铝合金汽车转向节精密铸造工艺研究

目的 对某铝合金汽车转向节的精密铸造工艺进行设计与优化研究，以得到合格的铝合金汽车转向节的精密铸造工艺方案。方法 结合铝合金转向节铸件的结构特征、铸件材料特性和铸造经验，在转向节铸件主体部和鹅颈部各开设一个内浇口，设计了铝合金转向节初始浇注方案;通过在初始工艺方案中铸件缺陷较严重的区域设置补缩冒口、在铸件顶部增设排气道等措施给出了铝合金汽车转向节的优化浇注方案，基于ProCAST软件建立了铝合金转向节精密铸造2种浇注方案的有限元模型，对铝合金转向节精密铸造的充型过程、凝固过程及缩孔缩松特性进行了数值模拟与分析。结果 铝合金转向节铸件初始浇注方案的充型过程相对稳定流畅，铸件在凝固过程中有孤立液相区的形成，完全凝固后铸件中间部位存在大面积缩松缩孔缺陷;优化浇注方案能够控制金属液的流动、充型顺序及凝固特性，铸件的整个凝固过程基本呈中间对称分布，最后凝固区域位于补缩冒口内部，最大缩孔缩松率控制在2%以下。结论 优化浇注方案的设计合理且有效，能够有效地消除铝合金转向节铸件的缺陷。

Precision Casting Process of Aluminum Alloy Automobile Steering Knuckle

The work aims to design and optimize the precision casting process of a certain type of aluminum alloy automobile steering knuckles to obtain a qualified precision casting process scheme of aluminum alloy automobile steering knuckles. Based on the structural characteristics, material properties and casting experience of aluminum alloy steering knuckle castings, an ingate was opened in the main body and the goose neck of the steering knuckle casting respectively, and an initial pouring scheme of aluminum alloy steering knuckles was designed. The optimized pouring scheme of aluminum alloy automobile steering knuckles was given by setting feeding risers in the area with serious casting defects in the initial process scheme and adding exhaust ducts at the top of the casting. Based on ProCAST software, the finite element models of two pouring schemes for precision casting of aluminum alloy steering knuckles were established, and the filling process, solidification process and shrinkage porosity characteristics of precision casting of aluminum alloy steering knuckles were numerically simulated and analyzed. The filling process of the initial pouring scheme of the aluminum alloy steering knuckle casting was relatively stable and smooth, and the isolated liquid phase zone was formed during the solidification process of the casting. After solidification, there was a large area of shrinkage defects in the middle of the casting. The optimized pouring scheme could control the flow, filling sequence and solidification characteristics of the molten metal. The whole solidification process of the casting basically presented a symmetrical distribution in the middle. The final solidification area was located inside the feeding riser, and the maximum shrinkage porosity was controlled below 2%. The design of optimized pouring scheme is reasonable and effective, which can effectively eliminate the defects of aluminum alloy steering knuckle castings.