The Department of Energy's Oak Ridge National Laboratory has made what may be a groundbreaking discovery in the field of metal additive manufacturing. They were able to microscopically control the properties of the Electron Beam Manufacturing process to change a variety of material attributes. More details on their work, and just what this may mean for the future of additive manufacturing can be found here: http://3dprint.com/19477/ebm-printing-3d-ornl/

Below is an example print in which they were able to control the grain orientation of a nickle alloy during the print process.