US Patent 10124408 Additive manufacturing method and apparatus

A method and apparatus for fabricating an object. The method and apparatus entail applying a pulsed laser energy to a first quantity of a powder material on a substrate so as to fuse particles of the powder material into a first layer on the substrate, and then forming at least one additional layer on the first layer by applying a pulsed laser energy to at least a second quantity of the powder material on the first layer so as to fuse particles of the powder material into the at least one additional layer on the first layer. The pulsed laser energy is applied in a controlled manner such that solidification dynamics of the first and second quantities of the powder material are altered to promote at least one microstructural characteristic of the first and additional layer.