| 摘要 |
A method and apparatus for manufacturing a three-dimensional object by additive layer manufacturing. The method includes providing layers of material in powder form on a support inside a chamber, and irradiating each layer with a beam before providing the subsequent layer. A gas atmosphere is maintained inside the chamber during the irradiation steps. The pressure and/or the composition of the gas atmosphere is controlled where at least two different gas atmospheres having different predetermined pressures and/or compositions are inside the chamber during irradiation of the layers, the beam spot size on the layers is controlled such that at least two different beam spot sizes are utilized during irradiation, and/or the temperature of the gas atmosphere inside the chamber and/or of the layer being irradiated is controlled such that at least two different temperatures of the gas atmosphere and/or of the layer being irradiated are present during irradiation of the layers. |
