| 摘要 |
Various embodiments of the present invention relate to a method for operating an additive manufacturing apparatus (21) in which a three-dimensional article (3) is formed. Said method comprising the steps of: providing a vacuum chamber (20a, 20b) having at least a first (20a) and a second (20b) section, wherein said first and second sections are openly connected to each other, providing a predetermined vacuum level inside said vacuum chamber, providing a layer of powder material on a work table (2) in said first section of said vacuum chamber, directing an electron beam from said at least one electron beam source (6) provided in said second section over said work table to fuse in first selected locations according to said model to form a first cross section of said three-dimensional article, purging said second section with a dry gas (from 46, via 44, 50) when said vacuum chamber is open for prohibiting ambient air into said second section. |
