Numerical simulation of rheo squeeze casting of 7075 aluminum alloy

(1) Based on the calculation module of AnyCasting, the material thermal property model and parameters of 7075 aluminum alloy wheel shaped squeeze casting were set, and the process parameters and boundary conditions were set according to the experimental data; the wheel shaped part was modeled, and the pre-processing of numerical simulation of 7075 aluminum alloy wheel shaped squeeze casting was carried out.

(2) The filling process of wheel shaped squeeze casting parts was analyzed. It was found that defects such as gas entrapment and shrinkage cavity were easy to occur at the top of the center of the parts. The alloy melt flow intersection occurred at the junction of the narrow annular channel and the outer side of the annular channel. Inclusions, pores or cold shut defects were easy to occur at this part. The simulation results showed that the probability of defects could be reduced by setting the vent and overflow slot, and there were some defects It is beneficial to improve the quality of castings.

(3) With the increase of pouring temperature, the probability defects gradually disappear, but the probability defects in the core increase. There is an optimal pouring temperature near 630 ℃. The mold temperature has obvious influence on the temperature field of the parts, and there is a better mold temperature between 160 ℃ and 200 ℃.

(4) When the filling speed is 0.4m/s, the air entrainment is serious and the probability of defects is increased. When the filling speed is 0.2m/s, the smooth and high quality parts can be obtained.

(5) The process parameters of 7075 alloy wheel shaped squeeze casting parts with good quality were obtained by orthogonal experiment method. Through comparison, the defective parts were basically consistent with the simulation data. The results show that when the pouring temperature is 635 ℃, the filling speed is 0.2m/s, and the mold temperature is 200 ℃, the probability defect parameter distribution is the least, and the quality of squeeze casting parts is excellent, which is consistent with the experimental results in Chapter 4.