Al_2O_(3sf)/LY12复合材料液固挤压成形中温度场演变的三维有限元分析

3D FEM ANALYSIS ON THE TEMPERATURE FIELD DURING LIQUID-SOLID EXTRUSION PROCESS OF Al_2O_(3sf)/LY12 COMPOSITES

建立了液固挤压Al_2O_(3sf)/LY12复合材料三维非稳态传热过程的有限元数学模型,并对其进行了三维热传导数值模拟,直观地显示出材料内部和表面在不同时刻、不同位置的三维温度场分布及其演变情况.模拟结果表明,坯料内部和表面的温度场在保压过程中分布均匀,而在挤压过程中则随时间推移而剧烈波动,从而造成坯料表面局部过热,由此导致制件表面龟裂现象的发生.模拟结果与实验结果基本吻合,为合理确定工艺参数和保证成形质量奠定了理论基础.

The 3D finite element model which characterized the heat conduction in the liquidsolid extrusion process of Al2O3sf/LY12 composites was established, and the 3D temperature field was obtained. The results indicated that during the pressure-keeping stage, the temperature fields at the surface and inner part of the billet distributed evenly. In the extrusion process, however, they fluctuated tempestuously, which led to partial overheating on billet surface and resulted in superficial crack. The simulated results were verified by the experimental ones. The work laid a foundation for the rational choice of process parameter to enhance product quality.