| 摘要 |
<p>The present invention provides a new and improved method of making an improved turbine engine component having an annular array of airfoils connected with inner and outer shrouds. The airfoils are cast separately from the shrouds to enable the airfoils and shrouds to be made from either the same or different materials. The airfoils advantageously have an elongated columnar grain structure with grain boundaries extending parallel to the leading and trailing edges of the airfoils. The inner and outer shrouds are formed of a plurality of arcuate sections which also may have an elongated columnar grain structure. The ends of the arcuate shroud sections are interconnected in such an orientation that the grain boundaries extend circumferentially around the circular shrouds to minimize the extent to which ends of the grains are exposes. In another embodiment of the invention, each of the arcuate shroud sections is formed of a single crystal. In accordance with a feature of the invention, the forming of a shroud segment which includes a pair of arcuate shroud sections and one or more airfoils is facilitates by using a spacer bar. The spacer bar holds the shroud sections in a fixed spatial relationship relative to each other while airfoils are connected with the shroud sections. Once the airfoils have been connected with the shroud sections, the spacer bar is removed.</p> |
