On Mathemodels Of Solidifsegregation Homogenization And Its Kinetic Control

In the thesis,the effort is to research on controlling phase transformations and physico-metallurgical qualities by kinetics on condition that meets the needs of thermodynamics. In view of generality and importance of effects of dendrite segregation on structures and properties of casted alloy materials, accurate mathematical models of diffusion homogenization of dendrite segregation must be set up,thus parameters of physico-metallurgical quality control can be found. As an example the dendrite segregations of alloy Fe-C-Mn-Si are selected for experiment to analyse controlling effects of diffusional mass-transfer kinetics on structures and properties of materials.First, according to solute concentration equations of solidified dendrites and measures of practical concentration distributions, the Gauss equation rather than sine equation can be estahlished as the model of diffusion homogenization of dendrite segregation. As for a single dendrite, the concentration equation of its diffusional element can be given as follows:Then,The concentration distribution equation of (2n+1) segregational dendrites with different interspaces and forms can be obtained through proper mathematical treatments as follows:...