Seal and a method of manufacturing a seal

摘要

A seal (48) between a compressor rotor blade (26) and compressor casing (28) comprises an abradable structure (59) on the compressor casing (28). The abradable structure (59) comprises a metallic foam (60) having pores (66, 68). The metallic foam (60) has a first a region (62) and a second region (64). The first region (62) of the metallic foam (60) is arranged adjacent to the compressor casing (28) and the second region (64) of the metallic foam (60) is spaced from the compressor casing (28) by the first region (62) of the metallic foam (60). The pores (68) of the second region (64) of the metallic foam (60) contain an abradable material (70) and the pores (66) of the first region (62) of the metallic foam (60) do not contain an abradable material.