The reasonable gating system, riser, pouring temperature, pouring speed and other boundary conditions are optimized by using the criteria of mold filling and solidification time, solid rate distribution with time and shrinkage porosity percentage of sand castings. The specific results are as follows:
- Through ugnx8 The three-dimensional model of the cylinder head is created by 0 software, and the rapid sand casting design of the pouring system, sand core, riser and casting process parameters of the cylinder head is carried out by using the sand casting process CAD system developed in the laboratory;
- The powerful modeling function of UG provides a powerful guarantee for CAD design, and realizes the integration, visualization and agility from the three-dimensional creation of sand castings to the design of die structure. This method is conducive to the repeated modification of the model and improves the flexibility and efficiency of the design;
- The special thermocouple wire is used to collect the data of the experimental temperature field. Using the reverse heat conduction model established by ProCAST and combined with the temperature data collected from the experiment, the interface heat transfer coefficient between sand casting and mold is accurately solved. The specific values are as follows: the liquid temperature of ZL105 aluminum alloy is above the liquidus (622 ℃), and the heat transfer interface coefficient is 811w / (m2k). In the liquid-solid two-phase region (622 ℃ to 536 ℃), the interface heat transfer coefficient has an obvious decreasing trend. Below the solidus (536 ℃), the interface solidification coefficient decreases to 310W / (m2k), and then cools down and basically stabilizes at 230W / (m2k);
- Three kinds of mold filling and shrinkage system are used to simulate the mold filling and shrinkage process of castings, which can not only reduce the mold filling and shrinkage defects, but also obtain a good numerical simulation of the mold filling and shrinkage process of castings under different mold filling and shrinkage conditions;
- Through theoretical calculation and practical simulation, it is determined that the reasonable pouring temperature of ZL105 molten metal is 690 ℃ and the pouring speed is 0.22m/s.
- Phenolic urethane resin sand is selected as the molding material. The ideal ratio of components is component I: component II = 1:1, and component I accounts for 0.8% ~ 1% of the quality of the whole raw sand.