CRITICAL ISSUES CONCERNING THE MECHANISMS OF DUPLEX GRAIN-STRUCTURE FORMATION AND INTERPRETATION OF DUPLEX NIO GROWN ON PURE NI AND CR DOPED SUBSTRATES DURING HIGH-TEMPERATURE OXIDATION

Duplex layers are a very important class of film microstructures and f orm under a wide variety of conditions on a large number of substrates . In this paper, the available models for duplex layer formation are r eviewed in detail and the basic assumptions which are based upon them are examined. The mechanisms of formation of the duplex layers based o n microstructural observations in pure Ni and Ni-lat. % Cr systems dur ing high-temperature oxidation are addressed.