List of publications on a keyword: «melting»

The SLM-process has been optimized for manufacturing of parts from Co-base alloy powder on the machine ПТК-ПС. The XRD analysis is researched and physic-mechanical properties of the samples made on optimum parameters of selective laser melting are defined.

This article brings together previously published evidence of the unified nature of physical processes and phenomena in terms of changes in the energy of a substance molecule. The unified physical nature of all these physical phenomena has been proven, as a single multistage process of energetic unpacking of molecules of a substance, which is logical to call the molecular-energy concept of unpacking a substance. The considered processes include the following processes. Surface rupture, characterized by the surface tension coefficient. The melting process of a substance characterized by its melting point. A boiling process characterized by the boiling point. Evaporation (and condensation) process characterized by internal energy and enthalpy as well as critical point. The conclusions of the theory are confirmed by well-known empirical dependences and by reference books of the physical properties of simple substances: internal energy, enthalpy, surface tension, melting point, boiling point and critical point.

According to the properties of melting points and boiling points of the elements of the periodic table of D.I. Mendeleyev the application of the unpacking hypothesis of the substance was verified. The article contains the results of the verification. In general, according to the data for 98 substances taken from the information in Internet, convergence of results with an error of up to 40% for 73 substances was obtained. The effect of periodicity on the result is found. An exception to the calculated dependences was obtained for ten substances: noble gas and most halogens. A large discrepancy between the theoretical formulas and the reference data was also caused by the 14 elements of the middle groups.

We received theoretical formulas of the interconnection between melting, boiling and critical temperatures. Uniform physical representation of melting, boiling and evaporation processes was the basis for deriving the formula of interconnection between them. We use the concept of the material substance internal energy in terms of the molecules “unpacking” idea. The reference manual data on 85 substances from 13 to 855 degrees Kelvin confirms the theoretically derived formulas. We carried out the comparison of theoretical formulas and experimental data by their mean values. A simple ideal substance model with spherical molecules was considered as a model of substance molecule. The melting point is 1/3, and the boiling point ranges from 1/2 to 2/3 of the critical point for this model.