A literature review on powder spreading in additive manufacturing

Powder-bed additive manufacturing, including powder bed fusion and binder jetting, has a wide range of applications in various industries. Powder spreading is a critical step of powder-bed additive manufacturing and has a determinative impact on powder bed quality and thus final part quality. This paper provides a literature review on powder spreading, focusing on the effects of influencing factors on powder bed quality. Three groups of influencing factors are discussed: spreaders, spreading parameters, and feedstock powder properties. Besides the effects of individual factors, the interaction effects between these factors are also discussed where applicable. Powder bed quality is discussed in terms of powder bed density and powder bed surface condition. Furthermore, knowledge gaps and research opportunities are presented as concluding remarks.