Influencing the contour of spray-formed sheets and billets by changing the scanning kinematics of the atomiser

Billet spraying is one of the most commonly used applications for spray forming. An optimised as-sprayed geometry of the billets head reduces post-processing steps in terms of the shape of the endproduct. It also generates desired thermal conditions inside the billet, which are responsible for the development of a homogenous microstructure. This work shows the influence of different scanning kinematics on the head contours of billets. Usually, the atomiser is scanning mechanically with a prescribed kinematics. Here a programmable servo actuator is used to control the movement of the scanning atomiser, which makes it possible to change the movement profile during a spray run. Billets are sprayed using different atomiser velocity profiles. The different contours generated are described and compared.