Structural Basis of Interface Engineering

Abstract

The paper analyses in a systematic manner these structural factors of interfaces in relation to their properties that constitute the background of "interface engineering". It is shown that the specific properties of interfaces are related to their structure. A brief description of recent structural models of interfaces is therefore presented. A new concept of interface microstructure composed of different kinds of interfacial defects is introduced and their role in determining the interface properties is emphasised. It is shown that interfaces control the processes taking place in the material under external solicitations or during the microstructure formation, mainly through their interaction with other crystal defects. Various examples illustrating the possibility of controlling and improving the material properties by appropriate changes of interface structures are presented in the case of metals, alloys, intermetallics and ceramics.

AFM study of austeno-ferritic stainless steel microstructure after cathodic hydrogen charging

“…In state B, the recrystallisation that occurs during ␥ growth destroys the habitual N-W and K-S orientation relationships between the ␥ and ␣ phases and leads to a more random misorientation between these phases. This means that the main difference between the two states results in special IBs structure that is characterized by low energy in state A (where the IBs fulfill special ORs) and is random in state B (for which the IBs deviate from special ORs) [6]. Samples in the form of bars (8 mm in diameter) were machined to reduce their diameter to 3 mm and next sliced to 0.2 mm thick discs using a wire saw.…”