Turbine bucket with turbulated cooling passage and electrode for electochemical machining.

摘要

An electrode (18) having a dielectric coating (20) is patterned to provide axially spaced rows (22) of insulating material (20) on the external surface of the electrode with one or more gaps (26) in the insulating material of each row. The electrode is placed in a preformed hole (16) of a turbine bucket and an electrolyte (32) is provided for flow between the electrode and the walls of the hole. Upon application of an electrical current, portions of the material of the interior wall surface directly opposite the non-insulated portions of the electrode are dissolved, forming grooves (29). The insulated portions of the electrode leave axially spaced rows of projections (30) extending toward the axis of the hole. The gaps (26) in the rows (22) are axially misaligned. The projections (30) form turbulators in the cooling flow passages of the bucket, enhancing the heat transfer coefficient. <IMAGE>