| 摘要 |
The present invention provides a formed material for a turbo-compressor wheel with which it is possible to manufacture a turbo-compressor wheel having strength at elevated temperatures, excellent rigidity, and excellent dynamic balance, and moreover having an optimal performance corresponding to the different characteristics required of each part. The starting material for this formed material for a turbo-compressor wheel made of an Al alloy is a small-diameter continuous-cast bar stock, or a forged material formed by hot-sealed-forging a small-diameter continuous-cast bar stock. In addition, the structure of the continuous-cast bar stock or forged material is such that the average number of grain boundaries crossed in a circumferential direction in a transverse section orthogonal to the casting direction or the forging direction is minimal in a central portion and is maximal in an outer peripheral portion. The casting direction or the forging direction of the starting material is parallel to the direction of the central axis of rotation of the compressor wheel. |
