Inverse Algorithm And Experimental Research Of Interfacial Heat Transfer Coefficient During Casting For Copper Alloys

With the practical requirement of casting simulation technology gradually increasing,it has significance for optimizing the casting process and improving the overall performance of casting,to study the forming defects during numerical simulation processes.However,there are three main sources of error: model error,method error and parameter error.The parameter errors include the thermal property parameters,initial conditions and inaccurate boundary conditions.For metal casting,interface heat transfer coefficient is more important to the accuracy of simulation.In the process of numerical simulation,the model and solution method are often difficult to change.Therefore,how to obtain the accurate interface heat transfer coefficient has important practical significance.In this paper,the interface heat transfer between GKMS60 copper alloy and copper alloy mold is solved,and the heat transfer behavior between castings and mold is analyzed by solving the results.Then,by applying the identified IHTC in low pressure die casting process,it can accurate simulate the flow of casting in metal mold.Therefore,the accuracy of the simulation has been greatly improved.The main work of this paper is summarized as following:(1)Considering that complex model can lead to low efficiency,a one-dimensional antiheat conduction model was established,and a computer program was developed.The accurate of the inverse model is verified,and the accuracy and stability of the results are analyzed.Through the known temperature field data,the interface heat transfer coefficient is obtained.(2)In order to calculate the IHTC more accurately,a series of orthogonal experiments and temperature measurement tests were conducted to obtain thermal physical parameters of GKMS60 copper alloy.By acquiring the optimal test,the thermal physical parameters are obtained.Using the thermal physical parameters to the calculation of positive heat conduction in the process of interfacial heat transfer coefficient.(3)Gravity casting experiment was designed.The interface heat transfer coefficient of GKMS60 copper and copper chill is obtained based on measured temperatures near the interface position.And It is found that the IHTC varies in the liquid-solid phase.The values are in the range of approximately 1000-2700(W/m2/K).(4)Using the IHTC calculated by inverse heat conduction method to the simulation of low pressure die casting.The compared results between the numerical simulation and the experiment confirm that the accuracy of numerical simulation is improved,which provides an important reference for optimizing process scheme and improving product quality.