Patent ID: 7854885

Claim:
A method of making an article, comprising: (a) forming a preceding layer of metal powder on a base; (b) exposing a selected portion of said preceding layer to the energy of a laser to thereby fuse one portion of the layer of metal powder and leave another portion of metal powder in the layer un-fused; (c) subsequently reversibly bonding a bulk of un-fused metal powder of said preceding layer including at an exposed surface of the preceding layer; (d) forming a subsequent layer of metal powder on the preceding layer after the un-fused metal powder has been reversibly bonded in the preceding layer; and (e) exposing the subsequent layer of metal powder, which is located over said exposed surface of the preceding layer, to the energy of a laser to thereby form a re-entrant surface of fused metal powder, wherein the re-entrant surface has an interface with the bulk of reversibly bonded but un-fused metal powder of the preceding layer, and the reversible bonding prevents said bulk of metal powder of the preceding layer from balling up when the metal powder of the subsequent layer is being fused by the energy of the laser.