Study On The Preparation Of Aluminum Semi-solid Slurry

Semi-solid forming technology is an important part of research with the application of new materials and new technologies,the preparation of semi-solid slurry is the basis on semi-solid processing technology.1 series aluminum alloys(hereinafter referred to as "aluminum")used in chemical equipment,rail transportation,food industry,heat exchange.etc.For controlling the solid ratio in the preparation process of small solidifying interval and semi-solid slurry is easiness,it is difficult to obtain high quality parts by semi-solid forming technology.To solve this problem,a control approaches that controlling semi solid slurry ratio by controlling the heat change process was proposed by this paper.According to the approaches of the technology,this paper studies a latent heat control method for semi-solid slurry with solidified interval,and studies the preparation parameters of aluminum semi-solid slurry.The specific research works are as follows:(1)Simulating the stirring process of aluminum semisolid slurry.The electromagnetic-heat complex simulation is a means to study the heat transfer process in the preparation of semi-solid slurry.The electromagnetic field was simulated with the ANSYS electromagnetic module,and the FLUENT convection field was used to simulate the electromagnetic field.According to the change of the temperature field and the heat transfer process of melt flow,the expression of the solid fraction and the latent heat was derived.This method to relate the stirring time and the solid state rate,and it's provides guidance and reference for the follow-up experiment.(2)Preparation experiment of aluminum semisolid slurry with heat release.With the simulation of the stirring process,the semi-solid aluminum slurry was prepared by the electromagnetic stirring device.This experiment adjusted asbestos and heating tube to control the solid fraction of the semi-solid slurry.A number of fast-cooling quenching test specimens and their metallographic images were obtained at every constant exothermic time.The relationship between the solid state rate and the exothermic time of the semisolid slurry was obtained by the microstructural analysis of the specimens.The correction coefficient was obtained by comparing the experimental data with the simulated data for correcting simulation expression.(3)Preparation experiment of aluminum semisolid slurry with heat absorbs.The power of heating pipe was control method to control the solid fraction of the semi-solid slurry which affects the absorption of latent heat of melting.The power of the heating tube was determined by the simulation results.A number of fast-cooling quenching test specimens and their metallographic images were obtained at every constant endothermic time.The relationship between the solid state rate and the endothermic time of the semisolid slurry was obtained by the microstructural analysis of the specimens.Controlled by the release of the latent heat and the absorption of the latent heat in the solidification process of the solidification interval,the solid fraction of semi-solid aluminum slurry was controlled.This study provides a theoretical reference for the preparation of the 1 series aluminum alloy and the preparation of the semi-solid metal slurry with narrow solidification interval.