The Research On Flow Field And Blade Wear In The Foaming Agitator With Aluminum Melt

Aluminum melt foaming and stirring is the key process to prepare aluminum foam.The final forming quality and properties of aluminum foam are determined by the dispersion of foaming agent in aluminum melt.But in the current aluminum foam manufacturing industry,The problem of uneven structure and low porosity is a technical problem in the preparation of high quality aluminum foam.In addition,the corrosion and wear of the impeller in the stirring process greatly affected the agitation efficiency and caused the contamination of molten aluminum.Therefore,it is of great significance to improve the dispersion uniformity of foaming agent in aluminum melt,to reduce the corrosion and wear of agitator,to reduce the power consumption of stirring,and to improve the stirring efficiency.In this paper,firstly,the two-fluid Euler model and standard k-? turbulence model are used to study the mixing flow field and the dispersing rule of foaming agent in aluminum melt,and to explore the factors influencing the dispersion of foaming agent particles.Secondly,the factors affecting the stirring power and the wear trend of the blade are analyzed.Finally,the experiment of foaming and stirring was established to study the corrosion and wear mechanism of the blade in aluminum melt,and to explore the factors of influencing blade wear and stirring power.Specific studies include:First,the basic law of stirred flow field and the dispersing law of foaming agent particles in aluminum melt were analyzed by analyzing the distribution of velocity,the distribution of turbulent kinetic energy and the trajectory of foaming agent particles.According to the local solid holdup and axial and radial velocity of particles in agitating tank,the effects of stirring structure and process parameters on particle dispersion were studied.Second,according to the similarity principle,the power correlation formula is derived,and the effects of blade structure,stirring speed and melt temperature on stirring power are studied.The distribution of shear stress and equivalent stress on the surface of blade is simulated and the wear condition of blade is analyzed.On the basis of this,the relationship between stirring parameters and blade wear is analyzed.Third,the relationship between stirring parameters and stirring power,and the relationship between stirring parameters and the wear of blade were verified by the experiment.The structural changes on the blade surface in the stirring process were analyzed microscopically,and the corrosion and wear mechanism of the blade was analyzed.