Surface and internal energy of metal

Metal products form the main baseinfrastructure support of engineering communications, act as raw materials for the machine-building industry and construction. In each of these areas, the use of such elements is associated with high responsibility. The installation and communication structures are affected by both chemical and mechanical loads, which necessitates a primary analysis of the properties of the material. To understand operational parameters, a concept is used, such as the energy of a metal, which determines the behavior of an individual element or structure under various operating conditions.

Free energy

A lot of processes in the structure of metallicproducts is determined by the characteristics of free energy. The presence in the material of ions with this potential leads to their transfer to other media. For example, in the course of interaction with solutions containing similar ions, the metallic elements go into the contact mixture. But this happens in cases when the free energy of metals exceeds those in solution. As a result, a positive electric field of the double electric field can be formed due to the free electrons remaining near the metal surface. Strengthening this field also acts as a barrier to the passage of new ions - thus creating a phase boundary that prevents the transitions of the elements. The process of such displacement continues until the limiting potential difference is reached in the newly formed field. The peak boundary is determined by the balance of the potential differences in the solution and the metal.

Surface energy

When new molecules get on metalsurface is the development of free zones. During the migration, the molecules occupy the surface of the microcracks and the areas of separation of small grains - these are the segments of the crystal lattice. Under such a scheme, the free surface energy changes, which decreases. In solid bodies, it is also possible to observe processes of facilitating plastic flow on surface areas. Accordingly, the surface energy of metals is determined by the forces of attraction of molecules. Here it is worth noting the magnitude of the surface tension, which depends on several factors. In particular, it is determined by the geometry of the molecules, their forces and the number of atoms in the structure. The location of molecules in the surface layer is also important.

Surface tension

Typically, tension processes occur inHeterogeneous media that differ in the interface of immiscible phases. But it should be noted that along with the tension, other surface properties are also manifested, due to the parameters of their interaction with other systems. The combination of these properties determines the majority of the technological indicators of the metal. In turn, the energy of the metal, from the point of view of surface tension, can determine the parameters of the coalescence of droplets in alloys. Technologists, therefore, reveal the characteristics of refractories and fluxes, as well as their interaction with the metallic medium. In addition, the surface properties affect the speed of thermotechnological processes, among which the evolution of gases and foaming of metals.

Zoning of Energy and Properties of Metal

It has already been noted that the distribution configurationmolecules on the structure of the metal surface can determine the individual characteristics of the material. In particular, the specific reflection of many metals, as well as their opacity, are due to the distribution of energy levels. The accumulation of energies in free and occupied levels contributes to the allocation of any quantum by two energy levels. One of them will be located in the valence band, and the other in the conduction regions. It can not be said that the energy distribution of electrons in a metal is stationary and does not imply any change. Elements of the valence band, for example, can absorb light quanta, migrating to the conduction band. As a result, light is absorbed, not reflected. For this reason, metals have an opaque structure. As for the brightness, it is caused by the process of light emission when returning electrons activated by radiation to low energy levels.

Internal energy

This potential is formed by the energy of the ions, andalso by the thermal motion of conduction electrons. Indirectly, this value is characterized by the intrinsic charges of metal structures. In particular, for steel that is in contact with electrolytes, its own potential is automatically set. Many unfavorable processes are associated with changes in internal energy. For example, in this indicator, it is possible to determine corrosion and deformation phenomena. In such cases, the internal energy of the metal causes the presence of micro- and macro-faults in the structure. Moreover, the partial dissipation of this energy under the action of the same corrosion also ensures the loss of a certain fraction of the potential. In the practice of the operation of metal products, the negative factors of the change in internal energy can be manifested in the form of structural damage and a decrease in ductility.

The energy of an electron in a metal

When describing the aggregate of particles thatinteract with each other in a solid, quantum mechanical concepts of the energy of electrons are used. Usually, discrete values ​​are used that determine the nature of the distribution of these elements over energy levels. In accordance with the requirements of the quantum theory, the measurement of the electron energy is carried out in electron-volts. It is believed that in metals the electron potential is two orders of magnitude higher than the energy, which is calculated from the kinetic theory of gases under room temperature conditions. In this case, the energy of the electrons from the metals and, in particular, the velocity of the elements do not depend on the temperature.

The ion energy in the metal

Calculation of ion energy allows one to determinecharacteristics of the metal in the processes of melting, sublimation, deformation, etc. In particular, the technologists identify the tensile strength and elasticity. To do this, we introduce the concept of a crystal lattice, in which the ions are located. The energy potential of an ion is usually calculated taking into account its possible destructive effect on a crystalline substance with the formation of composite particles. The state of ions can be affected by the kinetic energy of electrons knocked out of metals during the collision. Since under the conditions of increasing the potential difference in the medium of electrodes to thousands of volts, the velocity of particle motion increases significantly, the accumulated potential is sufficient for splitting counter molecules into ions.

Power of communication

Metals are characterized by mixed types of connection. Covalent and ionic bonds do not have a sharp distinction and often overlap with each other. Thus, the process of hardening of a metal under the action of doping and plastic deformation is explained just by the flow of a metal bond into a covalent interaction. Regardless of the type of these links, they are all defined as chemical processes. At the same time, each link has energy. For example, ionic, electrostatic and covalent interactions can provide a potential of 400 kJ. The specific energy will depend on the energy of the metal when interacting with different media and under mechanical loads. Metal bonds can be characterized by different strength indicators, but in any manifestation they will not be comparable with similar properties in covalent and ionic media.

Properties of metal bonds

One of the primary qualities thatcharacterize the binding energy, is saturation. This property determines the state of the molecules and, in particular, their structure and composition. In a metal, the particles exist in a discrete form. Previously, the theory of valence bonds was used to understand the operational properties of complex compounds, but in recent years it has lost its significance. With all its advantages, this concept does not explain a number of important properties. Among them, we can note absorption spectra in compounds, magnetic qualities, and other characteristics. But when calculating the energy of the surface in metals, one can identify such a property as flammability. It determines the ability of metal surfaces to ignite without detonating activators.

Status of metals

Most metals are characterized by a valenceconfiguration with electronic structure. Depending on the properties of this structure, the internal state of the material is determined. On the basis of these indicators and taking into account the relationships, one can draw conclusions about the values ​​of the melting temperature of a particular metal. For example, soft metals, including gold and copper, have a lower melting point. This is explained by the decrease in the number of unpaired electrons from the atoms. On the other hand, soft metals have high thermal conductivity, which, in turn, is due to the high mobility of the electrons. By the way, the metal accumulating energy under conditions of optimal conductivity of ions, provides high electrical conductivity due to electrons. This is one of the most important performance characteristics, which are determined by the metallic state.

Conclusion

The chemical properties of metals largely determinetheir technical and physical qualities. This allows specialists to focus on the energy performance of the material, in terms of the possibility of its use under certain conditions. In addition, the energy of the metal can not always be regarded as independent. That is, its own potential can vary depending on the nature of interaction with other media. The most expressive relationship of metal surfaces with other elements is the example of migration processes, when the filling of free energy levels occurs.