【作者】 张燕；

【导师】 李锋；

【作者基本信息】 沈阳工业大学 ， 材料学， 2006， 硕士

【摘要】 本课题利用仿真软件Flow-3d对480sc气门室罩盖、ZJ1、ZJ2空压机支架及S11空调机支架等镁合金压铸件的充型过程进行了模拟仿真。模拟仿真过程分为前处理、数值运算和后处理三个部分,而前处理是比较重要的部分。首先利用三维建模软件建立各铸件的几何模型并将其导入到模拟软件中,根据各铸件的形状壁厚等不同特点进行剖分,避免剖漏或增加网格数量。随后设定边界条件确定合金液入口方向,设定物性参数及工艺参数进行模拟,进而得到一系列模拟结果。根据温度场及缺陷分布的模拟结果针对480sc气门室罩盖的模具进行了优化,对ZJ1空压机支架的模具温度、ZJ2空压机支架的冲头速度及S11空调机支架的浇注温度等进行了优化设计,以确定优化工艺。在相应的工艺参数条件下进行实际压铸件的压制,分别在压铸件上取样并制备非标准拉伸试样,检测实际压铸件的拉伸性能,并对其断口进行了扫描,分析断口形貌。在压铸件上取样制备金相试样,分析各压铸件的显微组织。 研究结果表明,利用Flow-3d仿真软件进行压铸模拟仿真时,网格剖分环节是比较重要的,充分利用软件所提供的非均匀网格剖分的功能可以大大减少运算时间。压铸时浇注系统的合适与否对充型过程有着很重要的影响。根据模拟结果对480sc气门室罩盖浇注系统的改进大大地改善了充型的效果。通过不同工艺条件下模拟结果的对比分析确定了优化的ZJ1空压机支架的模具温度、ZJ2空压机支架的冲头速度及S11空调机支架的浇注温度等工艺参数。在优化的工艺参数下进行压铸避免了材料的无畏损耗,也缩短了试制周期。实际压铸件的检测分析表明压铸件性能良好,优化比较成功。更多还原

【Abstract】 In this paper, the mold filling simulations were done with the aid of Flow-3d software. The magnesium alloys die casts referred in the paper were 480sc valve chamber cover, ZJ1 dynamotor support, ZJ2 dynamotor support and S11 air condition support. Simulation comprises pre-process, solver process and post-process. The pre-process is an important process. The 3-D geometrical entity should be imported into the simulation software first. Then the proper meshing should be done according to the die-cast features in order to avoid the incompletion or the increase of the mesh quantities. The boundary conditions and process parameters should be determined subsequently. Then the simulation could be done. The gating system could be optimized based on the analysis of the simulation results. At the same time, the process parameters such as the temperature of the melt alloy, the temperature of the die and the injection velocity could be optimized. In this paper, only one example was explained about each optimization item. The mold optimization was done on 480sc valve chamber cover. And the optimizations of die temperature, the injection velocity and the melt alloy temperature were respectively done on ZJ1, ZJ2 dynamotor support and S11 air condition support. The practical die casts were made under the optimized process parameters. The nonstandard tensile specimens were gotten from die casts. The mechanical properties of die casting magnesium alloys were investigated. And by means of SEM, observations on fracture surfaces were carried out.The study shows that meshing is an important part in the die-casting simulation process. Solving time could be obviously deduced with good use of non-uniform meshing. The gating system has great influence on the filling process. So the filling results could be improved through modifying the gating system according to the simulation results. During the checking process, the properties of the die casts could be determined. On one hand, the die casts in this paper are complex and the specimens are nonstandard, while the referred values are of simple die casting round bar. On the other hand, maybe the process parameters are still not the mostoptimized. But these results already meet the need of the practical engineering. So the experiments are comparatively successful.更多还原