壁厚不均匀是轮毂类铸件的结构特点之一，这类铸件易在热节处形成缩孔、缩松并于缩孔和缩松处产生应力集中，使铸件的机械性能显著降低。由于轮毂是汽车上的重要零件，故对这些缺陷的限制更严格。影响轮毂缩孔、缩松的主要原因是由于铸件在凝固过程中，合金的液态收缩和凝固收 Inhomogeneous wall thickness is one of the structural features of the wheel hub castings. Such castings are easy to form shrinkage cavities at the hot joints, shrinkage and stress concentration at the shrinkage cavities and shrinkage, resulting in a significant reduction of the mechanical properties of the castings. As the hub is an important part of the car, so the limitations of these defects more stringent. Affect the hub shrinkage, the main reason for shrinkage is due to the casting in the solidification process, the alloy liquid shrinkage and solidification