Due to various causes, process interruptions during powder bed fusion of metal with laser beam (PBF-LB/M) can occur. This can be performed deliberately, e.g. as part of sensor integration or hybrid manufacturing. However, unplanned interruptions are also possible, for example, due to a power outage. In particular, long-term interruptions may result in significant quality losses, making it necessary to cancel the build job. Depending on the extent of the print job and the location of the interruption, this can mean a major economic loss. Most of the previous studies have found only minor reduction of the mechanical properties. However, these studies often dealt with the effect of planned interruptions and relatively short interruptions of about 1 h. Significantly longer interruption times are also realistic, especially when they occur overnight or during weekends.
The aim of this study is to investigate the effects on the component quality of a process interruption when the manufacturing process is continued several hours after the interruption. For this purpose, the effects of different interruption durations (1, 4, 10 and 16 h) on the microstructure, hardness, tensile strength and fatigue properties of the PBF-LB/M-fabricated components made of AlSi10Mg were investigated. In addition, the layer shift resulting from the interruption is measured and described geometrically. The results show that for AlSi10Mg specimens in which the layer shift was removed and which are not highly loaded, an unplanned long-term process interruption up to 10 h does not result in a significant loss of quality under the considered conditions. Furthermore, it is apparent that the procedure for restarting the process is very important for the resulting component quality.