Tham khảo tài liệu 'surface engineering of metals - principles, equipment and technologies part 11', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | composition physical diffusion permanent deformation of mechanical and thermal origin melting or solidification structural recrystallization phase transformations causing a change of properties relative to those of the core . microgeometry of the surface microstructure microhardness brittleness adhesion adsorption residual stresses etc. . Changes in the properties of the superficial layer relative to core properties obtained as a result of the treatment operation are of a potential character. In simple words the superficial layer has such and such properties. There may be changes several times in the desired direction by subjecting already obtained surface layers to successive treatment operations. Always the final properties of superficial layers obtained as a result of the considered treatment operation also called initial feature initial properties for the next operation etc. And each time these properties are of a potential character. Fig. Diagram of basic transformations taking place in the superficial layer as the result of friction. These properties acquire a usable or functional character only after exposure of the superficial layer usually formed on a tool a machine component or other object to a definite external technical hazard single 1999 by CRC Press LLC or multiple like contact with another system . air lubricant material or to the effect of an external system . external mechanical or thermal loading . A change of potential solid geometry and physico-chemical properties of the superficial layer causes changes of usable properties of the object. These changes usually although not always go in the direction of the enhancement of those properties which are connected with the physical surface of the object beginning or occurring at the surface such as tribological fatigue anti-corrosive decorative electrical thermal optical and other. During service the technological superficial layer will be subjected to similar external hazards as during .
