With 16 FiguresThe aim of this chapter is to review mainly the elastic and anelastic behaviour of metallic glasses and to discuss their relevance to structure, atomic dynamics and other properties. Since metallic glasses are usually only available in the form of thin foils (ribbons, splats or thin films adherent to a substrate), a brief description of the experimental techniques appears to be appropriate also. The chapter will be divided in different sections according to the different types of stress-strain behaviour exhibited by metallic glasses.
OverviewThe mechanical properties of crystalline metals are well-known to be, in many respects, strikingly different from the behaviour of., say, a window glass which is commonly considered to be a typical representative for a glassy material. Glasses are usually very hard and brittle, whereas metals apart from a few exceptions are soft and ductile. Since the mechanical properties have their roots in electronic as well as structural properties, metallic glasses may be expected to present interesting behaviour.But how do metallic and glassy properties combine in one material? Do we get materials with intermediate properties or do we get materials which show in some respects glass-like behaviour and in others metallic behaviour? From the point of view of basic science, this is certainly an interesting question which to a great extent is related to fundamental problems in the understanding of mechanical properties. The more application-minded engineer, on the other hand, may expect to find materials with a yet unknown combination of properties probably suitable for particular applications.Furthermore, it is well-known from numerous investigations in crystalline materials that the mechanical properties are highly dependent on short-range order and the presence of lattice defects and impurities. This seems to be true also for amorphous solids with an almost equal sensitivity and therefore represents, in many cases, additional motivation to look into the mechanical properties of these new materials. This fact is in marked contrast with the behaviour of other physical properties such as the electrical resistivity which is known to be highly sensitive to deviations from a perfect order in crystalline metals; in amorphous materials the electrical resistivity merely reflects the