Theme: application of a rule of the lever in двухкомпонентных systems of knitting materials. System Al2O3-SiO2., Na2O-SiO2
Lecture № 23 ФХС
The diagrams of a condition will allow not only qualitatively to define(determine) a sequence of phase transformations at change of parameters of system, but also to make quantitative accounts of the contents of phases in multicomponent systems. In a basis of these accounts the so-called rule of the lever lays.
к М n
If one phase at change of parameters of system is decomposed to two other phases, the quantitative parity(ratio) of formed phases will be back to proportional lengths of pieces from a point of structure of an initial phase up to points of structures of formed phases. The points of structures of all three phases on the diagram of a condition lay on one direct line, and the points of structures of formed phases always settle down till both parties from a point of structure of an initial phase. Let's assume that the phase which structure is expressed by a point М is decomposed to two phases which structures are expressed by points to and n (for example, at cooling a liquid phase of structure М there is its(her) partial кристаллизация, therefore the liquid is decomposed to a crystal phase of structure to and liquid phase of structure n). According to a rule of the lever the quantitative parity(ratio) of phases to and n will be in inverse proportion to lengths of pieces Мn and Мк from a point of structure of an initial phase М up to points of structure of formed phases to and n. Thus we can write the following parity(ratio):
As Мк + Mn = кn the quantitative contents of phases expressed in percentage is possible to find from:
The contents of a phase to = of %
n = %
Mn, Мк, kn, are lengths of the appropriate pieces.