode, the damping initially increases as the filling ratio decreases, reaching a maximum at filling ratios between 35 % and 50 %, before decreasing again at lower filling ratios. In higher modes, the damping decreases with lower filling ratios. The results demonstrate that there is no universally optimal filling ratio. Instead, the effectiveness of damping depends on the dominant particle motion type, which is determined by factors such as frequency, amplitude, and filling ratio. The method presented in this study allows the targeted reduction of the filling ratio in PBF-LB/AlSi10Mg particle dampers, thereby extending their potential applications, particularly at low frequencies.      «

Additive manufacturing by laser beam powder bed fusion (PBF-LB) enables the integration of particle dampers into components through enclosed, powder-filled cavities. However, the filling ratio of these dampers cannot be specifically adjusted during the manufacturing process, even though it is known to have a significant influence on the damping performance in the case of conventional particle dampers. In this study, a heat treatment is employed to systematically reduce the filling ratio of PBF-L...     »