The thermophysical parameters of materials are used in the computer simulation of sand casting process, and this parameter plays a very important role in the accuracy of simulation results. Therefore, in order to obtain accurate simulation results and guide practical production, it is necessary to obtain more accurate thermophysical parameters, but it is very difficult to obtain the thermophysical parameters of materials, This is also one of the main factors affecting the numerical simulation of sand mold casting process.
There are many materials involved in the numerical simulation of sand casting process, and the performance parameters of material properties are also widely used. In the initial stage of numerical simulation of sand casting process, the temperature field of sand casting is mainly simulated, which mainly uses the thermophysical parameters of materials. As the application range of numerical simulation becomes wider and wider
The more widely used, the more and more material performance parameters are used, which are not limited to the range of thermophysical properties. Generally speaking, the material performance parameters mainly used in the simulation of sand casting casting process can be divided into several categories: including performance parameters for mold filling and solidification simulation, performance parameters for microstructure simulation and performance parameters for thermal stress analysis. Specifically, it mainly includes the physical parameters of the material itself, such as density and other thermophysical parameters related to heat transfer, such as specific heat capacity, thermal conductivity, specific baking and other parameters related to the shrinkage of sand castings, such as linear shrinkage coefficient, volume shrinkage coefficient and liquid flow, such as surface tension, viscosity and other parameters related to tissue changes, such as solute diffusion coefficient Phase transition temperature and other parameters related to mechanical properties, such as Poisson’s ratio, Young’s modulus of elasticity, yield stress, and electromagnetic parameters, such as conductivity.
The sand casting process involves many materials, including molding materials, casting materials, core making materials, etc. these materials have essential differences. To sum up, it can be seen that most of the casting materials are molding sand and metal materials, and the sand casting materials are basically metal materials. The molding sand is mixed with many kinds of materials, most of which include raw sand, water, binder and other additives. For example, the frequently used green molding sand is raw sand It is composed of water, clay and pulverized coal. For those materials with many kinds of mechanical materials, only their apparent parameters are basically obtained in numerical simulation. For sand casting materials, with the change of temperature in the process of sand casting, their existing forms will undergo three transformations: liquid, solid-liquid two-phase region and solid. The mold material will also change in the sand casting process, such as the evaporation of water, so the thermophysical parameters of the mold will change with the change of temperature.