Numerical Simulation And Process Parameter Optimization Of Twin-roll Cast Magnesium Alloy Thin Strip

Magnesium alloy,as the lightest metal material,has special scientific research value and broad application and development prospects in China's electronic and electrical industry,defense military industry and other related fields due to its excellent comprehensive characteristics.At present,there is a large demand for magnesium alloy sheets in the market.Due to the limitation of its own element structure,there are many problems in rolling and forming,which leads to the complexity of the production process of magnesium alloy sheets,which seriously limits the development of magnesium alloy materials and use.Twin-roll casting technology is an international frontier technology in the field of material processing.It can greatly shorten the processing flow of magnesium alloys and reduce production costs.It is one of the main research hotspots in China's magnesium alloy industry.However,in the process of magnesium alloy twin-roll casting and rolling,there are many process parameters.If the process parameters are verified and optimized through experiments,it will be a waste of time,manpower and financial resources.The development of computer simulation technology has solved this problem.The use of numerical simulation can cost less in a shorter period of time and produce meaningful results to effectively guide the experiment.In this paper,the twin-roll cast magnesium alloy thin strip forming process is selected as the research direction,and the numerical simulation of the magnesium liquid flow,heat transfer and solidification process in the molten pool during the twin-roll cast magnesium alloy thin strip forming process is carried out.The results obtained by the research have theoretical significance and practical value for the industrial application of the technology.This paper uses ANSYS finite element software to systematically study the key problems in the process of twin-roll casting magnesium alloy thin strip,and obtains the expected research results.The main work and innovative research results of this article are as follows:(1)According to the characteristics of the twin-roll casting process,a control equation that can describe the turbulent flow,heat transfer and solidification process in the twin-roll casting process is established.The key issues such as solid phase rate,latent heat of solidification and turbulent viscosity are dealt with,and a unified equation describing turbulent flow is given.(2)According to the characteristics of solidification and deformation of casting and rolling,the prediction model of the position of solidification point is established by the method of heat balance calculation,and the relationship between the casting and rolling parameters and the position of solidification point is obtained.(3)Combining hot rolling theory and modern continuous casting theory,a casting force calculation model is established,which solves the shortcomings of the calculation difficulty and large amount of calculation when solving the stress equation algorithm,thus simplifying the complicated casting force calculation.(4)The flow field and temperature field in the twin-roll cast magnesium alloy thin strip forming process were numerically simulated using the theory of heat flow coupled finite element analysis.The influence of different process parameters(casting speed,casting temperature,roll gap size,casting zone length)on the temperature field of casting zone and casting force is revealed.(5)The method of finite element simulation analysis combined with orthogonal analysis is used to optimize the casting and rolling process parameters(casting speed,casting temperature,roll gap size,casting zone length,water cooling strength),and optimize to obtain the best Process parameter combination: casting and rolling temperature is 720 ?,casting and rolling speed is 1m / min,roll gap width is 2mm,casting and rolling zone length is65 mm,and water cooling strength is 12000.