Slitiny s jevem tvarové paměti na bázi Ni-Ti-X, typy, vlastnosti a použití

Abstract

The object of this bachelor’s work is to introduce Nitinol, a modern technical material made of a shape memory alloy based on a NiTi intermetallic compound. The basic types of shape memory behavior and their characteristics are mentioned. The basics of the shape memory effect are only outlined because a full description of its physical and chemical principles is too extensive for this work, furthermore, it is still an object of scientific research. The work is focused on a possibility of creation of ternary systems, or more precisely alloying with other elements, mainly with copper, niobium, hafnium and wolfram. The object is to acquire new materials with promising usable characteristics. The process of industrial production of Nitinols is described here as well. The characteristics of shape memory alloys depend highly on the precise chemical composition. For that reason, pros and cons of each melting method are mentioned and, above all, the method of vacuum induction melting is highlighted. The important DSC method is mentioned here, too. Some concrete industrial applications of Nitinol parts, for example in connecting technologies or in medicine, are mentioned, whereas the origin of the superior biocompatibility is outlined. At the end, there is metallographic processing of testing samples of selected experimental alloys based on NiTi shown.