Solidification refinement and general phase transformation control through application of in situ gas jet impingement in metal additive manufacturing
Provided are a jet device and systems and methods using the jet device for manufacturing objects by additive manufacturing, especially titanium and titanium alloy objects, wherein the jet device directs a cooling gas across a liquid molten pool, or to impinge on the liquid molten pool, or to impinge upon a solidified material adjacent to a liquid-solid boundary of the liquid molten pool, or to impinge on an as-solidified material, or any combination thereof, during the additive manufacturing process. The application of the cooling gas can result in an additively manufactured metal product having refined grain structure with a high proportion of the grains being approximately equiaxed, and can yield an additively manufactured product exhibiting improvements in strength, fatigue resistance, and durability.
1. A jet device, comprising:
a first conduit comprising:
a first inlet for accepting a cooling gas; and
a first aperture connected to a first nozzle for dispensing the cooling gas; and
a second conduit comprising:
a second inlet for accepting the cooling gas; and
a second aperture connected to a second nozzle for dispensing the cooling gas;
wherein:
the first conduit is attached to a melting tool on a first side of a thermal energy source produced by the melting tool and the second conduit is attached to the melting tool on an opposite, second side of the thermal energy source;
at least one of the first nozzle or second nozzle is configured to produce a turbulent flow of the cooling gas as the cooling gas is dispensed during material deposition;
the first nozzle and second nozzle are configured to direct the cooling gas to impinge on one or more of a molten pool and a liquid-solid boundary of the molten pool; and
the first nozzle and second nozzle are positioned to prevent blowing the cooling gas toward the thermal energy source.
2. The jet device of claim 1 , wherein any one or more of the first and second conduits comprises:
a plurality of nozzles; and
a plurality of channels, pipes, tubes or lines within each conduit, each one of the channels, pipes, tubes or lines separately attached to a single nozzle of the plurality of nozzles.