ABOUT STRUCTURE AND PROPERTIES OF SOME HEAT-RESISTANT NICKEL ALLOYS
Various models of metal melts structure are considered. According to modern research, the structure of the liquid is complex and consists of various atomic associations. They are clusters and intercluster space. There are no clear boundaries between the individual structural components. Intercluster ruptures are gaps about 0.1 nanometers wide that are opened and closed when clusters diverge and convergence during thermal oscillations. Thermodynamic calculations allow to determine the number of clusters and atoms in the cluster and some other characteristics of structural parameters of liquid metal, as well as to find their temperature dependence. The proposed approach to the analysis of structure and properties leads to new information about the state of metal melts. In particular, it is known that properties such as kinematic viscosity, density and surface tension are significantly dependent on the size and number of clusters, as well as the characteristics of intercluster space. In addition, the polytherms of calculated parameters adequately reflect the nature of temperature dependencies of properties. The work examined samples of pure nickel and four heat-resistant alloys. Characteristics of the structure of the researched heat-resistant alloys were close in size and type of temperature dependence. The data on liquid nickel are described by a similar temperature dependence and slightly different from heat-resistant nickel alloys. The type of temperature dependencies of the properties of heat-resistant nickel alloys differs significantly from the patterns characteristic of pure metal. Polytherms of kinematic viscosity, density and surface tension of heat-resistant nickel alloys change illegally and are characterized by hysteresis, i.e. a mismatch of the magnitude of properties received by heating and cooling. Polythers of specific resistivity of heat-resistant nickel alloys in the temperature interval “solidus-liquividus” varies by 3-4 % almost in a leap. The use of various existing models of metal liquids structure allows to expand the possibility of discussing the structure and properties of the studied object and revealing its significant features. Keywords: liquid metal, high-resistant alloy, structure, claster, intercluster space, properties