Research On Automatic Casting Process Equipment And Parameter Optimization Of Zinc Alloy Large Ingot

The level of casting technology has become an important symbol to measure the level of a country’s manufacturing industry,a high level of casting technology can not only produce excellent performance,good quality castings,but also improve the production efficiency of enterprises and reduce production costs.At present,the domestic production of zinc alloy large ingots has a low degree of mechanisation,manual labour intensity and other problems,while foreign casting technology has achieved mechanisation,automation and intelligent production.On the basis of the existing zinc alloy large ingot production equipment,the thesis uses casting numerical simulation technology to carry out research on the automatic casting process equipment and parameter optimisation of zinc alloy large ingots.As the follows show,this paper main research contents are:The traditional zinc alloy large ingot casting mould was used as the research object to complete the design optimisation of the mould.Firstly,the mould sample was designed,the mould interior was designed as a cooling channel,and the mould water cooling system was designed according to the low inlet and high outlet.Then,the mould sample simulation analysis and water cooling tests were completed.The results show that 15 CrMoR is suitable for mould welding material and the channel cooling can reduce the cooling time of the casting,reduce the difficulty of demoulding and improve the surface quality of the casting.Finally,the overall design of the channel cooling mould and the design of the mould water cooling system were completed.Numerical simulations were carried out on the designed channel cooling mould for the casting of large zinc alloy ingots under conventional cooling and channel cooling.The numerical simulation results show that the channel cooling method has a greater advantage than the conventional cooling method: the cooling time is reduced by approximately 1354s,the outer surface of the casting is smoother and the total shrinkage porosity of the casting is reduced from 46.54% to 0.79%.According to the designed channel cooling mould,the optimisation of the process parameters and the structure of the mould water cooling system for large ingot casting of zinc alloy were completed.Firstly,a four-factor,three-level orthogonal experiment was designed to determine the order of strength of the four process parameters on the casting quality based on grey correlation analysis: pouring temperature>cooling water flow rate>mould pre-heating temperature>pouring speed.Then,based on the response surface method,the casting process parameters were optimised and the optimum process parameters were obtained as follows: pouring temperature 413℃,pouring speed 4.7 kg/s,mould preheating temperature 140℃,cooling water flow rate 1.5 m/s,and the total shrinkage porosity of the casting was further reduced to 0.49%.Finally,the structure of the mould water cooling system was optimised based on computational fluid dynamics.After optimisation,the overall cooling water flow rate was increased,the backflow phenomenon was alleviated,the dead water area was reduced and the mould water cooling effect was improved.