摘要 |
This invention concerns an additive manufacturing apparatus comprising a build chamber (101), a build platform (102) lowerable in the build chamber (101) such that layers of flowable material can be successively formed across the build platform (102), a laser (105) for generating a laser beam (118), a scanning unit (106) for directing the laser beam (118) onto each layer to selectively solidify the material and a processor (131) for controlling the scanning unit (105). The processor (131) is arranged to control the scanning unit (105) to direct the laser beam (118) to solidify a selected area of material by advancing the laser beam (118) a plurality of times along a scan path (200). On each pass along the scan path (200), the laser beam (118) solidifies spaced apart sections of the scan path (200), each subsequent pass solidifying sections that are located between sections solidified on a previous pass. In a further embodiment, the additive manufacturing apparatus comprises a laser source for generating a plurality of laser beams, the processor (131) arranged to control the scanning unit (106) to direct the laser beams to solidify a selected area of material by consecutively advancing multiple ones of the laser beams along a scan path, wherein on a pass of each one of the laser beams along the scan path, the laser beam solidifies spaced apart sections of the scan path and a pass of one of the laser beams along the scan path solidifies sections that are located between sections of the scan path solidified by another of the laser beams. The processor (131) may be arranged to control the scanning unit to direct the laser beam to solidify a selected area of material by solidifying sub-millimetre sized sections of the area non- continuously and in an order such that consecutively solidified sections are spaced apart. |