Powder spreading and spreadability in the additive manufacturing of metallic materials: A critical review

This review aims to build a coherent picture of the problem of powder spreading and spreadability in metal Additive Manufacturing (AM) because of its impact on ensuring highly consistent production, optimization of the process and reduction of the manufacturing costs. The review shows the current progress in understanding spreading dynamics, the role of powder characteristics, the spreading systems and the testing tools developed for assessing powder spreadability. The problem of finding appropriate quantitative metrics and the recent advances in the use of standardized methods to assess powder spreadability is critically discussed. Attention is given to future trends and research gaps and opportunities.