| 摘要 |
<p>Solid freeform fabrication of a body by providing first and second precursors, melting at least a portion of these precursors to form a substantially molten alloy which solidifies at a temperature lower than the melting points of the precursors. Further solid material with a melting point greater that the solidifying temperature of the alloy is deposited on the molten alloy and then least some of this further material is melted. By repeatedly depositing further solid material and melting at least some of it an object is formed. The molten object, which can have a eutectic, hypereutectic or hypo-eutectic composition, can be solidified as a single crystal by controlling its cooling. Also disclosed are apparatus for performing the above method and a method of forming a molten body by repeatedly depositing material and heating at least a portion of this material above its melting point and then solidifying at a controlled rate, thereby controlling its microstructure.</p> |
