A new method with ultrasonic mechanism for efficient depowdering of parts produced by electron beam melting

Abstract

Among metallic additive manufacturing technologies, electron beam melting (EBM) requires a specific operation called depowdering once a part is built. With the help of a powder recovery system (PRS), this process consists in blowing titanium powder onto a "cake"of a manufactured part in order to separate sintered but not melted powder from the part itself. However, the depowdering of some geometries can in fact become difficult, even impossible, due to the part shape. This article aims at proposing an ultrasonic depowdering mechanism that allows to improve and to quantify the depowdering capabilities of the PRS system currently used. Experimentations are led onto geometries that include canals. A "depowderable depth"/diameter criterion is then applied for comparing the depowdering capacity of the proposed system with the traditional one. First results show that the quantity of powder removed onto samples is highly enhanced with an ultrasonic process. This outcome creates opportunities since additional tests could be implemented onto more complex shapes such as, for instance, parts with internal complex shapes.