SELECTIVE LASER SOLIDIFICATION APPARATUS AND METHOD WITH SCANNING SEQUENCE SELECTED TO MINIMIZE EFFECT OF DEBRIS ON BUILD QUALITY

摘要

This invention concerns a method of selecting a scanning sequence of a laser beam in a selective laser solidification process, in which one or more objects are formed layer-by-layer by, repeatedly, depositing a layer of powder on a powder bed and scanning a plurality of laser beams over the deposited powder to selectively solidify the powder layers, wherein a gas flow is passed over the powder bed in a gas flow direction. The method comprising selecting a scanning sequence for the plurality of laser beams to include the simultaneous exposure of an upstream point together with a downstream point located downstream of a flow of debris carried from the upstream point by the gas flow, the downstream and upstream points selected for simultaneous exposure based upon the downstream point being within a maximum separation distance from the upstream point.