Laser pulse shaping for additive manufacturing

A method involving a substrate having an interface layer, wherein the interface layer forms only an upper surface portion of the substrate, and a feedstock material placed on the interface layer, the method comprising:

• generating, using a first laser, a first beam component providing a first power flux level;
• generating, using a second laser, a second beam component providing a second power flux level which is greater than said first power flux level;
• using a mask configured between the feedstock material and the first and second lasers to produce a 2D optical image using the first and second beam components;
• heating the feedstock material to a first level short of a melting point of the feedstock material, using the first beam component, at which point the particles of the feedstock material begin to experience surface tension forces relative to the interface layer of the substrate;
• further heating the particles of feedstock material to a second level to melt the feedstock material and also to melt the interface layer of the substrate, wherein the interface layer of the substrate comprises a layer having a thickness less than a full thickness of the substrate, such that a portion of the interface layer remains unmelted by the second beam component as the particles of feedstock material and the interface layer are bonded together in accordance with the 2D optical pattern;
• and
• configuring the laser system such that the second beam component has a duration less than the first beam component by a factor of at least 1×10−3, and a power controlled to be sufficient only to melt the interface layer of the substrate.

A method involving a substrate having an interface layer, wherein the interface layer forms only an upper surface portion of the substrate, and a feedstock material placed on the interface layer, the method comprising:

• generating, using a first laser, a first beam component providing a first power flux level;
• generating, using a second laser, a second beam component providing a second power flux level which is greater than said first power flux level;
• using a mask configured between the feedstock material and the first and second lasers to produce a 2D optical image using the first and second beam components;
• heating the feedstock material to a first level short of a melting point of the feedstock material, using the first beam component, at which point the particles of the feedstock material begin to experience surface tension forces relative to the interface layer of the substrate;
• further heating the particles of feedstock material to a second level to melt the feedstock material and also to melt the interface layer of the substrate, wherein the interface layer of the substrate comprises a layer having a thickness less than a full thickness of the substrate, such that a portion of the interface layer remains unmelted by the second beam component as the particles of feedstock material and the interface layer are bonded together in accordance with the 2D optical pattern;
• and
• further configuring the laser system such that the second beam component has a duration less than the first beam component by a factor of at least 1×10−3, and a power controlled to be in a MW range in order to only melt the interface layer of the substrate.