Recycling powders for re-additive manufacturing (r-AM) is of great necessity to develop the circular economy, via making the process more efficient. In general, recycling powders for r-AM can be achieved by re-melting powders. However, re-melting powder is very different from melting bulk materials, due to the presence of a significant oxide layer on the particles. To date, it is unclear about the effect of the oxide layer on the re-melting process. In this talk, the Al-Ce based powders are used as the model system to investigate the formation mechanism of the oxide layer on the powder via multiple-scale multiple-dimensional characterization methodologies, due to their excellent printability (no cracks, less pores) and performance at room and elevated temperature (up to 250 °C). The aim is to elucidate the formation mechanism of the oxide layer and thereby to control its formation by tailoring the oxygen concentration, temperature, and pressure within the atomization chamber. Re-melting the powder always occurs during AM. In fact, AM can be regarded as a re-melting and rapid solidification process. The obtained results can be used to elucidate the effect of the oxide on the microstructure and properties in as built condition.