A system includes a chamber to receive a powdered material to be used to form an object. The system includes actuators coupled to the chamber. The actuators apply pressure waves to the powdered material in the chamber. The system also includes a controller to activate a plurality of the actuators in a sequence. Activation of the plurality of actuators in the sequence converges pressure waves on a particular volume of powdered material in the chamber to compress the particular volume and to transform at least a portion of the powdered material in the particular volume to solid material of the object.