STUDY OF PREVIOUS POWDER-PARTICLE BOUNDARY CARBIDES

The previous powder-particle boundary (PPB) problem has been studied in P/M superalloy FGH95. The results indicate that the PPB carbides begin to form on the powder surface during atomization and continuously precipitate during HIP-consolidation. As a result of complex composition of carbides the different types carbides interact probably. The amount of PPB precipitation increased significantly during post-HIP heat treatment. The formation of PPB carbides is related to the amount of residual oxygen in alloy.