COMPOSITE ELECTRODEPOSITION INCLUDING PARTICLES OF CRAIM.SUB.2 WHERE M.SUB.2IS Y, SI, TI OR RARE EARTH

摘要

A substrate such as a single crystal gas turbine blade is given a protective coating by composite electrodeposition of a metal matrix M1 containing particles of CrA1M2, where M1 is Ni or Co or Fe and M2 is Y, Si, Ti, or a rare earth element. The preferred matrix is Ni or Co or NiCo and the preferred particles are CrA1Y. The particle size is important and preferably 75% by weight of the particles are between 3.9 and 10.5 .mu.m. The coating is heat treated to produce interdiffusion between the constituents of the matrix and the particles.