Metal Additive manufacturing using Powder Sheets (MAPS): technology review within the contest of the state of the art and future perspectives

The widely used laser beam powder bed fusion (LPBF) additive manufacturing (AM) technology suffers significant challenges including powder safety issues and insufficient mechanical properties of manufactured components. To address some of these limitations, we developed a novel polymer-bound powder sheet-based metal AM method known as Metal Additive Manufacturing using Powder Sheets (MAPS), which offers critical safety improvements and enhanced manufacturing capabilities. In this technology, powder is encapsulated within a polymer binder to form thin and continuous sheets. The sheets are flexible and do not break when bent and are characterized by a high metal powder packing density. Powder is therefore no longer loose, resulting in considerable handling and safety improvements. When the sheets are irradiated by a laser, the polymer binder degrades, and powder fusion is achieved at the same time. We are able to achieve +99% density parts without the necessity of any post-treatment. We have applied MAPS to a variety of materials (Ti64, SS304, In718 are examples) and we have demonstrated the possibility of multi-material prints with very practical material change overs. In this paper, we are reporting a comprehensive review of the process spanning from sheets manufacturing to laser processing and microstructure formation. The potential advantages of the process are therefore described, alongside possible drawbacks and open research questions. We will also compare our MAPS results against the more established state of the art in view of better positioning the process in the technology readiness level (TRL) scale and within an international contest.