Melting metal - is a specific thermodynamic process in which the metal lattice is destroyed and it goes from a solid phase to a liquid.
melting temperature - outside temperature of the heated metal, above which begins the process of phase transition (melting).The process of the return of crystallization and is inextricably linked with it.In order to melt the metal?it must be heated using an external heat source to the melting point, and then continue the supply of heat energy to overcome the phase transition.The fact that the temperature itself indicates the metal melting temperature at which the material will be in the phase equilibrium at the interface between a liquid and a solid.At this temperature, the pure metal can exist simultaneously in both solid and liquid.For implementation of the process need to overheat the metal melting slightly greater than the equilibrium temperature to provide a positive thermodynamic potential.Post a kind of impetus to the process.
The melting point metal constant only for pure chemicals.The presence of impurities will shift the equilibrium potential in one direction or another.This is because the metal impurities with a different crystal lattice forms, and the forces of interaction between atoms in them will be different from those that are present in pure materialah.V depending on the value of the melting point, divided by the fusible metal (600 ° C, such as galliummercury), medium meltability (600-1600 ° C, copper, aluminum) and refractory (& gt; 1600 ° C, tungsten, and molybdenum).
In today's world, pure metals are rarely used due to the fact that they have a limited range of physical properties.The industry has long and densely uses different combinations of metals - alloys, types and characteristics of which are much larger.Melting of metals belonging to the various alloys will also differ from the melting point of the alloy.Different concentrations of the substances cause the order of their melting or crystallization.However, there are the equilibrium concentrations at which the metals belonging to the alloy melt or solidify simultaneously, i.e. behave like a homogeneous material.Such alloys are called eutectic.
know the melting point is very important when working with metal, this value is required in the production, for calculating the parameters of alloys and metal goods during operation, when the phase transition temperature of the material from which the product is made, determines limitations in its use.For convenience, these are summarized in a single table.Table melting metals - the combined result of the physical characteristics of various metals research.There are also similar to the table and alloys.Melting point metal also greatly depends on the pressure, so the data tables relevant to a particular pressure value (usually a normal condition when the pressure is 101.325 kPa).The higher the pressure, the higher the melting point, and vice versa.
