System and method for building three-dimensional objects with metal-based alloys

A method for building a three-dimensional object in a layer-by-layer manner with a digital manufacturing system, the method comprising:

• substantially removing oxygen-containing gases from a build chamber of the digital manufacturing system;
• heating the build chamber to one or more temperatures of at least about 400° C.;
• providing an alloy comprising aluminum;
• heating the alloy to a temperature that is above a solidus temperature of the alloy and that is below a liquidus temperature of the alloy;
• depositing the heated alloy in a predetermined pattern from a deposition head disposed at least partially within the build chamber onto a build platform—disposed within the build chamber
• controlling a flow of the alloy from the deposition head by selectively relaying a coolant from a coolant solenoid located outside of the build chamber to a freeze valve assembly of the deposition head disposed within the build chamber;
• and
• solidifying the deposited alloy.