Development prospect of sand casting simulation technology

Since the 21st century, solidification numerical simulation technology has been developing continuously, and is now in the stage of optimization design. The numerical analysis of flow field and temperature field in the process of filling and solidification of axle housing has been relatively mature, and the simulation analysis technology of sand casting will develop in the following directions:

(1) Microstructure simulation. The previous numerical simulation analysis focused on grasping the profound changes of metal in the solidification process from the macro aspect. At present, scientific research institutes such as Kunming Institute of technology and FAW casting have focused on the research on the microstructure of axle housing. The main research methods include phase field method, Monte Carlo method and automatic cell machine method. The microstructure observation is carried out in the form of the combination of levelset technology and phase field method, but it is still in the exploration stage, and the simulation of too small units can not be divided accurately.

(2) Thixotropic sand mold casting simulation. Thixotropic sand casting is the key development direction of modern sand casting industry. Shooting and pressing semi-solid metal into the mold, increasing shear speed, reducing metal viscosity and improving fluidity, and using power cut-off model for analysis and calculation is a new hot spot at present.

(3) Artificial intelligence system. The production structure is mainly composed of knowledge database of rules and facts, control strategy inference engine system, knowledge acquisition module and man-machine window, including numerical analysis, quality analysis function and even learning function. The system can comprehensively analyze the defects existing in the sand mold casting process and put forward corresponding solutions, And improve product quality.

(4) Metal inclusion simulation. According to the relevant theoretical knowledge of metallurgy, the introduction of primary inclusions and the formation of secondary oxidation inclusions in the smelting process are simulated and analyzed.

(5) Study on complex multiphase flow. Specifically, the liquid metal is the liquid phase; The entraining and precipitating gases are gas phase; Oxidation inclusions and washed sand particles are solid phase. Therefore, in theory, if you want to accurately simulate the filling process of sand mold casting, you must study and fully integrate the multiphase flow, such as the calculation and analysis of inclusions, stamping and cavitation are inseparable from the simulation of multiphase flow.