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在前期Al_2Y/AZ91镁基复合材料流变性能的研究基础上,将建立的Al_2Y/AZ91镁基复合材料表观粘度模型导入模拟软件,对Al_2Y/AZ91镁基复合材料液态及半固态充型及凝固过程进行了模拟,对压力场、速度场、固相分布和成形过程的缺陷进行了分析,结果表明,液态充型压力分布比较紊乱,熔体的流态为紊流,在型腔中容易产生涡流现象,在凝固过程中,铸件内部的冷却速度不一致,后续凝固的涡流区域在凝固过程中得不到有效的金属液的补充,进而容易产生缩孔缩松。半固态充型过程熔体内部压力传递相对比较平稳,速度分布均匀,熔体的流态表现为层流,不会产生涡流,铸件内外凝固速度相差不大,在整个凝固过程中不容易产生缩孔缩松等缺陷。为了验证模拟结果的正确性,进行了复合材料的流变成形实验,由实验可知,流变成形铸件显微组织以球状晶为主,没有孔洞缺陷,铸件成形质量较好。实验结果与模拟结果较吻合。
Based on the previous study on the rheological properties of Al_2Y / AZ91 magnesium matrix composites, the apparent viscosity model of Al_2Y / AZ91 magnesium matrix composites was introduced into the simulation software to investigate the rheological properties of Al_2Y / AZ91 magnesium matrix composites. The process of solidification is simulated. The defects of pressure field, velocity field, solid phase distribution and forming process are analyzed. The results show that the pressure distribution of liquid filling is disordered and the flow state of the melt is turbulent, which is easy in the cavity Resulting in eddy current phenomenon. During the solidification process, the cooling rate in the interior of the casting is inconsistent. The subsequent solidification of the eddy current area can not be supplemented by the effective liquid metal in the solidification process, which leads to the occurrence of shrinkage shrinkage. In the process of semi-solid filling, the pressure inside the melt is relatively stable and the velocity is evenly distributed. The fluid flow in the semi-solid filling process is laminar and eddy current is not generated. The solidification speed inside and outside the casting is similar, and it is not easy to shrink during the whole solidification Hole shrinkage and other defects. In order to verify the correctness of the simulation results, the rheo-forming experiment of the composite material was carried out. It can be seen from the experiment that the microstructure of the rheo-formed castings is dominated by spherulites and has no hole defects, and the forming quality of the castings is good. The experimental results are in good agreement with the simulation results.