METHOD FOR APPLYING POLISHED LAYER TO COM- PRESSOR AIRFOIL MADE OF TITANIUM ALLOY

摘要

PURPOSE: To provide a structural member having an excellent polish characteristic by plating the tip part of a blade with primary and secondary layers with specified thickness, applying the surface with a third nickel plating layer in which fine particles are buried and furthermore specifying the bond thickness of the third and fourth nickel layers. ;CONSTITUTION: The tip 15 of an engine blade of a titanium base alloy is electroplated with a primary nickel layer having about 12 to 18 micron thickness. The surface is electroplated with a secondary nickel layer having about ≤1 micron thickness. The surface is plated with a third nickel layer, and fine particles 20 are buried in the third nickel layer. The surface of the third nickel layer is electroplated with a fourth nickel layer. The bond thickness of the third and fourth nickel layers is regulated to the one smaller than about 15% of the average thickness and higher than 50% of the average thickness. The blade 12 is subjected to heat treatment at a temp. in which diffusion is generated between the primary nickel layer and the tip 15 of the blade. In this way, the member useful for the compressor part of a gas turbine can be provided.;COPYRIGHT: (C)1991,JPO